Turbo selection
Thread Starter
Launching!
Joined: Nov 2014
Posts: 234
Likes: 16
From: South dakota
Turbo selection I contacted VS Racing for recommendations for a turbo to go with, In the email I included all the details of my truck and what the intended use of the truck, They replied with their 80mm T6 1.32 AR 96/88 turbine wheel. I don't know much about turbos, obviously, but that size seemed little bigger then what I thought I should look for, But I bought it anyway haha. So for peace of mind, I'd love to hear some feedback on the sizing.
Vehicle is a RCSB CHEVY, Awd, auto w/ 2800 stall, 80/20 (DD/TRACK), the motor is a built 398, 11-11.50 compression, SS2 cam.
thank you
Vehicle is a RCSB CHEVY, Awd, auto w/ 2800 stall, 80/20 (DD/TRACK), the motor is a built 398, 11-11.50 compression, SS2 cam.
thank you
TECH Fanatic
Joined: Jan 2022
Posts: 1,034
Likes: 468
From: Seattle
That T6 housing is huge, nothing wrong with that of course, but it makes packaging a little tougher. T4 would have been a little easier to cram in there, you didn't mention what year truck? GMT800? 900? That size Turbo is capable of 4 digit HP numbers no problem, so start getting $ for that trans build. 
You thought about piston ring gap at all? Also, that CR is pretty darn high for a forced induction engine. 
You thought about piston ring gap at all? Also, that CR is pretty darn high for a forced induction engine. 
TECH Enthusiast
Joined: Dec 2011
Posts: 531
Likes: 5
I run a T6 S475 in my 90 OBS RCSB. LQ4 with SS2 cam. T56 Trans and 4.88s.
I LOVE the performance of that turbo.
That compression ratio you speak of for your combo is not ideal for boost. Compression makes power. But boost makes more.
I LOVE the performance of that turbo.
That compression ratio you speak of for your combo is not ideal for boost. Compression makes power. But boost makes more.
Thread Starter
Launching!
Joined: Nov 2014
Posts: 234
Likes: 16
From: South dakota
That T6 housing is huge, nothing wrong with that of course, but it makes packaging a little tougher. T4 would have been a little easier to cram in there, you didn't mention what year truck? GMT800? 900? That size Turbo is capable of 4 digit HP numbers no problem, so start getting $ for that trans build. You thought about piston ring gap at all? Also, that CR is pretty darn high for a forced induction engine.
You thought about piston ring gap at all? Also, that CR is pretty darn high for a forced induction engine. Thread Starter
Launching!
Joined: Nov 2014
Posts: 234
Likes: 16
From: South dakota
Last edited by 98Zeric; May 21, 2022 at 03:49 PM.
TECH Fanatic
Joined: Jan 2022
Posts: 1,034
Likes: 468
From: Seattle
Trending Topics
Thread Starter
Launching!
Joined: Nov 2014
Posts: 234
Likes: 16
From: South dakota
No, i made it awd, I used the front axle from a 01 escalade and used NP149 transfer case..also converted to dual piston calipers (unrelated to awd conversion) from the 99-06. There is room, i am thinking behind the AC compressor, the turbo is a bit big, but i think I can make it work
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo TECH Fanatic
Joined: Jan 2022
Posts: 1,034
Likes: 468
From: Seattle
No, i made it awd, I used the front axle from a 01 escalade and used NP149 transfer case..also converted to dual piston calipers (unrelated to awd conversion) from the 99-06. There is room, i am thinking behind the AC compressor, the turbo is a bit big, but i think I can make it work
Thread Starter
Launching!
Joined: Nov 2014
Posts: 234
Likes: 16
From: South dakota
I do have some pictures
TECH Enthusiast
Joined: Dec 2017
Posts: 676
Likes: 72
that answer comes with the qualifier of how good is your tuner. Ive run 21psi plus on a 12 to 1 engine on e85 but my tune was spot on. The higher your compression ratio the smaller your tuning window but with e85 it's still a fairly large window. whats your hp goal if I might ask.
A baby sized 67MM turbo is a well known application for an lq9, because of a kit some years back. Such said kit would easily brake boost over 7lbs of boost and insta spool off the converter.
Thread Starter
Launching!
Joined: Nov 2014
Posts: 234
Likes: 16
From: South dakota
that answer comes with the qualifier of how good is your tuner. Ive run 21psi plus on a 12 to 1 engine on e85 but my tune was spot on. The higher your compression ratio the smaller your tuning window but with e85 it's still a fairly large window. whats your hp goal if I might ask.
as i mentioned in the reply above to ddnspider, i don't really have a goal, the most i can get safely and reliably (to the motor). But if i had to put a number around 700hp would be pretty cool
TECH Enthusiast
Joined: Dec 2017
Posts: 676
Likes: 72
I'm thinking 10psi would get you 750+ at the flywheel. That is doable for sure on e85. That is figuring 450 on motor alone. That is a low estimate but I figured for worst heads possible. I always try to err on the low side. Under promise and over deliver. The turbo you bought will easily do way more. 4 digit power is possible with a s480. Rwhp I'd rather not even try to guess since it's awd and the drive train loss is going to effect it alot.
Thread Starter
Launching!
Joined: Nov 2014
Posts: 234
Likes: 16
From: South dakota
I'm thinking 10psi would get you 750+ at the flywheel. That is doable for sure on e85. That is figuring 450 on motor alone. That is a low estimate but I figured for worst heads possible. I always try to err on the low side. Under promise and over deliver. The turbo you bought will easily do way more. 4 digit power is possible with a s480. Rwhp I'd rather not even try to guess since it's awd and the drive train loss is going to effect it alot.
OP - Please don't put a baby turbine T4 turbo behind 398CI, even the 88/96 turbine is kinda small for that engine size. If sticking with VSR their 85/102 would be about the smallest thing I would want on a 11:1 398.
Not sure why so many people want a lazy engine with a turbo, compression works great with boost.
Thread Starter
Launching!
Joined: Nov 2014
Posts: 234
Likes: 16
From: South dakota
OP - Please don't put a baby turbine T4 turbo behind 398CI, even the 88/96 turbine is kinda small for that engine size. If sticking with VSR their 85/102 would be about the smallest thing I would want on a 11:1 398.
Not sure why so many people want a lazy engine with a turbo, compression works great with boost.
Not sure why so many people want a lazy engine with a turbo, compression works great with boost.
Last edited by 98Zeric; May 16, 2022 at 06:55 PM.
The turbo i have has the t6 flange,that was my thought for a higher compression, to get away from a lazy motor, however my motor is closer to a compression of 11.55-11.65, I'm beginning to worry my current compression might be to high. i was shooting for up to 11:1... thank you for the recommendation