Hi... I have a 88 mustang gt... with speed density.... underdrive pulleys.... and I use regular fuel... What timing should I have my car set at... Can bad timing affect idle problems???
Well it has alot to do with what tranny you have also. I've read some places there are 5 speeds running up to 18 degrees of timing. I'm not that insane but im just running 10 degrees on my 5 speed. Thats really common
oh ****, i mis typed that. ha yes im running 13 degrees. Thats really common. I'm running 90 octane. I want to convert my car over to E85 cause of the 105 octane. Plus my dad owns a gas station and sells all those fuels and i get them even cheaper haha.
As you can see, it varies car to car. On 87, 10-12 is generally safe, and there are folks whom can run more advance per octane, but it just takes experimentation.
If you are having issues, I'd suggest 10* and 87 octane as a starting point.
Been running 14* on 91 octane (or 92, depends on the place) for awhile now. You gotta play it by ear. I'd say start by running a tank full of premium through, then refill and THEN bump your timing up as high as you feel safe (I'd say 16* tops), then back it off a degree at a time if you get pinging, until you find the sweet spot. It might take you all day, having to pop the hood, re-set timing, go out for a drive, go back and re-set it again, re-test-drive it, etc. until you get it where you want it. I lucked out and found that 14* is my car's happy point for the moment on the first try - anything more and it knocks, anything less and it feels sluggish.