Wanna Bump Up The Timing

[Joey5.0]

I have a 1990 Gt with 118K Miles With the following mods

BBK U/D Pulleys
BBK CAI
Electric Fan
Shifter
D/S
Flowmaster Catback.

I would like to know if i can safely bump it up to maybe 12 or 13 Safelt without hurting the motor or Pinging. I run nothing but Synthetic Oil, And Chevron 92 Octane. And do i do this with a timing gun, or a tune/chip?

 

[JChalfan]

You can usually run 14 degrees timing safely with 92 octane gas.

It's easy, you just need a timing gun. Don't forget to remove the spout connector first though! It's the little grey plug that comes off the wiring harness running to the distributor. Base timing always has to be set with the spout removed, you can just unplug it while the car is idling.

Then take your timing light and set the timing to 14 degrees, put the spout back in, and you're ready to go! If you hear any pinging back it off a degree or two, but it shouldn't be an issue.

Jeff

 

[HISSIN50]

Here's some info on bumping timing .

Good luck.

 

[GreatWhite]

make sure you mark the balancer so you can see the timing marks... alot of the time it's rusted and you can't see them anymore... i used white out to mark mine

 

[willys1]

Instead of going rite to 14,go 2 degrees at a time is a good idea.Go to 12, lock it down and start it.Then go back and go to 14.

 

[stang22]

Here is another one... Sorry I was late.

http://leemotorsports.com/stang22/timing2.htm

Tim

 

[Joey5.0]

thanks guys ill give it a try soon.

what kind of gains can i expect?

 

[JChalfan]

I used to have a book of 5.0 dyno tests, which claimed about 5 rwhp from bumping up the timing to 14*. I would say it's noticable.

Of course with gas prices what they are, you have to decide if those 5 horses are worth a couple bucks every fillup...

Jeff

 

[68keyblr]

I've never done this myself, but a friend of mine who is a *very* experienced engine builder does not set initial timing at all. He sets the total timing at 3k rpm to 36* and lets the initial timing fall where it may.

 

[vristang]

I've never done this myself, but a friend of mine who is a *very* experienced engine builder does not set initial timing at all. He sets the total timing at 3k rpm to 36* and lets the initial timing fall where it may.

Is this for EFI motors?

I think a carb would handle that ok, but the computer could have issues?

jason

 

[68keyblr]

Good point, I believe he does mainly carbed apps. It would be interesting to do it and then see what the initial timing comes out to be. I just might try it and see how it turns out.

 

[Joey5.0]

I used to have a book of 5.0 dyno tests, which claimed about 5 rwhp from bumping up the timing to 14*. I would say it's noticable.

Of course with gas prices what they are, you have to decide if those 5 horses are worth a couple bucks every fillup...

Jeff

Sounds worth it to me. Ill try it out for awhile and make a descion

 

[HISSIN50]

The thing is that with pump gas, the octane spread isnt enough to notice any real power difference (running low vs high grade). Higher octane burns slower, so of course one can run more advance. But the two (higher octane allowing more timing) kinda mitigate eachother.

I'd note that there is often a point of power drop-off before the onset of audible detonation. So running on the ragged edge of detonation is not always the ticket.

Good luck.

 

[JChalfan]

I've never done this myself, but a friend of mine who is a *very* experienced engine builder does not set initial timing at all. He sets the total timing at 3k rpm to 36* and lets the initial timing fall where it may.

That's what I used to do with my carburated motors too, but I agree with vristang that it might not be a good idea with an EFI motor.

I've seen specs on the spark advance for the A9L computers. If someone has that information, it would be pretty easy to figure out your total timing on a 5.0.

I had a moderately built 250 inline 6 in my '66 Mustang years ago, and if I recall, I set total timing around 42* which is more than I would ever recommend. But that engine loved it and I never heard a hint of detonation, even though initial timing ended up around 17 or 18*. I've been told those inline 6's like a lot of advance.

Jeff

 

[HISSIN50]

The above info is correct - one plays with the dizzy's advance on a carbed application, to reach the desired total timing and application of said timing.

On an EFI motor, without tuning, once can only play with the base timing, and allow it to phase shift the entire timing curve.

 

[68keyblr]

The above info is correct - one plays with the dizzy's advance on a carbed application, to reach the desired total timing and application of said timing.

On an EFI motor, without tuning, once can only play with the base timing, and allow it to phase shift the entire timing curve.

Cool, I learn something new everyday on this forum!! Thanks gents