The Awesome GM Tuned Port Injection System of the 80's

[@VetteSource]

Be sure to check out the follow up tear down video for this Tuned Port Injection system - kzbin.info/www/bejne/hX6zlWythZymq6M

[@fontaineking5158]

Can You put a TPI on a 95 LT1?

[@VetteSource]

Unfortunately not. The LT1 cools the block first so the heads and intake are different and won't interchange.

[@fontaineking5158]

@@VetteSource Thanks for the answer. Ya, no water in a LT1 intake. Too bad.

[@VetteSource]

No problem, man. Glad to do it👍

[@fontaineking5158]

@@VetteSource I have a 95 2door S10 4x4 Blazer with a 95Vette LT1. Very sharp ride. Eerything works, air, push button 4x4, perfect interior never been smoked in. Vette steering wheel, carbon fiber everywhere inside, Micky Thompson wheels and tires, stainless duel exhaust, wraped headers, TV, remote CD changer cherry red and silver two tone. I always liked the tuned port intake. Wish I could put a picture up.

[@xds1919]

I agree... when i popped the hood on my 88 Vette waaaay back in 1993... it took every bit of self control i had the keep from shedding all my clothes and rubbing up against it! very beautiful injection system!

[@VetteSource]

very well said😂

[@Jimmy-c7l9v]

Thats the best way to Describe how I felt when I pop the hood on my 91 formula I just bought and saw the engine

[@VetteSource]

For sure, not many Formula's were produced in 1991. Did you find a 305 or 350 car?

[@carloscervantes8196]

I just got one, same year!

[@traderman4378]

@@VetteSource OMG that is hilarious!

[@scoutleader06]

mine is an 87 L98. The TPI was automotive genius by Chevy engineers. Think about it... a little box ECM with a chip that with sensors all over the motor sending signals controlled every critical motor function. Who comes up with that ?? Every injected SBC is a build-off of the TPI. Chevy engineers if you're out there stand up for a round of applause !!

[@VetteSource]

Agree 100%. Still looks incredible almost 40 years later👍.

[@LXRD-SUPREME-]

What's you're perspective the the 90's corvette Lt1 ?

[@briansmith8361]

I love this system. I love the name, that little plaque that says "TUNED PORT INJECTION" on the throttle body, I love the 30 horsepower jump over the Cross Fire Injection 350, etc. Those intake runners look really cool, and GM even had a dual throttle plate design before the plenum. I would still like to have an IROC Z or GTA Trans Am.

[@VetteSource]

Couldn't have said it better myself. Thanks for the comments👍

[@ScottsFormula350TPI]

This intake in combination with Borg Warners 9 bolt 3.27 made these cars jump off the line.

[@OcRefrig]

Yea, Mine has been a great Car ! 1986 iroc z28. 305 Tpi. 17-21 mpg city. 30 Mpg All Hwy on a Long trip. 2 people. No problems ! All Original. Totally stock. Black / Gold. T-Top. 170,000 miles.

[@scoutleader06]

I had a buddy with a TPI trans am. Driving it was better than sex.

[@BlackRam17]

Love how it falls on its face at 4500 rpm

[@dukeman7595]

Brian you're one of the most knowledgeable mechanics regarding corvettes I have had the pleasure to find on KZbin. I have watched many of your older videos and I'm amazed how well you know corvettes, thank you for the entertainment and mostly the nuggets of knowledge learned..

[@VetteSource]

Hey Dalton, appreciate the kind words👍. I'm glad I've been able to find an outlet to share my passion and enthusiasm for the great cars with fellow enthusiasts.

[@fifteenbyfive]

I don't know anything about this fuel injection but that intake looks so badass. I can only imagine what it must've looked like in 1985. You could tell right away you were looking at something special.

[@VetteSource]

you hit the nail on the head. Even 35 years later this intake setup manages to wow people that have never seen it before. You should see how good they look when the whole thing is polished to a mirror finish.

[@peterlinton]

Wow...I want this in my chevy c1500...beautiful 😍.... looking motor..

[@VetteSource]

Yep, very cool compared to the industrial sewing machine look of today's engines.

[@scoutleader06]

it is till special . in the mid 80s it was automotive genius by Chevy engineers. until youve seen those runners , throttle body and plenum you havent seen a very cool motor

[@chevrosmith]

Tbh this setup was never known for high hp capabilities but because of those long runners it put out better torque than we probably realized until we seen dyno numbers,makes you wonder why Gm didn’t install this setup on the trucks also……I seen a few months ago that they now offer a tpi/vortec intake

[@NewDesignVinylGraphics]

From someone coming from bmw and just getting into f body’s I really appreciate this video! Not many on KZbin detailing the l98 l69 lb9 specs

[@VetteSource]

Hey Cody, thanks for the feedback, glad the video was able to help you out👍. I have a few more TPI videos in the playlist below in case you haven't seen them - kzbin.info/aero/PLAM-V1w3acpg9ThDD75FSzjNaemyMEJLl

[@ShawnStafford-1978]

I was subscribed to you until January when my channel was terminated. I like you have knowledge of and TPI cars. I love my 89 GTA and the original setup.

[@VetteSource]

Hey Shawn, I appreciate the kind words and am sorry to hear about your channel. I do love the L98 cars👍

[@ShawnStafford-1978]

@@VetteSource Thanks, it was my bad luck with too many strike's. I tried not getting into trouble. I agree with you on the L98 Tpi setup. 👍🏻

[@bradleymadosh3596]

Loved my tune port injection Camaro 88. FASTEST CAR I EVER HAD. DID THIS JOB ONCE IT WAS EASY. IT WAS WHITE WITH T TOPS AND GOLD WRITTEN ON IT WITH GOLD RIMS. MISS THAT CAR

[@VetteSource]

Bradley, thanks for sharing. Sounds like you have quite a few great memories of it. The White/Gold combo IROC-Z's looked really good, and were a great alternative to the more common red and black cars.

[@backyardbuck6362]

If you need o rings for fuel system get Viton o rings. Here are the sizes. Fuel return line for fuel rail 010 Fuel supply line for fuel rail 0 11 Fuel rail cross bars 110 Return line at fuel pressure regulator 109 Stub aluminum tube between fuel pressure regulator and rail 012 Fuel lines to fuel filter in and out 011 Fuel injectors 203 I bought the the Viton assortment o ring kit from harbor freight and it had all of these sizes except 109 and 203.

[@VetteSource]

Good info, thanks for sharing👍

[@backyardbuck6362]

@@VetteSource no problem. There are two more o rings for the tpi cars that had the ninth / cold start injector but I don't know what sizes they are. My formula is a 89 and does not have the ninth injector. I believe in 88 or 89 gm did away with the ninth injector.

[@VetteSource]

@@backyardbuck6362 yep that is correct with 88 being the last year of the cold start injectors. That one has a much bigger o-ring but the exact size escapes me at the moment.

[@OcRefrig]

Yea, Mine has been a great Car ! I Love the Car !!! 1986 iroc z28. 305 Tpi. 17-21 mpg city. 30 Mpg All Hwy on a Long trip. 2 people. No problems ! All Original. Totally stock. Black / Gold. T-Top. 170,000 miles.

[@VetteSource]

Yep, they are very reliable when properly maintained, and like you mentioned get pretty good gas mileage as an added bonus.

[@bunzino8617]

Just bought a 305 glad I found your videos they're very well done and detailed.

[@VetteSource]

Awesome, thank you!

[@DrivingTheClassics]

Good info- I've had to do that a number of times. Having to do it again this weekend to replace injectors on the 88 Vette.

[@VetteSource]

I hear ya. I am about to tear the Yellow Gold Formula 350 down over the holidays to do a top end job on it. Thanks for watching👍

[@billmaggie8736]

A real game changer in the mid 80s

[@VetteSource]

For sure, pretty much the rebirth of the horsepower wars. Thanks for watching👍

[@milesmania1150]

Yes the TPI engine is the most intimadating and interesting. I agree, even if it's not as powerful as the ls1

[@VetteSource]

It is a design that even today nearly 30 years later still causes people to stop an take a second look at it. Definitely form over function. Thanks for watching👍

[@olddog3728]

Soooo so glad to see this video, I look forward to to watching the rest of the series. It will be beneficial to me as I'm doing the same thing on my 87 Corvette. Thanks for putting this out there 👍!!

[@VetteSource]

Glad you enjoyed it! Appreciate the feedback. I will be updating shortly with the first part of the tear down on this unit to do a top end job. Thanks for watching👍

[@scottypalmer2158]

Tpi is a high torque low rpm intake system. Biggest bottleneck is the small tube runners. Arizona Speed & Marine sells large tube runners. Firstfuelinjection sells a complete intake manifold, along with runners and throttle body.If using large tube runners port and polish the lower intake manifold to match the runners.The smoother the finish the better...air loves smooth finishes. A 58mm throttlebody will require port matching the plenum. Siamese the plenum where the air exits and radius the openings on the inside as much as possible...air likes a smooth radius when exiting. Do not siamese the runners because some torque will be lost. Keep the cam profile on the low side 218/ 220 112 lsa along with good set of heads "summit racing" and be prepared to smile.

[@VetteSource]

Excellent rundown of the system and how to get the most power out of it. A couple of other good items to add would be a looser stall converter in auto trans cars, and some deeper gears out back. Then you're really able to holeshot from the stoplights. Thanks for watching👍

[@BlackRam17]

@@scottypalmer2158 is there anything to be gained by just going with bigger runners? How much can be gained with just an entire ported intake system?

[@scottypalmer2158]

@@BlackRam17 : Any larger runners would be a good choice especially if you smooth down the casting flash in the base intake runners.

[@scottypalmer2158]

@@BlackRam17 : kzbin.info/www/bejne/eGStlmSDgbmjntUsi=O2xtKSUkyU8qcztn

[@BlackRam17]

@@scottypalmer2158 even without porting the intake and base to match?

[@marck3122]

Thanks for sharing bro nice Car good old school GM system

[@sebbonxxsebbon6824]

One of the best truck motors ever, to bad it wasn't put in a truck.

[@VetteSource]

For sure, its definitely held up over the years and still draws attention.

[@VetteSource]

To see more of my vehicle/ parts tear down videos check out my playlist below - Cars and Parts Tear Down Videos: kzbin.info/aero/PLAM-V1w3acpg_B2sVlXEL7UPOGVwiKmtL

[@45auto82]

Wow! Never knew those intake runners went to the opposite side! No wonder the engine has such great low-end power!

[@VetteSource]

Definitely a very unique design

[@45auto82]

@@VetteSource Yup! But I like the ZR1 even better…Lotus designed 4 Cam, only multiple cam engine ever by Chevy, then built by Mercury Marine! What a story!

[@VetteSource]

Yep, they're incredible machines. Be on the lookout, I'm going to begin reassembling a 1990 ZR-1 soon. I'm trying to put it together as a entire series before I release it.

[@mds00]

The TPI design is definitely superior to the LS for street use. I had a 383 ci TPIS miniram setup that made on a dyno 545 torque but it was at 4000 rpm like an LS. I swapped to the factory TPI intake system this summer and peak torque dropped to 406 but it moved the peak of the curve to around 2700 rpm. The car feels faster than any ls powered car I have driven on the street. People only care about high horse power numbers, but if you don't race on a track it doesn't matter since horse power is not a real thing. It is something abstract and based on torque which is real. The only thing the ls probably has on my 383 TPI is gas mileage. I get around 20 combined mpg without an overdrive trans the last time I checked. The ls motors probably getting like 30 mpg nowadays. With an overdrive trans and lock up I could probably get 24 mpg.

[@VetteSource]

Excellent writeup and perspective on HP. Torque is definitely that "seat of the pants" factor that gives car that powerful and fast feeling. Sounds like your car can leave other racers in tears at the stoplights.

[@josephforcino8099]

Torque is were its at.

[@VetteSource]

Agreed, HP numbers are fun to talk about, but it's the torque that really matters in the long run.

[@retroMartin]

You think a 350 TPI uses 50% more fuel than stock 350 Crossfire? Im considering buying a 1982 Corvette C3 with TPI transplant on it.

[@VetteSource]

No, if anything the TPI will give you better fuel economy than the Cross-Fire setup. As long as you keep your foot out of it, I've seen people getting North of 20 MPG out of a TPI 350.

[@ericmiller2052]

I know I'm a year late, I'm sure you know by now, but I figured I'd say anyway. The tpi in f bodies was a 305 for 85 and 86. In 87 they introduced the L98 to the f body exclusively with an automatic trans, and the LB9 got a manual trans for the first time as well.

[@VetteSource]

Yep, we have a few comments mentioning the same information, but thanks for sharing the knowledge 👍

[@scoutleader06]

awesome video my friend !!!! every nail hit on the head

[@VetteSource]

Thanks David, appreciate it👍.

[@Jason-fp7vi]

Hey just a tidbit, you said in this video you weren't sure if third gen F bodies had the TPI 350. Yes, they did. The IROC and Trans Am came out with an automatic Trans only TPI 350 later in their life cycle. Thought I would just "let you know". Thank you for teaching me so much about corvettes!

[@VetteSource]

Thanks for sharing the info man. It's all about passing along the enthusiasm and passion for these now "old school" cars. Glad to hear you enjoy the videos, I'll keep trying to make them interesting for you guys.👍

[@Jason-fp7vi]

@@VetteSource thank YOU for passing on so much knowledge. Like you said it's all about passing on the enthusiasm. We just have to be careful to pass on true and tactful knowledge. That means not parroting stuff about how a high flow cat is good for 100 wheel horsepower and some of the other silliness you'll see on corvette forum. And that's where your channel comes in. Just factful knowledge spreading the love of these great machines. You are awesome

[@BlackRam17]

@@Jason-fp7vi Formula did too

[@danwilson9530]

Bosch TPI was developed for the 305 to give it low-mid range torque. It was modified and adapted to the 350 soon after.

[@VetteSource]

Yep, but don't forget the L98 350 TPI was first installed in the Corvette in 1985, with the LB9 305 TPI offered in the IROC that year. I think it wasn't until 1987 that they finally began installing the L98 in the F-Bodies.

[@danwilson9530]

@@VetteSource Correct, the L98 was not available for purchase in an F body until 1987, which was “nice” but due to how the F-Body used a variation of the L98 configured with iron heads, among other differences, and was probably de-tuned, it offered more in bragging rights than improvement in performance over the LB9. Of course a 350 offers significantly more potential for high performance modification than the 305, but stock from the factory in 87 there was as little as a 10HP difference between the LB9 and the version of the L98 found in F Body cars. Due to the 305 being designed with emissions and fuel economy in mind, not high performance, it completely lacked low-mid range torque. That's why GM approached Bosch to develop Tuned Port Injection. It was designed specifically to give the 305 that missing torque expected in the performance versions of the F Body, the Z28 or Trans Am. It made a huge difference to the 305 performance-wise in those cars. It makes my bone stock 1987 LB9 Trans Am a 190HP blast to drive. While a modified version of TPI was adapted for use on the 350 for Corvette, leading to the L98, TPI was not originally designed for the 350. The 1985 L98 was a VAST improvement over the 1984 L83 w/ Cross-Eye Injection used in Corvette, but the TPI part of the L98 did little more for that engine performance-wise in '85 over what a carburetor could. I know this from first hand, real world experience. I had a 1979 Vette with a transplanted L98 that came out of a 1985 Vette. My L98 had the TPI fuel injection system removed and replaced with a Holly 4BBL. I do not recall which model Holly or it's CFM. I raced my friend and his bone stock 1986 Vette at the track and he beat me consistently by an average of 2/10ths of a second according to out time slips. My point is TPI did the wonders for the performance of the 305 it was designed to, but didn't add much to the 350 from what I could see. It was just better then the Crap-fire. TPI is not the most advanced or robust FI, but it has a coolness factor its more capable successors all lack, most likely due to it's aesthetics. It's the most beautiful fuel injection system intake manifold ever. Great eye candy under the hood.

[@VetteSource]

Excellent point, and you are spot on. You lift the hood of modern cars to be greeted by what looks like an industrial sewing machine. When you lift the hood of a first-generation fuel injection, be it a TPI or Ford 5.0, the wow factor still knocks people's socks off to this day👍.

[@Unhinged219]

Have a 85 and 89 irocz they came with the 350 tuned port which is a high package

[@VetteSource]

Yep, great intake system that looks fabulous👍

[@Kwakcrazy]

I'm live in the UK & looking to buy a 3rd gen camaro project car with a 305 tpi engine and videos like this are awesome & very helpful 👍🏼

[@VetteSource]

glad to hear it man! Even though the 3rd gen F Bodies are kind of a lost car of the 80's they are a blast to drive and simple to work on compared to many other cars. You can see more of this car and the story behind it in this playlist I made for it - kzbin.info/aero/PLAM-V1w3acphkZJyLroCKcyLO9GzqR6q4 I will let you know if I come across anything that may be what you are looking for. Do you prefer an automatic, or the 5 speed manual?

[@Kwakcrazy]

@@VetteSource I love the 3rd gen Camaro, a cousin of mine who lives in the USA had one as his first car but his was a iroc z and I love the shape of the car. The one I'm looking at buying is a automatic but it needs welding in the floor pans due to t top seals leaking, it has been sat for 21 years so once I've finished my Audi b3 90 I'll be doing a complete strip down rebuild and I'm trying to get as much information and planning as I possibly can before I do so.

[@VetteSource]

@@Kwakcrazy definitely the way to go. Sounds like it deserves a new lease on life after sitting 21 years. Let me know if you need any further information.👍

[@Kwakcrazy]

@@VetteSource yes it definitely needs a bit of TLC after sitting that long and will be very grateful when I get it for any help

[@nestorcaamano307]

I just got a 90 Iroc z 5.7 love it

[@VetteSource]

Great cars, you'll really enjoy it👍

[@robertwest3093]

Best looking factory intake manifold ever 👍🏻 I could care less if it dies at 4500, because it’s making killer torque up to that point. That makes a good 0-60 street car.

[@VetteSource]

exactly...

[@jamesbowman7963]

Ok so I have played with these motors a lot at one time. Yes they are not a high RPM intake system the resonant frequency tuning is from 2500-4800 RPM's. Yet the reason they drop off so much in part is the garbage heads only flowed like 185 CFM which just kills the top end. I installed Brodix 180cc runner heads, AS&M runners, TPIS Big Mouth lower intake, 58MM throttle body and we hand ported the plenum ourselves. This and a few other tricks like taking out the screens and fins in the MAF sensor, bigger injectors I think 26lb from memory? Relocated the MAT sensor from the plenum to the plastic air intake with a K&N filter. On the exhaust side it was Lingenfelter Tri Y headers through two huge cats a big single and no mufflers. Internally we had a TPIS cam some where around 224 degrees duration with big lift and Comp Cams 1.6 roller rockers in the stock 350. With the T56 my dad and I installed it would just about pull the front wheels in the air. Car pulled very hard to about 3,000-5700 RPM then dropped off. Stock it was falling on its face at 4800 RPM. Sorry I know that was a lot of info but if done right TPI cars are very fast and besides tuning from induction length these motors were just flow restricted period. Even with the bigger intake runners they still aren't quite big enough for 383 and larger engines. If you own a TPI car the very simple almost free mods were move the MAT sensor from the plenum it gets hot from the aluminum and thinks with the MAF input the car is getting much less air than it is and leans it way out. Then you probably are getting knock and it retards the timing too. Someone makes a different sensor that thermally isolates it from the aluminum and I hear that works well, but I bought a longer cable and moved mine like I mentioned above. I did this took out the MAF screens and installed a K&N filter and we wen't from 15.3 second 1/4 mile times to 14.7... That is a cheap easy half a second and the car didn't get sluggish when it warmed up and felt very snappy. If you are super cheap you can just hand port the plenum radius the inlet to the runners like 3/8" and probably drop a few more tenths. Yes take off the smog pump garbage too. I didn't get to track test the car unfortunately but I don't think I'm exaggerating when I say it was an easy low 12 second car with the 350. I think a well set up TPI will net you 11 seconds but that is about the limit with out NOS or forced induction... One more trick remove the brown timing wire and set the base timing to 12 degrees advanced. They really like the base timing in that range, might help to put some Teflon around the knock sensor too. FWIW my car was an 89 Formula 350 and there was countless Mustangs that got their lunch eaten and everyone had souped up Mustangs then. Here is a good article www.superchevy.com/how-to/engines-drivetrain/sucp-0703-stealth-tpi-induction. Look at the torque it is amazing that is why they can be very fast they get the car moving instantly. kzbin.info/www/bejne/bF7CgIKcermEo9k Very much runs like my car did except 383 vs 350 so I'm guessing it is was a bit quicker and watch it eat LS Corvettes lunch.

[@VetteSource]

James, thanks for taking the time with such a thorough reply. You are correct about the inherent limitations in the "as delivered" from the factory Tuned Port Injection systems. Personally I believe they were trying to make a compromise between power and government mandated fuel economy standards at the time. However, like you said, with the right mods, a Tuned Port can stomp all over quite a few cars and cause quite a bit of embarrassment when engaging in stoplight to stoplight action. In the early 2000's, I was running my 85 Corvette with a .40 over 350 4 bolt main, Lingenfelter roller cam, AFR heads, Hooker Super Comp long tube headers, and topped off with a Lingenfelter Superram. I also backed it up with a 2800 stall converter and 3.73's in the factory Dana 36. It wasn't the fastest, but you can bet I left many a competitor with a gobsmacked look on their face after we finished running them. Good times, thanks for reminding how much fun the TPI's could be!

[@Slowgroovin]

They aren't much on top end power, but definitely are a blast from stoplight to stoplight.

[@VetteSource]

Exactly, we used to call them the stoplight killers👍

[@scoutleader06]

true enough, but there are fixes for that.. but speed costs money !

[@iroczfan1620]

They started putting the option for tuned port 350s in Camaros and firebirds in 87. 85 and 86 only had the 305 tpi option in Camaros and trans ams.

[@VetteSource]

Yep. I can remember when the Formula 350 cars were announced. It was cool to have the L98 Corvette engine installed in the f bodies even if they didn't have the Corvette D Port aluminum heads. Thanks for watching👍

[@777bhana]

They made a limited amount of 350 TPI 5.7 in 86...... they're very rare.

[@VetteSource]

Interesting, I've never heard about those before.

[@777bhana]

@@VetteSource they're out there bro..... if you find one buy it, restore it, & keep it. IROCs are going way up in price now days.

[@VetteSource]

Yep, I'll keep my eyes out for one. Thanks for the heads up👍

[@dodgeguyz]

The only problem I had with this system was the batch fire injection. It wasn’t sequential like the Ford was. That makes it cleaner and perform a little better.

[@SKRooU2]

I owned a black1986 IROC with the 305 TPI and the limiting factor on these motors was not the TPI. It was the mild low lift / duration cam and restrictive exhaust. Put a hotter cam, headers, dual exhaust with low restriction mufflers plus the high performance chip and these cars went from mild to wild. The stock TPI could easily handle 400 hp without going to bigger injectors

[@VetteSource]

Great suggestions, thanks for sharing👍. The TPI's are great platforms to work with, and look fantastic and exotic by today's standards when you pop the hood.

[@limabravo6065]

Tpi is the first mpfi v8 from gm, and the Camaro / firebirds had 350’s as the top engine from 87 - 92

[@limabravo6065]

The runners are long and narrow which makes a lot of torque, the combustion chamber size has nothing to do with the intake design, and no “performance head” for a 350, you can buy comes with a combustion chamber bigger than 64 - 67 cc (stock 305 heads have 58cc chambers and 350’s have 64 cc chambers) and there’s only one head on the market dedicated to the 305 and that’s from trick flow. So if someone puts 350 heads on a 305 with a bigger combustion chamber then they are lowering the static compression ratio

[@VetteSource]

Yep, I believe I remember that I misspoke when referring to the combustion chamber size, but couldn't go back and change it after the video was already posted. My point was that installing larger aftermarket heads on a stock TPI manifold wasn't going to do much good without also upgrading to the aftermarket TPI runners and intake. Thanks for the input👍

[@brucegillies1694]

The first tuned port fuel injection for Chevrolet was offered in Spring 1957 ! Non efi

[@VetteSource]

Good point. It was also made by Rochester like the TPI and was a mechanically operated unit. The trick is finding a complete unit for under $10,000😁

[@tthoy7338]

Ohh wow, this is a really, really, good video 👏👏 well done

[@VetteSource]

Hey T, thanks for the feedback. Glad you enjoyed it👍.

[@paulthesoundguy1]

The key to TPI is no vacuum leaks, and proper sensors all working correctly. THEN you can consider the typical mods….larger throttle bore or larger runners for intake…then typical small to medium bore headers. But still you have the L98 heads to deal with…. If you can wrap your mind around 3500-4500 max rpm the L98 TPI engine is for you

[@VetteSource]

Good information, thanks for sharing👍

[@sysawatphaly2903]

Hi thank you from Houston...I have 91 firebird LT 1...good info

[@VetteSource]

No problem, glad to do it. Thanks for watching.

[@agentwade]

Did you swap the lt1 into it

[@oberday]

Stoplight to stoplight, it's great engine. I'm a 0-40 kind of guy anyway.

[@VetteSource]

For sure. That's where all the fun is at😁. Thanks for the comments👍

[@emilianocruz11]

The Last túned port injection was a 1990 to 1991 corvette zr1 or c4 l98 but they replace the tpi with the throttle body injection was in 1991 to 1996

[@VetteSource]

Close, but your forgetting the 1992 F Body Camaros and Firebirds still had the Tuned Port Injection. In 1993 they switched over to the Corvette LT1 which had debuted in the 1992 Corvettes.

[@muzik858]

I've seen this type of setup on the 1991 Vector W8!

[@VetteSource]

Yep, if I remember correctly they reversed the intake manifold so it's facing backwards and used coil packs instead of the normal distributor. Thanks for the comments👍.

[@SKRooU2]

I like the lawn chair work bench LOL

[@VetteSource]

Oh yea, I'm an old Army groundpounder, and we learned quickly to work with what we had😁.

[@BigCaucasoid]

Very neat and detailed explanation, thank you.

[@VetteSource]

Thanks for the feedback, glad to hear it was helpful👍

[@kmas8229]

That's fine and stuff, but could you do a video on removing the smogpump and getting off the lines going into the headers? It would clean up the bay nicely

[@VetteSource]

Good suggestion. I will see if I can work it into the series as I begin to install everything back together on the passenger side. 👍

[@kmas8229]

@@VetteSource thank you

[@VetteSource]

NP

[@JK-of6bq]

I was thinking about trying to upgrade my ECM to something aftermarket to increase hp after rebuild to try getting as close to 500hp as possible. Which back in the day was something actually Attainable as the 305 was used on Circle track racing and they were able to get m up to 500hp. But I've already took the plenum off to replace my fuel pressure regulator few years ago, had my #Beast for 8 plus years now. Hit a couple good sized deer, been in the ditch and all with little to no damage to the car! That's why I call him #Beast!

[@VetteSource]

Sounds like you been through thick and thin with your car. Definitely a keeper👍. Are there any suppliers making ECM's for the early TPI's? That would be a good complement to some upgraded heads, camshaft, and intake.

[@javiersanchez1661]

Just bought a 1986 monte carlo ss with the same motor.

[@VetteSource]

That's interesting, they must have swapped it sometime in the past. TPI was only offered on the Corvette, Camaro, and Firebird from the factory. Should make for a fun crusier👍.

[@LogiDude]

My 88 IROC-Z has the 350 TPI, I got some coolant in my oil :( thx for the vids man

[@VetteSource]

No problem, man. Glad to do it👍. I should be getting started with the final reassembly soon. Be sure to look out for the videos detailing the process.

[@dantresohlavy7323]

TPI lower intake question... if memory serves, GM didn't re-angle the inner 4 intake to head bolts until 1986. Does than mean the 84-85 TPI lower intake will bolt up to a traditional carburetor set of heads, such as the '80 and older? Making it somewhat of a unicorn...

[@VetteSource]

Hey Dan, youre correct, the change was made on all 1986 convertible Corvettes with the aluminum heads, and the coupes mid year when they switched from iron heads to aluminum. 84 was still a Cross Fire, so the 85 TPI intake is a stand alone and a unicorn like you said. They will bolt up to the old school style heads with no problems.

[@twatson6252]

Hey I am needing a drivers side head light motor for a 85 vette and also some help with the same car. I just bought it in Houston and seen your viseos thanks.

[@VetteSource]

Hi T, congratulations on the purchase. You can send me a DM through FG or IG @VetteSource.

[@boboneal4711]

Hi, Just found your series on TPI as I am working on a 86 Vette and having difficulties finding out why it runs good cold and Crap when hot. Perhaps some voice time would be great...Thanks in advance Bob in Germany.

[@VetteSource]

Hey Bob, sure that would be fine. You send me a DM through my IG or FB @VetteSource

[@YoungGearHeads]

Good info, thanks.

[@VetteSource]

No problem, glad you enjoyed it. Thanks for watching. 👍

[@billybobbubbawubba9457]

This is very intriguing. I came here for some general knowledge. What is the biggest plus, I can see is the low-end power potential for a truck. These are dirt-cheap in the ads. Most of the stand-alone controllers, run about $900. Is there a cheaper way to go without a degree in McGuiverism?

[@VetteSource]

You're correct, these are not overly complicated and have the computing power of a Commodore 64 PC. Once you figure out all the tricks, they are very reliable and look awesome when you lift the hood as an added bonus.

[@John-ze4qy]

Looks like i, a year late to the party,but the camaro iroc did recieve the 350 in 87,also the trans am

[@VetteSource]

Don't worry about it, this is one of those videos that people keep finding because as the years have gone by, the TPI still looks awesome. Thanks for the comments👍.

[@dantresohlavy7323]

Crossfire Injection, 1982-83 Camaro/Firebird (yes Gen2 1981 also) was first. Two separate 1 barrel injector assemblys. The 2 barrel TBI wasn't until 1987... TPI wasnt first, it was second.

[@VetteSource]

yep, that is correct. I didn't mention them since they are still more of a carb/fuel injection hybrid rather than a full on injection system with an individual injector for each cylinder. Thanks for watching.

[@bryanolivo8093]

The TBI went till 1995. Ty.

[@dantresohlavy7323]

@@bryanolivo8093 Yes, I should've inserted one extra word: "available" ...wasn't available till 1987...

[@mcqueenfanman]

I've got an 84 vette that I removed the crossfire intake & injectors and replaced it with a holly tbi intake and 87 350 tbi. I used the factory crossfire wiring & ecm to run it. It was plug and play and has a nice increase in power. The holley intake is good through 6,500, I bet the crossfire doesn't do anything past 4,000.

[@VetteSource]

Sounds like a smart conversion to make. Trying to go from Cross Fire to Tuned Port Injection will get you in the weeds very quickly.

[@garywellborn4139]

Is there a difference between the TPI units found on 305 engines and that found on 350s, say, some Irocs and early C4 Corvettes? I have a '74 Corvette with an L82, and I would very much like to swap the carb for a TPI system.

[@VetteSource]

Hey Gary, the biggest difference is the fuel lines, which come in from the PS on the Corvettes and the DS on the F-Bodies. Also, 305 TPIs will have 19 lb/hr injectors versus the larger 22-24 lb/hrs injectors found on the 350 cars. Also, 85-89 TPIs are MAF, and 90-92 Speed Density across all models.

[@terrancecook3357]

It's a shame GM never put these in thier trucks. those long runners a great at generating low end torque. kind of like thos beer keg manifolds on the Dodge Magnums.

[@VetteSource]

Yep, that would have been a cool sight to lift the hood of a mid 80's square body and see a factory installed Tuned Port Injection system sitting there.

[@jdogmcnasty1980]

“Chucklehead” 😂 thought I was the only one that said that

[@VetteSource]

Yea, that's an oldie but a goodie for sure😁

[@76629online]

You got a lot of facts wrong here. GM had a multiport electronic fuel injection system on the 500ci Cadillacs in 1976. I still remember working on them.

[@VetteSource]

Cool, thanks for setting me straight👍

[@darrenporsch]

87 was the first year to get a 350 in an f body

[@VetteSource]

Yep, I have read somewhere it had something to do with the chassis flex, but not sure if that is true or not. Thanks for the comments👍.

[@darrenporsch]

@@VetteSource I think you're talking about t-tops and 350 f bodies. some people say you couldn't get them, some people say you could, some people said GM discourage the dealers from selling them but who knows. apparently there's examples of them out there

[@VetteSource]

Yea, it's funny how certain things get lost to time. Somewhere in the back of my memory I recall that the 350 became available with the introduction of the Formula 350's in 87, so it makes sense that were offered in the Chevy and Pontiac both. I know I haven't personally seen any 350's installed in pre 1987 cars and don't remember seeing any back then when I was a teen.

[@Joesmusclecargarage]

@@darrenporsch It’s not “apparently”. Out of the 16 thirdgens I’ve restored and built over the last 25 years, 6 of them were L98/CC1 cars.

[@locotrucker46]

I have a 86 camaro z28 305 tpi that runs one day and then won't run at all. I have fuel pressies and spark so I can't figure out why it acts that way. Any advice would be helpful because I don't know much about the tpi setup

[@VetteSource]

Hey Harry, with an intermittent no start I would take a closer look at the ECM and determine whether or not it is pulsing the fuel injectors while cranking. If you don't have a fuel injector pulse tester, you can also spray starting fluid in the throttle body to see if it fires off. You may have an ECM wiring failure, or a bad ECM causing the issue. Let me know how it turns out👍.

[@titolombre7004]

305ci engines were available with the 5 speed manual transmissions where the 350ci's were only available with the 700R4's. Give me the 5 speed any day🇺🇲⚡💥☄

[@VetteSource]

I do like the stick over auto, but the torque and power of the 350 TPI is quite fun.

[@Sandhill1988]

How difficult would it be to adapt one of these systems to a TBI motor? I've got an 89 formula with a 305 L03 engine wondering what it would take to put one of these on I think that the performance gains would be well worth it if not too complex and costly.

[@VetteSource]

I'm afraid you would probably get in the weeds pretty fast with this conversion. The fuel system, engine and dash harnesses, and many of the under hood brackets are different, which will require quite a bit of work to source and install. Not saying it can't be done, but make sure your ready for the mechanical and financial commitment necessary before going down that road.

[@backyardbuck6362]

If you still have the L03 in that Formula you can put cowl induction . If you can find the under hood set up from a 82-84 TA. I did that to my 88 formula L03 and noticed a nice little boost in hp. You wouldn't want to drive it in the rain or keep the car uncovered when it's raining though. I believe there is a video here on yt where a guy did it also.

[@VetteSource]

Good info, thanks for sharing👍

[@javialvarez1859]

Great video, very informative. Looking forward to watching the rest of them.. Love the low end torque these make. I have an 87 trans am with a 305 and thinking of swapping it with a 350 this summer (keeping the tpi). Any suggestions for improving high end torque?

[@VetteSource]

Thanks, glad you enjoyed it. Unfortunately the limiting factor with the TPI is the length of the runners. To develop the higher RPM oomph you're looking for would require modifying the intake to the Super Ram or Mini Ram style with shorter intake runners. The only problem with that is you lose that awesome look of the Tuned Port Injection. Thanks for watching👍

[@javialvarez1859]

@@VetteSource thank you for your feedback!

[@VetteSource]

No problem, anytime👍

[@masong8359]

Check out the F.I.R.S.T. Tpi intake. It’s a beefy design of the gm tpi it is pricey though

[@shadowopsairman1583]

You can get different intakes for LS derp.

[@VetteSource]

Yep, lots of different aftermarket intake options, some of them you lose the unique look of the TPI injection system.

[@blvelpa]

I don't know if anyone out there is interested in one of these engines, but I have one complete with the auto od behind it. It ran so I made a short video of it before pulling it. I have the wiring harness and computer. I don't need it now.

[@VetteSource]

Cool . I will let some of my customers know. How much are you asking and what part of the country are you in?

[@blvelpa]

@@VetteSource I live in south East PA. About 30 minutes from Harrisburg. I'll send you an email, not sure of cost yet. I could take it 100 - 150 miles or so - work out cost for fuel. I'll send you the video, it was minutes before pulling it out.

[@VetteSource]

Ok, sounds good👍

[@shadowopsairman1583]

The TBI was EFI. TPI was 305, 350, 265. FI was on the 327 in the 60s.

[@VetteSource]

Yep, that is correct.

[@ashlland7clips]

I have a yellow 85 iroc Camaro it only came with a 305

[@VetteSource]

Yep. The early IROCs were only available with the 305 TPI at first. That yellow IROC is quite rare👍.

[@ashlland7clips]

@@VetteSource Ya its crazy and some how the stock injectors still work

[@SolidSnake4Ever2003]

it is all but impossible to find a running driving reliable 3rd gen firebird/camaro for a reasonable price that isn't beat to absolute hell with a million problems on top of that these days, I appreciated this vid for some knowledge on tpi. The few 3rd gens I see for sale for a reasonable price have oddly all happened to be TPI. I finally sold a defunk project car 92 305 tbi firebird last year for a few hundred, dear lord almighty the problems that car ended up having, the cherry on top being a multitude of wiring problems which I said nope to.....as much as people dog the 305 and tbi system online, the 305 tbi firebird was more than peppy enough to me for intown driving and accelerated much quicker than I thought it would on the highway and cruised extremely well, I can only imagine how much better a 5.7 tpi would feel haha. 3rd gens have an extremely fond spot in my heart since my mom had an 85 firebird growing up. I wish I knew about mechanics stuff back then like I do now, it was absolute HELL getting the car started in the running, carb was absolutely trashed. Since I heard you mention it in the vid, I happen to be in Tx too. If you EVER see any reliable running and driving automatic 3rd gen firebirds or camaros for a reasonable price please let me know :)

[@VetteSource]

Hey Whitesnake glad you enjoyed the video. The 3rd gens are well built cars, and can be pretty reliable daily drivers as long as they haven't been beat up like you mentioned. I'll let you guys know if anything shows up around here. Thanks for the comments👍.

[@61066clocks]

WHAT would need to be reworked on one that has been sitting and not run for over 10 years?

[@VetteSource]

Hey Tim, it will all depend on if it was stored properly or was exposed to the elements. First thing I would recommend is putting battery power to it with a fuel pressure gauge on the fuel rail to see if the pump is still working. You should see 42-46 PSI at the rail. While you have it hooked up you can check for leaks at the injectors and fuel rail fittings. If that looks good, I would put fresh fuel in it and see if it will fire up to see how it wants to run and whether it starts throwing codes. Keep a fire extinguisher handy during this step, since fuel leaks can appear once the system gets warmed up. From there it's simply a matter of how it's behaving. Any fuel leaks in the rail or injectors will require you to tear into it further, and if you've gotten that far, you might as well replace the intake manifold gaskets. Be sure to take pictures of the components before you tear down, and take your time. Let me know if you need anything else, always glad to help👍.

[@61066clocks]

@@VetteSource Wow ,Thanks for the Quick responce and answering that question. Subbed...Yea I have a great chanch to get a 1987 with 87000 miles.. I said 10 yrs.. more like 14 yrs.. since 2007.. I saw the TPI insignas on the motor and hood cowl and started researching the make and that is how I got here..lol..thx for the info..

[@VetteSource]

No problem, glad to do it. Thanks for the sub👍. If you're looking for more information on the TPI's I have a playlist of a teardown and rebuild I am doing on an 88 Formula 350 here - kzbin.info/aero/PLAM-V1w3acpg9ThDD75FSzjNaemyMEJLl

[@61066clocks]

@@VetteSource Will do.. It is a 87 VETTE..5.7 L. SAME TPI procedures .Thx

[@cuzz63]

I have a Chevelle with a 383...would love to put a TPI on it...are you aware of anyone making kits to put one on with the more modern controls?

[@VetteSource]

I know Painless Wiring used to make a stand alone kit, but the system is setup for a computer with the processing speed of a Commodore 64, so I'm not sure if anybody in the aftermarket has put the $$$ into updating it.

[@cuzz63]

@@VetteSource after asking this I found that it looks like FAST makes a controller kit for multiport injections systems which should work ...will have to do some more research.

[@VetteSource]

That's great. If you don't mind, pop back in and share the information once you finish your research👍

[@petersheamorris4852]

Will that motor go into and later model 97 firebird and if not why what blockage is right has heard that I wasn't able to put it in there no mods or worried about whatever it takes to get in there I'm working properly if it won't go in there and work properly then that's why I'm asking

[@VetteSource]

Hey Peter, theoretically you could forward integrate a TPI system into a 97, but it would require a complete removal of the wiring, computer, and fuel system that eas originally installed in the 97. Furthermore, the Tuned Port Injection is an OBD1 system versus the OBD2 system that was in the 97 so none of the dash or transmission outputs will work correctly.

[@petersheamorris4852]

@@VetteSource what I was asking though the phone that I'm on records things that I haven't said, the 1997 firebird trans am that I've got came with the V6 3.8 somebody told me that a V8 won't fit between the tire the shock towers and the engine well so I said that it can't be done you can't put a V8 in place of the V6 dimensions of the car are different am I correct

[@jayflores4336]

I want to swap a TPI manifold onto my 90’ firebird with a 305. What all is needed to do the swap? Harness/ecu?

[@VetteSource]

It's not the easiest conversion to make on these cars. The engine and dash harness have to be changed, as well as the fuel pump and assorted TPI specific TPI engine brackets. Not trying to say it can't be done, but proceed with caution as it a a pretty major undertaking to make it work correctly.

[@jayflores4336]

@@VetteSource cool thanks

[@VetteSource]

No problem, anytime👍

[@cobra30689]

I'm REALLY showing my age here.....but the TPI system wasn't exactly GM's *first* attempt at port fuel injection. That award actually went to Cadillac back in 1975, with the Bendix system on the 500 big block. Port injection, with a air-only throttle body on basically a modded carb intake.

[@VetteSource]

Matthew, that's good info, thanks for sharing. That early system was an interesting approach, and I'll bet paved the way for the TBI systems that followed. If you look back at the evolution of automotive fuel systems over the last 50 years it's amazing how far we have come, especially now that so many of them are now using the direct injection method like a diesel. Makes you wonder what's next😁.

[@joeyvillarreal7281]

Will an 80’s tpi and aluminum heads fit a early 70’s 400 sbc ? Want to keep my iroc looking orig but have power.

[@VetteSource]

Hey Joey, yes it can be made to work, but I would recommend running some AFR heads along with the SLP runners and Accel intake to accommodate the extra cubic inches. Joe Formato ran a 406 SB in his 89 Corvette that was pushing deep 12's/high 11's if memory serves me correct.

[@keydavis4581]

Tpi intake will work on any older engine. It's the newer vortec heads that you have to modify the base mounting bolt holes. One of my tpi projects twin turbo 305. kzbin.info/www/bejne/sH-Ud4qmoLN1o80

[@VetteSource]

Yep, one of the cool features of the TPI intake system is its versatility and interchangeability between the older and newer engines. If you happen to have the new Vortec style heads, you can just search for an 88 and up TPI base manifold with the correct bolt hole angles for the center bolts.

[@mikeceli]

Is that you Lincoln Mark VII? I am the second owner, for the last 20 years, of my '88 Mark VII LSC. Great car! I have a 1989 IROC Z Vert, LB9 TPI 305. I am restoring it.

[@VetteSource]

That is my Lincoln. One of my favorite daily drivers and best scores I have had in the salvage business. Here is a playlist of me bringing it back from the dead - kzbin.info/aero/PLAM-V1w3acpgO6anPzNgy5srRhD2CztAu I love the IROC verts, awesome look with the top up or down. Thanks for watching👍

[@wood123firebird]

Hello just found and subscribed since you sound very knowledgeable on these cars. wondering if you can guide me with my issue. i have a 1986 transam 305 TPI have been troubleshooting this car on and off for a number of years for lean condition code 44 , have checked everything I can think of and in the GM service manual . this car has 105 miles on it all original and followed all the testing in the service manual. also replaced, maf, o2, egr temp switch, thermostat, ECU, gutted the cat converter due to back pressure. when the car is started o2 is around .440 volts then steadily goes down to under .2 volts and stays there and results in the code 44. the engine is running lean and smells rich I have no vacuum issues, confirmed egr works(not used anyway at idle) as well as the egr solenoid, air injection system in tact performed the injector balance test(passed) checked the cold start injector, (fine) fuel pressure regulator is fine, fuel pump is fine delivers spec. pressure and holds pressure, no leaks intake or exhaust, vacuum booster on brakes is fine, new idle control valve and i did calibrate when i installed, timing was checked and is correct, checked the gas and there is no water in it I am at my wits end and need some smart guidance. please help me

[@VetteSource]

Michael, sounds like you've dug pretty deep into the car in an attempt to diagnose the problem. One question to start. Are you able to establish communication with the ECM? One thought that comes to mind is that you may have some wiring that is internally degraded or damaged due to age causing the intermittent.

[@blazeroranger]

Sound like bad ecm. Check TPS to see if it change itself, check tps output & input. Subscribe me too

[@joshalbright4027]

these cars were known for ecms going bad .first tpi has a set up that u can change over to its like 1500 for the set up and u get bigger runners plenum and computer set up

[@VetteSource]

Thanks for sharing the information Josh, that's help some viewers find solutions to these older ECM systems.

[@shadowopsairman1583]

LT1, LT4, TPI was up to 95.

[@VetteSource]

ShadowOps, Thanks for the comment👍. To clarify for people not familiar with the engines - TPI - 1985-1991 Corvette/1985-1992 F Body LT1 - 1992-1996 Corvette/1993-1997 F Body LT4 - 1996 Corvette 1 year only/1997 F Body SLP 100 produced.

[@tazwestminister7147]

My 1990 IROC Z 350 5.7 had 63000 miles when i bought it. Does any one know what the injector oms are supposed to be?? Im doing some trouble shooting.

[@VetteSource]

They should be +10 Ohms across the board.

[@peterlinton]

Can I put this intake on my 350 motor? I have a 1989 c1500

[@VetteSource]

Yep, it will bolt right up. There are a few different intake base differences due to the Vortec style heads on the 95 and up, so you will want to look atbthe later TPI systems from 87 forward.

[@mrmete]

Was the Airfoil work on the throttle body?

[@VetteSource]

It will work and is an easy install. However any gains are pretty much imperceptible. Thanks for watching and let me know if you need anything else👍

[@wiktors4566]

Hi. My tps is only 3.6 v at WOT. I bougt new one and it is doing the same thing. Only 3.6 v at WOT. What to check next ? Wires? Computer? Or maybe new TPS IS faulty too? Pls help

[@VetteSource]

Sorry I missed your message. I would suggest taking a look at the wires to see if you can find something that would be causing a voltage drop, like a bad ground, or damaged wire causing a short to ground. Let me know how it goes

[@danielcastillo7343]

Have a 91 Camaro anyway u can send me a diagram of vacuum line of cruise control and charcoal evaporated

[@VetteSource]

Let me see if I still have the diagram available. You can reach me via PM @VetteSource on FB or IG.

[@tazwestminister7147]

Hey whats up. My 90 IROC Z has been setting for years. I was young dumb before i parked it. I beat myself up a lot and my car is a reflection of that. Sad but true. Once again I have developed an interest.Q: " Injectors, ok. Wires/injector plugs. Ive gotten the wires mixed up and the care runs like sh*t. What do the wires do and how do i solve this problem. Ill be starting with fresh injectors.

[@VetteSource]

I would make sure you have the wires in the correct position on the distributor cap to start. I don't remember exact location on the f body cars off the top of my head, but you should be able to Google the wire routing pretty easily. After that it's just a matter of checking your fuel pressure and ECM outputs to see how the system is performing. Let me know if you need anything else👍

[@tazwestminister7147]

Wire routing. Yes. The wires that i am shooting don't come from the distributors, do they? The injectors each have two wire plug. The wires are pink and green, i think. Do they connect to the ignition control module?? Thank you for your reply. Something new to think about.

[@VetteSource]

If the ignition module was disconnected it wouldn't start at all, so that's probably not what you're looking at. The injector harness connectors run in a straight line parallel to the valve covers and only have enough wire lead to plug into that particular injector it is closest to. I would also suggest looking for a factory service manual for your car on ebay. They have an incredible.amount of wiring diagrams and troubleshooting sections that can assist with the diagnosis. Luckily your computer system is still pretty basic, so it's not that hard to dig into.

[@Mr.Frost181]

Is it still good to use today for the 350 to make some good horsepower

[@VetteSource]

Definitely, with certain mods you can see north of 400 HP

[@Mr.Frost181]

@@VetteSource yeah that's what I'm looking to make with probably at least 460hp

[@Mr.Frost181]

@@VetteSource I currently have a 350 an TH350 in my 86 Monte Carlo SS

[@VetteSource]

Cool, the Monte Carlo's are great looking cars.👍

[@VetteSource]

Yep, that should be enough to wake that car up.

[@eduardozelaya2811]

Me podes mostrar su motor de arranque. De ese motor

[@VetteSource]

si me envía un DM @VetteSource en Facebook o Instagram puedo enviar una foto

[@eduardozelaya2811]

Busco motor de arranque para este motor por favor

[@VetteSource]

Buenas noches, tengo el motor de arranque.

[@xse-qb2vv]

Ls is way prettier lol, loved the tpi mani.

[@VetteSource]

Definitely way prettier if you like the look of industrial sewing machines😁.

[@xse-qb2vv]

@@VetteSource Ls6 intake is just as pretty, and higher flow to romp on 'stangs all day.

[@xse-qb2vv]

@@VetteSource your car is yellow...just letting you know man.

[@charlesmoore1307]

Coolest LOOKING, but stops performing at about 4k.

[@VetteSource]

Exactly, but oh that low end torque🤣.

[@jaysenblakburne5834]

It will be at a shot 5.3 4.8 6.0

[@jasonh9957]

As much as I loved the TPI I hated the loss of power above 4,000 RPM. As soon as I drove an LT1, I realized the intake that should've been on cars in the 80's. The Miniram! TPI is an ideal half ton or even 350 truck intake. Low end torque perfect for pulling. But back in the day this was exotic and GM probably couldn't roll the cost into a truck, so it ended up on a performance car :(

[@VetteSource]

True, but the design has aged well. Hands down one of the best looking fuel injection intakes of the era. Thanks for the comments👍

[@cuzz63]

Sexiest EFI ever.

[@VetteSource]

You speak the truth👍

[@martingomez6802]

I have a 1989 firebird gta 5.0 tpi but I'm getting weak injector pulse so the car won't run on its own but will run when u spray starter fluid on the air filter. I've replaced the computer, ignition module, fuel pump I have fuel pressure but weak injector pulse idk what it could be could use some help pls I'm ready to scrap the car lol jk

[@VetteSource]

Hey Martin, sorry to hear the old boy has been giving you such trouble. At this point considering the components you've replaced, I would suspect a ground issue within the engine/injector harness. You can confirm this by testing the injector driver wires coming out of the ECM to the injector harness to verify the full 12 volt signal is being sent. Let me know if you need any more information. We'll see if we can get your GTA cruising the streets again.

[@blazeroranger]

Fuel filter….

[@VetteSource]

Yep, good simple thing to check first👍.

[@salmonaco007]

Junk port injection test were done a elbow & throttle body out flowed that mess. Yea leave behind mustangs & grand national did always leave them cars behind

[@traceydeanrainey]

You could get the 5.7 v8 in the IROC Camaro only with the automatic

[@VetteSource]

Yep, that's correct

[@pranays]

You could get the iroc z in a 350 but it only came with an automatic transmission

[@VetteSource]

Yep, that's correct👍

[@jonsixxx6569]

but they used the same intake from the 305 on the 350 hense why the thing has no power past 4800 rpms

[@VetteSource]

Yea, it definitely didn't help the engine in the higher RPM ranges.

[@jonsixxx6569]

@@VetteSource I solved that issue using a lt1 intake now pulls all the way to 6000rpm

[@dantresohlavy7323]

Question? Who is revving to 6 grand when the speed limit in the city is 30mph. Idle to 4000 is all that's needed for normal driving

[@limabravo6065]

jon sixxx / the intake runners are long and narrow which produces a lot of low end torque

[@toddrobbins392]

It is spelled “hence”!