What affect does the ignition modual have on performance. Does limit rpm. Have problems reving to 6000rpm. I have a new car with stock hei old motor from previous car. Hei is one of the changes also a 600cfm edelbrock from a built 750 q-jet. Wondering if I'm running out of spark or carb? I know stock hei is good of 5000rpm or so. My old hei had a accel modual and super coil lighter springs, and ran with out aa problem.

What y'all think?

What module do you have in it now? If it is a GM 990 series module, and it is in good condition, then you should have no problem.

If you don't have a GM 990 module, the best way to go is to either get a NEW 990, or go to a NAPA autoparts (do they have those in Canada?) and get a NAPA TP45 module. I guess you could order it from www.napaonline.com (http://www.napaonline.com) too.

These modules are on par with the MSD units as far as RPM capability.

If this doesn't fix it, think about getting the MSD dust cover that converts your HEI to external coil. This will help because the in-coil design of the HEI makes any in-cap coil too hot, reducing its RPM ability.

Use a CHROME MSD Blaster 2 external coil for this. Don't used the red one!! Some are made in the usa, some in mexico, the mexican ones have poor quality control issues.

Or you could use Summit's Chrome coil, it is made in the USA and looks identical to the Blaster 2 minus the MSD sticker.

I have the External coil/Blaster2/GM990 set up on my weak little 355 and I've been darn close to 6000RPM and I didn't get the "hit a wall" feeling I used to get with my in-cap coil.

If you want to talk to a really knowledgable HEI builder, email Dave Ray: sparkman451@earthlink.com

I've run to 6K plus plenty of times with the stock HEI module and coil
Maybe its your ignition timing or fuel system.
What is your base and total timing and at what RPM?
Plus,if you do have 2.56's as your signature states,that would explain alot too.Those gears are NOT made for revving quick,thats for sure.

I'm with Slowpoke. Get a good module first. I just went through this with a buddy's Elco with HEI. His car died so he bought a module. It would't run over 4K without breaking up. He went and bought an Accel module. Wouldn't get over 4500rpm. I put an old module out a Proform HEI I had on the shelf in it and it ran to 6K - no miss. He called Summit and got a Pertronix module for $40 I think and it still wouldn't get over 5K so we put my module back in and bingo - it ran fine. The module is very important. MSD or the GM are probably the best bet but sometimes it's just Trial and Error. I will sat this. I have always seen a suspect module exhibit a miss at some RPM in the upper range or just not run at all. I haven't seen them limit power witout some noticable miss. Good luck.

Troy.

thanks guys Going to try a better mudual the dist. came out of a 82 t/a and is stock now I'll take it apart and change the mudual. It doesn't break up now just slows the pull. Even with the 2.56's the top end kick is impressive with the old car it would snap 6000rpm topped at 6300rpm or so 6000 was nice and clean. Would richer secs on the 600 edelbrock help? I'm kicken myself I had a sweet set up in the old car now got to work the bugs out of this car. At least i know what is different. to recap
Old= after market modual accel coil
New= stock
Old built 750cfm q jet
new = 600cfm edelbrock electric choak
old 2.5" duals with glass packs
new 3" single with dyno max ultra flow I have been told it'll flow enough for I have but i doubt it
What do ya'll think of single 3" sounds awsome and i notice better bottem end the previous owner had it installed for what ever he had in the car guessing a 307.
thanks for the input!!!

Originally posted by mod malibu:
the dist. came out of a 82 t/a and is stock now I'll take it apart and change the mudual.The distributor is from an 82 Trans Am? This distrbutor is computer controlled and does not have vacuum advance or a mechanical advance..

What is wrong with the red MSD Blaster II coil? I've been running one for 5.5 years.

My Red Blaster II seems OK too....

This distrbutor is computer controlled and does not have vacuum advance or a mechanical advance..
Not if it is a Canadian car. smile.gif