What Size Turbos for a 434ci street/race build

[BlownZ]

Hey guys....I am putting together a 434ci RHS block for a project. 9.25 compression, Mast LS7 heads, Cam TBD, 4L80e and a Coan 3600 stall. I was planning on building it out as a supercharged car but I am strongly considering going twins on it. It's intended to be an extremely fast street car although it will have a 10pt cage to keep it legal. I want to run upper 8s, low 9s....in a 2011 SS Camaro body.

What would you guys recommend for turbo sizing and why? TIA.

 

[bison]

60-1, 6176, 6262 will all get it done under 25psi. Tang .81 or .96 ex housings. Your converter will probably need adjusting or replacement. They are all capable of supporting the power you need at "street car" pressure ratios on gasoline, and they are relatively cheap and plentiful. A grain of sand on the beach for part of the cost building a reliable combo that will run 8's in mostly street trim.

 

[Dusty Bradford]

Twin 6262's. Twin 6765's would be overkill, they are low 8 capable.

 

[BlownZ]

60-1, 6176, 6262 will all get it done under 25psi. Tang .81 or .96 ex housings. Your converter will probably need adjusting or replacement. They are all capable of supporting the power you need at "street car" pressure ratios on gasoline, and they are relatively cheap and plentiful. A grain of sand on the beach for part of the cost building a reliable combo that will run 8's in mostly street trim.

What do you think would be right for a converter? I have no qualms changing it out but I already have this one so I will likely see what it actually stalls to and how it works but if it needs to be changed then so be it.

 

[bison]

A ptc custom converter. Probably a 9.5".

 

[Dusty Bradford]

What do you think would be right for a converter? I have no qualms changing it out but I already have this one so I will likely see what it actually stalls to and how it works but if it needs to be changed then so be it.

Have the 4l80e built as a non lock so you can avoid having to use a lock-up converter. I have done several 9.5's for the 4l80e