I found a t70 turbo, but it has a 1.05 ex A/R. I'm not sure its big enough for my 355. I'm shooting for 650-700 fly hp at what ever neessary pressure. Here's my motor

sbc 355
Ported GM 441's (285/237 @ .600, 2.05/1.60)
Comp 274nx cam (274/292, 230/244) hyd flat tap
10.5:1 comp (Using meth/water inj.)
all forged bottem end (supposed to be good to 800hp/8,000rpm)

Currently making ~430 hp n/a, but has never been properly tuned, so maybe 460 when tuned.

I tried the rayhall turbo calculator and it suggested 1.22 A/R, but i thought i'd seen some smaller ones used on some f-bodies and such.

 

It its a front mounted system then yes you can run a 1.22, but it also depends on the turbine wheel in the unit. If its a rear mount, forget it, stick to a small .81 or so.

Jose

 

well i'm not quite sure. This is going into my 72 truck, which has 4.11's and 700r4 so i'd rather have something that spools up at about 3000rpm so i can maintain somekind of traction off the line. I also can't run much more than a 10.5" slick, maybe 28" max heigth. My plan was to is to use some hooker pro comp headers into a Y, and then run that back up the engine bay to the turbo (next to the passanger side header). I know it sounds like a lot of piping, but i have enough room. I guess with all the distance til the turbo i should go with the .84 A/R since that right there is going to provide some lag.

 

I would concentrate more on shortening the piping and get the larger A/R. Use some shorty headers flipped or something.

 

Hm. ok, so a 1.5 primary should ok then.
Also, does my cam seem like too much or is it fine? its a 113 lobe serpation.

 

I think 1.5 would be Ok since some are making 1000 hp with 1.625.

The cam isn't too big, but it's not really a turbo cam either.