Drag racing Handling.

[craig_mr2_mk1]

I need some advice on my car as I took the car to USC this weekend and the car was deadly to drive! I usually use my car for track days and also to compete in the TSS and It's always handled brilliantly. This weekend at santa pod the whole car was completely unstable once I was into 3rd gear and higher. The front wheels felt as if they were aquaplaning and the rear end just felt as if it was going spin the car around instantly.
I've checked all the nuts and bolts are tight on the suspension and sub frame and there's no play in any of the components too but still the car was trying to kill me! It definitely was getting worse as the weekend went on too.

Anyone have any Idea's as I want to enter the Jap Drag Series @ Rotorstock.

[dawesy]

tyre pressures can have a deadly effect on drag handling. dont forget too that the 2 has very little weight on the front and when you launch all that weight goes to the rear, basically the car will be trying to do a wheelie (take a look at roy ashbys vid). ideally you want the rear soft and a lot of travel on the front wheels or a wheelie bar

[craig_mr2_mk1]

I started at 24psi (R888's) and dropped them progressively to 10psi. I don't think it was tyre pressure's that was causing it. My launches were pretty good, it was only when I got into 3rd gear the car got very hard to control. My best time was 12.0 and that was rolling through the finish! It felt just like a rear wheel was loose, but obviously wasn't.

[greeny]

It sounds like mine feels on slicks!

Sounds like something is a miss though on r888's, mine will get light on the top end but go pretty straight on dr's or r888's.

What's your suspension setup? Stock bushes?

[craig_mr2_mk1]

Stock bushes, Tein Coilovers, TRD ARB's, Widened track strut braces ect. I softened the rear shocks up and took off a chunk of pre-load off the spring too. I've had a bar in where ever I can get it and can't see any movement or anything loose. I'm going to get the tracking bars out tomorrow and see if something had changed since I set it up in March.

[mr2toby]

Off topic, but what bhp are you running? 12.00 dead is quick! What was your terminal trap mph?

[craig_mr2_mk1]

465hp Mapped by Ryan last thursday. 12 is ok, there's a easy 11.5 in the car if I could hold my foot flat for the 1.4 mile. Heres a video of one of my runs from the weekend. http://www.youtube.com/watch?v=DNl68EE718w

[teddybare]

nice run craig....now i know why i want a mr2 .. im a big drag race fan my e46 diesel runs nitrous and is fast but jeeze these cars can go when modded.

regards ted

[Quigonjay]

nice run craig....now i know why i want a mr2 .. im a big drag race fan

they pull nice wheelies too with enough power and grip

http://www.youtube.com/watch?v=Lg4AZAgjsc4

[teddybare]

oh i watched that only yesterday and loved the chap shouting fakin hell lol

[Al-sw20]

Check your alignment

[Quigonjay]

Check your alignment

gday stranger, not seen you about for a while

[craig_mr2_mk1]

Yea, I'm going to re check my alignment and get my wheel balancing checked over.
Thanks for the comments on the vid too.

[Driftlimits Performance]

Go see nath at century!!!

[Century Motorsport]

Sounds like your springs are too stiff and 10psi is too low!

Stick some rev 1 stuff on there and see what thats like

[craig_mr2_mk1]

I was softening the springs off after each run and I had 24psi in the rear tyres until Saturday afternoon. I do gave some std springs and shocks which I'll take with me next time I go to Shakey.
Why would stiff springs make the car do that half way down the strip when it doesn't do it on the track?

[Century Motorsport]

Trying to put too much through the tyres.. although I would have thought with road tyres this shouldnt really be a problem.

Go back to basics. Was it just under heavy acceleration or on a gear change?

What can move during the time the issues arise? If your tracking is wildly out it could be that. If you have play in the bushes it would be more severe when you lift off and get back on the gas.

How are you tracking the car? Are you doing it on full bump? These cars have a lot of bump steer so needs to be done with the cars weight on the wheels.

There has to be something up ... perhaps your bonnet mod isnt working right and your getting a load of lift at high speeds?

[craig_mr2_mk1]

It was only happening when I was in 3rd and 4th gear, when I had my foot too the floor and also when I let off until I'd slowed down again.

I've had a bar on all my bushes and all my suspension and there was no play or movement where there shouldn't be. The only thing I've found since I've got the car home is that there's a couple MM's of in and out play on the passenger side of the steering rack. I don't have any play in the driver side though.

I tracked it up on the floor with a square around the car just as we used to do on the FFord. I used some settings I found on here, Front set at 0 and the Rear 3mm towing in each side.

I was thinking it could of been my boot not being vented enough as I haven't fitted your vented boot lid, I just cut out the boot behind the light panel. I removed the boot for one run which made no difference at all.
We were thinking about the bonnet but by Saturday afternoon I was too annoyed to bother with it! I do have some sheet coming this weekend so I'm going to have a propper scoop built and cut the bonnet out a lot more.

[Century Motorsport]

Does sound a little aero related!

Have a good look at it!