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Hey guys, ok so I went racing this weekend past for the first time this season. It was very disappointing. Over the winter, I replaced my broken tranny with a new MMR pro 750 and one of their built clutches, and I must say WOW....amazing pieces. They worked flawlessly....however..the suspension let me down.

My car is a full bodied 94 GT. It has lakewood 70/30's in the front, and MMR Drag coil overs. In the rear it has lakewood 50/50's, oroso trick springs and a bag in the right spring w/ 20lbs of air in it.

I took off the quad shocks as the 60's were terrible like 1.8-9's...lame.

Brand new M/T 28x11.5 et streets with 11-12 lbs in em.

Car went 1.66's last year with lowering springs in it!!! So this is not good!

My car went 11.81 @ 120 this weekend, the same thing as last year, but now with a best of 1.75 60 foot.

What gives?? It seems as if as soon as the car weight transfers to the back, it then bounces all the weight right back to the front. One pass I tried to slip the clutch out (very hard I find in my car w/ new clutch) car picked the wheels off the ground, but then unloaded the tires and spun hard.

I'm losing my ET in the 1 and 2 gears. car has a 5700 rev limit, and it KILLS me, but car should still go fast. I need to get my shift light working, but my car's factory tach says im out of rpm as my rear bumper is just pasing the tree. My spotters outside say i am short shifting first way too soon, which I agree with as when i hit second, it boggs the motor down. I just don't understand why those BRAND NEW tires won't hold??? I was a very unhappy camper this weekend as I saw nothing from all the money I had spent.

Plan now is to adjust the front coils some more, and put stock springs in the rear. and if that still doesn't work, then put stock shocks in the rear too.

please help me, this was the worst weekend I'be ever had racing.

Chris
 

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Brand new M/T 28x11.5 et streets with 11-12 lbs in em.

Car went 1.66's last year with lowering springs in it!!! So this is not good!
My ET streets didn't start hooking good until about 5-6 good long 10 second burnouts. I'm hitting 1.74's with them, and I still haven't gone above a 4500rpm launch yet. They are still sticking. I'm running 10.5's, 14psi. 2nd gear burnouts(about 5-6 seconds), 3.73's.

Sounds like a suspension issue also.
 

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One pass I tried to slip the clutch out (very hard I find in my car w/ new clutch) car picked the wheels off the ground, but then unloaded the tires and spun hard.
New clutch? Maybe it hits too hard? Seems like everybody is overclutching their cars these days. Have you got a spec stage III or something ridiculous like that?

What is your first gear in the new trans? What was it before?

Steve
 

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Need to break the tires in more, the first burnout on them should have been a very long nasty burnout.

Put some stock V6 or V8 springs in the back and get an ARB....get rid of the airbag setup. What coil rate spring did you put on the front?
 

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Discussion Starter #7
The coils in the front are 200lb I believe, they are the MMR DRAG ones. Ya , i'll be sure to give a real good burnout on them next time I"M out, only have like 8-10 passes on them.

The clutch is a MMR RBT700, puck on one side and full face on the other, rated for 700hp, more than enough for me.

yeah, I have a brand new set of stock rear springs, and they are going in right away. I was told to keep the bag in though, as my car squates hard on the pass side, (then, in theory unloading the drivers rear tire )????

Whats an ARB stand for?? Anti roll bar I assume?

My trans has a 3.27 first gear, stock t5 was was like 3.31 or something??
Maybe I should have bought the pro900 with the 2.87 first gear?? It apparently required more servicing, which my car is a street car and didn't want that, but maybe i bought the wrong one,

my car has a 3:55 gear and the 28'' tall et streets, you'd think it wouldn't be a problem at the track??

Thanks guys, keep the ideas coming!

Chris
 

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stock t5 was was like 3.31 or something??
Chris
3.25 or 2.95 depending on model/year. V8 only. V6 and four cylinder models are different.

I am in the middle of rebuilding one, not trying to be picky, just wanted to share what little I know.
 

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i would also recommend you keep the air bag in, i have them and they do help, i also love that i can adjust the pressure depending on what tires i run and track prep.
 

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If you put in an anti-roll bar you don't need the airbags any longer. The airbag is a crutch. I still use one, but am finding more and more that I need to install an ARB myself (soon).

If it is rebounding, then the rear is not working right. Rear suspension on a good track should be somewhat stiff. If the track isn't hooking, you can loosen it up a bit, but then you face rebounding issues like you're having. I have adjustable rear shocks, so that helps control the rebound without the ARB.

The car squatting over to the passenger rear is not unloading the drivers rear tire. Actually it is the opposite. The tq of the engine is twising the rear end and planting the driver side tire hard into the pavement and making the car roll over, basically unplanting the passenger side tire. Putting the anti-roll bar in eliminates the roll over effective planting both tires more evenly.

200 lbs springs up front would be way too stiff. Typically a drag coil-over kit comes with 175 lbs springs as recommended. I am now running 130-135 lbs springs in the front of my car, but its pretty light up front being carbed and bumperless.
 

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I agree 200lbs is way to stiff, 150-175lbs should be a good starting point. I prefer 130-150lbs myself
 

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Also, like previously mentioned on the tires, they liked to be heat cycled and then let completely cool down before they start hooking good.
Every time I buy new slicks, I take the car up the road with a little water and do a good 20-30 second burnout in 2nd gear and smoke the hell out of them. Drive straight home and park it until race day.

They need to get really hot, then really cool.

Last time I bought a set, I had a race the day of. So I had the car/trailer at the tire place, got the tires/wheels mounted on the car and did a good burnout right there in the parking lot before putting it back on the trailer.
 

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ARB = Anti-Roll bar or a drag specific sway bar.
 
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