guess I am just looking for the relationship.
My chip timing is 6 should the dist. timing always agree with the chip timing? i.e. if I change my chip timing to 8 then shoiud I hook up the timing light and adjust the dist. to 8?
or should I leave the dist. untouched at some given valve and only change the chip timing? if so what value for dist. timing.
thanks.
I believe that now that I have my VE tables closer, I will look at timimg issues. My timing curve looks like it comes on a little early for the engine set up(low valve Kpa), mike

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90'GTA L98
Blk/Blk leather
355-4 bolt aluminum heads
10/1 forged pistons
comp cams 510 lift 320/330 @.050 114 LSA full crane gold RR,
1 3/4" SLP headers
ported lower/SLP runners 52mm TB, 24# SVO inj.
T700R4 rebuilt by ME.
all the trick stuff. superior shift kit. Fairbanks 9 clutch-noburn/.5" TV boost/Vette servo/Kevlar band/all new bushings etc.etc.etc.

 

Mike,

This is a interesting question. Without a doubt the best way to approach this is to always have your distributor timing match the chip timing. This makes things much easier because you won't forget about the difference in timing that you have 'dialed in' to the distributor. Furthermore, Diacom reports both ....

1) Spark Advance relative to TDC
2) Spark Advnace relative to Reference.

Spark Advance relative to TDC displays the overall advance INCLUDING the amount of advance indicated in the Chip for distributor initial timing. Spark advance relative to reference displays only the ADDITIONAL spark advance in the SA lookup tables (and WOT PE).

IMHO, I like to view the total advance in the scan tool. This means that the indicated distributor initial timing in the chip equals the actual distributor timing that you set at the engine.

However, it doesn't 'need' to be this way. For the longest time I had 10º of initial advance at the distributor yet only had 6º set at the chip.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

 

I woke up last night with this thought! If the computer is solely responsible for timing, then, within reason,it should not make any defference to engine operation were the distrubutor is timed. because the rotor tip is fairly wide the spark is deleverd by the computer signal, and as long as the cap/rotor is at the proper timed position + or - a few degrees the spark plug will not see any difference in "timing".
thought/comments?

 

you sould set the disributer to factory specs. then use the chip to advance it. you should never have to move it again. the computer only tells you what it thinks it is at. say you set you distributer at 5 deg. adv. and then set the chip to 5 deg advance now if you check with the timming light it will be at 10 deg. adv. but, the comuter only thinks it is at 5 deg.