First the specs: 289 bored and stroked to 343 - 202 twisted wedge alum heads - edelbrok intake paxton supercharger - mild cam - roller rockers - solid lifters - MSD ig with 6200a box (manual advance) c3 tran with kevlar plates -1500 stall convert - with green dot shifter - 295 x 15 rear tires - and factory rear gears ( i don't know exactly what they are but highway i would guess ) 2k rpm is 65mph -

All that said it is a DOG on the line. If i try to power break the engine will flat stall and die is this what should happen? Or is something jacked up in the timing?

thanks in advance!

David

 

Sorry for the typos c4 tran not c3. I tried swapping out the distrib to one with a vac advance and it did run a little better but still a dog.

 

Your factory gears (2.79) are killing you.

 

Your flooding your self

 

So is this because I am over carb'ed or is this typical of a supercharged engine?

Can I just twist in the back jets some or do i need a smaller carb?

 

Is it running rich? What is it timed at? Was the cam installed straight up, advanced or retarded?

 

It is running a little rich but not bad. The timing is set at 12 adv which is where the cam was setup to run. It has better bottom end if I roll it up to 21 adv but then is way over advanced at 4,000 rpms. I am wondering if with the cam and charger that I really needed to change the stall to 2,000 or 2,200 rpm? This car has been an experiment for me and thus far I SUCK at getting it dialed in properly!

 

If it wants timing on the bottom end and has too much timing on the top end change the curve in the distributor. I don't think you said what type you have, is it vacuum advance? electronic? In any case I'd recurve it using springs/weights, or whatever it uses. You might even try going straight mechanical advance and take the vacuum advance off.

And if its really got 2:79's then get those changed too.

 

Okay, I am running a manual advance MSD. After your post I decided it would be good to do some reading before playing and it paid off! thank you for the advice. I changed the advance block in to limit the amount of advance available to the min advance and I changed the springs to one super soft and one mid soft (1 grey 1 blue) then I dialed the timing to 21. Now even though the torq is locking in between 1200 and 1500 it is building enough power to spin the tires through a soft break.

Thanks to all for your advice !!! and I will change the rear gears when the cash is available

 

Glad it helped. In our circle track cars we spend a lot of time getting the advance curve right. It makes a huge difference because we're working with a very specific set of RPM numbers and we have to optimize it.

I'd still tweak it and try to get both springs the same tension. Otherwise the softer spring is getting worked more and will fatigue sooner which will throw off the timing again. Try using lighter weights on the softer springs, or heavier weights on stiffer springs. Experiment some more, I bet you can get it better. Aim to have all the advance in several hundred RPM below your normal top end use.