The_Bishop

iTrader: (10)

I've been reading about ignition timing both here and on the HP Tuners site. It turns out that the '98 computer has a fairly aggressive timing table in it, stock. Would it be worthwhile to change any of it, or is it close to 'maxxed out'? Car is completely VE/MAF tuned to within 0-1%, and command AFR is right on the button.

Stock '98 motor, SLP lid, new GM stock replacement plastic MAF, ported throttle body, LS6 intake, Dynatech Headers, Off-road Y, Magnaflow exhaust is pretty much the majority of the engine mods.

RJB01camaross

Every car is different. You could add a degree of timing and then do a scan log to see how it effects the car.

JonCR96Z

iTrader: (33)

You're not gonna "see" how it effects the car with that little amount. Unless it is just too much and it causing knock retard.

The only way you can really tell is by having it on a dyno. Even then if it's not a 'load bearing dyno' a few rwhp more or less may not be real world.

As long as it's high 20s it's only gonna be a few rwhp off at most. Get your PE in the high 12s/low 13s and leave the timing alone and you'll be just fine.

The_Bishop

iTrader: (10)

That's what I have going on now, PE is 12.9-13.0 and timing is stock.

I was reading about how the later LS1 motors had much tamer timing tables with the different casting heads and the LS6 intakes, and was wondering if I should be running a timing table like the newer model cars.

The_Bishop

iTrader: (10)

As I posted on HPTuners.com, a more concise explanation:

I have a question regarding the ignition timing table in my 1998 Camaro in regards to how it compares to the later model cars.

My car is modified from stock. I have deleted the EGR, installed an ls6 intake manifold, headers, etc. The long block is vintage 1998, with the 806 casting heads and 1998 camshaft, unmodified.

From what I've been able to find, the combustion chambers in the 806 heads are identical to the later 241 heads. The compression ratio is likewise the same. I know there is a difference in camshaft timing (1998-2000 is 202/210 int/exh @ .05" on a 116 LSA vs. 2001-2002 197/207 int/exh @ .05" on a 116 LSA) and they were equipped with the ls6 style intake, but this doesn't explain the rather vast timing table differences.

My question is should I be running the later style timing table? The high-load/high-rpm cells show 28 degrees in my stock tables, while the later model cars show 19 degrees. Surely the camshaft and intake change aren't totally accounting for the timing changes, or am I missing something else?

JonCR96Z

iTrader: (33)

The factory does not always do stuff with most power in mind.

LSx engines like timing in the upper 20s (for the most part), but by all means put 19 in it. You'll probably not even notice the difference on a stockish car.

The_Bishop

iTrader: (10)

I wasn't hell-bent on running 19 degrees of timing, I was just curious as to why they changed it so radically and if there was some good reason. Still wrapping my head around tuning.