To any of you racing a small block 400 (track racers only please, I daily drive my car too, but this does not apply).

Question(s): What ignition system did you end up running? I hesitate to ask, because of the variety of answers I may receive, but I am looking for an economical aftermarket ignition that will work with stock computer (my own chip). I have heard some of you running Crane Digital 6s, Jacobs ignitions, and others. How do they compare? What did you gain (ET) over other ignitions you have tried?

Details: My ignition (Stock HEI w/ MSD6a) seems to give up at higher RPMs (over 4800), even with the 6a, and I feel I am not getting the full potential of my motor. I know I am limited somewhat by my LTR setup, however, with close to 10:1cr, Ported TW-G1 heads, 276/282 (224/230 @ .050), 502/510, 110 LSA cam, full roller valvetrain, an Edelbrock base, ported SLP runners, heavily ported plenum, a 52mm TB, and 3.23 gears, I should be able to pull higher than 5k before this thing runs out. I am also running SVO 30# @ about 45psi, and my WOT O2 readings are good (not leaning out or anything).

Thanks for your responses.

 

I am going to post this over on the TPI board also.

 

I once read an article about the msd's and they said that if the coil and box isn't grounded to the engine it will not act right in the higher rpm range. grounding it to the frame (body) and the frame (body) to the engine isn't good enough, if I can find it I'll try to post it.

 

Well it certainly couldnt hurt to try it. I was told to make the ground wire run as short as possible, but I can also run it to the block.

 

You just shot yourself in the foot. What makes you think a 400 SBC will be ANY different then any other small block as far as ignition systems ?

 

I found the article I was talking about, its a short blurb on mortec.com in the information page about the msd boxes. they say use a heavy short ground wire from the block to the box, it should help eliminate the high rpm missing.

 

And your point is? A 400 is different than most other SBC. They like a lot less timing, they are externally balanced, and create gobs of torque. Racing a high torque, lower rpm motor is different than racing a 7-8k high rpm motor. But thanks anyway for your comment.

My question was 2 parts... Ignition systems, and performance. Since I have limited myself by my intake and by keeping the cam mild for emissions, I was looking for other 400 owners with similar setups to see what they are running as a comparison for how far off of my potential I am. I also am running a stock Vette converter, which probably is only good for 16-1800 stall. A better converter would give me a good .5 ET improvement, as long as traction is not a problem.

I may not have an ignition problem at all. It could just be I need some further prom tuning, but wanted to eliminate as many possiblities as I can before I start changing things again.

 

Hey man, if you were to get a less restrictive tpi unit i think that you would have a pretty kick *** motor/car. That motor needs to breath! I am sure you already know this but i just wanted to let you know that you are well on your way to having a sweet motor! Good luck with it, wish i was as far as you!

 

Thank you. There is one additional reason why I used the intake I did. See below:

 

Oh, you have the whole TPIS LTR setup? It looks real nice! I got their miniram for fastburn heads. That will go onto my fastburn crate motor, i can't wait! Tommorrow i am swapping cams in it, i got the hot cam. Hopefully by next week i'll atleast have the new motor in and will be messing around with it trying to tune it. later

 

No, actually the TPIS is just a TB plate. That was the old stock TB.