99 head a necessity for 300whp?
#1
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Ive search plenty and still no answer. My current setup is a gt2560r @10psi. Car runs 13.4s@104 in the quarter. Im in the process of building up a forged motor for it. This isnt a dream or a maybe someday build. Ive allready purchased a new gt2871r, forged rods, pistons, boundary pump, ati damper blah blah blah
is a stock 95 head that shitty that i wont beable to hit 300whp with a 2871r at a reasonable boost level ?
is a stock 95 head that shitty that i wont beable to hit 300whp with a 2871r at a reasonable boost level ?
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I'm using a smaller turbo and hitting 300 at 19ish psi on a '95 head for now. 2867r
Yes, better head flows better but he's asking if it can be easily done with what he already owns and the answer to that question is yes.
Yes, better head flows better but he's asking if it can be easily done with what he already owns and the answer to that question is yes.
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Yes, 99-up heads flow better than 94-97 and create less boost to reach same power.
You can run SUBs on any of them.
HLA noise indicates an oiling problem. You will still have an oiling problem no matter what head you use. Fix that first.
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Long branch polymers used to increase the viscosity of oil with an increase in temperature are broken down by mechanical actions within the engine. For cheaper oils with less sophisticated additives this breaking of polymer chains occurs much more quickly. One test cited on bobistheoilguy.com noted a 50% reduction in viscosity extension in an inexpensive motor oil within 2000 miles of operation, to my recollection. So the 10w-30 was behaving as a 10w-20. This is likely why many run-of-the-mill Miata owners report having HLA noise when the cars are overdue for an oil change at 4000, 5000, 6000 miles.
Thinning is also a direct consequence of the oil being hotter, so if you have oil that is old, cheap, too low a viscosity to start with, or all of the above and then run the engine hard it will be more likely to have HLA noise due to inadequate oiling.
If the clearances at the bearing surfaces in the block and heads are greater due to wear, the oil pump is worn, and the lifter to bore clearances are looser than original, the oiling system may produce a volume less than adequate to silence the HLAs. This can of course be exacerbated by oil thinning for the reasons listed above.
Add to the equation partially clogged oil passages due to sludge and varnish in an older motor.
HLA noise is no mystery.
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A couple runs of rotella T6 cleaned all the gunk out of my engine and shut up my HLAs. So as long as your engine isn't worn too badly, they should be easy to fix too.
Man, that first change of rotella was nasty. 1000 miles and the oil was black. Now it stays clean for the 5k mile.OCIs I run.
Man, that first change of rotella was nasty. 1000 miles and the oil was black. Now it stays clean for the 5k mile.OCIs I run.