Race gas or no race gas

[elchankoblanko]

Hey everybody, recently I had my Rs engine completly rebuilt, Im talkin split cases and had everything replaced. When it was all done my engine builder told me to run race gas in it. Its basically a stock motor but i did have some porting work done on it and I do not have a dome on it. So i was wondering what do you guys suggest running it with race gas or no race gas. I really dont want to buy it if I dont have to because as you know its wicked expensive. Thanks

[Dave83]

Depends on your compression.Anything above 190 and you better run at least 101, 108 would be best.200+ you start needing 112.When you had the port work done,the shop may jave cut the head to close up the squish,raising compression.

[baseballplaya23]

you can run VP U2 its for stock or mild worked 2 stroke applications.

[Quadude32]

Yup depends of the compression Bud. I ve always run race gas in all my Race "R's" and also in my stock trail 250R's i think it burns better IMO and it will have quicker throttle responce and the smell Ahhhhhhh but it s expensive


I was always told the higher oct. the better for a 2 stroke i ve always run 110 Oct or 108:D

[YFZRob]

I'd run race gas. I've burned up two top-ends due to lack octane. I made the mistake of listening to ESR and not follow their instruction sheet with the motor. All of them claim over the phone that the pump gas dome is fine for 93 octane pump gas. But the instruction sheet shows 98 octane for the pump gas dome and 108 for the race gas dome. Well, when going to the THRID top-end, I switched to 110 along with the race gas dome and bam....problems gone. I'm so anal now, I've gone as far as removing the head a couple times now to make sure there are no signs of detonation. Sure enough, the motor is happier than ever. I will NEVER put pump gas in my motor again. Maybe a bone stock R, pipe and all, would be overkill going to race gas, but anything that's going to be run harder with aftermarket parts, I'd use race gas as extra insurance, even if you only have 160 psi. Also, remember that the richer the oil mix, the lower your octane. If you run 32:1 or richer, your octane content will be lower. Oil burns at a lower octane than gas....like 75 or something, so the richer your mixture, the lower your octane.