I have just read thru the Jan '01 issue of CHP, and there were 2 good articles that I read. One was about upgrading HEI ignitions, the other about how a fella tweaked his timing and got some better performance out of his '67 Camaro. Here are my Q's. One article talks about upgrading your distributor, by changing the control module to a performance version. Is it worth it on our cars? I read that our cars have the EST system, with no mechanical or vacuum advance. Will an aftermarket module do anything for an electronic ignition?

The other article talks about making a advance timing curve, and tweaking how the timing comes in at various rpms. They do this with a timing tape on the balancer, or an advance timing light. They also talk about changing the springs in the distributer to pull the timing in sooner. They also adjusted the initial timing advance. My question applies to our cars with an EST HEI. Is the spark advance controlled only by the programming in the ECM? Is there any way to modify the timing curve besides a chip change? Obviously the intial advance can be adjusted by turning the distributor.

These were good articles, but I just want to know if any of this applies to our cars.

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Best ET 14.413 @95.57 without
pulling valve covers or manifolds.
Also with stock 2.77 rear end!!!

 

You can change the base timing in you 88 IROC (I'm assuming it's got the 350 TPI). Read the label under the hood. It tells you how to do this and also tells you to set it at 6*, but if you bump it to 8-10 or even 12*, you will most likely see better throttle response and better et's. You will need to use 93 octane though; don't try to be cheap with the fuel or it will cost you big time.

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'88 GTA 350
Headers, catback, free mods, Xtreme energy cam, intake pieces and 2100 RPM TQ

13.40@102.55 MPH
1.90 Sec ----- Best 60FT
104.23 MPH -- Best Trap Speed

AIM HIGH!

 

I have been running my initial timing at 10deg for over a year. I also use the highest octane gas that I can get. Untill this summer when prices were so high that I put some 89 octane in it.

What about answers to my Q's?

Thanks anyone.

 

MIke, the PROM in the computer must be changed to re-work your ignition curve. Sorry. There are other ways to MODIFY your spark/fuel curves, like 160 IDIOT thermostats and MAP adjusters and TEMP adjusters but they are just idiot ways to get around PROM rework. You should either try a buddies aftermarket PROM and/or have one burned OR burn your own.

 

So what you are saying is that replacing the control module in the distributer with an aftermarket version will not help me?
I have allready done the basic mods; 170 tsat, MAF,MAT, port plenum, gasket matching, fan control, coil,cap, rotor, wires, plugs, injectors,exhaust, SFCs, LCA's, etc. I just don't list them in my sig since I think it takes up too much space!!!

Anyways, I am running an ADS superchip now, it was my first mod about 7years ago. I am looking into the equipment to burn my own chips. I guess then I could make my ignition curve!!!!

 

me read the article too. its just basically saying how important the little things can be when in outlaw street one car is running 6.784 and he wins over the car running 6.795. by changing the springs he made the ignition curve START earlier....but it didnt change it. you already have the rest of the ignition go ahead and get a dist. from msd or somethin. it should help throttle response and maybe .05 et hehe

 

The control module is high quality already. Unless you have high miles on your ignition system and/or its giving problems....don't replace it.



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91 Formula
305 TPI 5speed
1LE/G92/WS6
Custom cold air intake w/K&N, SLP airfoil, ported plenum, TB coolant bypass,Crane AFPR (47psi),94 octane,Crane Extruded Alum. 1.6 full roller rockers, Timing set from 4*BTDC to 10*BTDC,MSD6AL, Holley 9mm Annihilator Laser shot 50 wires, Ac Delco cap,rotor and plugs, Bosch O2sensor, SLP 1 5/8 headers,SLP catback,3:73s,JET 195* fan switch, Macewen white face gauges, Intellitronix Digital Gauges

Stock throttle body, runners,intake manifold,cam, and heads.

 

Thanks Formula, that's what I wanted to hear. I will look into the equipment to burn my own chips.