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-   -   Will WI enable 12 psi @91 octane / GT2560 on a stock VVT motor? (https://www.miataturbo.net/diy-turbo-discussion-14/will-wi-enable-12-psi-%4091-octane-gt2560-stock-vvt-motor-37151/)

JasonC SBB 07-16-2009 06:02 PM

Will WI enable 12 psi @91 octane / GT2560 on a stock VVT motor?
 
And run close to MBT or at least have EGT's under control?

JasonC SBB 07-16-2009 06:07 PM

P.S. Don't clutter this thread with "build the motor and turn it up to 20 psi" posts please.

hustler 07-16-2009 06:18 PM

have you read any WI threads? Also, do you mean "water" injection or "methanol" water injection?

gospeed81 07-16-2009 06:20 PM

Aren't you still in the efficiency island at that point?

I don't see why not if you're at 77friggin% efficiency....even without WI.

Am I missing the point of this thread?

neogenesis2004 07-16-2009 06:35 PM

I agree, you really should not be having EGT issues at that boost with a properly tuned spark map.

JasonC SBB 07-16-2009 06:54 PM

Water, no methanol.

Main point is, can the 10:1 c/r work at 12 psi / 91 octane+WI?

I know from experience that 9.5:1 and 10 psi is marginal at 91 octane without WI.

EGT issues are possible if spark needs to be retarded a lot to prevent knock.

SKMetalworks 07-16-2009 07:21 PM

Doesnt higher intake temps and/or too much timing cause higher EGT's?

sounds like you need dyno time for the spark mark and let them determine boost level/spark ratio. More boost = more power... But, more advanced timing does also. I say put WI in and get a good tune.



Or the answer you were looking for,

Yes

y8s 07-16-2009 07:30 PM

what power level is a 2560 at at 12 psi on an 01 motor? 275 rwhp?

hell, try it without water.

hustler 07-16-2009 07:52 PM

advance and egt are inverse relationships

JasonC SBB 07-16-2009 09:02 PM


Originally Posted by y8s (Post 431254)
what power level is a 2560 at at 12 psi on an 01 motor? 275 rwhp?

hell, try it without water.

Nah, when I was running 9.5:1 and 91 octane, it was at the ragged edge of MBT at 10 psi.

Probably 260 whp.

Savington 07-16-2009 09:14 PM

Probably. Meth would get you there for sure.

Miatamaniac92 07-16-2009 10:08 PM

Jason,
Can you get e85 reasonably?

Chris

thesnowboarder 07-16-2009 11:17 PM


Originally Posted by Miatamaniac92 (Post 431336)
Jason,
Can you get e85 reasonably?

Chris

He drives his car on the street iirc, he will need to be able to fill up anywhere in the country, hence his "91 oct" in the thread title :loser:

Jason, Sav was able to hit MBT @ 11 psi on a stock 99 motor with a 2554 without WI, i dont see why WITH WI you wouldnt be able to do the same.

JasonC SBB 07-16-2009 11:37 PM

Well even a stock 2001 will ping on 87 octane...
The difference between 10:1 and 9.5:1 I think is pretty significant in terms of ping resistance...

magnamx-5 07-16-2009 11:58 PM

I dont know if the cooling of water alone will get the job done. With the adition of 10-15% methanol i say its acheivable.

y8s 07-17-2009 11:50 AM


Originally Posted by JasonC SBB (Post 431374)
Well even a stock 2001 will ping on 87 octane...
The difference between 10:1 and 9.5:1 I think is pretty significant in terms of ping resistance...

I guess I underestimated the whole role of MBT (or didn't read closely). I take back what I said about not running water.

The question can't really be answered without experimentation. I think you'd know more looking for MBT at the boost target you want (rich mix for now) and see how far you get at various RPMs that are knock prone.

musanovic 07-17-2009 11:26 PM

At what boost will you start spraying water? I occasionally run 12 PSI on a 01 and spray 100% water meth at 5.5 psi with no problems so it all depends like Y8 said

magnamx-5 07-18-2009 12:19 AM


Originally Posted by y8s (Post 431512)
I guess I underestimated the whole role of MBT (or didn't read closely). I take back what I said about not running water.

The question can't really be answered without experimentation. I think you'd know more looking for MBT at the boost target you want (rich mix for now) and see how far you get at various RPMs that are knock prone.

MBT scales with VE and bsfc mat so you are not wrong you are just thinking of mbt as a set variable when it is actualy very maleable given intake flow, temperature, and overall chemical composition in the combustion process.

y8s 07-18-2009 10:16 AM


Originally Posted by magnamx-5 (Post 431752)
MBT scales with VE and bsfc mat so you are not wrong you are just thinking of mbt as a set variable when it is actualy very maleable given intake flow, temperature, and overall chemical composition in the combustion process.

Right but MBT is relatively tolerant of mixture so you can get fairly close to it with an overly rich mixture to get an idea how far you can take the non-WI setup.


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