firebirdjones

I have done some searching on here with small success but I still have a question. I have an 88 Iroc L98 that is mostly stock.
I am going to check base timing. Question: I am curious if bumping the base timing up 2-4 degrees will yield any performance gain on this computer controlled car? I am still running the stock computer chip at this time. Just curious if this is benificial. I am not looking for huge gains here, just wondering if this is normal practice on these cars for better performance or does the computer override this or compensate for it somehow? Eventually I plan on burning my own chips but for now is this a bandaid alternative for a little better performance? Sorry if this is a silly question, I am just not too familiar with computer controlled cars, I am very old school so please have mercy on me, Thanks for any input, Larry.

vortec77

When adjusting the timing on these cars you have to diconnect the ESC (engine spark control)connector before you try and adjust timing. Otherwise the computer will automatically compensate for the advance while the connector is connected and youll have wasted your time. As for performance gains maybe a little, but advancing is good for off the line out of the hole from a stop but you sacrifice a little at top end and vice versa when you retard Timing, off the line like crap and gets better at top end. Timing is mostly something you mess around with and get to where you feel most comfortable with.

firebirdjones

Thanks vortec, I understand the concept but I don't have the equipment at the moment to play with the curve since that is controlled by the computer. That is something I will fine tune in the future. I am used to playing with springs, weights, advance bushings and adjustable vacuum cans so this computer is a little new to me. I understand the process with the esc plug to set timing and what not. I am just curious if there are any short term gains from bumping up the intitial timing a few degrees. What I mean is instead of factory 6 degree setting, is it beneficial to run maybe 8-10 degrees initial or will the computer take that back out once the esc is plugged back in? Will this add 2-4 degrees to the entire timing curve that is preset in the computer? Just looking for a little improvement in performance and was wondering if this has been done before. If it is a waste of time then I won't bother. Guess I could satisfy my own curiousity when i go to the track to baseline this thing. It is all stock other than converter and smog pump removed. I may experiment with initial timing there and see if there is any change in mph etc.... Thanks again for the help and if anyone else has ideas please let me know. Later ..............Larry.

firebirdjones

Well I decided to check it for the heck of it. Unplugged esc and was surprised to see only 3 degrees. I figured maybe the timing chain stretched a little but the car has only 50,000 miles plus the timing mark was rock steady which is a good indication of no chain stretch. Anyway I decided I better get the wrench and adjust timing. Well guess what, found the problem, the bolt was loose, guessing the distributor slightly moved, car has been running fine though and getting 20 mpg in the city. Anyway, set the timing and decided to just go right for 8 degrees instead of 6, I figure a 5 degree change (from 3 degrees) I should be able to tell some kind of difference in driveability. Anyway I thought this car had no butt to it for an L98 Iroc, timing may have been some of the problem. Only a test drive will tell. I still don't think this thing will have enough ***** to satisfy me though. Larry.

firebirdjones

Oh ya, I decided to check fuel pressure while I was tinkering too. Hooked up the gauge with vacuum line disconnected and had 44 lbs. with all stock fuel system. I am guessing from what I have read here that is about right. I shut car off and let it set for 15 minutes with gauge still installed and still had 44 lbs. after 15 minutes, no drop at all so I am assuming this is good, everything in fuel system is working as it should. Larry.

firebirdjones

Well I guess I answered my own question. I bumped the timing from 3 degrees initial to 8 degrees initial and went out to run some errands. According to the trusty Butt dyno, the car is more responsive than before, it spins the tires much easier than before and also much further. Still not stellar performance but a slight improvement none the less. Now if I could just burn a chip and play with fuel and spark curves then the car might actually start running more to my liking. I guess I will never be happy, gives me a reason to keep tinkering with it Larry.