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Drag Rb25Det, Fuel ?

BloodBath

By BloodBath,
in Engines & Forced Induction

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R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Your going to need a fair bit more power to run consistant mid 12's from a 13... Id spend some time taking weight out of the thing first. Then a ethanol tune.

Or nitrous.

Agreed to an extend only given his current time of 13.30 @ 107 & 2.0 60ft is quite decent, so the OP can certainly pilot well enough.

If he can get the 60ft down to 1.7 with the ET Streets then he is looking at a 12.8 up the other end (or there abouts)

Get the 60ft down to 1.6 and then it'll be pretty close to 12.6-12.7

Not quite a 12.5 but it's not gonna be far off that marker.

Lithium Grand Master

Lithium

Posted
Posted

Does anyone know the answer though, as far as to how much timing I can add at wide open throttle??

If only we could tell what timing we could put into setup changes without looking at a car... "more" is usually the answer, but really it needs to be tuned to suit to find out the amount. Possibly none at some points, and possibly several degrees at other points :)

STATUS Grand Master

STATUS

Posted
Posted

What sare some of the fastest stock turbo RB25's that you all have seen out there??

How much timing can I add at full boost when going from 91 oct to vp 116???

I'm shooting for a mid 12 on 12 psi, stock turbo.

10.61 @ calder std engine.

Beer Baron Grand Master

Beer Baron

Posted
Posted

E85 could work quite well, fyi 98RON we get in NZ and Oz is equivalent to 89MON :(

yeah maybe, but US fuel is not MON either. it's an average of MON and RON so their 91 is still not quite as good as our 98 but not as far off as most people think.

Beer Baron Grand Master

Beer Baron

Posted
Posted

MON is tested under load. Someone do correct me if I'm wrong.

yeah kind of wrong. both RON and MON are a measurements of the fuels ability to resist knock on a test engine. MON is tested at a higher RPM that RON which makes it a bit more relevant in most peoples eyes (we are still talking very low rpm, like under 2,000). both tests run the fuel in a special test engine with variable compression till it knocks but the mon test is at higher rpm, with heated fuel and the also advance the ign timing. RON (and MON for that matter) is out of 100 as compared to the control 'octane'. however since some additives in fuel have better knock resistance than the control (iso-octane) you can get a number higher than 100.

US 91 AKI fuel is about 95 RON. our 98RON is about 94 AKI but there is no direct correlation between RON and MON. some substances will be as much as 20 or 30 points higher in RON vs MON, some will be only a few points apart and some (like the control octane) are actually equal in RON and MON.

if you want more info i'm sure there would be some fuel info site or even wiki or howstuffworks etc on this.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

yeah kind of wrong. both RON and MON are a measurements of the fuels ability to resist knock on a test engine. MON is tested at a higher RPM that RON which makes it a bit more relevant in most peoples eyes (we are still talking very low rpm, like under 2,000).

if you want more info i'm sure there would be some fuel info site or even wiki or howstuffworks etc on this.

Yeah Wiki says 900rpm for MON and 600rpm for RON. Pretty low indeed.

Link for the lazy: http://en.wikipedia.org/wiki/Octane_rating

Some interesting reading, and will just lead to more google action if you wanted to know even more.

  • 2 weeks later...
KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted

You are doing very well for the power level you have. The answer to your original question is to be found only on a dyno if you want to keep your engine in one piece. Your next mod should be an aftermarket computer - Link or Motec or whatever you can get tuned where you are.

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