bugalu said:
to fully benifit, especially on such a small turbo wouldn't he also want a larger tb/ intake mai? or is my thinking backwards and since it is a small turbo he would not want to go any bigger on those? also how much more will it flow with the stock intake componets in place arent they still more of a restriction than the head(besides cams)?
VERY true. I plan this for later but its not in the budget now. I'll get one over the summer or fall. Everything else I talk about below I already have or will get now though.
The point of my post is to determine whether headwork is worth the money, based on the gains made in power AND spool. If a built head would help a 2871R or 3076R spool significantly better, AND make much better power, it would be worth it to me. Or if headwork was not wasted on the GT28RS but gave 50rwhp or something, that would be worthwhile too.
Basically I am sitting on two options:
1) I have an Extremeboost based 2540R kit coming, which can take another GT series turbo instead of the 2540R. So I plan to switch to another turbo, but I don't know which one, and I can cater it to a built head if necessary...
2) I will definitely have 272/264 cams in my Gen 3 head, that is a low cost upgrade which is definitely worth the hp/$$$ to me. However, futher headwork is PRICEY, and so I need to know that I would stand to gain ballpark Xrwhp or Xspool with X turbo. I know there isn't hard data for this, which is why I am asking more generally.
Make sense? I am basically building a motor from the ground up, I can mix and match turbo and headwork to make the best combo for spool and power and price. Rest of the engine mods I will have, since they have become relevant, are:
-Gen 3 head with 272/264 cams, cam gears (OS valves and porting is a ???)
-Stock Gen 3 bottom end
-Extremeboost based GT turbo kit with GT___turbo: exhaust mani, external Tial, SS lines, etc...
-3" downpipe and exhaust
-Power FC (which I have, or some other standalone if I decide its better)
-720cc HKS injectors in HKS rail, SS lines, walbro pump etc...
-Berk Tech intercooler kit
-MBC (might go EBC)
-Etc... probably some other stuff
I have all this stuff now. The only question is further headwork, which turbo, any other additional mods, and tuning. The goal is a compromise of spool and power, with a definite bias toward spool. 300rwhp on pump is fine (GT28RS) BUT if spool trade off is not that much (with or without headwork) a bigger turbo may be preferrable too.