Octane and timing..

[MrobsMan]

I have my tbi 350 set at 6 degrees advanced. And plan on going to 93 octane should I bump my timing up more or leave it at 6 degrees? It started pinging at 8 on 87 so I backed it off 2 degrees..

 

[GoToGuy]

What year, make, model, ? When reset the timing have you disconnected the timing wire from PCM?

 

[MrobsMan]

What year, make, model, ? When reset the timing have you disconnected the timing wire from PCM?

I already did that

 

[GoToGuy]

You don't have time to answer simple questions? Too bad.

 

[L31MaxExpress]

I have run them up to 10° advanced on the stock GM chip prior to starting to tune them. Needed good gas but made a lot more torque.

 

[MrobsMan]

You don't have time to answer simple questions? Too bad.

It’s a 1994 Chevy k1500 tbi 350

 

[MrobsMan]

I have run them up to 10° advanced on the stock GM chip prior to starting to tune them. Needed good gas but made a lot more torque.

Did you run 93 or 89?

 

[Komet]

If you're pushing the limits of knock, use the highest octane you can get. Detonation is engine death, btw. I'd be setting a stock engine to stock specs.

 

[L31MaxExpress]

Did you run 93 or 89?

91+

 

[L31MaxExpress]

If you're pushing the limits of knock, use the highest octane you can get. Detonation is engine death, btw. I'd be setting a stock engine to stock specs.

Except that gives up 30-40 ft/lbs of torque and 2-3 mpg. The auto manufacturers are not doing anyone a favor tuning engines to run on 87 (by retarding the timing) that should be running on 91. The low rpm/high load timing advance on TBIs and Vortecs even LS is a negative value to run on 87 crap.