Im used to tpi where you really couldnt run anymore then 6 degrees. I know base for the tbi cars is 0. Well today i decided to check my timing to see what it was and to my surprise it was set just below 10 degrees. I have been running 87 in the car since i got it and havent HEARD any detontion but i know that doesnt mean its not there. The car did kind of seem to bog alittle up top. So after checking the timing and finding out it was set at 10 i decided to fill up with 93 and the car did seem to feel alot better. I am just wondering if anyone else is running this. I kind of equate me being able to b/c the motor runs ridiculously cold...like inefficent cold ha.

 

Real cold motor probably helps. I run at 180*

I cant run 87 at all, or my car knocks like crazy. I made a video of it in a thread a while back. I have been running 93 lately, and noticing that it lasts alot longer, with no knock.

I tried 89 octain 2 days ago, just to see, and it statred knocking again. Also drank $10 of gas in 30 miles or so. Now I have 93 in there again, and it is gone all day on half of $15 driving alot. With no knock again.

 

Your TBI system uses a knock sensor so it's possible that's pulling the timing back and keeping you from audible detonation. Some can take more advance than others, but I usually set them about 4* advanced from factory specs when beginning to try to find the optimal setting for performance. Relying on the knock sensor to pull you back from detonation is not a good way to go- when the KS hears detonation it tends to "overreact" and pull out more timing than you would want it to for optimum performance.

 

Yea that was my first thought, that the bog was deff timing being pulled. Guess i will need to start datalogging and see whats going on in there.

 

10 degrees base is too much. Swirl port heads are fast burn heads by design, which means they don't need the same ignition advance that other head designs need. Running a higher base timing will reduce power and will negate the advantage of a fast burn head. Ideally, you want to run 4 or less with 87 octane. In the same regard, running higher octane fuel with these heads also negates some of the fast burn features of the heads. It simply isn't needed.

 

Good to know, thanks. I will knock it back down to 4 and see how she does from there.

 

I've played with the timing on my car and it pings like crazy at anything over 4 deg., I set it at 2 and it seems to have a little more spunk than at 0.

 

It depends on the cam. I'm running 11 deg. base timing (initial). on a voodoo
cam. The last cam I had liked 18.