Just curious to know if race fuel or an Octane booster would even be effective if applied on raceday.

Anyone?

 

Seems to me... if you don't have mods like turbo or SC that demand the higher octane, then anything more than the manual's recommendation would not only be a waste, but may even limit your HP potential.

Octane- raising additives are put in to slow the burn of the fuel, they don't add extra power. Slower burning fuel allows other power-enhancing things to work... higher compression, super charging, turbo's (NOS?)... without pinging and knocking that would cause the AKS to retard timing.

BuddyWh

 

Thanks Buddy. Here in CA we are limited to 91 Octane. So an additive is the only option.

Once again, my question is this: Does a change to higher or even a lower octane fuel require an ECU reset to realize immediate results.

 

Im not sure if your Chinkzilla noticed it, but the Audi guys had a few Gallons of Racing fuel... I know it helped on my Mustang and Trans Am, but the compression on those motors, as well as my mods were completelt different. It is a good question though !

 

Oh yeah, forgot this! AFAIK the ECU runs an averaging function for the engine control settings. So as you burn a particular fuel over a period of time it will settle in on settings it figures optimal. You don't make any changes... it does it itself. I don't know how long it takes to settle out, which would be helpful for your situation of course, but AFAIK an ECU reset would only make it start learning all over again and not help much. However, there some OBD-II diagnostic tools that allow you to dial in your own settings for some engine parameters, look for one that allows you to adjust SA curves at least.

I thought I had read of some other Californians burning some 93 octane Sunoco gas? oh well... but my point is the same even using your own additives. Burning higher octane than the engine actually needs may have a worsening effect on horsepower, not an improving effect, so mix well.

BuddyWh

 

No 93 in CA...

I thought about the getting a scanner to verify my hypothesis. Maybe one day I'll try it and find out.

Using the latest ECUs on engines these days, its my understanding that many new cars automatically respond to variations in octane and driving conditions. For example, to compensate for less- than-optimal octane, they slow down spark timing. Other adjustments compensate for ups and downs in altitude while driving. Like you mention, I'm wondering how long it takes for a ECU to adjust or "learn" when exposed to a new variable like altitude or octane change. My guess is it would never be an immediate change realization without reseting the ECU..but I've been wrong before (but only a few times)

-Left

 

On the East Coast, you guys can get Sunoco 94 ! ... We can't go higher than 91 here .... From what Ive been told, from my trips to Colorado, the car programs itself fairly quickly... what "fairly" means, im not sure....

 

Sunoco 94 = a waste of fine $$

just get the 93 octane for 10 cents cheaper...