CARB DYNO SHOOTOUT: EDELBROCK 750cfm VRS-4150 VS RACE Prepped 800 CFM Q-JET

[@gilbertwashburn7095]

Thanks for the video back in the '70s I built a69 Camaro drag car 427 tunnel ram mechanical cam 13 to 1 compression with two 800 CFM quadrajets my friend said it would never work it worked all right it screamed I got the car on the nines on race gas have a great day thanks for inspiration I can't build cars anymore but I enjoy your videos

[@briansd2772]

For an Emissions Carburetor, the Quadrajet more than holds its own. Thanks for this feature Andy!

[@UnityMotorSportsGarage]

Hey I will never talk junk about a Q-JET again.. I believe for a Street car this Carb will be extremely hard to beat! Andy

[@johnelliott7375]

If you send the Q-Jet to your buddy that does your carburetors and he hogs it out it will crank like you would not think it would.

[@nova467spanker]

@@UnityMotorSportsGarage to bad you were not able to test a Holley Hp 750 or Demon 750 after running the Edelbrock to see the difference between those 4150's.

[@UnityMotorSportsGarage]

Don't worry I have a killer test coming! Andy

[@anthonyking4387]

@@UnityMotorSportsGarage im thinking the holley hp 800 is the best all around box stock carb ive ever bought! It picked up over all the carbs i had tuned

[@georgekalafatis7286]

If the choke assembly is set right on the quad jet it's a beautiful cold start carburetor

[@speedandmarine9066]

I'd say that is a pretty stellar win for the OEM spreadbore Q-jet that it made close to the same power as a modern "race' carb. Q-jets definitely have their limits, but they're a pretty decent carb for what they are.

[@timfarley8106]

Hello Andy thank you for another great video. I made an incorrect comment a wyle back to a few friends, saying that KZbin is for entertainment not for education as I have seen so many video's that show incorect methods or the person lacks mechamnical experience. when I was about eight I found some of my Dads old Car books in his garage I dusted them off and asked I could look at them, 28+ years ago the magazines ranged from HOTCAR, Cars & Car Conversions, Popular Mechanics & heaps of others from late 60's to the early 80s. Reading these magazines as a kid I became a real fan of one writter David Vizard, as a teenager with my fist job I started purchasing his books I have nearly all of them execpt the Chevy ones lol. So when I found David Vizard on KZbin I had to take back what I had said about youtube. The man is an absolute Legend, I learned my lesson a long time ago, what he says is 100% correct every time. After watching David Vizard on here, I found your Channel & I Love it great viewing everytime.

[@servediocylinderheads]

I have a similar story with D.V. he is awesome and so fun to be around!

[@timfarley8106]

@@servediocylinderheads Good stories are awesome. You are very lucky to of met D.V one of my all time mentors, the three of you guys are my main youtube watches thank you for great content.

[@servediocylinderheads]

@@timfarley8106 I am lucky! Thanks!

[@v1-vr-rotatev2-vy_vx31]

Used to enjoy tuning Q- Jets because the results where rewarding,,the 850 cfm Q Jets especially...

[@glennmanchester5696]

They only made a 750 and an 800 cfm

[@Shop209]

I’d like to see a Dyno shootout of production carbs on same engine. Qjet Vs thermoquad vs Holley etc.

[@six4standingtall]

I think you are the 1st to dyno this carburetor at least from my search. Should be good content for a heads up shoot out.

[@Carl_Jr]

Actually, Riley's Rebuilds did the first one. She got the carb straight from Edelbrock before it was even released to the public. The video title starts "First Public Dyno Test . . ." or something like that. Just search Riley's Rebuilds VRS. This is, however, the first back to back I've seen against a Q-Jet.

[@UnityMotorSportsGarage]

@Carl_Jr you are about to see the first test of two on a TunnelRam! Stay Tuned Andy

[@Carl_Jr]

@@UnityMotorSportsGarage You're mean coming in here teasing us like that! 😂

[@NightWrencher]

Very cool test, the only thing I would say we can confirm from this test is the Q-Jets are good street carbs but have a lower ceiling than a 4150 square bore carb. I'd like to see VRS vs traditional 4bbl holley 😂

[@58sportsuburban]

@NightWrencher there are plenty of quadrajet cars running in the 9’s. It’s a perfectly capable carburetor.

[@UnityMotorSportsGarage]

I was going to do a 3 way carb test but we ran out of time... Thanks for watching Andy

[@NightWrencher]

@@58sportsuburban Imagine how much faster they would be with a square bore carb 🤯

[@UnityMotorSportsGarage]

Most of those cars are pulling close to 5" of vacuum at WOT they run them because they have too in most cases... Andy

[@NightWrencher]

@@UnityMotorSportsGarage without a doubt!

[@elainestamper3873]

If the QJet is to rich change the metering rods, also most Qjets were 750cfm (small block) ,800cfm was a big block carb. I’d bet you had a 750. With out getting it in the right air fuel mix range it wasn’t fare to the QJet. With the right fuel air mixture the QJet would have matched the new carb. Qjets are awesome carbs people that don’t like them don’t know anything about them. I did many carb tests on my personal dyno years ago, my 1967 Galaxie 500 with a 390 it ran the very best with an 800cfm QJet! It would do 150mph like clock work and was very fast on a drag race . Every other carb I tried the car was slower! Thanks for the video! Go QJet ! And by the way 429 Cobra Jet came factory with a QJet so even Ford approved of them!

[@thereluctantgearhead4544]

Even Mopar used a few Q-jets in the 70s.

[@kimdearrington258]

I can appreciate an aftermarket carburetor over the original GM factory carburetors, with that being said, the quadrajet has always been an extremely reliable carb, as well as a performance carburetor and a daily driver for decades and i love their consistency of performance whether that be making horsepower, or the reliability of it's performance in everyday driving, cold starts or hot starts, its been a proven reliable carburetor for all purposes!

[@christopherc3017]

Thank you Andy. Being a budget minded builder I thank you for showing what I’ve been saying about the q-jet? It’s a great street carb when rebuilt and tuned.

[@gilbertwashburn7095]

Great video that proves you don't have to spend a truck load of money on a small block to get big Power great small block everybody needs one like that nice carburetor that Edelbrock

[@reevesautomotivefarm9614]

That's pretty impressive in particularly considering the relatively budget friendly build. I spent a bunch more money in hopes to get the same power with my 327. That crate engine look is pretty cool especially at 500 horsepower

[@Z06Doug]

That proved a lot about the quadrajet. Almost a very slight tuning difference in the old and new, and one gets great mpg. And probably half the cost.

[@etenterprises]

I know you spent a lot of time on that vintage street dominator intake but I think that engine at that RPM range probably needs a Performer RPM Q-Jet or an RPM Air Gap. The RPM Q-Jet intake would still be pretty stealth. Or there's the cast iron bowtie/marine intake which is like the Z/28 or LT1 intake but for Q-Jet. I think your porting guy Charles Servedio did some videos on that being the king of stealth SBC manifolds (I have a couple if interested).

[@thereluctantgearhead4544]

I have one, real good dualplane intake. Kinda heavy tho.

[@edsmachine93]

Nice Dyno session Andy. Great Edelbrock carburetor test and results. Very impressive out of the box test. Thanks for sharing. Have a great day.

[@UnityMotorSportsGarage]

Thanks for watching Ed! I will say the new Edelbrock is really good! Andy

[@kramnull8962]

From what I remember a Qjet is awesome sitting still.... In a quarter mile the bowls run dry from the shift of the gas level in the bowls. This is more of a question about the issue, not pointing a finger I have a 1970 350/300 Qjet sitting in a tub right now awaiting a rebuilt Qjet swap or rebuild. I'm sure this has been addressed over and over, but this is 2024 and most up to date qjet build to date; I'd say...... Every single day people work with the Qjet seems to be a better day for those old carbs....

[@briansd2772]

Try using a smaller float from the '75 and later Q-Jets, setting it at 1/4 inch, and shave a quarter inch off the bottom of the black phenolic float bowl insert to free up more space for gasoline. Also a great high volume mechanical fuel pump like the ones by RobbMC help ALOT.

[@ThomasELeClair]

@@briansd2772 ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,Most know about the smaller float,,,and using a large .035 inch needle and seat,,,,,,,,,,,,,But,,,,,,,shaving a quarter inch from the bottom of the insert ,,,,sounds great,,,,,,,,,,,,,,,,,,,,,,,where did that idea come from??????

[@dalehulst4518]

That’s pretty good for out of the box. You have to really know what you’re doing and figure your time involved to tune the Q-jet to get the same results. All things considered,time, effort, the Edelbrock is worth the money. Very impressive throttle response too. Excellent work Andy!

[@MrJak427]

Can’t wait to see you tune it for mixed up boss people need to see the in’s and outs of this carb being tuned as it has heaps of circuits that are tuneable especially off the dyno getting it all working on the street😊

[@tedjones-ho2zk]

Can't wait to see those carbs on the MIXED UP BOSS Engine

[@GregsAirplanesandAutomobiles]

This is a great video. The old Quadrajet held it's own pretty well considering it's origins. As mentioned a couple times in the video the VRS had a manifold pressure advantage, which gives it a real advantage here. The probably slightly better mixture didn't hurt either. I would buy that VRS rather than mess with an old Quadrajet, but that's just me. I can see someone really concerned about original appearance using a Q-Jet.

[@UnityMotorSportsGarage]

The QJET did really well and it is what Joe wants to run on the Chevelle.. he is wanting it to drive like a stocker and I believe it will! I can't wait to see how it runs at the track... I'm sure it will surprise some folks.. BUT for me it would be VRS all day long.. Thanks for watching Greg Andy

[@robertwest3093]

Oh and I love the sleeper look with the Targetmaster style stock valve covers.

[@cuda6496]

What do the Fuel injection guys say " I don't want to pump the Carburetor to get it started😭" 😂😂😂

[@Olds_Pwr]

Most probably doesn't even know what that means this day.

[@gordocarbo]

Sounds rediculous no? Too lazy to move thier right foot once to set the choke? OH my...lol Take a good sorted carb any day never left me stranded, didnt have to drop a tank and spend $500 on a fuel pump either

[@braddenning1617]

I built or modified several Q-Jets in the late 70s early 80s and the 850CFM Q-Jet made 481HP ON A STOCK LS6 Crate and 490 with a 1050 dominator , We never out a hand on the Holley, Never changed a jet !!! It never gave me a problem in 2 racing seasons ,I Spent weeks modifying the Q-JETS So much potential . If you have a Cadillac 472-500 with air ,remove the A/C Compressor get the Q-JET worked and use a 1 inch spacer to raise the carb. The factory intake is recessed to fit all the crap under that hood. What happens when you open it up full throttle the rear (secondary blades cut of most of the fuel / air to the cylinders .By raising the carb WITH A 1 INCH SPACER you will pick up a noticeable amount of power .but your sacrificing the A/C and your going to fabricate some kind of air cleaner or cut the hood ,raise the center 2 inches ,(you will need a donor hood) and raise the center ,Its not difficult just time consuming and find a good donor hood. I've made several

[@michaellankford8358]

Back in the 70's we ran our old 396/360's and 396/325's with quadrajet carbs...were good carbs but us teenagers didnt know how to tune them...we'd turn a wood screw into the secondsry linkage turning them into mechanical secondaries... we had lots of fun with these setups but when we went for cam changes we would replace the stock cast iron and quad set up with an aluminum intake and 780 holley carb and never looked back....an old 396 made lots of power with just a few mods, and seemed like most the old 66 thru 70 SS chevells came with one

[@JohnShackelford-k2l]

Nick's garage canada 🇨🇦 no screaming but Air Fuel ratio 👌 500 hp VRS 4150

[@JohnShackelford-k2l]

I received reply to comment Knurled spelled with K. Ford Chevy same 4in bore .

[@servediocylinderheads]

Just the radius inlet and annular discharge boosters are worth power. Excellent video!

[@UnityMotorSportsGarage]

Yup! You are exactly right Andy

[@josephdavis6198]

Let's talk about the amazing sound that, only a Q-Jet can make, if you have never felt the rush of those huge back barrels its a hell of a rush.

[@UnityMotorSportsGarage]

Exactly..

[@edfarmer154]

I do love that!!! And miss it

[@edbeck8925]

True

[@8092DJ]

It does sound good but…

[@gordocarbo]

Thermoquad also. My 69 SS 350 Camaro had a Qjet...I never had to touch it i 5 yrs of daily driving. Choke worked perfect very responsive mpg was decent also. Still ran points dist too

[@Torquemonster440]

Awesome video Andy. Thanks for your efforts and information. Cheers 🍻

[@randylear8264]

I am going to buy an Edelbrock VRS 4150 for my 340. Seems this carb has really good tuning possibilities. Fine tuning this most modern carb is definitely a game changer. Thanks for the Video.

[@davidleonard8369]

Cool test! Kinda figured that a racing carburetor would make way more power on the dyno but I was surprised at that fuel curve. If you really want to see just how different those carbs are try both of them on the street. You might actually be ok with the top end power loss of the quadratoilet when you get a taste of light switch throttle response.

[@mikedeal8659]

I had a good time watching this. Good fun.

[@tonyblackburn5002]

He said less fuel and more piwer, but more than likely it was more air that made more power. Good stuff guys!

[@terrypikaart4394]

I have found, the Qjet performs well on a dual plane intake. Just as well as a holley. I ran a well tuned QJet on a single plane, switched to a holley and lost a over a sec on my ET.

[@chrisreynolds6520]

Something is not quite right on that Q-Jet. I made 502 hp with an 850 cfm on a performer rpm dual plane on a 383. It had a little over 1 in/hg at 6,200. Fully open the air door by hand, measure between the top of the airdoor and the center rear of the secondary air door opening in the airhorn casting. For maximum flow it should be 1.27" from the backside top of the butterfly to the airhorn casting. Also with the carb off, open the throttle blades up fully and make sure the secondary butterflies are not over centering and starting to close again. 3 in/hg does not make sense even for an 800 model. Cliff Ruggles and I talked about a 406 he built that had a Q-Jet and stock GM cast iron dual plane on it making over 500 hp.

[@UnityMotorSportsGarage]

Was your cam only 224 @ .050 ? This engine really needs a cam but we are going for the stealth look and it has an almost stock idle Andy

[@etenterprises]

True and Deano's carbs a lot of times are setup for stock eliminator with dual planes, although I'm sure he set it up to what you spec'd. We had a Deano carb on a 402 Big Block in our Stock eliminator Monte Carlo and one on a 400 SBC in IHRA GT stock on my Regal and both were fast. Even set IHRA record in like 2007 I think.

[@UnityMotorSportsGarage]

@@etenterprises yeah we told him exactly what we were doing and I have to say I'm very impressed with it.. we were going to go with a good dual plane but Joe has the stock hood on his Chevelle and didn't want to deal with clearance issues You will get to see videos of the car in action at the track next month! Andy

[@chrisreynolds6520]

​@@UnityMotorSportsGarageMine has a hydraulic roller, 271/284 @ 0.006, 218/224 @ 0.050, 108 LSA with 0.578 lift degreed in on a 106 LSA. It was cammed to be a midrange stump puller for dragging around a heavy fullsize van towing a trailer. Not exactly stock sounding but still pulled 18 in/hg @ 750 rpm with the vacuum advance limited to 12-13* hooked to manifold and about 17* initial timing. It was idling fairly smoothly at about 30-31* of idle timing.

[@UnityMotorSportsGarage]

@chrisreynolds6520 yeah we needed a cam like that! The 224/234 on a 110 is giving up quite a bit of torque! But Joe had the Cam and so we ran it... Andy

[@baby-sharkgto4902]

Another banger video! Awesome results and great job with that ole small block 🔥🔥🔥

[@UnityMotorSportsGarage]

Thanks Brother! Andy

[@robertwest3093]

Thanks for this Andy! The Qjet hung right with the Edelbrock to 4000. Some tuning would close the gap. I run a Qjet whenever I can.... I've even used them on small block Fords 😮 I'm trying to figure out how all these companies are copying the Holley design? I figured they would have patents or something on the design.hb

[@Thumper68]

Q-jets are actually good carbs and one of the best things is they will stay running on side hills and can start on side hills as well

[@thomashalley7258]

The real question is, for a street machine what gets the best mileage. I'd sacrifice so hp if the quad saved on the mileage.

[@LeftForDeadGarage]

Man I was standing right beside him at the Lincolnton crusie in yesterday and kept thinking “man I know I’ve seen this guy somewhere lately “ 😂😂😂🤦‍♂️🤦‍♂️🤦‍♂️

[@UnityMotorSportsGarage]

That's funny! Andy

[@69JANKS]

Awesome vid👌🏼, thats very strong power n Tq such low rpm’s also👍🏼🏁

[@UnityMotorSportsGarage]

Thanks brother! The old Holley Street Dominator that I ported seemed to do pretty well.. Thanks for watching Andy

[@69JANKS]

@@UnityMotorSportsGarage 💯 very impressive that intake Andy nice work👌🏼, the Ci etc all came to play…..very tuff💪🏼🏁

[@Inthefoxhole]

I put a large Q Jet on a 351 M ford Engine Stroked to 400 cu in.30 thousands over size .That engine ran great.I also put a GM Hei distributor modified to fit ford Engines. Only way to make a FORD run😅

[@DragBoss351Cleveland]

I like the looks of the Edelbrock, and impressive over the hot quadrajet, great video/dyno comparison Andy

[@Comet-hn3gm]

Now the price is going to go up 🤦‍♂️ on the Edelbrock carb. Sheesh. Thanks Andy.

[@lukesimeon5756]

Great testing guys thanks

[@TonysHotRodGarage]

Pretty amazing Andy! 20 HP right out of the box. Wow! I'm just about sold... I really want to see how those things behave on the street with a more radical cam like what's in my 451. Looking forward to seeing them on Casper. They're expensive but I'm about a gnats ass away from just buying one LOL.

[@UnityMotorSportsGarage]

I'm really happy with how it ran! I'm looking forward to them putting in work on CASPER! Andy

[@xxkingslayemxxgamer5553]

The right person can make them quadra Jets work

[@dalewarriorofthesea3998]

VRS 750 pays off by well thought out design features 😊

[@95Sn95]

I had a summit racing Qjet on a mild 355 and it ran great in the midrange to upper rpm but down low it ran pig rich and the fuel economy was about 8ish mpg, the idle mixture screws made no difference on the idle, I'd say the hole in the blade truck may have helped. The cam and intake combo was the issue I imagine it had a 240/230 .480" 108lsa cam and a original Torker with a 2" spacer adapter. I tossed the cheap Eddy 600cfm on the same combo spacer too and it ran absolutely beautiful and the mpg went to 13-14 or so but I did feel a power loss up top, I left the Eddy on because the small amount of gain wasn't worth it, I was my daily and it ran so good I still have it, it's getting a fresh short block in the near future I do want something else my absolute favorite carb is the Holley 650 double pumper spread bore Qjet replacement carb, I had the vacuum version of it also and I hated it. I also picked up a nice old 300-31 contrnder intake to replace the Torker.

[@edge2sword186]

The factory Q jet carbs always had loose throttle shafts almost like they needed bushings so many times smooth idling would be a problem and they never held enough fuel in the float bowl so we took out a wall inside of the carb to expand the volume of fuel and eliminate the early bog on acceleration.

[@finnroen2334]

Thanks. This was good confirmation. :)

[@ThomasELeClair]

,,,,,,,,,,,Man ,,I've been waiting for this...............................thanks Andy....................

[@ssnerd583]

500 and 500 is stout numbers for an 'economy' build 400 SBC, no doubt.....and that is MY fav thing to do...take all the parts nobody thinks will make power and MAKE POWER!!

[@UnityMotorSportsGarage]

Absolutely! Thanks for watching Andy

[@jimmyrwilkesjr5127]

Andy that a great comparison and test ,ELDERBROCK HIT IT OUT OF THE PARK , IF YOU PAY CLOSE ATTENTION TO THE PULL ON QJ THE ENGINE IS BUCKING ALMOST LIKE DETENATION ,BUT THE RUN WITH THE ELDERBROCK WAS AS GOOD AS IT GETS 👍 CAN'T WAIT FOR THE KING OF CARBY TEST .TAKE CARE ANDY MY FRIEND ,-Jimmy from Sanford, former employer of maggnetti !!

[@rumplestiltskin509]

What kind of carb is an Elderbrock ?

[@jimmyrwilkesjr5127]

@rumplestiltskin509 ,it is a aftermarket carb ,started of as a alternative to weber AFB -(AFTERMARKET FOUR BARREL) MANY YEARS AGO THRU EXTENSIVE RD AND HOUSING CHANGES ,ELDERBROCK CARBERATORS ARE EXTENSIVELY PERFORMANCE PEICES ,AN D THE ELDERBROCK NAME IS WELL KNOWN IN THE PERFORMANCE INDUSTRY IE INTAKES ,HEADS,ETC THANK FOR THE REPLY ,FROM A INSIDER OF THE EARLY STAGES OF RD of ELDERBROCK carb ,and fuel injection for harleydavidson etc, thanks

[@landoncustomclassics]

I have the 650cfm VRS on my 429 Thunderjet. Couldn't ask for a better carb! Great video brother!

[@justinadams1360]

Awsome! Big block power out of a small block. Have to ugly up that new carburetor a little bit lol. Maybe some patina magic lol

[@gordocarbo]

Drop base GM air cleaner off a dually (use a 3" element) would be perfect

[@edberry78]

That thing is undoubtedly what my 440 needs.

[@jasonnelson6624]

Not a thermoquad? 😢

[@rumplestiltskin509]

Comparing the vrs against an older engineered driver style carburetor was not really apples to apples. For only a 20 horsepower gain with recent technology and engineering, that old quadrajet performed exceptionally well. I've worked with quadrajets many times and they are very good carburetor when you know how to set them up. You can't bash the q-jet......

[@dennislafoot4905]

You are comparing Apples to Oranges here! A fair test would of been Edelbrock Performer Series carburetor. A true comparison test would be Holley 850 Dbl pumper and the Edelbrock VRS-4150 race carb. I still like everything you show us, keep up the good work.

[@UnityMotorSportsGarage]

That is coming! Stay Tuned Andy

[@alexandertoshich765]

Love the Q-jet test.

[@donreinholz8121]

Edelbrock carb for the win!

[@brracing7861]

A Quadrajet will do anything a Holley 4150 can do till the Quadrajet runs out of CFM. Then Big CFM Racing 850- 1085 cfm 4150 Holley 4,-bbl reigns Supreme. In the Pontiac V8 Performance Racing world many have obtained 500-750 Hp with a Quadrajet and many report up to 20 mpg cruising at 70-90 mph in Firebirds Trans Ams. Muncie 4-speed and a Quadrajet dialed in is lots of Street cruising Fun. Usually able to drive all weekend on 1 tank full of Gasoline. Best Holleys huge CFM I am a Fan of. I Csn report Gas Mileage is absolutely terrible a BLP Bo Laws 1085 cfm 4150 on a 520 Hp 455 WOT at 7000 rpms. Get maybe 1 mike per gallon only

[@bluecollarcook]

That sleeper might have something for em!

[@UnityMotorSportsGarage]

Not too bad its a runner! We will see it at Shadyside next month Andy

[@apachebill]

My only issues with the Q Jet were fuel boiling in the float bowl when heat soaked and running it out of fuel on the back end of a hard run. Put a 4150 on it and never looked back. But I do miss the Q sound. It has a home on an upcoming 350 build.

[@UnityMotorSportsGarage]

I agree the lack of fuel is a big issue! Andy

[@SimpsonsSpeedShop]

Lookin good bro! Love the test. Would love to see it verses a Holley 4150 next!

[@UnityMotorSportsGarage]

It's coming! I have a 3 way shootout coming on CASPER.. Hope all is well your way Andy

[@richardmoerke9329]

Dam!!!!! From the box! I have had my carb worked on for years and still haven’t gotten it right.

[@rapidride2]

It's either by way of chance or the edelbrock guy he mentioned had a heads up on engine specs. Either way the q-jet wasn't tuned.

[@BigBlock402]

So far I like everything I see about the new VRS 4150. Still need to see how they do on a Tunnel Ram before I buy 2 Holleys.

[@UnityMotorSportsGarage]

Won't be long Brother! Andy

[@ThomasELeClair]

@BigBlock402,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,WOW..................................................................

[@robertgraham1626]

Quadrajet still dominates for practicability ease of build ability hands down number one and surpasses dependability like nobody's business race on Sunday drive it to work on Monday

[@outlawbillionairez9780]

Would have liked to see a side by side graph of A/F as well as H/P. The Q is designed for economy at partial throttle, and immediate response to full throttle at lower revs under load. So, how do the number compare at the beginning of the pulls? Where did the pulls start?

[@outlawbillionairez9780]

@@bigboreracing356 Quadrajet is a 59 year old design.

[@SpecialAgentJamesAki]

Great test! Some notes -cliffs book on the qjet is a great thing to utilize when working on these -There are a LOT of different qjets most people think there are only two, I’m curious which this is. -I believe the qjets cfm was rated differently than we do today so it most likely doesn’t flow as much as the eddy -qjet definitely doesn’t atomize as well especially on the secondaries -I’d like to see how a stage 3/circle track jetchip qjet stacks up -also curious how the qjet behaves with different manifolds, single vs dual and runner length and spacers, cliff recommends the factory heat “spacer” they ran on the Oldsmobiles where it’s open on the secondaries and separated on the primaries I’m currently running two qjet cars I use them because I like how they drive especially in LA traffic and I road trip the cars a lot. The first car is a 68 impala 383 chev stage 3/circle track jetchip qjet with CK secondary rods, with a 243/257 @050 580 lift 107 lsa cam, 270 cfm cnc ported aluminimum heads and dual plane qjet specific air gap intake, I use the Oldsmobile spacer on it 10.5:1 compression, 3.07 gears th400. Starts up, idles perfect, and runs great in all conditions. I daily that car. Second car is a 71 olds 98 with a 455 running a stage 2 jetchip qjet out of the box, q jet specific dual plane performer intake, Oldsmobile spacer, 230/230 @050 530 lift 113 lsa cam, big valve G heads, 13:1 compression, 2.73 ratio and th400 also starts perfect even after sitting or in sub freezing temps or over 100 degrees, idles perfect and runs good in LA traffic. I used to run a 750 holley on the olds but switched it to qjet after the holley caught fire 😆 from leaking at the bowls.

[@josephdavis6198]

This q-jet was built for me by Dean Oliver.

[@NelzC]

Have you asked David Vizard to modify that Q-Jet? He wrote a whole chapter in his book How To Build Horsepower Vol. 2 (1996) Carburetors and Intake Manifolds on how to mod the Q-Jet. Chapter 8. Page 82-92. DV showed how to modify a Q-jet to over 1000cfm....

[@brokentoolgarage]

That's cool, thanks for sharing!

[@No1414body]

Pretty impressive, considering the small cam, I wonder if you could do the pseudo 3 barrel mod they used to do

[@johnelliott7375]

I was making the same exact numbers with my engine and ran a huge Q-Jet from a Cadillac that I had a wonderful man that is no longer with us. I believe that it was the biggest one that was on a 472 from back in the day and he hogged it out and played with it for 3 days. But I couldn't buy a Edelbrock like that back in the 80's

[@MichaelMares-zn8qk]

Would have liked to see results with some slightly leaner secondary rods in the Q-jet . Just goes to show you a $50 core , and a $25 rebuild kit can give results similar to modern aftermarket carbs costing hundreds of dollars.

[@UnityMotorSportsGarage]

The Q-Jet we have is a Race Prepped unit by Dean Oliver. He prepares most of the NHRA Stock and Super stock QJets. Andy

[@frizzellracing]

I told you 😜. Right out of the box. I’ve got to get a second one so I can put a pair on my Galaxie

[@UnityMotorSportsGarage]

I know it's crazy! Now the Q-Jet was built by one of the top names in the country, Dean Oliver. The QJET did good but it can't compete with the VRS! We plan on having the Chevelle at Shadyside for the Steel in Motion show so we might do a track comparison with them Andy

[@frizzellracing]

@@UnityMotorSportsGarage awesome. I’m trying to come up with a second one. I want to put a pair of them on the Galaxie now.

[@generalsixty2133]

GM did their homework on the Q-jet. Look up Dominator carb on a dual plane intake. It’s surprising!

[@prevost8686]

There was a day when GM worked with the smartest people in the room. Sadly that day has passed.

[@Matt-e4x]

Need to tune the Q-jet. Next is what does that manifold carb base look like? You can’t compare when the base is not set up for a q-jet.

[@UnityMotorSportsGarage]

kzbin.info/www/bejne/fZCuc4luf6ehgrssi=c0X-jXc2iAQhsCB0 Hopefully this will answer your questions Andy

[@donames6941]

To me, Q jet is harder to tune for most guys, but when tune right it by fare better carb

[@outfitsgarage88]

Great video Andy.

[@chevyfan82]

Been looking forward to seeing more on the vrs. I think the quadrajet could come closer to matching with some jetting and adjustments but no comparison to the new Edelbrock.

[@gearhead7896]

That VRS is awesome and I've wanted one ever since they were released. They spend millions in development and it shows. I'm ready for the price to come down and then I might pull the trigger. I'm curious how the VRS would fair against a same CFM AED carburetor.

[@theshed8802]

That bsfc is impressive for an out of the box carby

[@Null-h6c]

I saw a 340 dyno yesterday on youtube . And it seem the 2 to 4 barrel transition was wrongly adjusted . I saw a huge lean spot during transition . From 2 barrel to 4 barrel . Also that 340 performed best when dyno vacuum detected stayed at zero the longest .

[@chrisweibelzahl6081]

I noticed you have been testing both types of carbs with a carb spacer , what was being used?

[@UnityMotorSportsGarage]

Both had 1" open Andy

[@andrewbecker3700]

This test means what? A carb that's set up optimally will make more power irregardless of make or model. On the street, the spreadbore will actually work better in most cases. How often are you at WOT for more than a few seconds when driving? That's where the spreadbore Qjet shines, in that half throttle transition area that your gonna be in 90% percent of the time.

[@karlsracing8422]

Through the whole curve!

[@joeinmi8671]

Look at that, it picked up even at the load in on the dyno.

[@gordocarbo]

Opinion on adjustability of the Eddy over the HOlley? Had my eyes on these for awhile What have you done internally to the 408? Nice numbers! Top off the stock look with a factory air cleaner housing off a dually. They have a huge snorkel and use a very tall element. Nobody would suspect! When I changed the element in my 90 Dually had yrs back I thought...man perfect sleeper air cleaner.

[@josephdavis6198]

Andy done the videos on the engine build check them out .

[@rogerstill719]

If the Quadrajet had the same A/F ratio, how much closer would it have been to the Edelbrock carburetor? Although some people wouldn't consider it, but a Chrysler Thermo quad is a monster on a 396 BBC. I'd like to see one on a 406. BTW, good video. Keep them coming

[@383mazda]

I took a Qjet off my brother's old 454 truck and stuck it on my 383 and it stopped making the "chwWWAAAA" noise. Disapointing, but still ran great.

[@bloviatormaximus1766]

sure it can get better loosen the secondary air valve spring finish playing with metering rods to reduce that high rpm restriction and help lean it to best torque

[@UnityMotorSportsGarage]

If you look at the Q-Jet at the beginning of the run the air door is fully open as the dyno pull begins. I really wish I had some metering rods to mess with it on the dyno but we were out of time.. Thanks for watching Andy

[@thomasward4505]

I would be interested to see how the vrs carburetor drivability wise is. I have plenty of Holly's that work great at wide open not so much at Cruise.

[@fishstix2620]

Gotta love that Quadrajet plus it held its own. Not to mention you can still drive around town with the small primaries and not stop at every gas station. 👊🇺🇲

[@Boostismyfriend]

👍

[@daniellefraser2350]

Thanks Andy 🍺

[@jumpsuite]

The new Edelbrock against the denominators I don't know that might be a fight to the finish like to see that

[@JeffKopis]

Q-jet: Not pretty. VRS: Pretty. Andy: Not pretty. Me: Very pretty 🤣. (Happy Birthday Andy 😉)

[@rotaxtwin]

Wow, I'm surprised. I thought there would be very little difference between the two. I think the freshly worked over QJet (replated maybe?) looks pretty cool, but disappointed to see that it's pulling 3" of vacuum at WOT halfway through the run - that's not cool. It's really not meeting the 800 CFM claim if that's the case. I"m a manual gearbox guy so I want the mechanical secondaries anyway...

[@bigmotorhead2908]

I would go with a Holley double pumper to save money and make the air cleaner hide it. Quadrajet for daily driving