samirali

Hi guys. Before I get flamed, I did try to search this but didn't come up with any satisfactory replies.

I am taking part in an autox this weekend in Prepared category. I have a Mazdaspeed M'z 2007 model which came with Bilstein Coilovers. I have to run slicks to be competitive and the only set I can get hold of are slightly used Hoosier A6 255/35/18 rear and 225/40/18 front. I am in Pakistan so there isn't much choice as importing a new set will cost an arm and a leg and take weeks.

Will this set up be ok for autox. The guy selling these used them on a RX-8 before and crashed (hence he is selling them). This makes me nervous about using them.

TopGear8

iTrader: (3)

They will be fine, would 255 all around be faster? Yes most likely, but will a staggered setup make you crash...No only you will make you crash. Staggered setup is just going to give you more understeer than you will desire.

samirali

Haha, yeah I get you TopGear8! The thing that worries is that in an autox you are pushing hard and with this setup, I expect to get understeer right up to the point the rear breaks loose and ends me up in the nearest wall.

godesshunter

If the people setting up the course know what they are doing, they wont put any sharp corners near any walls. That supposed to be the glory of autocross. low risk.

Sparky

I'd put the 255s on the front. That's normally where i'm traction limited.

TeamRX8

iTrader: (25)

If the vehicle begins to understeer you either have to reduce the steering angle and/or reduce speed. Either you as the driver are in control of the car or you're not. Don't try to defy the laws of physics and you will be fine.

samirali

This is where we autox. Walls and pavements are never very far away unfortunately.

TeamRX8

iTrader: (25)

What is that banging around noise in the interior?

samirali

Not sure. I've heard similar sounds in quite a few in-car autox videos. It coincides with the car's weight shifting right and left.

EricB

iTrader: (7)

water bottles?

definitly sounds like something is in the trunk since it coincides with the cars weight shifting. water bottles?

godesshunter

sounds like some junk rattling around in the center console.

TeamRX8

iTrader: (25)

It sounds like something loose banging around. If you can hear it while driving it is likely distracting you whether you realize it or not.

Junirol

iTrader: (24)

lol looks like a sketchy place to autox. Very tight course, as far as staggered set I don't really see anything wrong using them, as teamrx8 said, its all in the drivers mod. Only bad thing is you can't rotate them.

samirali

The video isn't of me driving. Its the guy who won in A-prepared category. Have no idea what is banging around in his car. I just put the video up to show how tight the course is.

samirali

Thanks for all the feedback. I am leaning towards getting the staggered set. Will putting on a lot of camber (3 degrees) and a bit of toe out on the front help counter the understeer?

Junirol

iTrader: (24)

Negative camber will give you more grip around corners/turns, not sure about adding toe out. I know messing with toe can lead to excessive tire wear. I think toe out will want the wheels to pull away from each other, it will want to dart in the direction you want to turn, also straight line stability maybe affected. Sounds like a good thing but I wouldn't mess with toe, just learn to drive better .

samirali

So I used the 255 Hoosier A6s on the back and 225 on the front and it worked great! The good news is, I won in my category. Here's a pic of the run which clinched it by a difference of 0.11 of a second between my time and the 2nd position.

TeamRX8

iTrader: (25)

Mubarik ho samirali, yeh bahut achi khabar hai

samirali

HAHA! Thanks TeamRX8. You speak Urdu very well