OK, I have a 1979 Corvette, with and L48 and a automatic transmission. It has stock heads and carb (tweeked by LARS), Edelbrock Performer Cam and intake. I also have Dynomax headers. With this combination, I was able to push this 3640 car (and driver) to a best ET of 14:03

This past winter, I've installed an MSD-6AL complete with a set of 8mm MSD wires, new Rapidfire Plugs, even added a 3 Step for safety. I also had the transmission rebuilt and added a shift kit, then I installed a new TCI Streetfighter converter.

Having made those additions, I decided it was best to install a set of slicks. So I did 26 x 9 x 15 Hoosiers which I ran today at 13 psi.

The big problem was my times and I'm still looking for almost 6 miles an hour I lost. After running 14.0's last year today I have 14.23, 14.25, 14.27, 14.23, and then 14.10 just this evening (better air) to force my breakout.

The estimated stall of this converter is a between 3000-3500 rpm. With my sorta stock setup, should I be looking for a better cam to match this converter? Or do I just need to learn how to drive this setup. My 60' times at 2 tenths better than last year but everything else has me scratchin my head.





[Modified by Indynut, 8:20 PM 6/27/2004]


[Modified by Indynut, 8:22 PM 6/27/2004]

 

Yes, you can run a lot more cam w/ that converter.

 

That's a pretty steep stall speed for a performer cam? I mean that cam was designed for street/stock stall speed. If thats the only problem part here then maybe your losing some of your effective power range/rpm at the low end? But you didn't post your rear-gear ratio or the previous tire size. Well 0.2 faster out of the hole but 0.2 slower at the end means your either running out of breathe (but no engine changes) or wheels are spinning slower at top speed. If you've gone to a shorter tire I can see this hurting things too - maybe .
I'm starting to think thats why the new corvettes are so much faster on about the same power is they match thier gear ratios to thier power band and optimize what they got.
How about having the distributor curve checked and optimized on a machine? Should be less than $100. Try lars tech tips for setting up advance?
And for stock heads I like Iskenderian (Isky) Mega Hydralic cam with 108 lobe separation angle. And you could run any duration you want with that stall-converter. That 108 LSA will tighten up your power-band but use thier website to choose a duration that matches your gear-ratio.
Just trying to help. cardo0
Hey try a post in drag racing section of forum.

 

Im not sure if you are looking for better times or what, but i would be looking for something different than just a cam. You already have a cam, so i would look at new heads, which can drastically increase your hp. On the other hand, if you are only looking at a cam, yes you can run a bigger cam, somthing close to .5 inches of lift, lots of people run xtreme including me, and it works well, but since your valvetrain isnt modified i wouldnt suggest it, look at the series comp cams have that is for stock valvetrain with better lift and durations.


[Modified by billlambeer, 1:24 AM 6/28/2004]

 

Sounds like a pretty loose converter for your combo. If it stays on the converter (slipping) too long it can kill a lot of E.T.

 

Well cardoO,

I'm running the 3.55 rear gears and the T/A's I ran last year were P255-605-15 which I think were 27inches high.

So this could be a part of my problem.

Now, I'm supposin that in order to get my lower ETS and higher MPH's I'm gonna be lookin at a better suited cam, and likely a set of bigger slicks. This may have to wait awhile for my play budget to recover.

 

Also a bunch of MPH on a street car! I have tried everything from 7400 to 8400 converters on my SS/DM and actually ran faster with the 8400 (all 7") but I make the 1-2 shift at 9400 to get back on the converter a little more for torque multiplication and it recovers faster and then the 2-3 shift at 9600 for less slippage.

 

Good hints from all the guys who responded, personally I'd look at a pair of heads. A good set of heads with that Performer cam can probably get you 40-50 hp over your stock L48 heads. A bigger cam won't gain you much if you heads can't get the air and fuel in and out of the engine.
If cost is a problem then look at some used L98 heads, the 58 cc heads will raise your compression a couple of points. L98 heads are pretty cheap, they aren't the best flowing but they are pretty much a bolt on for you engine. Vortec cast iron heads are cheap and are probably better performing than the L98 heads, but they need some modification to the springs and valve guides, to use anything other than a fairly mild cam. They also require a Vortec special intake.
Good Luck!