[prophet455]

All, I am still moving ahead with the turbo build and need recommendations.
The setup is a fairly mild blow through on a 400 (mainly for street duty), automatic transmission, 79 trans am. The short block will be around for a few years and is fresh, but since I am not a big 400 fan, I am sure it will be replaced by a 461 or possibly another 535 down the road. Right now its somewhat a budget build and targeting mild boost in the 9lb range.
The rods are eagles with ross pistons, small roller cam, but the weak link right now is probably the cast crank. 300cfm edelbrock heads, ram air 2.5” manifolds
I need to pick up a single turbo, wastegate, and blow off valve so I can start figuring how to run the exhaust and plan the mounting. With the future in mind of a larger bottom end, I know I wont find a great fit that can do both but I definitely want to pick something that has some room to grow left in it.
I’d like the opinion of the knowledge here for the turbo, wastegate and blowoff, keeping in mind this is a fairly budget oriented build (as much as a turbo can be). I appreciate it.

[er455]

Get a Borg Warner s475 cheap and will make good power ... my 2 cents.....

[BruceWilkie]

Don't worry about big displacement. A 400(probably a 350) with a turbo can make more tq and HP than an na 535 in street form.
Watch the rpm and stay below 6000 and crank shouldn't be a huge issue. Forged 3.75" - 4" stroke is plenty especially in a factory block.

Single S475 for now... Build an aftermarket block same stroke suggestion and add a second s475 and you have potential to @1800-2000 HP.

Highly recommend intercooling. A/A or A/W(better)

Good luck

[prophet455]

For the 475 I’m assuming a t6 flange is the better way to go? 75mm with a 1.32a/r?
What I am looking at is an S400SX-75.

[GTOGEORGE]

Originally Posted by prophet455

All, I am still moving ahead with the turbo build and need recommendations.
The setup is a fairly mild blow through on a 400 (mainly for street duty), automatic transmission, 79 trans am. The short block will be around for a few years and is fresh, but since I am not a big 400 fan, I am sure it will be replaced by a 461 or possibly another 535 down the road. Right now its somewhat a budget build and targeting mild boost in the 9lb range.
The rods are eagles with ross pistons, small roller cam, but the weak link right now is probably the cast crank. 300cfm edelbrock heads, ram air 2.5” manifolds
I need to pick up a single turbo, wastegate, and blow off valve so I can start figuring how to run the exhaust and plan the mounting. With the future in mind of a larger bottom end, I know I wont find a great fit that can do both but I definitely want to pick something that has some room to grow left in it.
I’d like the opinion of the knowledge here for the turbo, wastegate and blowoff, keeping in mind this is a fairly budget oriented build (as much as a turbo can be). I appreciate it.

I had 4 bolt mains on my factory block with a cast crank and eagle rods and it broke at around 7-9 pounds of boost around 700-800 hp, of course I was strictly drag racing it a lot.


GTO George

[70 bird]

Originally Posted by prophet455

For the 475 I’m assuming a t6 flange is the better way to go? 75mm with a 1.32a/r?
What I am looking at is an S400SX-75.

That's the right one.