LOW BUCK LS TURBO TEST-BIG SINGLE VS SMALL TWINS

SINGLE VS RACING 7875 vs TWIN GT3582s-WHAT WORKS BEST? DO SMALL TIME TURBOS OFFER BETTER BOOST RESPONSE THAN A BIG SINGLE TURBO? WHICH TURBO SET UP MAKES MORE POWER? CHECK OUT THIS TEST WHERE I COMPARED A SINGLE 7875 GEN 2 FROM VS RACING TO A PAIR OF GT3582s FROM CXRACING. I RAN THEN AT 4 DIFFERENT BOOST LEVELS AND MONITORED BOOST AND BACK PRESSURE.

[@bestusernameevahhh5802]

By a show of hands, how many people now have a Disassembled LS in their shop right now because of this guy? We love you Richard. Thanks for kweping hotrodding alive.

[@One_LuvZ]

L59 currently to install on Z32

[@kobygrimes1234]

✋️

[@patrickbecker2481]

Currently have a fully forged 408 waiting to go into my Tahoe 😩

[@clutchboi4038]

Lol I just got a 5.3 I'm putting in a buddies CTSv he got for cheap. Trying to select turbos rn

[@One_LuvZ]

@@clutchboi4038 what's the car gonna be used for and power goals?

[@lucasmullins5100]

Richard Holdener proving that not all heroes wear capes’s and also making me want to spend more money

[@toob247]

@james avery more money not all the money's

[@georgeschnakenberg7808]

All the money's

[@davelowets]

One has to pay, to play..

[@Cultofpersonality09129]

Hero? Get help.

[@allenl9031]

I just read from Freiburger, that Sonny Leonard has passed away. RIP to a race engine legend.

[@8bert9]

I would have never thought that the bigger turbo would bring bigger power in at the same lower RPM. Nice test!

[@davelowets]

@@stevenp3176 What "stock turbos"? A 4.8 LS never came with ANY turbos... 🤔

[@niknasstie]

It took intill 2021 for some bad ass enough to do this test.

[@Its_Jimmy132]

Matt Happel made 1K+ WHP in a SBE gen III 6.0 Colorado in 2017

[@sanfordrhudy774]

I almost pulled the trigger and order a couple GT35's. Richard Holdener, thank you for all of the knowledge that you freely feed us!! YOU DA MAAAAN!

[@BlindBatG34]

I've got to imagine turbo lag is the only thing keeping the driveline from doing an emergency eject from 700+hp in a 4500lb truck.

[@natemartinez4595]

6000lb truck in my case lol

[@brooks3racing1]

It not the HP it’s the torque. Most guys will pull timing at peak torque to help.

[@davelowets]

I CAN tell you that a 4L60 lasts about 3 weeks behind a setup like this... 😞

[@cooperechols7322]

rip🤧

[@smp3745]

Sir I Thank you. Dude is spilling out real racecar knowledge more than any collage you will ever goto

[@GregoryBirulkin]

This is one of your best comparative KZbin videos. Thank you!

[@drs2000rr]

Awesome video !!! Richard, Running twin gt3582rs, with turbo blankets and header wrap helps the spooling consistency. Being that the twins are less responsive on the 4.8. It Would be great to compare responsiveness in a twin gt35 setup in the 5.3 and 6.0 vs the gt45. These are the things that keep me up at night, Thanks again for all of the shared Knowledge.

[@delagto_5340]

Exactly what I was thinking. As long as the early lag could be minimized it should be fine. The gt45 I would assume will always have the upper hand despite displacement. Although the displacement could aid the spool for the gt35s they are pretty big for a no lag twin set up.

[@drs2000rr]

@@delagto_5340 I’m running them due to space constrictions, they love to be Brake boosted prior to a launch and they love to rev to 7600 rpm. I think more boost and a high revving Ls would show the benefit of twin gt35s.

[@delagto_5340]

@@drs2000rr I’m trying to figure out something for my car and I think that might be the way I’m going to go. The twins can be mounted right next to the bell housing. I’m a cam only car and personally rather have something that can me tamed and wild when wanted to be. Plus I can just turn it up haha 😆

[@drs2000rr]

@@delagto_5340 awesome, make sure you address heat control with heat wrap and aluminum tape over every wire and hose running through the area, and you should be ok, get a good scavenge pump to pull all the oil out of the turbos, and run a low psi warning light incase the pump fails. Happy Boosting

[@delagto_5340]

@@drs2000rr thank you for the tips ! I’ve been searching the forums and reading up everything I need to do. Most of it is exactly what you said. If I take it on i will document it for sure. Thank you!

[@MrLightning54]

To me it sounds like whichever kit packages better in your vehicle is the one you should choose if the right size turbo / turbos are available for your power goals. Great video!

[@bradspeed]

100% agree, if there is no space to run the twins a go single.

[@MrLightning54]

@@bradspeed I have a single on my car (2011 5.0 Mustang) and love it.

[@blixxy1320]

@@MrLightning54 I bet she rips

[@dee9117]

Dude you are freaking awesome keep up the great work and I’ll absolutely keep watching likeing and sharing

[@bcbloc02]

So now we need this test rerun with tighter ar housings to see what happens. 🤠

[@austindoud273]

It's probably just gonna give you a couple hundred rpm and choke the top

[@LaimisBMW]

@bcbloc02 Or just up the boost and see how the single will perform with that excesive back pressure.

[@littleherms3285]

.63ar is as small as they get in a T3.

[@JimOrr_OK]

As a long time truck driver I’ve known about putting some heat into the turbo before a hard pull but I never had the reason explained like this. Thank you

[@Drekoushranada]

I'm looking forward to setting up my system. Your videos been beyond educational!

[@patlandymore7035]

An absolutely super test! Really liked the lower rpm comparison showing the twins 150 lb/ft down compared to the singles. I wasn’t expecting that. Thanks for doing what you do Richard!!

[@KreatorOfDeath1985]

I'm thinking more about a single turbo now after watching this. Hmmm

[@BronkStang]

Same dude. Plus cheaper n easier

[@nowayjose596]

It depends a lot on packaging in your individual application i.e. the room to run 1 big downpipe or 2 smaller downpipes, etc.

[@BronkStang]

@@nowayjose596 I’ve got plenty of room but after watching this it’s like dude look at how much more torque he was making under 3500 RPM with one single big turbo

[@KreatorOfDeath1985]

@@nowayjose596 68' chevelles have a LOT of room under the hood. I could put 4 turbos in there hahaha

[@nowayjose596]

@@BronkStang I think if he kept going up in boost you'd see the lower RPM responsiveness of the single and twins start to mirror each other more closely and the twins then starting to make more power at the top end thanks in part to their lower backpressure. That's why he emphasizes the sizing of your turbo(s) for your displacement/boost level/preferred RPM range is more important than if you go single or twin.

[@heytonyman]

Great lesson in boost threshold. I suppose what a loaded dyno can’t show is the lag difference between single and twins. I suspect the lighter mass twins will come to life faster when stabbed from a 5000rpm roll, and also recover faster after a gear change in a stick car.

[@button-puncher]

Another great video. Thanks! Lag makes sense. Turbine maps only start at 1.25PR, really get going at 1.5PR, and are fully spooled at 2.0PR. One of your setups is at 1.0 and the other is 1.5. GT3582's are good for 1,000HP at 7psi. Like you said, too big for the 4.8L but perfect for a 6.0L. Better match would be Twin GT3082R turbos. They'd be good for 800HP at 7psi and 1,110 at 15psi. Borderline too small would be twin GT3076R turbos. Good for 600HP at 7psi and 875 at 15psi. Those would be great on the street.

[@TurbineResearch]

Thanks Richard ! You're the man

[@joetovar46]

Would like to have seen a comparison of the back pressure vs boost for both configurations. Also running each combination to its maximum boost/power would also be a good comparison.

[@nowayjose596]

Agreed. I suspect that as boost continued to increase the lower RPM responsiveness of the single would start to mirror that of the twins and the twins would make a bit more power up top thanks in part to their lower backpressure.

[@littleherms3285]

Ya, I was pretty disappointed he only went to 13psi. Should have at least gone to 18. All of those turbos don't get to their happy place until 16psi. Response is over rated. A good converter can fix A LOT. I had a 2.6L motor with a 70mm on it. Just gotta drive it like a man, it did rev to 8k which helped.

[@tomlenza2768]

Awesome vid. ! Love your channel ! I went to a trade school for automotive technology back around 2005 and learned a lot. it was great but god dam I wish u had been my teacher! Keep up the great work. I look up to u!

[@anthonybillings6554]

This is a great test!!! Specially the extra information you dropped at the end!

[@basscube5]

Great video as usual! I have a set of GT35s (Vs racing style) in a Fox. When the build started I had a garden variety 4.8 with a BTR stg 2 turbo cam and I'd describe the boost response exactly like you found. The power band was ~5000-7500. I currently have a 10:1 5.3 with ported 799s, all else identical and there's wayyy more midrange power now. Pump gas with meth, predominantly street car with a 4l80E for reference.

[@dbjunior1238]

Now lets see a compound turbo setup compared to the dual turbo setup

[@aaronkeller8269]

VS actually had me purchase smaller hot sides as response time was not ideal with a T56 behind a 5.3. Only $100 per turbo so it wasnt that bad of a hit. But once I put the 6.0 in the car, the larger hot sides were needed as they light off ALOT faster. About a 1500rpm difference in peak boost range.

[@billybadass-ru8st]

you read that wrong...at same boost..11lbs., single is much better! Thanks for all you do. You have best channel out there for engine development.

[@richardholdener1727]

1 is not better than the other-chose for packaging or looks (turbo sizing can make twins and single otherwise identical)

[@tonymorris3798]

Twins will make similar power to a big single. The real advantage of twins is "Transient Response" usually called "lag". The ultimate test would be - make sure the exhaust housings are equivalent (same back pressure and similar spool rpm), set the dyno rpm to hold peak-torque-rpm, run the engine at that speed with light throttle, nail the throttle and record the boost response vs time at constant engine speed.

[@richardholdener1727]

that's not how an engine dyno works-that is a chassis dyno

[@daveb1870]

I've been trying to tell people to wrap all of their exhaust leading up to the turbo(s) with refractory blanket, housing and past the 02 sensors. MAN Turbo AG has some great white papers on this, its all to do with energy, cold metals suck out heat reducing energy, less energy less power. Super insulating, short as possible distances to turbo(s) all equal higher efficiency. Wrap that stuff in refractory blankets, ceramic preferably but make sure you wear proper ppe when handling ceramic. Other substances such as the formable refractory blanket are less of a respirator issue. Once again thanks Richard for great testing!!

[@azreeal1]

I love to see this with a 1500hp goal. I'd bet the twin setup spools faster than a huge single, but there's only one way to know for sure :)

[@richardholdener1727]

if they are both sized for 1500 hp-then it's a toss up

[@dennisrobinson8008]

That heat in the exhaust test is similar to the rear mount result. The initial response is better but output over most of the curve is the same.

[@designsbynoz]

yep.. with a .82 A/R on the two small turbos it did exactly what I expected on a 4.8. I'd like to see what a .68 A/R or even a .58 A/R would have done.

[@michaelblacktree]

Interesting results. Thanks for sharing! 👍

[@corvetteZ3r]

Ready for your 4.2 atlas test my man!

[@jplperformance9073]

Love the tests and the channel

[@finnroen2334]

Excellent test. Thanks.

[@maclogan6872]

One if the more informative tests. Thanks R H

[@CanadianOnlooker]

The heat issue & turbo response reminds me of learning turbo spool is effected by energy as heat & pressure not just pressure from exhaust flow. EGT & air fuel ratio had a big effect, & because of those the variable cam timing had spool effects. I then looked into WRC anti lag using a gas turbine pre turbo, & a pressure tank to create not only air pressure to the turbo, but burning fuel to create heat/ energy to spool.. Subaru called it the rocket anti lag & its cool af if you Google it

[@richardholdener1727]

I''m familiar

[@jasonrodgers9954]

Richard, thank you for taking the time to make the video! On the gt35 turbos, what kind of increase down low would you have with an all ball bearing better quality gt35?

[@JPANDLIFE05]

I think the response of the single turbo is much better than the twins because all the 8 cylinders of exhaust gas is being feed into one turbine housing, while the twin turbo set-up splits the exhaust flow into 4 cylinders of exhaust gas flow per turbine housing. This tells me the exhaust pressure and volume from all 8 cylinders into 1 exhaust turbine housing is much higher than the 4 cylinders per turbine housing. This might be the reason for the greater responsiveness on the single turbo setup. This is only my opinion. I've never tested this theory, but this just makes the most sense to me. Now, if you do a compounded twin turbo setup, i think the outcome will surpass the single turbo setup in every aspect!

[@richardholdener1727]

it's turbo sizing

[@MrBlackbutang]

Yes it does! Back pressure is the key. Why did you run different turbos? True test would have been same turbo’s single vs twin. They would be air flow capabilities

[@richardholdener1727]

your choice is not a single or twin of the same turbo, you would never pick two turbos that size unless your goal was to make twice as much power. Sized properly for the desired goal, single and twin can do the same thing

[@tangstanggt5006]

I would like to have seen both at higher boost levels. Id bet the twin turbo setup would maintain the same boost rate and make more power at the same boost when reaching peak power potential. Lets see some 25+ psi runs.

[@besearchingforwisdom6267]

You've gained 100k subs since I started to follow, Congrats dude.

[@richardholdener1727]

thnx-it has been amazing

[@sinistersilverado965]

@@richardholdener1727 you are a hard working guy, you deserve it

[@DoctorMotorcycle]

That's very surprising to me that you had a 1:1 Pressure Ratio on the T3 Flanged GT3582's on 13psi of boost. I suspect you could go even smaller on the turbo's and still keep the PR under well under 2:1. I've always thought it would be cool to do a twin GTX3076 setup (or hell, even GTX2867's) with a small a/r to have a more "factory sized" setup that spools really fast and has the OEM turbo sized punch on a 4.8/5.3 LS.

[@richardholdener1727]

we could use gt3076s at this power level

[@Brock_Landers]

Thanks Rich. I'm really depressed tonight, so thanks for posting such an uplifting video buddy. I really appreciate it.

[@SMOKEY-JAYS-DIESEL]

Hey Richard, please do this same test using the same big turbo and one of the little twin turbos Do a compound build that way it gets rid of exhaust back drive pressure I bet the numbers will be a lot better

[@richardholdener1727]

I have compound turbo vids up

[@SMOKEY-JAYS-DIESEL]

@@richardholdener1727 awesome brother. I will check them out

[@speedbuggy16v]

you sir are a bad influence, but you are correct, "twin turbo" does roll off the tongue nicely, I know in my head that a single will make way more power than I need... But twins oh boy, who does not love a set of twins.

[@MD-lm7fj]

Big turbo? Small turbo? Richard why are you making us choose? Let's see some big/small compound setups!

[@keithwilson8624]

So exhaust wrapped exhaust on a turbo setup will improve your spool and performance especially if you’re running aftermarket tubular headers ? Interesting, I enjoy learning little tips and tricks

[@FastFoxx82]

Two 7675 🤪 test would be cool too

[@AdamOpheim]

Thanks again for the test! Might try the .63 housing GT35's, esp. on a 4.8. (you can buy just the housings pretty cheap) The .82 AR exh housings are on the large side. I run the .63 AR T3 GT3582's with the billet 64mm upgrade ($250 ebay turbos) and the response is like a light switch on a mild gen4 5.3 (gm "hot cam") ... Although like most turbo autos I run a stall that's around 3400 anyway, so maybe I'm not seeing the early RPM issues. Crank that boost up for us and see if the twins shine!

[@tonymorris3798]

Agree. The twins were effectively running a bigger exhaust housing than the single - later spool and lower back-pressure.

[@jackstoepfer1494]

Would do recommend the same .63 on a cam 6.0?

[@AdamOpheim]

@@jackstoepfer1494 depends how you want them to act. Do you want more response down low, or more power and rpm up high?

[@jackstoepfer1494]

@@AdamOpheim I would say low to mid range. It’s for an off road truck. I want to hear the turbines when cruising around.

[@AdamOpheim]

@@jackstoepfer1494 Hearing them is usually a matter of exhaust. Housing size won't change that. Some turbines are just louder than others in general too. Mine weren't that loud and I just had 14" of 3" pipe on them. If you don't plan to push it much past 600-700 range , and want quickest spool possible, the .63's are fine IMO.

[@MB-ib5ji]

I would so love to see a 1 liter Chevy Sprint turbo big Bang. heck you already have the turbo just take one of those who you got there... and has anyone else wondered if you could rub Richards head if some of that turbo knowledge would rub off?

[@ToddFordingLSX]

Will probably never happen but would be so cool

[@shaneshane1379]

13 pounds.of.back pressure on each head compared to 18 pounds total for both heads raises thought. Pressure is pressure, but in reference to the turbo efficiency, I would have to say the single is more efficient. At 18 pound the single made the same near power level than 2 turbos that took 13 pounds of back pressure each. As far as the engine, lower back pressure is less effort on the engine to feed the boost. Therefore, maybe it won't blow up the first day you get it running.

[@wayneallen2047]

Awesome. I'm getting ready to do the same now

[@strong_voice_of_truth]

I would have used twin 3076r on a 4.8 at those boost levels. Should spool quicker and be capable of nearly 1000hp.

[@harrisjoseph6355]

gt2867rs is the 500hp Garrett turbo, so 2 of those would be the 1khp setup. Might be a little more responsive.

[@richardholdener1727]

only if you get them from garrett-the off shore versions don't do that

[@harrisjoseph6355]

@@richardholdener1727 Yeah buying 2 gt2867rs from Garrett would definitely not be a budget build xD. Great turbos for a B-Series as well if you don't have lofty power goals.

[@nsmturbo5902]

I originally planned on twins but the plumbing takes up a lot of room. I'm gonna go back with a bigger single for ease of installation. I really wanted the cool factor of 2 but the S10 don't got the space.

[@fryloc359]

In one of the facebook groups I'm in, a guy built a quad turbo vette kart. I'd like to see the dyno chart for that.

[@martyhildebrand6392]

Would like too see more on a 408 Ford stroker twin turbos

[@UglyasUbutFaster2]

So for my daily driver in drag Radials I'd pick twin turbos so I can get some traction. Great test Richard thx!!

[@smp3745]

You need to do a run with a balance pipe in-between each turbo in the front of the engine and do another dyno pass

[@iancole85]

Epic video 🎉

[@KreatorOfDeath1985]

YYYEESSS can't wait!

[@SoFLaZ06]

The twins looked like older heavier casted compressor wheels, the single had the billet wheel advantage here

[@SoFLaZ06]

@@hondatech5000 that's a broad claim. there's numerous apples to apples real world comparison where the billet brings in power alot sooner.

[@nemanja162]

@@SoFLaZ06 due to aerodynamics not weight

[@troyclaerhout2412]

Twins and a trans brake is my pick.

[@tptrsn]

Great stuff Richard! I've been running a pair of those "GT35s" trunk mounted on a 4.8, and I can verify that they aren't super responsive, but on the other hand, up over 20psi, they really rip. I'm wondering if up in that low to mid 20s area, maybe they would have more capacity than the 7875? I've usually found that the ability to make power is pretty predictably inverse to the responsiveness of a turbo(s)... But I guess that means that the S475 really wins overall....

[@AdamOpheim]

I run the .63 T3 housing GT35's instead of the .82 tested here. They are very responsive on a cam only (small GM hot cam, TBSS int.) gen 4 5.3. Also really nasty at 20lbs! I don't know anyone that stops at 11lbs on a turbo LS! lol.. I agree this test may have favored the twins if the boost was run up to typical higher levels. We are talking 100hp+ HP difference once setup in a car and taken to a chassis dyno. For reference my twin gt35s made 565/600 on 11 lbs on the chassis dyno. All that heat he was talking about improving response... that REALLY shows on a remote setup too. What size piping to do have feeding them?

[@littleherms3285]

@@AdamOpheim I agree, I also have the .63 turbines and am glad I went with them instead of the .82s. Response is very good with a 3800rpm converter and a baby cam. Made 630whp on only 14psi, 16*, 10.5 AFR and E50. This year, shooting for 800whp on 20psi and E65.

[@tptrsn]

@@AdamOpheim Hey Adam, big fan of your builds!! :) I could probably write a book to respond to this comment, so I'll try to be concise. First of all, I was running 2.25" tubes for each side of the engine, into a 2.5" Y, and the wastegate just after the Y, so at the front end of the 2.5" exhaust running to the back of the car. Then Y-ing out into a pair of 2" diameter feeds up to the T3 flanges in the trunk, and .63 exhaust housings. After watching some of Richard Holdener's videos, it became clear to me that most likely my bad response was just because of my engine making no torque. The supposed to be 5.3 actually turned out to be a 4.8, and I had a Sloppy Stage 3 (Elgin 1841) cam in it, along with a very short runner sheet metal intake to fit under the hood of my E36 I was running it in. I put together a 6.0 with the same cam and intake, and it spooled those turbos like mad. But with the 4.8, the (drift) car eased off the line and ran 10.67 @143, on a 2.1-ish 60ft time, and no boost to speak of for the first chunk of the track. I shifted the 4.8 around 8k+, and up there it ripped real good.

[@AdamOpheim]

@@littleherms3285 those are great numbers and more typical. Folks get a little out of control quoting dyno cell numbers. My setup was non- intercooled , E60, and 8.9:1 or so as well.(241 heads) So the numbers weren't all that stellar. But it hits 20lbs so quickly you'd never know it was a low compression motor. My GT35's really woke up around 17lbs! I think you'll be surprised how much is left in them.

[@AdamOpheim]

@@tptrsn Thanks! Sounds like that combo was just missing a nice converter. I think a 19-2 stator 9.5 from PTC would have woken the bottom end up a TON and allowed a nice front half to go along with that killer back half! Good to see the gt35's doing work! That's a record MPH wise as far as I know? If you're running the cast gt35 wheel anyway. Is the car pretty light? Highest power level I've seen out of the GT35 is around 800whp and they were beyond tapped at 23lbs on an LS1. I haven't seen any trap worth a darn, myself included. only managed 134, but had issues and was booted for no cage. I always thought mine had 140 trap in it at 3000lbs.

[@johnhazel5385]

Maybe look at the compressor map. The units might have peak efficiency at different volumes and pressure ratios. If a unit with max effieciency at a pressure ratio of 2 (14.7psi boost) an another has max efficiency at pressure ratio of 1.5 (7.3psi boost) but higher volume the first would work well on low displacement engines and the second would work better on large displacement engines. (both producing the same power.)

[@richardholdener1727]

NO MAPS FOR MOST OF THESE

[@johnhazel5385]

@@richardholdener1727 Are the twins the GT 3582R? www.garrettmotion.com/wp-content/uploads/2018/05/Comp-Map-GT-3582R.jpg I haven't found the map for the single yet.

[@JethroRose]

twins enable you to do things like sequential or compound setups; if you're able to do that it isn't quite that simple. twins are going to be far more plumbing (i.e., it's a packaging and fabrication cost issue).

[@davelowets]

Not too many people use twin turbos in a compound or sequential setup of a gasoline engine. Thats more for diesel stuff

[@time8533]

I would like to see you run twin 7875 on a gen one 406 and see what kind of power it pumps out. 👍

[@shorty808100]

I know what it is on a big V8 a single is gonna spook up faster, but on a four cylinder or 2jz race engine I think a twin turbo or compound setup would be far better than a single turbo setup because they rev far higher and have a larger power band, I would like to see this done with a purpose built drag four cylinder or 2jz and see which is better I think for that the twin would be better but for V8’s you wanna make some boost get you a single 108mm turbo

[@derekconard8234]

Richard you need to do some twin turbo bbc testing and stuff I know you love ls but give us bbc guys some nice info and testing would love to see some 496-540 with vs racing turbos or borgs

[@richardholdener1727]

I have several twin BBC videos up

[@khg8519]

Two turbos are better than one thats simple physics I'd think a single turbo is easier to get set up correctly - you dont need blankets or anything unless you have heat issues under the hood

[@Mo5005]

This man needs to have a statue erected in his name for this sort of content.

[@BruceLee-xn3nn]

GMT gearheads has put LS heads and intake on a 351w block.With twin turbos.

[@MrZX1206]

what is gmt gearheads?

[@andersamby7802]

You did not mention the backpressure on the VS 7875 TURBO😢

[@DjHatZnBfan]

Or two BIG turbskis?

[@traitorhatergetarope3163]

Good video..

[@oliverscorsim]

This was awesome man but hey I really wanted to see just this test butt can you post the back pressure too I wanna see the curves

[@robertbenson1966]

Love your videos, i try to make sure that I like them to make your analitics good. Lmk if there is something we fans can do to help. So i road race, sebring, Watkins glen and other tracks, so how long do you think a motor can run at 1000Hp My laps are 1-2 minutes and we run 30 minute sprints. Full throttle is not long because tracks have lots of turns. I just bought a VS turbo and intercooler. I have a 10.5:1 small block chevy, dry sump circle track motor, bowtie block, brodix spch heads, im planning to have 5 pounds boost with a solenoid for 10 pounds on straight away. FYI i bought a VS racing turbo for my car based on your videos. You see guys are spending 50,000$ for 900Hp nascar engines, and i said thats silly, ive seen Richard make power with boost. So my plan is my 475 Hp NA engine will be 600Hp with 5 pounds and 875 at 10pounds. I only run race gas and will keep timing locked at 25 degrees. Your the best and i share your videos on Facebook all the time

[@collintrusty9203]

It's all about compromise.

[@cboy132]

Single with more response. I love it. Where's the remote? Building a 2011Caprice 6.0 with a S480 in the spare tire bucket. Thanks!

[@bdog3869]

Richard while you have shown that single vs twins are pretty close. My question is if your looking for a quicker spool, and I know you’ll loose some top end power does it still go that a single vs twins would have the similar results for spooling necessarily while also attempting to keep a somewhat higher HP outcome? Greatly appreciate your input on this.

[@richardholdener1727]

single vs twin is a non issue-turbo sizing vs na power curve dictates spool response

[@ThePeopleVerse]

I am a bit stunned. Probably like many others I had thought the 2 littles would been more responsive. My take away is maybe one big, one little in a twin setup..LOL Nitrous for the leave with twin big ones? Come on Richard! You're making my brain hurt...and my wallet. HA

[@rayevans3000]

I'd love to see how two of those 7875s do.

[@richardholdener1727]

I have tests up on singles as well

[@jaceyrondeau8133]

I'm building a twin set up with 2 of the VS Racing Gen2 78/75 turbos. They will be fed by a Dart SHP 427 sbf. Uncharted territory for me so will have to see how it goes)

[@nateynate1235]

I think it would have been helpful to explain the logic process of selecting a proper turbo for your setup. After watching your video, I still don't understand why the summit turbo did worse than the cheaper single, despite being more efficient.

[@richardholdener1727]

WASN'T THIS A SINGLE VS TWINS?

[@nateynate1235]

@@richardholdener1727 Yessir, but at the very end you compared the Summit turbo to the other GT45. I'm wondering what are the factors that make the GT45 a better match to the 4.8 than the summit turbo. That part wasn't really explained in your video.

[@GearlessChris]

Dang it. I have wanted something with twin turbos since the late 80's. I the other hand, maybe the low response would help with traction on the street.

[@JethroRose]

twins can be set up in many different ways - parallel like this, sequential or compound. the Skyline GTR, FD RX7 (and supra I think) run twins from the factory in sequential setup. More complicated, but the idea is you get the boost response from ONE smaller turbo low down and then the second one has exhaust diverted to it later when the first one is running out of legs. they're inline 6 and rotaries though - v8s sorta lend themselves to twins due to the exhaust layout, but this video proves that a big single can be probably cheaper and easier to fabricate without any major compromises - and in fact is probably easier to size appropriately.

[@randallmason9687]

It looks like the gt45 may be way to go on My 4.3.

[@GrowMotorsports]

If it's an ebay gt45 with a 1.05ar. You won't feel it until maybe 4500rpm

[@danielsullivan9865]

On the drag strip those twins will kick ass

[@buiItnotbought]

Hey i remember you recommended i go 94mm. I just bought two 72/68 t4 .81! Your guys tracks open up there?

[@danielsullivan9865]

72 mm turbos should move a lot of air but .81 AR May create a lot of back pressure I'm not sure. We're running twin 6973 . they came with .91 AR couldn't go over 5,100 RPMs without extreme back pressure. Changed to a .96 turbine housings picked up 300 horsepower. Do you have rev9 turbos or Turbonetics? They should be good for a 1600 horsepower but you may have to change the turbine housing. Good luck let me know how much power it makes

[@buiItnotbought]

Is that a s369? I heard good things about those. Yeah its a rev9 so i can get .96 housings. Ngl im not logging backpressure. All out of inputs on my ft450. Should i just install a gauge?

[@danielsullivan9865]

@@buiItnotbought yes pressure gauge will work. If you have too much back pressure you'll notice it in the sound of the engine and your power will fall off drastically after about 5,000 RPM. with the right camshaft and the right intake those turbos should keep making power to 8000 RPMs. It'll be scary fast!

[@buiItnotbought]

Haha now i still need to get a good trans. Split all my super t10s. Lookin at gf5r. What trans you run?

[@applebitefool]

Id be really curious to see twin GT28s at 13lbs.

[@yotaismygame]

Anyone make gt28s that aren’t internally gated? What about two small BW turbos?

[@adamspencer2515]

I understand getting heat into the turbo,it’s actually thermal expansion that makes them work. Compare ceramic coated headers vs non ?

[@justindube9513]

please do this exact test on a 6.0 liter and then a 408 stroker or any 6.0 liter stroker. I have a gen 4 stock bottom end 5.3 on e85 I'm building for my competition drift car. I have a spare 6.0 liter engine for when the 5.3 lets go. its a twin turbo build with vs racing gen 2 billet 6262 . I'm worried about what the 6.0 might do with those small turbos. don't wanna bend rods down low also wondering what back pressure would be. I built a custom twin set up and don't wanna have to change turbos and fab new pipeing. reason why i ask about a stoker with small turbos on it cause i have a sponsor that might build the 6.0 l wondering what foolish things would happen with a 408 with small turbos. Thanks

[@jefflaney9355]

Second that! Really curious to see the same tests on an LQ4 or Ly6 just to see the low rpm response difference.

[@outlawstang]

Hey Richard love the videos very informative do you think you could do this for a 4.6 2v with a on3 turbo kit thanks keep it up 🤩🤩🤩

[@kellyheath8547]

I would like to know the weight of the turbos. Light is right! if a s480, or 78/75 can save 10 or 15 pounds over twin 62's then that could be a deciding factor. The other challenge is usually packaging.

[@parkerwayne4323]

Will you please do an 8.1 vortec build

[@leepederson5254]

Got me there, I would have thought twins respond better. Probably because that’s what I’ve been told

[@danielsullivan9865]

it just depends on the AR and it doesn't make any difference because what that Holly you can use the Boost Builder to build boost or a dump valve

[@mpeugeot]

single big turbo will often beat twins, but not two sequential turbos.

[@Turbokrankenwagon]

I guess it all depends on power goals... but even the laggy t6 and twin turbo setup... you still have over 300ft lbs at 3000 rpm... on the street with rolling resistance and weight plus hot turbos... it’s enough. I’d much rather that fat power curve above 4000rpm, also having that progressive power curve and the lesser back pressure will save the bottom end. Win win. I still find it funny when V8’s worry about lag... lol

[@kst8engineer]

@Richard Holdener, now you've got my curiosity up as to how a big/small sequential twin turbo combination would compare in terms of power potential and responsiveness. I'm thinking the flow limitation on the hot side of the small turbo would still limit the power potential.

[@richardholdener1727]

NOT IF YOU SWITCH EXHAUST FLOW OVER TO BIG TURBO

[@robertwest3093]

GM struck gold when they developed the LS engine platform!