black_ws6

Guys, I really need some help diagnosing my car. Here is a quick rundown of the past year.

I had a TR220 cam, LS6 intake, ASP pulley, LT's, lid, loudmouth running the stock Goodyear F1's and I ran a best 12.75 @ 113.74 with a 2.0 60'

This year I have a TSP 231/237 cam, ported and polished TB, MT ET street radials, and all of the other bolt-ons from last year.

I have been out to the track twice and the best I could run is a 12.70 @ 111.89 with a 1.95 60'. With 376RWHP from this cam, shouldn't I be at least around a 12.4 @ 115 or so?

Here is my dyno graph. I can give any other info that may help. I am thinking the 3.42s are hurting me or my clutch isn't holding that great. Any thoughts?

Roarin_8

iTrader: (5)

I'd say it's the clutch. Even with stock power, that clutch screams when pushed to it's limit.

Villain281H

iTrader: (5)

traction, clutch, and your shift points/technique are all areas to examine. Keep in mind rwhp doesn't mean anything unless you can apply it. A lot of you time loss is in the 60 foot. My Nova only makes 379 rwhp and runs the times in the sig at 3500 lbs raceweight, so if you get it all hooked up, 11s should be attainable!

Good luck!

Derek

BlueSix

3.42's are killing you, if the clutch is slipping that's also hurting you. Your 60' isn't helping also. What rpm are you shifting at?

black_ws6

I dump the clutch at about 4500 on the launch and the car hooks, then just dies.

I have my shift light at 6300, so probably around 6400-6500 right when the HP starts to drop off.

I am leaving it in 3rd through the traps because I think i am too close to shift to 4th, but I am past the shift point before the traps so I may be losing MPH because the RPMs drop off.

rebersole2

Experiment with your shift points (higher rpm's in your case), the gears are definitely killing you and maybe the clutch as well. I have to agree with Derek on the power to traction issue, if you can't get it to the ground it is useless. I estimate my car has 275 horsepower, but a fairly efficient drivetrain and a set of DRAG SLICKS for traction. If you are DRAG RACING, use DRAG SLICKS for traction.

Villain281H

iTrader: (5)

I'm guessing closer to 310-325 rwhp b/c that's what mine made when I ran 12.0s at 111 mph at 3400 pounds.

Derek

BlueSix

Dead hooking on 3.42's is killing you. That cam needs at least 4.10's to really shine, the gears will also keep the car from bogging which is what it sound like yours is doing at the line. Shift into 4th and see what happend.

black_ws6

That pretty much sums it up. The car hooks pretty well then falls flat, very flat. I am going to try shifting a couple hundred RPMs early so I have time to shift into 4th, just to see what happens. I do think my next mod will be 4.10s. Then bigger injectors. I am probably pushing the 26lb ones to their limit by now.

UL LOSE

Get 4.10s,shift when your supposed to,get drag radials. And go run low 12s. You cam is dying for those 4.10s! Shifting into a higher gear doesnt really mean its gonna stop pulling hard. Depending on the torque curve it could very well pull harder when it hits the next gear. More rpms doesnt exactly mean your still making power but just spinning the engine past its desired redline.

BlueSix

Don't shift at a lower RPM in the lower gears just so you can get into 4th. I would also try varying your shift points, that cam may like to be revved higher than 6500. Get the 4.10's and find out.

glennster

iTrader: (1)

Get 4.10's and shift at 6200/into 4th.I know people on here scream to shift at 6800 but my B-1 bolt-on gets shifted at 6100 and runs whats in the sig.Just think how long a motor will last at that rpm level.Yes,I've tried higher with little gain.

UL LOSE

Higher than 6500rpm? Sure the cam might like it but i seriously doubt the valvetrain will enjoy it.

black_ws6

I have my shift light set at 6200 since my dyno sheet shows power starting to drop at 6300 so I am shifting right around 6300-6400.

glennster

iTrader: (1)

I just saw your mention of injectors and you should be OK.My stockers are close but not maxed yet.

BlueSix

Yes higher than 6500, as long as he's upgraded accordingly there's no reason the valvetrain can't handle it. Quite a few of the Stock Internal guys spin their stock valve train to 6500 rpm.

BlueSix

So you're saying that a 231/237 cam should be shifted at the same RPM at a 221/221 cam? Higher duration cams like to be revved higher.