ZTwentyAteU

iTrader: (12)

Been messing with my buddies car, its a 70 buick with a 370 iron block and stock 317 heads, t6 s475(standard, no billet wheel or race cover) and a 236 boost cam. 4l80/s60 rear.

It still falls off power at around 6100 on the dyno. I'm not sure if this is norm, I thought she would huff to around 6500. it has a edelbrock truck style intake on it if that helps.

We made 710rwhp tonight on 13lbs, pump gas. It makes peak and don't "fall" off, but more along the lines of flattens out.

Just curious on others s475 experience on peak power. I know all combos are different, just lookin for opinions. It dont nessesarily need to be wound up any tighter, but you never know! I'm also curious on where we will run into running out of turbo if its turned up more

ittwgn

hi mate what ar 1.10 or 1.32??? cheers

Sarg

iTrader: (6)

Also what turbine wheel?

mike13

iTrader: (27)

I would also take a look at the exhaust side of the turbo, might not have a large enough turbine wheel causing back pressure issues.

very respectable numbers, especially if it's thru a stall and unlocked converter.

cjmatt

iTrader: (4)

Generally speaking, those BW S475s are pretty open on the exhaust side for a 370...i wonder if there is not an issue somewhere else, maybe not enough fuel?

buick_lsx

It has a 1.10 ar and I can't remember which exh wheel it had, it's not the big 93, one of the 80 something ones

Plenty of fuel where it's at now, two 255's and 95lb injectors

hellbents10

iTrader: (10)

So it is a 83 more then likley. It will have BP close to 3:1 at 800+ hp. You need a bigger exhaust wheel. Also if it has a stock style intake it will not peak above 6100-6200 no matter what cam and tw.

mike13

iTrader: (27)

Would a LS6 manifold hold you back from making more power or just not above 6100-6200?

hellbents10

iTrader: (10)

Just not above 6100rpm, the runner length and size limit you there. A fast 102 will usually peak at about 6500 with the right cam. If you want more RPM you need shorter runners, via single plane or ramjet style holley or edelbrock.

MUSTANGBRKR02

iTrader: (91)

So would the 96mm turbine perform better or is a bigger unit need ie S480 etc?

buick_lsx

Has eldebrock pro flo on it

mike13

iTrader: (27)

I good turbo might be the 80mm compressor & 87mm turbine

dville_gt

iTrader: (5)

What downpipe size? Mufflers? Exhaust manifolds? Cross over size? Air filter?

buick_lsx

buick_lsx

4in down pipe, bullet muffler, truck manifolds, air filter is whaterver size the turbo inlet is, k&n

dville_gt

iTrader: (5)

might be interesting to know what it'd do with the filter off. also, i wonder if you are just pushing as much as that s475 can push, you a log of boost pressure across the range.

Sarg

iTrader: (6)

I was actually thinking of the 92mm. New wheel design from what they told me at FI and is a hot turbine (no pun intended). I am going with the 96mm in my personal application only because I might upgrade to the 82 billet or 88mm compressor wheel at a later date.

mike13

iTrader: (27)

That's funny, I have the new 83mm billet comp with 92mm turbine wheel

Sarg

iTrader: (6)

I wish I could afford it, but on a budget and I am REALLY looking forward to seeing the 92 turbine paired with the 88 compressor wheel. Over at FI they said they were making one custom for a guy now, so I hope to see or hear about the results!

mike13

iTrader: (27)

I made 583 @5200rpm, 10lb's unlocked 4L80, mustang dyno, It spun the tires on the dyno that's why the low rpm.

I'm at the 2:00 mark on the video

http://www.youtube.com/watch?v=iW6X9hDYHY4