WheelsUp84z

iTrader: (14)

About 6 months ago, the car would consistantly 60ft in the low-mid 1.5 range. Thats not great, but i'm a full weight 6 speed car on 28's with 4.10's. Lately my 60 fts have just been absolute crap, mostly in the high 1.7 to mid 1.8's. I went out and did a little inspecting of my rear end set up, my pinion angle is still at -2* which is good, but i've notice my LCA's are at 0* exactly. They are in the lowest hole of my LCA relocation brackets. My question is, is this hurting the car at all? Would raising the rear via the coilovers so that i have a positive angle (from the rear to the front of the mount) help out at all? I've tried everything as far as shock settings go from stiff to loose both front and rear, i'm running out of ideas. I dont think its the tires, they have barely 40 passes on them with relatively small burnouts, and the wear holes in them are showing at about 60-65% tread life still. It feels like the car is just blowing the tires off at the line. I've lowered my 2 step from 5200 all the way down to 3800 in various increments as well but still the same result.I dont even want to imagine what would happen if i tried to launch on nitrous... Here's some videos from the last time out, any help would be greatly appreciated.

http://www.youtube.com/watch?v=45O7ij9gSz8
http://www.youtube.com/watch?v=Z9P8w...eature=related
http://www.youtube.com/watch?v=XQy3x...eature=related

SSmoken

iTrader: (26)

well it appears youre spinning off the line in the videos. you cut 1.5's and then all the sudden 1.7's without changing anything??? could just be track prep if thats the case.

WheelsUp84z

iTrader: (14)

I dont know, the weather has cooled off since the heat of the summer when i was running better, but its been progressivly worse, not just one night out. And it has been on 4 different tracks in the area, not just the one.

Nitroused383

iTrader: (10)

Have you checked to see if your slip yoke is twisted? I was cutting 1.6-1.7 60' than next time at the track I could barely cut a 1.9. Turns out my slip yoke was twisted and binding up my suspension. The driveline needs to slide forward into the transmission when you launch as it pushes forward when your rear end compresses.

djfury05

iTrader: (30)

How was the pinion angle measured? relative to crankshaft or drive shaft? I will be setting mine up via the crank.

WheelsUp84z

iTrader: (14)

pinion angle...relative to the ground. Those other measurements are not pinion angle, thats driveline angle (DLA) etc.

nmass399

What psi cold do you run in the tires, and get someone to video from the back of the car close to see what the rear end is doing.

mel88643

Clutch type posi unit may be giving up. This happened to us with a new rebuilt differential with about 30 runs. Test with the rear end raised, One person would hold one wheel and other person will try to spin the other wheel. When it was new, they were locked tight. So we changed it to a locker. Its a little different street driving but no more tires blowing thru.
Hope this helps,,Good luck.

WheelsUp84z

iTrader: (14)

13 psi cold tire pressure, it has a locker in it now and both tires spin when it does.

nmass399

Mine spins bad at 13 psi cold, i normally run mine at 11 psi cold. You could try lowering it for one run just to see but it does not look like that is the problem.

Edit: actually looks like part of the problem or is the problem. I can run 13 psi cold at my home track and hook most of the time but when i go off somewhere it is almost always a problem.

WheelsUp84z

iTrader: (14)

Never did update this. I had a blown driver side rear qa1. It would stay compressed unless you adjusted it to full loose and then rebound. I ordered a new pair of Afcos and am putting them in as we speak. Letting the work light charge up some so I can finish the job.

SSmoken

iTrader: (26)

good to hear you got it figured out, but "sperm"?

WheelsUp84z

iTrader: (14)

Damn Iphone autocorrect...Speak is what i meant to put there LOL

Fbodyjunkie06

iTrader: (10)

iphone....right.....

WheelsUp84z

iTrader: (14)

made a few passes at civil wars with the afco's out of the box and their reccommended settings, 1.62 60 ft..a lot better! Car is still spinning on these crap QTP's, didnt get a chance to change anything for the true street competition (3 back to backs no changes) so i was stuck in the 1.6x's. And there were so many cars i didnt get any runs in accept those. here's a video, its deffinately transferring and staying there, just have to control my wheel spin, any suggestions?
http://www.youtube.com/user/SpeedJun...28/h7d3zeJMR38

djfury05

iTrader: (30)

Might be time to step it up with the tires.. MT ET Drags 3055s possibly. Or you can call Madman and pay him $75 and he'll tell you where to set everything at. Worth a shot.

Fbodyjunkie06

iTrader: (10)

Are those 26" tall QTP's? Or 27" tall? Might want to go with a 28" tire for more traction.

NC98Z

iTrader: (1)

Buy your AFCOs from Madman and the setup advice is FREE!

djfury05

iTrader: (30)

Yessir, that is the plan for this guy

AChotrod

iTrader: (17)

Thats what I did. Also got a bunch of other stuff from them too.