Starting to think about a totally different combo down the road. What is the opinion on the GT 42 T6 as I can get one cheap. It doesnt appear to spool up as fast as the PT 76 however top end flow appears better? Thoughts?

 

Also this is for a 402 or 408

 

What's the A/R on the exhaust? What size compressor is on that? A T6 turbo is a pretty large framed turbo, so what exactly are you plans? 4 digit hp/tq?

 

The turbine A/R is 1.15. The compressor exd is 102mm, it seems huge. I would like to be at around 900-1000rwhp on a 408. Im concerned about spool up time and back pressure. I can get one cheap so thats why Im considering it. I mostly drive on the street with the ocassional track run. What are you thoughts on performance.

 

Huge lag, thats a pretty big A/R and a huge compressor wheel for a street drive truck even with a large CI motor.

 

serious modifications to make it fit somewhere, the 101mm turbo my buddy had was huge

 

That is the compressor exducer size though, I thought turbos were called out by the inducer size which would be closer to 80mm on that unit??

 

The compressor inducer is 74mm - perhaps not that big? Still dont like the lag. Compressor map attached.

 

That turbo does not seem overkill to make 800-1000hp. I don't really know how the pro's and con's would weigh on decreased spool time vs. higher backpressure if you were to use a T4 flange. It seems like most people think a T4 76mm inducer turbo is on the small side for a 408, I am sure the response is excelent but it may not make great top end HP. Maybe the T6 74mm is a good balance between the two, responsive and still capable of big numbers without choking a 408. I was personally thinking about using a T6 88mm on my 408, but that will be a more race-specific truck.

What I am trying to say is; I don't know!

 

No way is that turbo going to be laggy on a 402 or 408. I think it would be great. Just take the correct converter.

The turbo is really not that big physically. It is bigger than a PT76 because thats what I had on my truck originally, swapped to a GT42-76 for 2 days till I blew it up, then went to a GT47-88.

Not my truck but my old setup on a different truck with some bling work.







At 23psi on my stock lightning longblock: