0.64 or 0.86 hotside for 280whp goal on a 1.8
#62
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Right, but this is not a smaller turbo, it's just a smaller turbine A/R. Will it still make torque with the exhaust restriction? RHarris' did not. People typically suggest that a smaller AR turbine housing will shift the turbine map left (effectively shifting the compressor map RPM and pressure ratio up) and all else stays equal, I don't think that's the case. Again, I don't think anyone is running the .64 AR turbine housing and liking it.
#63
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http://www.motoiq.com/magazine_artic...p-details.aspx
I believe one of the reasons I'm making so much torque at lower RPM is because I have so little pressure pre-turbo on the exhaust side.
#64
If the turbo with smaller A/R has a max topend below the OP's target, then the improved spoolup is worth it.
Last edited by JasonC SBB; 02-17-2012 at 12:25 PM.
#65
Read this:
http://www.motoiq.com/magazine_artic...p-details.aspx
I believe one of the reasons I'm making so much torque at lower RPM is because I have so little pressure pre-turbo on the exhaust side.
http://www.motoiq.com/magazine_artic...p-details.aspx
I believe one of the reasons I'm making so much torque at lower RPM is because I have so little pressure pre-turbo on the exhaust side.
A smaller turbine will have its max efficiency island at higher shaft RPMs and will be more efficient at lower flow rates, i.e. at spoolup. The "speed match" between a turbine and compressor tells you how well matched they are in that their sweet spots wrt shaft RPM. If for example, the compressor is oversized (or turbine undersized), spoolup will be affected because during spoolup the compressor is turning slower than the turbine's sweet spot, and the turbine can't deliver the shaft power the compressor needs.
A smaller a/r allows the turbine to operate more efficiently at low flow (spoolup), so spoolup is better. At higher flows (topend), however, it is less efficient and thus will generate more backpressure than a larger a/r.
#66
Sorry for yet again bringing this thread back to life, but my question in very much related...
I have an old and broken Turbonetics T3/T4 E-50 that I am replacing, and I was initially thinking of a GT3071 since my tubular manifold has T3-flange, but I am wondering if anyone has experience with a T3 housing on the GT2871? I am aiming for a responsive 350rwhp setup for autoX and trackdays.
And if so what the larger flow/area of the T3 would do to the .63 VS .82 debate?
I can also get a GTX2867 bolted to the same T3-housing, which also is tempting to try... Too many choices as usual! The EFR6258 seems to be on a 4-8month backorder everywhere, so at least that takes one candidate out of the equation :-)
I have an old and broken Turbonetics T3/T4 E-50 that I am replacing, and I was initially thinking of a GT3071 since my tubular manifold has T3-flange, but I am wondering if anyone has experience with a T3 housing on the GT2871? I am aiming for a responsive 350rwhp setup for autoX and trackdays.
And if so what the larger flow/area of the T3 would do to the .63 VS .82 debate?
I can also get a GTX2867 bolted to the same T3-housing, which also is tempting to try... Too many choices as usual! The EFR6258 seems to be on a 4-8month backorder everywhere, so at least that takes one candidate out of the equation :-)
#72
ATP strongly urges me to go with the GTX2863R instead of the 2867, 2871 and 3071. The powerpotential, according to them, is equal to the 2871 with much better response and spoolup.
Almost sounds too good to be true, but I think I will give it a go and be the guinea pig for the 2863 in a miata.
Almost sounds too good to be true, but I think I will give it a go and be the guinea pig for the 2863 in a miata.
#73
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Have you driven either? Is he using a tubular or log manifold? I say .86 GT2860rs at 16-18psi.
Has anyone put a .64 A/R housing on a GT2860rs and like it? If the little housing will work on any Miata it would be a 1.6.
I have a .86 housing I will sell you on the cheap if the .64 doesn't work out...but I think the larger housing is the way to go from the start.
Has anyone put a .64 A/R housing on a GT2860rs and like it? If the little housing will work on any Miata it would be a 1.6.
I have a .86 housing I will sell you on the cheap if the .64 doesn't work out...but I think the larger housing is the way to go from the start.
me know what that .86 housing might be worth in a pm?
#75
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ATP strongly urges me to go with the GTX2863R instead of the 2867, 2871 and 3071. The powerpotential, according to them, is equal to the 2871 with much better response and spoolup.
Almost sounds too good to be true, but I think I will give it a go and be the guinea pig for the 2863 in a miata.
Almost sounds too good to be true, but I think I will give it a go and be the guinea pig for the 2863 in a miata.
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