Advanced timing on 5.7 tbi

[CoullionWillis]

Hey guys I have a 5.7 tbi with a mild rv cam. I haven't felt like it was running right so I advanced the timing a little bit. It's running much better but I'm not sure how much I can advance it without getting premature detonation etc. Any imput would be helpful.

Thanks, Josh

[1988 GMC 355]

I have mine at 6* with no ill effects and a few guys on here run at much as 12* advanced with a cam and increased fuel psi

[CoullionWillis]

Well it's a daily driver so I definately want it to be safe! And I run 89 octane in it at least. I like running premium but gas is sooooo high!!!! 

[1988 GMC 355]

I hear ya on the gas deal!!!

But where is the timing now?
are you running higher fuel psi?
id say increase it at 2* intervals until you think its going to get as good as it can get. prob 8-10 would be good and safe for sure

[1.721afr]

Eh?..What year?
Ya we have added a bunch of timing & fuel to crappy .bins, but those are an exception not the rule.

As always I must insist that just dialing in more advance via distributor position without data interface is a is a BAD idea.
As a rule you run into the Knock Sensor between 4 & 6* advanced from factory settings.
I hope your KS functions correctly or you risk major engine damage.

TBI tuning is a matter far greater than boosting fuel pressure & timing.

[dave w]

Here is a screen shot of my timing table. My timing is set to ZERO. It's AGGRESSIVE! My 93 K1500 - 9:1 / roller cam / 1.6 rocker arms / 454 TBI / Shorty Headers / 3" Single Exhaust / 5.7 liter runs fine with 89 octane using a 180 degree thermostat.

dave w

http://i239.photobucket.com/albums/ff290/buildabot2002/TBI%20TEST%20BENCH/E6Timing.jpg

[helo]

HOLY CRAP that is aggressive, indeed. You run that on stock tbi heads?

Where are you in WA? Do you do any mountain driving? That's the true test of SA; I've found pinging tends to happen around 90map going up long steep hills...

I just got my SA to the point where i said "wow! there's my missing 50hp," but damn.. that's a lot of SA. I've got a vortec-tbi, and I'm now thinking I may bump mine a bit further and see what happens. :D

[dave w]

Yes, I use "193" TBI heads. I live close to Mt Saint Helen's, so I routinely see about 6,000 feet (or more) above sea level. The ambient air temperatures were I live rarely gets above 90 degrees F, and the humidity is usually about 70+ % most of the year! I guess the mild weather is why there is huge forest near by me!

[chris015]

Mine is Around 6. When i up'd it to around 12 it started pinging.