Max base timing advance on 89?

[Glacial]

It's an 90 2.5 auto, mostly stock (removed heated air flap, ported airbox), and currently running in the neighborhood of 14 degreees BTDC.

I've found a source for cheap 89-octane gas (30c/gallon cheaper than 87 :O) so I figured this could give me a little more room for timing -- anyone have any experiences? It's a daily driver that's pretty much never beaten on, I'm looking largely to maximize MPG.

Or should I just put the thing in gear with the ebrake on and turn the distributor till it starts to ping?

[turbovanman]

Leave it at 12-14, 89 won't give you much room for error.

[turbovanman]

Delete!

[Glacial]

Quote:

Originally Posted by turbovanman Leave it at 12-14, 89 won't give you much room for error.

Fair 'nuff. Somehow though, I know I'm going to end up disregarding this sensible advice and bumping the beastie to at least 16. Stay tuned for my upcoming "broken piston" thread!

Quote:

Delete!

Is my thread about to die an untimely death, or did I miss something entertaining?

[DaytonaTurbo87]

I run 90 octane with 16* timing, no detonation. Throttle response is a bit better, but other than that, didn't make any other difference. Only reason I bothered is cause 90 octane can be had for the same price here as 87, I just make sure I always fill with the 90 and it's all good.

[allmotor]

on my race car, I ran fixed timing @ 38° timing. no advance. on my street minivan, I tuned the timing with my adjustable light until I had 36° total advance at 3000 rpms. At base timing this came out to being 18°. 240,000 miles on the origninal head gasket, clutch, and timing belt (1994 caravan 2.5)

[tkelly27]

on my '89 horizon I ran 16* timing with regular gas, and when I'd get some pinging I'd put in 1/2 a tank of plus and it would go away. It made a seat of the pants difference and I got better mileage, like 3 or 4 mpg. My $0.02

[Glacial]

This is good news indeed. Looks like I'm putting in a new HEP tomorrow so I'll bump the timing while I'm at it.

Thanks everyone!