I have a pontiac 455 cubic inch whould a standard BG s475 be big enough for about 600-700 hp manual trans have a good rotating assmebly and running about 9.3-1 compression is that turbo to small for my set up or to big i will be mostly on the steet bit want strip power so quick boost thanks for any reply

 

I have a s475 1.32 ar on my pontiac 455 and it works great on the street. You should hit your number without any problem. Your compression will work but your timing needs to be on the conservative side. I am spooling by 2200 full boost by 3400 your car will be a handful on the street. Good luck keeping that stickshift in one piece! lol.

 

I don't think my super t10 will hold up to 600 LoL I have a turbo 350 I mite rum because of budget insted of a tko 600 or a t57 magnum

 

How much will I have to run to get that number and I have 6x-8 heads mild porting I am running ????

 

How much boost will I have to run to get 600 hp

 

I would go with a th400 for a trans. somewhere around 8psi. should get you 600+ hp.

 

So my engine is a 71 455 block with stock crank, forged I beam replacement rods forged pistons stainless vales can my engine hold that much power/ boost

 

That should be good to 7-800 if your tune is in check. There are a few guys over on py and pz forums running close to 1k with decent rods and pistons but thats pushing it! Just keep it under 6k and boost the shit out of it.

Build section here, use the turbo tech or gm section for questions.

 

You will be able to hit that goal easily. Just sneak up on tune. Conservative on timing and plenty of fuel. Make sure your fuel system is up to the task.
6x 455 1.32 turbine the 600 HP will probably show you 700 ft/lbs . Go th400.
I may have missed it...what vehicle?

 

A 1981 301 turbo transam leaving the 301 and going455

 

Good move. Swapped a few 301's back in the day.

 

You would deff be better off trying to gett the compression down closer to 8.5 ..."IF"... you are going to be using pontiac Iron Heads.

Boost will always make more power vs. compression. With a 455ci you wont have to worry about it being lazy off the line with all the torque. It would be a safer tune . And it will allow for more boost

You could dish the pistons, open the chambers or run a thicker headgasket to lower your compression on a budget.

"If" you are still needing to order pistons.... then you can have them dished or custom made for your app.


Beebe