67mm=700hp???
If I were you I would get my setup finished, and try the 67. It my make 700@ sea level. If not it should go low to mid 600's, and you may not tear up as many parts at first.
A honest 625-650 with good spool, and good low end power just might run just as quick in your car as a laggy, high RPM setup. I'd be curious if any of the following were wrong with that combo (I've seen all of these reduce boost/power):
- Leaking BOV
- Weak WG spring
- Damaged turbine or compressor wheel
- Restrictive muffler or exhaust piping
- Restrictive intercooler or intake piping/MAF/TB
- Too small an air filter
Either way, there's enough data out there to prove that a 4276 is capable of well over 13 psi on 370 cid.
Mike
FYI there is a HUGE thread on Yellowbullet about the GT42-76 and even the mustang guys saying stay below 347 cubes with it....... it running out of steam wayyy early...... Im not the only one...........
Brother its SELL, not sale......
Try with what ya got 1st and see where it gets you, then go from there.....
Or put it up for Sale........ only one way to find out.....
Kyle
I'm going to make one last post about this and then give up.
The GT4276 will support more power than my T76GTS. The 76GTS has a very similar compressor and the same exhaust wheel, but cut down. The GT42 has a larger exhaust housing too. Soo. . . my T76GTS should support less power and less cid than the GT4276. But. . . I still manage 17 psi on 388 cid with the 40mm wastegate WIDE OPEN and pull easy 9's at 146 mph in the quarter at full stock weight+++. I've easily (on accident) been past 22 psi too and have the blown head gaskets to prove it. How can you see my results plus countless others making 20 psi with T4 76's on large cid's and still maintain that the GT4276 max's out at 13 psi on only 370 cid??? What's your explanation on how my car works?
Then, to add to all this, a while back I reduced my displacement down to 360 cid after reading lots of posts about how the 383 is choking on the T76. The car went slower at less mph. I added the cid back next chance I got and the car picked up 3 mph and .5 seconds.
Mike
I can't wait to see what the ST80 does.
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