Kmspeedie

iTrader: (1)

So alot of people say for a motor over a 370 you should a t6 turbo, and defiantely on anything over 400inches. Well i wanted a capable street car witha quick spool, so a t6 84mm with like a 1.32 ar seems crazy to me, so on my setup im very happy with it, on my forged 416 and 13.5lbs of boost through a t4 s480 billet wheel, not even really tuned, it made just over 800wheel thru an auto.. so im hoping i can squeeze 17 or 18 out of it before its to much for the turbo. But damn man thats good power for a street car and a t4 on such a large motor, the only good thing is i dont have a t6 where id be able to crank it to 20lbs and then id b blowin **** up, and this lil t4 lights off damn quick.. Im gettin retuned here this week, i never made a build thread before,but this may turn into it, ill show everything ive done, but theres so many turbo builds so i figured who wants to see another one lol. Also its thru a modified Huron Speed V1 A/C kit... yes guys this car still has A/C...

Atomic

iTrader: (37)

On my 402 I started with a cast 76mm/87 turbine T4 borg, then went to a cast 80mm (same turbine), then the 82mm on a 96mm turbine T6. The T6 big turbine setup definitely pulled harder up top but was noticeably laggier than the T4 setup. You can make plenty of sauce with a T4 even on a big engine, and it will spool noticeably faster.

Forcefed86

iTrader: (4)

What kind of top end is on that 412? What exhaust wheel is on the S480?

I believe forced inductions "gangsta" t4 turbo line would be a decent match for the larger cube cars wanting T4's.

They have the 96mm BW exh wheels mated to T4 housings with better flowing V.3 comp. wheels. 76-84mm compressors are available I believe.

The older 76/92 V1 model was making 20+psi at over 1000whp on 366 cubes... I'd imagine the new V3 "gangsta" models could feed a 416 with a moderate top end.

Atomic

iTrader: (37)

WCCH L92 heads with a moderate cam and holley intake.

The problem with a T4 on a big engine is it peaks early and falls off fast, but still spools good. The T6 82mm I had made 1100ftlb at 4200rpm but made peak power at 5200rpm. A bigger turbo would move that torque peak to a higher rpm and make a bunch more power. 1100ftlb at 5500rpm would be 1150rwhp.

Kmspeedie

iTrader: (1)

On mine were only comfortable pullin to 6800rpm, and it comes in around 4200-4400rpm full boost and stays full power across the graph until we let off the throttle... 416 s480 96mm wheel and this one even has a conpact cover, not even a race or normal cover. This turbo is impressing the **** out of me for a street car, we hit 17lbs today and made right at 900wheel. This turbo isnt missing a beat yet..I wonder how high I could get this small of a turbo to make on such a large motor... i see no reason for a t6 unless i was goin for hp out of sight for 4bolt heads.. why have a huge laggy turbo for a street car. Now if it was a strip car... T6 all day no doubt
Thanks Lil John for sucha badass specd turbo

Forcefed86

iTrader: (4)

I'd get a gauge on your exh. system to check back pressure. Would give you a good idea how much more you can turn it up.

Kmspeedie

iTrader: (1)

Thanks for the advice! my tuner is watchin that for sure! i have a 4inch dp that has a cutout before it necks to 3inch to get thru the k member, so its free flowing but yeah that totally makes sense, i knew backpressure would be an issue, but i wanted to do somethin everyone said couldnt be done, or doesnt reccomend. Lil john helped me and my tuner is probly the best in the business, atleast in florida. Up there with formatto, theyre friends, im just so happy with the results so far. Amazes me i see alot of people runnin t6's to make my power level, yes theres more room to grow... but why suffer.. and for people like me i like that i cant go over what my motor can handle,because thas how everyone breaks their ****.. no cage and still got a/c.. ultimate street car

Atomic

iTrader: (37)

When you measure backpressure its between the engine and the turbo, not after the turbo.

I had one on mine. With the T4 and 4" DP it was usually around 2-2.5:1, with the T6 with a 5" DP it was around 1.5-1.7:1.

I also had a 5" cutout on the 5" setup and you would think that would be pretty free flowing, but just for ***** and giggles I did a 90deg 5" DP out of the fender and spool was noticeably faster.

Forcefed86

iTrader: (4)

I'd see 2.8:1 at 25lbs on the small 83/74 S475 T4 and an LC9 5.3. Open 4" dump. Went with the odd-ball 86/77 exhaust wheel S476 (1.25) and picked up almost 5 mph at the same boost levels. BP dropped to 2.1 ish at 25-26lbs. I really like to get a 96mm T4 setup on it and see where it's at.

Guard dog

Out of curiosity, what diamter tube is the hotside?

Atomic

iTrader: (37)

Mine was 2.5"

nubs4ck

This is very relevant to my current situation. Please post as much information and pictures of your setup.

I have a 408" rear mount setup with a ct43 from comp turbo 8079. My back pressure is so bad that it is forcing the wastegate open around 8-10 psi of boost. The wastegate is a synchronic with the highest spring rate spring installed and preload cranked all the way down. If I remove the boost reference from the wastegate it still opens.

My 408 peaks at about 550hp at the wheels now. Previous setup had boost creep that was limited to 15 psi because of backpressure.

I need information/advice.

denmah

iTrader: (2)

you can get a 96 turbine, t4, billet 84/85mm turbo from forced inductions wich would probably be the baddest **** you would imagine on a 400 inch motor

Guard dog

But you didn't just go T4 to T6, you went T4 87mm turbine to T6 96mm turbine. The real test would be a T4 96mm turbine which should give the best spool with the widest power range. I bet the T4 96mm would be killer on the OPs 400ci.

Kmspeedie

iTrader: (1)

Yes sir! I have the 96 turbine,and holy **** is this car nasty down low and all the way to the top of the 6800rpm or so onna 416, unheard of man. this setup is so nasty, i dont see a reason for a t6 for under 1k wheel... i mean i still have a/c and my rad in the stock location.. granted its a TIGHT fit... but it works and its workin its *** off.. this setup is suprising the hell outa me. Forced induction builds a badass unit.

Atomic

iTrader: (37)

Yea true, I pointed out the spool was noticeably slower with the larger hotside. I think in my case I was out of compressor since I was running 25psi of boost and not picking up any MPH between 19 and 25psi. Mine was the 82mm though.

LJMSJohn

Glad you are happy with it.... but the reality is... a T6 housing on that same turbo probably wouldnt spool all that much different considering the fact that you have the same turbine wheel currently as what you would have if we had done a 1.32 A/R housing. If everything was setup properly... Theres just not that much difference between the T4 1.25 and the T6 1.32 housings when it comes to spooling. I can affect spool to a greater degree with the camshaft than what the difference is between those 2 housings.

I'm glad that thing fit.... that was my biggest concern.... Interested to see how far you push that turbo and what it makes with the compact cover on it.

Tomhames

iTrader: (3)

Liljohn-I think I'm in need of something similar-
Can you pm me please- or maybe I should pm you I guess....
Thanks in advance ,
Tom

SPRAYED 01

iTrader: (22)

NUBS4CK

https://ls1tech.com/forums/forced-in...-help-ugh.html

Get rid of that comp 80/79. You will never get it to work.

Kmspeedie

iTrader: (1)

Yes the fitment is crazy tight! From one side if the compressor cover to the other theres an 1/8inch of space from the damper and rad, so its TIGHT. You are 100% correct about the T6 turbos as well know, however i was in the market to find the baddddest t4 that u could physically fit in the area i had to work with, and you came through with that speccing this bad boy out. Theres no other combo of a turbo this size on my motor that could outperform it, reason im so elated about the results. From TMS, they put a custom cam in it, but not for my turbo as i didnt know what turbo i was going to run yet, so I would love to get a cam speccd for my exact setup, and one that makes a lil lope sound, I know thats not what I should have with backpressure already risen, buttt if its possible id love that as its what i thought this TMS cam was going to do. From Huron Speeds V1 A/C kit, to the TMS 416 and LJMS speccd s480... I couldnt be anyyyyyy happier. Ill try to post pics soon, and will be maxxing the turbo out soon as well, as i figure itll max out around 18-19psi or so.