I have a 89 350 tbi, with a few air intake mods and headers and about 18" of pipe after each header. I usually run 87 octane, but I am going to the track and I put a tank of 93 in it and I was wondering what I could safely advance my timing to. There is absolutely no way that I can listen for a ping with the open headers. Would I be alright with 4 or 6 degrees advanced?

Thanks

 

Our cars respond very well to 4*, I had my best track time stock, at 4*, you can run probably as much as 10* with 93 octane, but just because you can, doesn't always mean you should, Timing is not a matter of more is better, try a few places and see what timing you run fastest at, i would bet it is somewhere between 3*-6*

 

Thanks, I appreciate the info. I just didn't want to run too much timing since I can't hear a ping or anything.

 

you should not hear pinging at all, the Knock sensor should pull timing if there is any ping, and should do it before it is audible. The best thing to do, is datalog, then you can actualy watch the knock count, and make sure you are not advancing the timing to a point that the ECM is pulling more timing out.

 

That is something that I want to start doing, but I am not too sure of what I have to have to get started.

 

a $50 laptop from e-bay. Free software, and $6 at radioshack to build the cable.

 

i am at 8 deg adv and ran 93 octane. 10/1 compression. with "stock" timing in bin i pulled KC at about 2800-3000 rpms under load. i pulled out 2 deg where the KC appeared in a couple cells and it disappeared. switched to 89 octance and no KC. now gonna add timing back in that area and add some elsewhere to see if KC reappears. with the timing i have i feel i may be able to pull more HP/TQ but will need a g tech to tell for sure. may run dyno as well but that is next year.