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.

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

@toob247

3 жыл бұрын

@james avery more money not all the money's

@georgeschnakenberg7808

Жыл бұрын

All the money's

@davelowets

Жыл бұрын

One has to pay, to play..

@Cultofpersonality09129

2 ай бұрын

Hero? Get help.

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

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

@davelowets

Жыл бұрын

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

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

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

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!

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

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

3 жыл бұрын

6000lb truck in my case lol

@brooks3racing1

Жыл бұрын

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

@davelowets

Жыл бұрын

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

@cooperechols7322

11 ай бұрын

rip🤧

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

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

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

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!!

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

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

3 жыл бұрын

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

@MrLightning54

3 жыл бұрын

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

@blixxy1320

2 жыл бұрын

@@MrLightning54 I bet she rips

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.

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

3 жыл бұрын

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

3 жыл бұрын

@@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

3 жыл бұрын

@@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

3 жыл бұрын

@@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

3 жыл бұрын

@@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!

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.

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!

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.

Thanks Richard ! You're the man

One if the more informative tests. Thanks R H

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?

Love the tests and the channel

Interesting results. Thanks for sharing! 👍

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.

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

@richardholdener1727

3 жыл бұрын

thnx-it has been amazing

@sinistersilverado965

3 жыл бұрын

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

Excellent test. Thanks.

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

@austindoud273

3 жыл бұрын

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

@LaimisBMW

3 жыл бұрын

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

@littleherms3285

3 жыл бұрын

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

In the diesel game we change timing down low to help with EGT heat to spool a big single

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

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

3 жыл бұрын

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

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

@BronkStang

3 жыл бұрын

Same dude. Plus cheaper n easier

@nowayjose596

3 жыл бұрын

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

3 жыл бұрын

@@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

3 жыл бұрын

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

@nowayjose596

3 жыл бұрын

@@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.

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.

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

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

3 жыл бұрын

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

3 жыл бұрын

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.

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

23 күн бұрын

it's turbo sizing

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

Жыл бұрын

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

When you run these gen 3 4.8's with the gen 4 rods and forged pistons, are you balancing the bottom end or just going full send?

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

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

Жыл бұрын

I''m familiar

wondering, in diesel just small change of boost is needed to fuel up. in gasoline, there is no necessary any adjustment with boost up?

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

Жыл бұрын

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

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!!

Silly question here, what if you plumbed your exhaust like a compound? All 8 cylinders' exhaust goes into one of the turbos, then into the other turbo making for quick spooling. Next plumb your cold side like a normal twin setup, where each one breathes out into the intercooler, then the engine's intake manifold (not stacked boost). I imagine your back-pressure would be super high, but could you bleed it down with strategically placed waste-gates? You could use your single turbo Y pipe setup, then add the 2nd turbo onto the output of the 1st.

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.

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 🤩🤩🤩

The heat statements with response outputs got me thinking about header wraps and turbo heat shields. Have you tested them?

nice test richard! what size is the twin turbos ? compressor inlet and turbin in and out?

Epic video 🎉

Ready for your 4.2 atlas test my man!

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.

Very informative; any ideas, other than cut and try, to determine which turbo is going to have the best response and good power? Are you familiar with "Maximum Boost" by Corky Bell?

This test got me thinking of another that would be interesting, and I apologize if you’ve done it already and I just haven’t seen it. In the coyote community, twins are generally the preferred method of turbocharging because it’s said that large singles end up having too much backpressure and that it causes issues with the valvetrain. That’s according to several tuners. I’d be curious just how different the total backpressure readings would be between similarly rated combinations like you have here and just how much that may or may not affect valvetrain. One can probably inference from the response rates of the two in this test that the single would have a fair amount more?

YYYEESSS can't wait!

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

@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

3 жыл бұрын

NOT IF YOU SWITCH EXHAUST FLOW OVER TO BIG TURBO

I wonder if you changed rpm climb rate on the dyno if it would show a bigger response (Turbo lag) difference.

I think I remember before you saying that headers help across the board with turbo, just like NA. Since in this test, the low RPM spool was where most of the difference was, I'm curious if the headers affect how fast it spools up, or if it is kind of a linear boost across all RPMs? I'd be curious to see a headers vs stock manifold test with a turbo (Or pair for that matter).

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

3 жыл бұрын

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

@jackstoepfer1494

Жыл бұрын

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

@AdamOpheim

Жыл бұрын

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

@jackstoepfer1494

Жыл бұрын

@@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

Жыл бұрын

@@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.

I'd really like to run a super reliable 408 w/706, stage 2 btr truck cam, cheap twin system ata intercooler. Could I do that on 91 and 10-12lb spring in a waste gate reliably? I'd like to not have to do all the extra for a boost controller hopefully just spring pressure.

Richard have you considered doing a video on single 7875 vs twin 7875? The 7875 can come in .96 backhousing helping with spool, but very curious on power differences between single or twin of the same turbo if there would be a big difference in power due to less heat, back pressure etc. Also curious if stock(ish) trim 4.8/5.3 could spoil two and see how it comes in on dyno

I don't know the flow rates, but is there something smaller than the GT35 that would pair it up against the single GT45? This was a great test and goes against everything I had thought. I don't think anyone is going to argue that a single turbo setup is way cheaper! Were those on 91 octane pump gas, or race gas?

I'm curious if smaller GT30's with large hotsides would do better. The gt35's have much larger compressors combined (40% more flow) but obviously more hotside restriction, so they could be acting like the tc76 in the previous test.

Thank you.

Two 7675 🤪 test would be cool too

If I go the twin route..gonna try a pair of G25-660 .72s I think the twin 3582s might have been a bit of overkill and hence not quite as responsive?

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

2 жыл бұрын

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

Whatever happened to the compound turbo idea? I know you started it but I think we missed the final run.

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.

Did you know you can get the GT45s with a .68 exhaust A/R? Would make an interesting test for twins.

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.

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!

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.

The difference between the twins and the single down low, how much difference would there be with a 5.3 of a 5.7 liter? Would the responsiveness with the twins down low not be as drastic?

Soo if i do twin turbo my 4.6 , for a good overall power gain like the gt45 single did, should i pick even smaller turbos the the gt35? What size twin would be the best? For exemple a max of 6-700hp?

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

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

3 жыл бұрын

Will probably never happen but would be so cool

Richard, what spring are you running in the gate for the single setup? I'm working on the same exact. VS 7578 single setup, on a very similar 4.8, with a turbosmart manual boost controller and turbosmart gate, and we are having trouble keeping the boost in check. We want to be around 12-14lbs of boost, and it runs away right now @ close to 18-20lbs. I'm sure it's just a spring issue, and we just need to find the right one..

@richardholdener1727

Жыл бұрын

check spring and position of the gate

@davelowets

Жыл бұрын

@@richardholdener1727 The gate WAS in the middle of the crossover pipe, and that REALLY worked like crap. I moved it to the end of the pipe right on the end of it before it turned and went up to the other bank, and it was better but still not good. So, I removed it from the crossover altogether, and put an adapter block up on the passenger manifold, right under the turbo and relocated the gate there. Now it works great, but it's just too much boost and the controller cant turn it down far enough. We only have a few random springs that we can't identify, and I'm sure they're all too big. I'd like to just go out and buy the proper one, but I don't know where to start as far as the correct spring "poundage". Any idea where to start to get the boost in the 12lb range with the manual boost controller in about the "middle" of it's adjusting range? Similar 4.8 to the one in the video, VS 7578, cheap manifolds with crossover.... Thanks!

Ok, what about one small turbo, and one large turbo. One adding all its boost at low rpm, then one that takes over all the way to top rpm? The idea would be to make more low end torque at low rpm to get the car off the line and out of the corner, then at a given rpm power gets extended to red line. Would a valve be needed to shut down exhaust to the small turbo once there’s enough flow to get boost out of the larger turbo, and the opposite on the low end?

Richard I am about to make a video on polishing piston tops or “crowns”. Have you done this type of testing on the dyno? If so, what were your conclusions? Thx buddy!

Amazing

Good testing. Could you provide links to exact turbos used ? (Web shops or manufacturers pages please!)

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.

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

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

@MrZX1206

3 жыл бұрын

what is gmt gearheads?

I like single gt-45 setup looks like more of street have setup twins or summit would make good drag race for top end.

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

Yo, Rich! New to building domestic motors. Love the info you put out, wondering if you have any content on which transmissions to use with these high HP motors? Which engine management?

@ruebenb83

3 жыл бұрын

roller rockers?

Good video..

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)

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

Now on the gt3582 do you have to run the water inlets if your using em on a daily driver

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

Twins and a trans brake is my pick.

Doesn't the non-uniform exhaust pulsing of the twins adversely affect their reliability??? Think firing order vs manifold output.... 18726543, one manifold 1_7__5_31, other manifold _8_26_4__8. Seems like that would make for alot of strange harmonics in turbo speed and affect boost.

Richard, how do you like that twin turbo air to water intercooler vs a traditional air to air? Also, for my 5.3L ( -5cc flat top pistons ) i was looking at he VSR 67/62 mirror turbos. for 800-1000wheel Im curious what you might suggest for A/R for these twins on that setup Thanks!

@richardholdener1727

Жыл бұрын

VIREN KNOWS WHAT WORKS-BOTH COOLERS WORK WELL-SEE VIDEO ON COMPARISON

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

3 жыл бұрын

NO MAPS FOR MOST OF THESE

@johnhazel5385

3 жыл бұрын

@@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.

Hey man, thanks for all the hard work you do putting out tons of good content! Quick question...for you, how come Dyno pulls don't really ever go below 3,000 RPMs? For example, when you want to build a daily driver, streetable combo especially in a heavier vehicle like a truck, it'd be nice to see what it would do from like 1,500 RPMs up. Is that an issue with how the dyno works, that it can't or they that gutless down low that it doesn't pay to? LOL Just wondering, thanks again for all your hard work.

@richardholdener1727

Жыл бұрын

the dyno can load down that low-but how often are you at WOT at 1500 rpm?

@dbjxxl4822

Жыл бұрын

@@richardholdener1727 I get what you're saying, I guess that's why they make different RPM stall converters and rear gear ratios lol. Thanks for the reply! Always looking forward to your next test!

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

3 жыл бұрын

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

3 жыл бұрын

@@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

3 жыл бұрын

@@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

3 жыл бұрын

@@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

3 жыл бұрын

@@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.