AbsurdFlow + GT2871R + TiAL pornography
07-26-2009, 09:15 PM
#84
Bravo Andrew. Bravo.
Emilio: "damn it, even with my amazing grip Savington is faster than the OGK... I need boost!"
*Emilio installs Rotrex, enter 200+ whp in OGK*
Savington: "Oh I was just getting started..."
*Built motor + GT2871R = Emilio takes his place in Savington's rearview mirror again*
Emilio: "damn it, even with my amazing grip Savington is faster than the OGK... I need boost!"
*Emilio installs Rotrex, enter 200+ whp in OGK*
Savington: "Oh I was just getting started..."
*Built motor + GT2871R = Emilio takes his place in Savington's rearview mirror again*
I must say though, Sav's manifold/turbing housing set up looks quite the business.
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07-26-2009, 09:53 PM
#86
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If you are looking at the efficiency at the center efficiency island, or the 'sweet spot', the 2860 is at 77% and the 2781 is at 76%. But if you look over at the right side of the map, the 2871 holds its efficiency longer; looking at 2.25 pressure ratio @ 35 lb/min of flow, the 2871 is at 72% and the 2860 is at 68% (and falling fast). The 2860 is also spinning about 25K RPM faster.
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07-27-2009, 05:17 AM
#94
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Care to share some data? I just went through some calculations. For 325hp with 11.5AFR and a BSFC of 0.55lbs/hr you need around 35lb/min flow.
Add a 95F MAT and 7200rpm redline. You'd need 99% volumetric efficiency to produce 325hp at 15psi on 1860cc. A standard 1.6 engine has a 88% VE. A 99 head means it's from 1999, not that it's 99% VE
Add a 95F MAT and 7200rpm redline. You'd need 99% volumetric efficiency to produce 325hp at 15psi on 1860cc. A standard 1.6 engine has a 88% VE. A 99 head means it's from 1999, not that it's 99% VE
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07-27-2009, 05:32 AM
#95
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You do realize that turbocharged engines routinely eclipse 100% VE, right? I'm basing my power goals mostly on what Hustler saw in his car. 262 on a Dyno Dynamics on pump gas at 15psi. You said flywheel horses, so factoring in 15% losses, that puts his car at 301.3bhp. I am running a larger turbo and 100 octane.
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07-27-2009, 05:43 AM
#96
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Source:
TurboByGarrett.com - Turbo Tech103
88% VE:
Mazda Miata performance handbook - Google Boeken
If you drop the AFR to 10.8, you'd get there if your head is 95% VE (99 head, valvejob):
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07-27-2009, 07:14 AM
#97
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No offense, but I ******* hate horsepower formulas. Every single one of them is pure, unadulterated bullshit. Paul made 300whp at 14psi on a 2560R. I've seen a guy make 275whp at 14psi on a 2871R, a '94 head, and a fucked bottom end (bolt went through it). Matt makes 257whp at 9.5psi. Can you honestly tell me that the formulas you use can validate all of those cases?
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07-27-2009, 07:48 AM
#99
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VE is so hard to approximate. You would think that when you drop compression, for instance, VE would decrease, but a drop in compression will normally ADD torque (and thus power) to a turbo car.
I despise formulas that calculate horsepower for that reason - they are never detailed enough.
I despise formulas that calculate horsepower for that reason - they are never detailed enough.
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