Car Popping Out of First Gear on Launch

[SirShaun]

I twisted and or broke my rear pretty bad on Thursday. See http://www.svtperformance.com/forum...or-not-to-Track-it-that-is-the-question!-WWYD

I never got a good run in because the car kept popping out of first gear on the launch and going into neutral. Has anyone dealt with this problem before? Is it possible I was just over powering the stock pressure plate? I figured the clutch would slip if anything but nope.

I even tried holding the car in first but it was coming out with enough force to make it difficult. I broke before I had a successful run.

I'll even post a time slip which shows a good representation of how my night went . 4+ second 60fts because neutral. I know it's 6 second capable if it would just stay in gear. This is me trying to find 1st after neutral all night.

 

[tktlwyr]

Too much traction!

Sorry to hear this happened to you. The same thing happened to me at the first MM&FF Mod Motor Shootout at Englishtown back in 1999. I also had issues with the axle tubes (and a whole bunch of other parts).

You need to change your set up to allow the tires to spin at launch or slip the clutch.

 

[SirShaun]

Build the rear and leave harder lol!?

 

[tktlwyr]

Build the rear and leave harder lol!?

Everyone talks 9". It's bigger, heavier and slower. A built 8.8 is plenty strong...axles, cover/gridle, a good posi unit and weld the tubes. When mine dead hooked at a 7,000 rpm launch and damaged everything, the 31 spline axles, gears and Detroit locker were all fine. The axle tubes shifted, upper control arms and drive shaft bent and sheared the output shaft of a Tremec. This was in my 1998 Cobra running on 26x10" slicks and 4.56 gears. It was an expensive lesson. Track prep at Moroso/Palm Beach was not nearly the level I experienced at Englishtown.

As for now, you can start by airing up the tires and slipping the clutch to get it moving. 325/50-15s are a BIG tire. Drag radial tech has come a long way from when the shop I worked at was testing the original DRs for BFG. You would be fine with a 275/60-15 and probably run a little more MPH.

 

[ShelbyGT5HUN]

How is having too much traction, the cause for it popping out of first?

 

[tktlwyr]

How is having too much traction, the cause for it popping out of first?

Because you're shocking the driveline when you dead hook on launch and the force of the rotation on the internals was causing the transmission to pop out of gear. The weakest link WAS the transmission until your axle tubes shifted. I've got videos of mine doing the same thing before it let go.

 

[ShelbyGT5HUN]

Because you're shocking the driveline when you dead hook on launch and the force of the rotation on the internals was causing the transmission to pop out of gear. The weakest link WAS the transmission until your axle tubes shifted. I've got videos of mine doing the same thing before it let go.

I'm guessing the OP is running the stock shifter POS. There is no way, with my MGW Gen 1, that it's poppin' out of any gear!

 

[SirShaun]

I'm guessing the OP is running the stock shifter POS. There is no way, with my MGW Gen 1, that it's poppin' out of any gear!

Definitely running the stock shifter. I was really leaning towards saving up for a 9 but I have been talked into building a 8.8. Currently trying to find a 8.8.

Built 8.8, Mcleod RXT, and MGW shifter all on the to do list before its back on the road. Also going to give a 275 tire a go. It's going to take me awhile. At least I can stare at it as it sits on jack stands for awhile.

 

[tktlwyr]

I'm guessing the OP is running the stock shifter POS. There is no way, with my MGW Gen 1, that it's poppin' out of any gear!

Trust me. It's not a shifter issue. If it was, it would be happening routinely and not on the track when trying to launch on 12" wide drag radials.

 

[GT500RedStripe]

Definitely running the stock shifter. I was really leaning towards saving up for a 9 but I have been talked into building a 8.8. Currently trying to find a 8.8.

Built 8.8, Mcleod RXT, and MGW shifter all on the to do list before its back on the road. Also going to give a 275 tire a go. It's going to take me awhile. At least I can stare at it as it sits on jack stands for awhile.

Here is an 8.8 close to you. Keith is a great guy!

http://www.svtperformance.com/forums/showthread.php?1077466-Rear-axle-out-of-07-gt500-with-extras-!!!&highlight=

 

[ShelbyGT5HUN]

Trust me. It's not a shifter issue. If it was, it would be happening routinely and not on the track when trying to launch on 12" wide drag radials.

Ok, so if I trust you, what is the fix, if traction is the problem? What shifter are you using? Thanks

 

[SirShaun]

Here is an 8.8 close to you. Keith is a great guy!

http://www.svtperformance.com/forums/showthread.php?1077466-Rear-axle-out-of-07-gt500-with-extras-!!!&highlight=

Thanks a million. Looks like I may be scoring the 2013 rear he has. Already has Tru Trac, FRPP Cover, and hes going to weld it for me. I think he's even going to finish building it for me with 3.73s and some Axles. You the man RedStripe.

 

[GT500RedStripe]

Thanks a million. Looks like I may be scoring the 2013 rear he has. Already has Tru Trac, FRPP Cover, and hes going to weld it for me. I think he's even going to finish building it for me with 3.73s and some Axles. You the man RedStripe.

Keith is "Da Man"! He also has a dyno and does my car and lots from our MACA club. He works with Lund doing live remote tunes.

His GT500 is BAD ASS so he knows what we are dealing with since he's an owner too.