Race Fuel

[IanS13]

My Car as of lately seem to have a miss fire, at 0vac right before it hits boost in low throttle. It does not do it all the time but if I try I can because it, I try to avoid this throttle position by just going into boost. So I put about half a tank of 100 octane race fuel, and my problems seem to have gone away and the car feels great.

I did not know if were safe for me to run race gas or not. I searched the forum but found no info on race fuel in our cars. But I did how ever find this one very interesting article on motor trend. http://www.motortrend.com/feat..._fuel/

[nismofly]

as long as your not putting leaded in you should be alright

as for the misfire cure, thats expected...race gas has a higher tolerance for that sort of stuff

[KATwo40]

Thanks for posting that article.

I wonder, when using fuel containing oxygenates, does the added oxygen reflect in the AFR and injector pulsewidth readings?

[IanS13]

am sure my car needs a re-tune which will be soon to come. but untill i get my new clutch in it won't be going on a dyno i realy need to wide band tune it for low trottle street driving.

Thanks for posting that article.

I wonder, when using fuel containing oxygenates, does the added oxygen reflect in the AFR and injector pulsewidth readings?

[Edub1]

That article is an infomercial. What do you expect the manufacturers of a product to say, "it's really just a scam"?

The only thing high octane does is "slows" the fuel ignition - it's like retarding timing only chemically.

Chances are you are getting bad gas. Try a different gas station or a bottle of dry gas. You'll get the same result.

Also, inspect your plugs for signs of detonation. If you are not getting any, high octane is not the solution.

[KATwo40]

I am coming to the conclusion that plug reading on a turbo car is a moot point. The operation conditions change so drastically, that, even when you operate to a given load / rpm, then shut the engine down, the plugs still don't tell the full story.

I'm considering purchasing a single plug from a company I found that offers plugs with built in pressure transducers.

To read the exact cylinder pressure accurately, you'd need some VERY expensive data processing equipment. However, to effectively use the plug as a diagnostic/tuning tool, you could easily use some lesser grade processing to establish a waveform that shows a pressure curve. Who cares if it's accurate, in terms of cylinder pressure? You just need a pressure curve to inspect for signs of cylinder pressure spikes.

I'll update further on this as I go along.

[Edub1]

The plug will show detonation. This is the only thing high octane will cure. If there is no detonation, high octane does squat.

[KATwo40]

Waiting to find specs of alluminum on the plug is not a good idea, regardless of what the internet says. Yes, the plugs will show it, but only if he catches it before the material is burnt off by the next boost run.