I ran my Crossfire at the Thunderhill Track. It was fun but it understeers badly. It was no fun having the Miatas waiting behind me in the turns. I slowed down and pulled over in the straights so they could pass. That really hurt. What can I do to reduce the understeer? Thanks. Vince

 

There are a couple track guys on here and hopefully the'll jump on. You should also post this on the Racing sub forum, they might see it sooner.
I don't track but I do autocross. I'll add
more later when I'm not on my iPhone with a sleeping pill kicking in. Racing tires, correct pressures (lower in back higher in front if I'm remembering correctly) and add some negative camber. And I've recently learned to weight the front just before, can be done during, the pushing. Then steer the front through the turn with the throttle (a little bit of drifting if you will)

 

I have to agree. Last time I pushed the roadster in some 90 degree weather, it was really bad, but going in hard, brake and throttle thru helped a bit...but Miata's will corner better, no doubt there. The trick is to stay out in front of them...lol...

 

Yes, the Crossfire is a car that understeers a long time and then the back comes very hard.

First tell us something about your car.
Did you drive with ESP on, or "off"?
Is everything stock concerning the chassis? Other springs (lowered), other shocks?
Other tyres, or wheels? (What dimension?)
How old are the tyres?
Do you run other tyres in the front, than the back? (brand)
Are the tyres in the front older than the tyres in the back?
How about the profile of the tyres?
Do you use spacers? (Front, or rear?)
Did you modify the camber?
...

 

10 mm spacers on the front (hub centric please) will help and is cheap and easy. (widen the track which also gives more - camber) The best thing to do is learn how to drive a car that oversteers. If you fight it, you will stay slow, accept that it pushes and learn how to go fast with that condition. You know what I mean, like learning to drive a FWD. You must do certain things to be fast. One thing that works for me is lightly braking into the corners to add weight to the front and inducing more grip. If you are too hard on the brakes you will just go straight so practice is necessary but it works. The other way is brake early and be on the gas throughout the entire corner. Again it takes practice and works better on slower corners, but you can steer with the throttle by making the back slip more than the front. Drift technique if you like ..... again it's easy to get it wrong. I imagine the real experts do both. Trail brake and throttle steer. I've done it right before and blown it before. Practice is key. On a side note, any Miata will outbrake you because of their light weight. They are as fast as anybody in the corners with decent rubber. The best you can hope for is to be nearly as fast and pull 20 lengths on the straights. There are other things you can do but it's better to learn how to go fast with what you have first. It will make you that much faster when you improve the car ........ I made mine worse before making it better, be careful what you change.

Les

 

Thanks for the reply. Yes, I drove with esp on.
Everything is stock, including the tires. <18k miles on car.
I didn't modify the camber and do not use spacers. (not sure what they are)
I have never had it aligned, but I'm considering changing the camber from factory -1.22deg to -1.6deg. What do you think?

 

Hmmmm..... to some degree at least it must be the way you're entering corners, maybe too hot? Last time I had my Crossfire on track (also stock tires, alignment, etc at the time) I managed to hunt down a Spec Miata racer running R-compound tires and finally over take him. Yes, he schooled me pretty well for a couple of laps, but once I figured out how to stay with him in the tightest sections of the track I just powered by him on the main straight and that was that.

I used to have a tendency to enter corners too quickly and I think that had a lot to do with the car not wanting to turn in as well.

 

guilty Mike. In law enforcement, we tend to hit the corners hot, stab brake, turn...that doesn't work as well with the XF as I have found out. I now come in hard, brake, throttle/brake out, accelerate and after awhile you get a rythem going. But, I don't get much track time anymore, nor have I done much with the XF in that regards.

 

I have yet to get my week old SRT-6 on the road let alone the track but my intuition would be the same as others have mentioned. A Miata has a significant weight and handling advantage. But, an SRT-6 will annihilate them on a power to weight ratio. So use the tools at your disposal. Brake hard, use trailing throttle oversteer to initiate the turn in, and finish with the throttle to keep your attitude balance. My 2008 S2000 is much like a Miata (with more power) and I'm pretty sure the SRT-6 would smoke it around a track once I get used to the suspension setup. You need to get comfortable with alternative methods of steering the car.

Also, you mention "stock tires". Would those be the Conti all season tires or the optional Michelin PS2 summer performance tires? If they are the all season Conti's, you're at a huge disadvantage on a track if everyone else is running race tires or extreme performance street tires. Even if your car has the Michelin summer performance tire option, those tires are ~5 years old now and they have 18,000 miles of wear under their belts (pun intended). The rubber has likely hardened. And the design has been surpassed by newer tires. You can make a huge change to the car's grip with a new set of Conti Extreme Contact DW, Dunlop Sport Maxx TT, or Bridgestone RE-11.

You may want to look at an alternative alignment ultimately but that decision likely comes with increased tire wear off the track.

 

Thanks for the replies guys.
I have the standard xfire.
The tires are Contintental Sport Contact 2.
OK, I'll start the turns slower and carry a little brake into the turn to keep more weight on the front tires.
When the camber adjust bolts arrive I'll have it adjusted from -1.22 deg. to -1.6. Seems to me that less understeer can only help.
Two of you suggested using "Trailing Throttle Oversteer". That's new to me.
I would appreciate someone explaining, in as much detail as possibe, the proceecure for that. Meanwhile I'll search it on the web.
All of your help has been and will be appreciated.
Vince

 

Also known as "the car tried to kill me", trailing throttle oversteer can be the bane of every unskilled driver or it can be another tool in your bag of tricks. It's simply coming in hard to a turn. When the front end starts to plow a furrow off the track, lift....carefully. The back end can be made to swing out a little or a lot thereby correcting the attitude of the car. Once you get back coming around, use throttle and steering to keep it balanced until you come out of the turn. Done properly, trailing throttle oversteer can be used for minute course adjustments rather than tire smoking drifts through the corners. Done improperly, the usual lament is "the car spun out for no reason".

And I should mention that it's most useful with cars that have neutral to mild understeering behavior. There are no tricks to save you coming in hot to a corner in a plowing pig like a Camry or the family SUV. Physics will not be denied. You will go off roading.

And, sorry to say, with a regular Crossfire you may have a hard time in a fight with a Miata. The little buggers have a 700 lb weight advantage and they are very well balanced cars. Don't underestimate the cute little secretary's car. An SRT-6 can compensate for weight and finesse with raw grip, power, and torque. You'll need to be very smooth in a base Crossfire and carry as much speed as possible through turns or they will eat you up.

 

tires are real important, as I don't care for my goodyears, so I will go a different route when they wear out. As for my coupe, it had new A/S on it, so it will be awhile before we change them out...so no track time for it. It takes some real work to get used to trying to corner this little car...I need a lot more track time to figure it out...but, have only been schooled by those who do it all the time...I stay with most others...