Would running a colder range spark plug help reduce high rpm detonation? I have a ba-ma 91 race tune and I am getting some detonation at WOT and higher rpm. Im in CA too by the way. I hear the gas out here isn't that great so I know that could be a factor as well. I have been able to dial back the global timing and that has made it pretty good but I feel like I can get more.
My performance mods consist of only the 91 race tune, everything else is stock.

 

I know there are some "brains" on this site. Someones got to know.

 

I would start by lowering the octane in your tune. Just because the pump says 91 doesn't mean its always 91. If that doesn't help you could try a colder spark plug, but if you go to cold you can also experience some detonation.

 

I would start by reading the threads on spark plugs breaking off in the cylinder head of our engines and find out the build date of yours to see if you are affected first.
(some 08's are and some are not)

 

Try using fuel from a different station/brand. Being basically stock, you don't want to run a colder step plug. If the different fuel doesn't help (give it a couple of tanks to confirm), you will need to pull some timing out.

Casey

 

I have pulled some global timing ( 6 degrees ) and that cures it. I just feel like I'm missing out on something though. I have always put chevron gas in the car and started using 91 well before I ever got my tune, because I knew I would be getting a tune for 91 octane. Any suggestion on a better gasoline? I was under the impression that chevron was the best for the most part, but I am open to suggestion, maybe shell or 76 would be better.

 

Is 91 the highest octane you can try? And yes, Chevron is some of the best gas; they meet Top Tier Gasoline standards.

 

That's affirmative, 91 is the premium octane here in CA. There are some stations that are 50mi+ away from me where I could get some race gas from the pump but its not really doable right now. Although I am going to do that in the future ( just to see).

 

i woldn't do race octane,imo......on a stock 3v

 

You should also have parameters to pull timing in the low, mid and high rpm range. You can put some global (adds or pulls timing to overall commanded timing) back in and pull some from the mid and high rpm range. This way, you can still keep your low end torque.

Casey