DiabloFormula

iTrader: (58)

I was down at the track (Cecil County Dragway) this past Saturday and run a new best of 11.58@120 with a 1.69 60FT, before that the runs were ranging from 11.7-11.9's. My new best was with my tires PSI at 12PSI and my 2 step at 5K, and my Eibach Drag bag at 10PSI. Almost every launch I did that day had a huge BANG on the launch, but I was still cutting 1.7 60ft too. Here's a basic setup of my suspansion.

MWC Fab 9" TQ arm pinion angle set at -2
Comp rear shocks set at 50/50
Eibach prokit drag launch springs and air bag set at 10psi
shock front shocks
Aftermarket panhard bar and control arms

I'm triing to figure out what would cause this bang, wheather its the new comp shocks which is the only suspansion part I changed for this season, I've read that people are pretty happy with 50/50 on these supposedly. I'm also running a spec twin which grabs like hell but it was in last year and didn't make anything bang like this......also could it just be a by product from using the 2 step now, considering my foot is to the floor as opposed to just hoving at an RPM and human error on launches (slow gas pedal down, slow clutch pedal up).

Vid Added....

http://www.youtube.com/watch?v=sePvnSDqir4

http://www.youtube.com/watch?v=2V1MHuTLjq8

JL ws-6

iTrader: (50)

Tranny mount torn? Motor mounts shot? Exhaust hitting the rear? Rear hitting the floorboards? Ujoints in the driveshaft getting loose? Bolts loose somewhere? I'd look at those things first, I'd suspect that one of those is probably causing the problem.

BlackScreaminMachine

iTrader: (17)

^ That and you going to have to visually look for any sign of rubbing or hitting. My BMR TQ arm had to "Clearence it self against the body of the car, been fine since.

94Z28rag

iTrader: (10)

I'm gonna bet trans mount.

DiabloFormula

iTrader: (58)

Checked all that and everything is tight and in it's place.


Added a vid of one of my launches.

DiabloFormula

iTrader: (58)

Added another vid....at .40 you can see a slow motion launch from the rear, which shows my pass side tire spinning and my drivers side hitting hard and you can also see the rear and pretty much everything under the rear of the car shaking, any guesses, I'm still running a stock rear sway bar and I know this perticular day my air bag was at 15 PSI.

camscam02

iTrader: (21)

Needs more air in the bag or a real sway bar on it. It squats hard on the right rear and moves right. Also make sure the rear is centered in the car and front to back, make sure everything is tight and go from there.

Thats what i got from your vid.

omcar

iTrader: (10)

i would vote for a rear sway/drag bar set-up from like BMR/Spohn, etc. That will plant your tires evenly. Also, adjustable front shocks and lower control arms relocation brackets.

mad_steve

iTrader: (2)

Give me a call at the shop. I may have a solution for you, and can also get you hooked up with a new rear sway bar. Our number is 225-673-3533.

JL ws-6

iTrader: (50)

Lose that friggin blue tape too, that's

ssvert99

iTrader: (26)

great to see you got a pb, but there are a few things the car needs. Front shocks and a sway bar for sure... I have an adjustable tube chromemoly anti-roll bar that bolts to the Midwest fab rearend. call me and I'll get ya taken care of.

not sure about the bang but i'd look for contact somewhere... top of torque arm over rearend maybe? if no then maybe exhaust pop from the two-step? wouldn't be a bad idea to check the driveshaft slip yoke for twisted splines also... M6 cars are hard on them.