I have a well modified camaro.I need to pull the timing when I am spraying to save pistons(LO3's have a 9.3 to 1 comp. ratio,too high for spray with cast iron heads).
I also think that even with my hypertech chip(thermaster 160)that this will puke the MAP into thinking that it is too lean.
I can get a duel PROM with a custom "2nd" chip to conquer this,but this runs $1000 which I at this point I may as well update to a 4th gen Z-28(a 1993 for it was the only one with a PROM and they go for only about $8500 bucks around here),though I love my RS
CAN ANYBODY GIVE INSIGHT!
HERE ARE MY MODS:
STARTED WITH STRIPPER(no air,or power anything)
T-5 with ripper
OPEN ELEMENT
EDELBROCK HEADERS for IROC w/3" outlet
CRANE compucam 2031(438/452-208/214@.050)
350 truck injectors
Hypertech chip
No Cat
Dynomax 3" with 2 chamber flowmaster
Summit roller tip rockers(1.5 ratio)
Edelbrock Valve springs
T&D Injector riser(not the spacer!)
Ported stock intake
NAPA p/n TS113 fan switch(turn it on at 187 degrees-look up for 1983 Celebrity w/2.5l)
Turbo City regulator
7.4l truck fuel pump
EDELBROCK water pump w/Water Wetter suppliment
....and a discman pumping rage against the machine!
14.5@95MPH on sunoco Ultra
THANKS!

You can pull timing very easy with MSD 6AL, or a Crane unit. I have one of each on both of my cars and like them both, although the MSD is more user friendly and has better instructions. What happens, is you hook a wire to your no2 system so when you activate it, the box retards the timing the amount you dial in. If you would like to see what I am talking about, goto Cranes website and read one of the online instruction manuals (in .pdf format) they show you different hookups for demand retard, etc. hope this helps!

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Jerry

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89 RS Lt Blue T-Tops T5
355 Crate, Compucam 2040
Pst Front Hotchkis Rear
Edle. TES 3" Flowmaster
Harwood hood, bla, bla, bla...
94 Z28, LT1 6M, Black
Most of the bolt-ons
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Thanks for your advice,but what is the computer going to think about Mr.MSD pulling timing out of the distributor?

This sites tech data says that the L03 has a 9.3 ratio, but my owner's manual says that the L03, LB9, L98 all had 9.5 to 1 in '89.

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1989 Pontiac Firebird Formula LO3 Auto
-180 degree stat
-Hooker Cat-Back
-vinyl security shade, velcro t-top bag
*****Possible summer '01 mods*****
Dual Snorkle, Auburn Posi, Keyless Entry, Wonder Bar from my IROC, 4th gen seats, T/A tail lights

http://www.geocities.com/krt80/

My owners manual says 9.3to1.It is a 1992 manual.

The computer isn't going to think a damn thing about Mr MSD pulling a few degrees of timing, it had no way to tell what you are doing.

My friend,how will it know the amount of fuel to spray?Givin thid systems touchy MAP(my knock sensor is wrapped with about 1/32 inch of teflon tape to deaden useless retard)
I have concerns that the computer in a maxed out mode may end up with a high RPM lean condition because I have seen it on (SORRY!) 3.8SFI Turbo Buicks.
I think I am just going to send 75hp at it and give you the results.(The car is in good shape,runs like a top).I will send times when I get SHOT(No PUN intended).

The ECM has no clue that you are spraying nitrous. It will fuel the car the same as if nitrous is off. It will not compensate for a lean condition at WOT.

You tune the fueling with the jets in the nitrous kit.