Ordering stainless pipe right now! lol

 

premier miata in the nation??? Getting there.

 

you suck


Wait...look at those maps...wtf? At 2BAR it looks like the GT2860rs is more efficient. WTF?

 

More that just a Rotrex going in

I must say though, Sav's manifold/turbing housing set up looks quite the business.

 

they both look to be around 75% at 30 lb/min... which point were you looking at?

 

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.

 

dope manifold/dp setup, i hope he made a jig so he can make these any time

 

duh...sorry, at 25lb/min. Sav and I were comparing at 300whp/15psi.

 

the problem is intercooler piping. I'd have that **** right now if I could find someone to make 2 pipes for me but everyone in Dallas wants $500+. Its crazy how similar they are though.

 

then he better run more boost to prove he bought the right turbo.

 

Wrong map fagglio. You posted the 48-trim map.

yourz:


minez:

 

Nice map. I expect to see at least 325hp at the flywheel at 20psi boost.

 

I expect to see that at 15psi. max.

 

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

 

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.

 

Sure, but in that formule, it's about the VE of the engine that is going to be charged, without the turbo that is.

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):

 

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?

 

I kept thinking about Paul's 300whp on a 2560 while I was punching those numbers. Apparently there are many more variables involved.

 

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.

 

Paul also did that on a dynojet, you're going to do it on a Mustang. I was on a DD.