What fuel are you high compression guys running?

[4000GT]

I have a nearly 15:1 20v... just wondering if you guys are running 15 - 30% ethanol or 98 RON pump mix etc?

Cheers.

[Celica RA45]

try 20 litres of 98 and 10 litres of E85 or just 10 litres of ethanol and use that as a mix i have 14.5 to 1 on the beams at the moment and the ign timming has only changed a couple of degress .was using 26 max on 13.5 to 1 now higher only 28ign total and 40 % more fuel as well
you had better change your injectors as well at least 440cc side feeds from a 2jzgte motor should help

[4000GT]

Yeah I am looking to get some 3SGTE ones, I heard they bolt up, do 2JZ / 1JZ fit as well? Good to know.

I was thinking of running E30, good to know you have actual experience in it. What do you think of running 98 with a good octane booster?

[Celica RA45]

e30 wont be good enough you need at least e85 as a minium with that comp 98 fuel you will have to cut ign timming by at least 4 degress to stop it pinging and use the link knock sensor on the dyno

[4000GT]

E30 has more ethanol than E85, are you saying less ethanol is better in this situation?

We would only need to drop timing in the low rpm range, in the high rpm range it would be less likely to det. which is where it will be spending 99% of the time.

The ole octane booster might help, just not tried any before hmmm

[Celica RA45]

E85 is 85 % ethanol and 15% petrol
E30 is 30% and 70 % petrol

also i run more timming up at the high rpm range and thats where it can detonate as well you take it out down low ,but i have the problem as i have dual vvti this changes every thing are you still using vvt at all

[4000GT]

Yes E30 has more ethanol than E85, so you are saying more ethanol is worse for detonation, which I dont get...

Well yes if you run more timing anywhere you will get more det, but with the same timing, there is less det in higher rpm.

I dumped the VVT, will be interesting to see how it goes.

[Celica RA45]

its better to have more ethanol than less as you wont get knock by the nature of the ethanol ,its more knock tolerent than petrol but you need more ethanol to make the same bang ,thats why you use more fuel

[4000GT]

Yes so you said E30 wont be good enough, and that I would need E85, which doesnt make sense then to me.

[Celica RA45]

using e 85 would be better for the 15 to 1 than the e30