first pass with my new build, 98 cobra+03 cobra motor+ Maximum motorsports goodies

[mustangcobra98]

So there I was..... At the track last nite. I got there early to get everything iced down and ready for some epic passes. most of you all know i've spent all winter attempting to build a 10 second daily driveable mustang even though it isn't my daily. So went and grabbed some 116 octane fuel and mixed it with my 1/2 tank of 93 in hopes of getting min of 105 switch to my race gas tune. then Iced down the supercharger and IC res, and anything else i could get ice on intake wise. Then dropped the radials down to 13 psi, and set the tokico d specs full light. let the car cool for about two hours then figured it was time. lit the tires up good. pulled up to stage. lights and Launch! car left the line HARDER than anything i've ever driven in my life! makes a loud pop. I stayed with it cause i wasn't sure if i broke or not didn't see anything outta the rear view. but something wasn't right. car fell on its face hard as i shifted to third almost like the rearend wanted to lock up. I'm pretty sure its something in the differential. the car still drives but not well and after putting it in the air and playing with the tire spin something is for sure wrong. Keep in mind its a factory GT500 diff. so heres the tail of the tape.

R/T: .424
60': 1.808
330: 5.113
1/8: [email protected]
1000' 10.26
1/4: [email protected]

any diff suggetions and reasons behind them?
deploying in august won't beable to do anything until then so plenty of time to research

for those that don't know I have Maximum motorsports Everything suspension, Kmember kit, rear torque arm and panhard bar lca weight jackers. 98 cobra with 03 engine steggy stage 4, and all the goodies,T-56 trans, solid rear 8.8 built with mossier axles, 3.73s and GT500 diff. :beer:

 

[alpha06]

So there I was..... At the track last nite. I got there early to get everything iced down and ready for some epic passes. most of you all know i've spent all winter attempting to build a 10 second daily driveable mustang even though it isn't my daily. So went and grabbed some 116 octane fuel and mixed it with my 1/2 tank of 93 in hopes of getting min of 105 switch to my race gas tune. then Iced down the supercharger and IC res, and anything else i could get ice on intake wise. Then dropped the radials down to 13 psi, and set the tokico d specs full light. let the car cool for about two hours then figured it was time. lit the tires up good. pulled up to stage. lights and Launch! car left the line HARDER than anything i've ever driven in my life! makes a loud pop. I stayed with it cause i wasn't sure if i broke or not didn't see anything outta the rear view. but something wasn't right. car fell on its face hard as i shifted to third almost like the rearend wanted to lock up. I'm pretty sure its something in the differential. the car still drives but not well and after putting it in the air and playing with the tire spin something is for sure wrong. Keep in mind its a factory GT500 diff. so heres the tail of the tape.

R/T: .424
60': 1.808
330: 5.113
1/8: [email protected]
1000' 10.26
1/4: [email protected]

any diff suggetions and reasons behind them?
deploying in august won't beable to do anything until then so plenty of time to research

for those that don't know I have Maximum motorsports Everything suspension, Kmember kit, rear torque arm and panhard bar lca weight jackers. 98 cobra with 03 engine steggy stage 4, and all the goodies,T-56 trans, solid rear 8.8 built with mossier axles, 3.73s and GT500 diff. :beer:

Did you do your swap? Any pics? I have an 89 Coupe with the terminator swap. Anyway, Sounds like something going on in you housing. Does your transmission feel okay? I would think your ring and pinion is broken.

 

[3rdplaceking]

Maybe a broke pinion gear tooth

 

[mustangcobra98]

maybe, I'm going to pull the cover off today. Im thinking its something with the diff, with the car in the air, its easy to hold one wheel by hand and spin the other side car still drives but getting a crazy sound. Yeah i have a build thread on here somewhere.

 

[Dark_5.0]

I run a pan hard bar, torque arm, LCA set-up as well. I knocked 3 tenths off of my 60ft going from radials to bias plys.

At least it is a minor repair. I would rather break a diff then a tranny or engine anyday.

 

[mustangcobra98]

I run a pan hard bar, torque arm, LCA set-up as well. I knocked 3 tenths off of my 60ft going from radials to bias plys.

At least it is a minor repair. I would rather break a diff then a tranny or engine anyday.

oh yeah me too! i'm kindof impressed with this break LOL, I'm overall very pleased with this rear set up as well. I see bias plys in my future too or atleast a 28inch tall radial with the same width. I got 315/35/17 mickey thomsons.

 

[Dark_5.0]

oh yeah me too! i'm kindof impressed with this break LOL, I'm overall very pleased with this rear set up as well. I see bias plys in my future too or atleast a 28inch tall radial with the same width. I got 315/35/17 mickey thomsons.

I could never hook on the radials. I spun way past the 60 ft and on the 1-2 shift. this was on 295/45/17's MT's. My best 60ft was a 1.81 and best 1/8th mile pass was a spinning 8.10 @93mph I went to 26X11.5X17 Mickey Thompson ET Street Bias-plies and on the first pass ran a 7.67 with a 1.63 60ft. Then I widdled it down to a 7.50 @96mph but I still spin at the top of 2nd gear.

In my experience the torque arm and a 5 speed works great with the Bias-plies and sucks with radials, but each car will be different.

 

[mustangcobra98]

hmmm interesting yeah i need to play with it more its a heck of alot better now. Um update pulled the diff cover off and theres nothing wrong with it?????? ok so im still getting a vibration so up the car on a lift and ran it i'm only getting the vibration during clutch engagement. ok that being said my drive shaft has hit my d/s loop all the way around it! and is showing signs of damage in the front of the shaft. My new theory my driveshaft is too short and under load the slip yoke is wanting to come outta the tranny. but I'm using stock 03 T-56, stock 03 shaft, and 98 cobra rebuilt solid 8.8. anyone else ever heard of this? I'm really confused. could my MM kmember be not square and that is causing this???? i think thats my theory now. still under investigation....

 

[Blk4V00GT]

Do you have an terminator pinion seal or whatever its called that the driveshaft bolts to the rear?

If so your driveshaft isn't too short unless its been shortened, all mustang 8.8s are the same other then different length tubes, wouldn't affect driveshaft length.

 

[mustangcobra98]

Do you have an terminator pinion seal or whatever its called that the driveshaft bolts to the rear?

If so your driveshaft isn't too short unless its been shortened, all mustang 8.8s are the same other then different length tubes, wouldn't affect driveshaft length.

I think my Kmember is too far forward in the car!!!!!!!! IDK how it happend but checking my measurements and i have a 102.75 wheel base from centercap to centercap. that is too much I think. Going to resquare the kmember and try again.

 

[whtcobra1998]

maximum motorsports k member and arms move the front wheels 3/4" forward, and the arms that have the extra forward movement of the ball joint go 1.5" forward