78Chevyc10

I'm pretty sure that I want to go with a s475 with a t6. I could either run a 83mm with a 1.10 a/r, or a 96mm with a 1.32 a/r. The motor is a 5.3 with stock bottom end. The motor will have a turbo cam, but i'm not sure which one yet(any input on cam appreciated as well). Th350 trans 3.07 rear gears. It will rarely see a track, if ever. Hoping to be around 550 wheel horse.

DavidBoren

I feel the 83/1.10 would be a better match for a 5.3L, unless you are spraying NO2 to spool the 96/1.32, which would be awesome although ill-advised on a stock bottom end. T6 is a pretty large hotside for a 5.3L, as well. Shouldn't have any problems with backpressure, ever.

Either turbo will give you room to grow, being as both of them are too big for a 5.3, in my opinion. I think a 73/1.00 S366 with a divided T4 flange would be much better suited for a stock bottom end 5.3L that will rarely (if ever) see the track.

Dimeomboost

^^^^^^^^ troof right here so many ppl ovee turbo there cars its unreal my turbonis considered small but it lights off like a match and makes plenty of power love the little s366 plus a t4 packages so much easier. if its a streer vehicle keep it simple man give yourself the largest powerband u can for fun and not have to run crazy big stall converter. i feel like most ppl over cam there turbo motors that are already over turboed just my two pennies

78Chevyc10

I know that it is big but eventually i would like build a 6.0 or even make it a 408, so i would like a setup that will give me plenty of room to grow.

Busted67

iTrader: (1)

83/1.10 with 2" crossover would be my choice.

SteenH

A friend of mine ran the s475 T6 with the 83/1.10 (2.5 hotside) on his L33 and he claimed "lightning fast spool". He ended up swapping it out for the s480 96/1.32
it's definitely slower spooling, but it's a non issue on the trans brake. I personally think if you don't want to replace the turbo, over size it and enjoy it for the time being, risking a little bit of spool time with the small cubes.
My t4 s75 83/.96 on my lower compression ls1 doesn't light off until around 3500. And if I had to do it again I would have just gone t6 with the big s480, I'll end up doing this when I build an engine anyway.
I have traction problems as it is, the more sluggish turbo probably would have helped that situation. Lots of guys are going to disagree. It just comes down to what you want to do in the future.
Best of luck making a decision!

DavidBoren

Jose93z28 just posted a 10.9s pass with a 5.3L and S475 combo, so you might want to PM him.

forcd ind

iTrader: (7)

If its a heavy veh. and street only, I would prob go with an 83/1.10
I have an S475 with a 93/.125, switched to a 1.00 AR to improve spool
Some people have run the 83 with a 1.25 AR I think.
On the street you're not living in the 6K range a lot, lol, so you want the power where you drive-@ 6K just in second I am over 90 MPH and 13 PSI,
with 3.25 rear gears
If you are going to change the engine combo, then build for that.
You want to pick a cam for your setup, that will help street perf.

Jose93z28

iTrader: (3)

I went ahead and picked up the S475 earlier this year I got the T6 1.32 divided Ar, If you are just rolling at slower speeds it does take a few more hundred rpms than my tc78 to spool but at higher speeds its pretty scarry lol, I had it on street tires while trying to dial it it for wot and would spin the tires around 80mph, my only issue Im having now is having trouble to spool the turbo on take off but that is due to a tunning issue that Im trying to figure out, once its solved It should take off pretty good, last week I just ran a 10.9@138mph on my camaro that weights 3600# at bandimere speedway in morrison Co, 5800+feet, Iseen a lot of other people get good results out of this turbo thats why I went with it.

LJMSJohn

Might need to have the converter loosened a tick or two if you dont have a transbrake.

Jose93z28

iTrader: (3)

I have Denmahs 3rd gear mod and can rev to 4k plus only issue is the timing dropping really low and taking off with no timing, then timing picks up around 20mph or so and it starts pulling.

3 window

iTrader: (1)

I've got an s475/83 1.25 AR t4 on my SBE 5.3 and I think it lights off pretty good. I'll try and post a pic of a datalog tomorrow. I want to say 3-4 psi to 15 in about a second or second and a half. I'll post up the log when I can.

Nitroused383

iTrader: (10)

With the right tuning, cam and converter the 96mm wheel is worth it no doubt. I have a stupid tight nitrous converter that only stalls to 2500 on the trans brake and I still can spool up the 1.1 ar. T6 92mm wheel with a 6.0. If I had a ptc converter that flashed where it should I could build boost in seconds. I spent a lot of time tuning on the t brake and trying different techniques for quickest spool. 2500 rpm flash 3200 rpm 2 step. First video was my previous quickest spool I could get with testing.


Almost cut my time in half


3rd gear street spooling just mashing it around 2500 rpm

78Chevyc10

Thanks for all of the replys guys!!!

autoaddictions

I just sent my Box stock S475 1.32 t6 out to jose for the 80MM ETR wheel upgrade. I should have it back next week and I will post back dyno results before and after.
My s10 made 650hp @ 16psi.puimp gas with the stock s475. Very laggy with the 1.32AR. I should of went .96ar

DavidBoren

I see a lot of people talking about building boost on a transbrake, so I feel inclined to ask...

78Chevyc10, does your TH350 have a transbrake? Do you plan on ever installing one or using one?

BT802

iTrader: (1)

I keep looking at these as well and can't decide. Rather stay T4 as the GTO has little room. I'm a 402 LS2, TFS 225s, stalled auto. Planning on swapping the Vindicator for the LJMS stg 2 cam.

DavidBoren

BT802, you have an entirely different set-up than 78Chevyc10, so whatever S475 may be best for his combination could be the absolutely wrong turbo for yours. For a 402, though, the 96/1.32 is the smallest I would go. Whereas I still think the 83/1.10 is too big for 78Chevyc10's street driven 5.3L that will rarely see the track.

3 window

iTrader: (1)

The boost ramp is on the bottom panel. This is a 475/83 t4 1.25 A/R with no pressure on the gate, full exhaust out the back, through a Treadstone vertical flow intercooler.

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Forcefed86

iTrader: (4)

For 550WHP, either S475 is over sized IMO. Get a little T4 turbo 78/75 VS racing unit for $400 shipped will easily meet your goals and it's half the size/weight. So it's easier to package.

A $190 shipped (GT45 69/77 T4) will easily meet your goal as well. And have been proven to be very tough turbos.

If you want a brand name turbo the big S366 OR S369 will both make 550whp on a 5.3.