Quote:
Originally Posted by steve shadows
5 angle valve job, deshroud the valves, gotta go to a guy who knows his shit seriously though to do that right, polishing and port matching is more importing than porting the shit out of an SR, the benefits are nil on just the porting end, slight porting and lots of polishing is what you want to do and it will help. We had an SR recently on the dyno we did, 12 psi of boost, 2871R .86 housing, stock intake manifold, 740cc injectors, AEM EMS - we pumped out 355 whp on a dyno dynamics....polished, very slight port and port match with BC 264 cams. Literally weren't even in the efficiency range at 12 psi on the turbo yet and we were already pumping out 355 on a Dyno Dynamics dyno (which if you don't know are the lowest reading in the industry) so we were very close to 400 whp on a dynojet basically. A lot of it was my tuning but the head work definitely helped a lot. So might be a good idea but make sure the guy knows what he's doing with the head that's critical.
Hope this helps.
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I know we have duked it out before but that isnt what Im wanting to do here. I really would like to see the graph for this. I dont doubt for a minute that with a really good flowing head that a 2871r could make that much power on a sr at that low of a pressure but what I dont believe is that it had much more left in it after that. Otherwise why would anyone have stopped at 12psi after spending that much money on the head, the turbo setup, the ems, and then tuning to be like thats enough! stop there.
Im guessing there was 25-30whp more possible that that turbo could make and it would have been accomplished in just a couple more lbs of boost.
Flowing the heck out of the head just allows for less air to back up in the intake manifold and more to make it in the engine, so you flow the same amount of air at a lower pressure. The pressure its happening at is kinda irrelevant.
grab that graph up if you can.