When running race fuel....

[lazer96gt]

Is it just the timing that is advanced to run race fuel or are there other paramaters to be adjusted?

[95 GTS]

on what car?

[txlen]

if yer A/F is correct then all ya need to worry about is the timing...but get the A/F correct first...

[lazer96gt]

Well on my car in particular but I was assuming it would pretty much be the same with the majority. Would the timing make the car run any leaner by more efficiently burning the fuel?

[Nighthawk]

Originally Posted by lazer96gt

Well on my car in particular but I was assuming it would pretty much be the same with the majority. Would the timing make the car run any leaner by more efficiently burning the fuel?

on a wideband, adding timing will show a leaner mixture; if all other variables remain the same.

I would be VERY suprised if you were able to get any hp from running race fuel over 93 octane on your car.

There is a such thing as too much timing.

[lazer96gt]

Would a higher compression ratio justify higher octane? What WILL be necessary to see hp gains from race fuel on stock long block. Just Tuning??

[blu89hb]

yes, and I only used race fuel when I was spaying my stock block with a 175 shot. I dont think tunning alone will do much with race fuel on a stock block w/ stock compression.......but if you want to give it a try go for it, just dont over do it. Mix it up with regular gas.

[lazer96gt]

that pretty much answered it for me. Check this out though; my buddy has an SRT-4 with the Mopar Stage 3 turbo (txlen knows him as well) and he has a "high octane mode" switch. he runs straight leaded 116 octane and with the switch on it's about 40 whp increase. is it because he's boosted that the computer is able to dial in so much power?

[Nighthawk]

Originally Posted by lazer96gt

that pretty much answered it for me. Check this out though; my buddy has an SRT-4 with the Mopar Stage 3 turbo (txlen knows him as well) and he has a "high octane mode" switch. he runs straight leaded 116 octane and with the switch on it's about 40 whp increase. is it because he's boosted that the computer is able to dial in so much power?

in a boosted application, you have to back down timing and dump a good amount of fuel when you run pump gas. There's just so much more air going in to the engine compared to a N/A application...and more heat.

116 octane would allow the engine to run a lot more timing and probably less fuel at the same time. This is great because he can bring up the timing back to reasonable levels. And in boosted applications, timing makes a huge difference in power.

On your car, you could run say 16 degrees of base timing on 93 octane. Well, going any higher than that probably won't net you any power. If you were running nitrous, as blu said, on pump gas you'd have to run about 10 degrees of timing to run 100 shot. So with the race gas you could bump it back up to higher levels or even run a 150 shot on the same timing as 75 or 100 shot on pump gas. Same situation with compression. Higher compression needs less timing to avoid detonation. You just wouldn't as much as a gain in this situation as you would with a forced induction setup.

[lazer96gt]

thanks nighthawk that was very helpful. I was actually afraid to go over 13 degrees base timing but 16 sounds real good. i've always been under the assumption that you shouldn't exceed about 3 degrees but I didn't know that these sources were refering to 87 octane not 93. so basically no benefit from 109+. that's what i needed. someone should write up and sticky a post about race fuels as far as requirements etc.

[embler]

race fuel is only needed to suppress detonation. if you dont have any trouble detonating then race gas is a waste of money, imo.

[95 GTS]

Originally Posted by lazer96gt

Would a higher compression ratio justify higher octane? What WILL be necessary to see hp gains from race fuel on stock long block. Just Tuning??

"waste of money" comes to mind

[lazer96gt]

^word. damn I need heads & cams!!!!