87 octane!! help
 

Hi,

I need help with some numbers about the octane rating that my WI should increase.. I have a 1/4 mile race this weekend and unfortunately there is no high octane Gas higher than 87, yeah no more than that...
I was wondering how much does the WI would increase my octane ratings with a 80/20 Water Meth injection and a M5 Nozzle on a RB26DETT.

Thanks

87 octane is a difficult one to estimate because not many people use it. I take a guess, W80/M20 at 10% W/F ratio will probably raise a 1 to 2 points. If you can 50:50, at 20% W/F ratio, you can gain around 4 octane point.

To work out W/F ratio, divide M5 by the total flow of all your injectors I cannot work out the flow of the M5 until I know your fluid pressure.

Thanks Richard!!! I have actually read a lot of posts you made!! and I wanted to ask you a lot!! specially about the pre turbo injection. Going back to the actual subject, My car has the standard rb26dett 440cc injectors. I?m planning to push about 18 psi (around 28 psi absolute pressure) and we will be racing at 3831 meters above sea level. Atmospheric pressure is about 9.6 Psi. I calculate 20 Celcius degree temperature....I actually have the "150 Psi" shurflo pump it comes with the stage 1 kit for devilsown injection. The M5 is rated at 315 cc/min @ 100 psi.

I have an M7 nozzle too, That would make around 17%.. with the info provided... what would you recommend?
Thanks!

Cid