It should be ok if taken easy but start cranking it up egt's and back psi will be thru the roof unless it is a custom large turbine T4 76. I have seen a S480 on a 522 CI BBF live for quite some time at 10~12 psi and 5500 RPM.

 

Sounds like a certain Red car we had on the dyno awhile back. Your last sentence was my verbatim advice about 4min. after lookin' over the setup (which has some great fabrication work). That thing would rip with a pair of those 76's. "Horse to Water".....etc.

 

I just realized that was my 1st post on here. See what I get for scouring the Classifieds, now I look like the proverbial 'newb'.


Carry on, men!

 

It gets out of its efficiency zone on the compressor side, not the turbine. The 1100 HP 2JZ would be flowing more exhaust than a 700 HP LS1, so to blame the turbine is incorrect.

 

Well the turbo is just mismatched to the cubes altogether, you're not going to pair a 106mm compressor to a 75mm turbine and fix this problem.

Start out with any turbo that has a good compressor/turbine ratio and the more displacement you run it with you will find power shifts to the left and max power realized will be less.

In this case of a 7675 on a 427, it would be done just after 5k rpm. Weld the wastegate shut and it wouldn't hold 20psi boost. Just all around too small of a unit for that displacement. (unless your goal is to have a very low rpm engine).

 

Thanks for the advice.

 

My local highly reputable shop told me that 383 is as as they would go on T4 turbo. I am having a billet 7675 put on my car now and that is what they suggested. He said anything any bigger he would have recommended a T6 but I was right in the middle ground where I could go T4 or T6.