View Single Post
Old 09-10-2012, 07:05 PM   #35 (permalink)
SAM@GTM
NOT AN ACTIVE SPONSOR. DO NOT BUY
 
Join Date: Dec 2008
Location: CALIFORNIA
Posts: 913
Drives: 370Z
Rep Power: 17
SAM@GTM is a splendid one to beholdSAM@GTM is a splendid one to beholdSAM@GTM is a splendid one to beholdSAM@GTM is a splendid one to beholdSAM@GTM is a splendid one to beholdSAM@GTM is a splendid one to beholdSAM@GTM is a splendid one to behold
Default

Cliff,

Congratulations on getting the car up and running. Looking at your dyno graph, it does look like a classic exhaust restriction, especially when you get to the high rpm and instead of the power continuing to climb, it gets wavy and starts to fall off. The .64 A/R housing you have are capable of 700+whp easily and I'm being conservative. We have done more.

I'm posting a couple dyno graphs for comparison. Both these cars have built engines. One of them is a VHR with our Stage 2 (GT 2860RS with .86 A/R). As you can see, we're accomplishing 608whp at 15psi of boost on 9:1 compression. If you are at 19psi with GT30's with 10:1 compression and only at 613whp, either you have a major exhaust restriction or something is not right. It is not a turbo sizing issue. Also, another way to look at it is that if the dyno graph did not fall off at high rpm, then I would expect you to be at 700whp at the same boost level.






Quote:
Originally Posted by Boosted Performance View Post
It will be interesting to see what the larger exhaust does, but I think you nailed it with the post above. The .86 a/r housing would have been the way to go, considering these are small T25 housings.
As for T25 housings being small, remember that this is a twin turbo setup, not a single turbo. You can't look at these dyno graphs and still say that the T25 housing is too small.

Sam
SAM@GTM is offline   Reply With Quote