autocross tomorrow, yeah yeah!!

[brocklanders]

I'm taking the uno to the autocross tomorrow. I finished sixth out of nine last month which was my first time, against mostly m3's. Last time my game plan was to not crash, this time I'm going to go for smooth and clean. Although I did get my best time when I was plowing into the corners.

[JimD]

I've only done autocrosses in my bimmer at the BMW performance center. The instructors will break out the M cars and give fun rides. I find these rides much more valuable than the walk through our practice laps. I can't drive like those guys and my car isn't as fast but it's helpful to know how hard you can be on it through the corner without loosing it. If you have an opportunity like that, I would take it.

They get really upset if you hit a cone in this autocross so it isn't a good space to push real hard. But it's fun to try to go a little faster each lap. I don't do great either but I have fun.

[edisapimp]

Good luck! Let us know how she performs!

[lastMleft]

Sounds like a blast, have fun

[Helltime]

Have fun! The only "autocross" I have participated in is at a go-kart track (big enough for cars, but not a full on road course, and don't have to worry about getting lost in cones) and it was a blast. Also discovered my car needs LSD VERY badly.

[brocklanders]

An lsd would be nice but after doing my shocks, springs, bushings, and sway bars my opinion is these front tires are entirely to skinny.

[mike@x-ph.com]

Good luck !!

[brocklanders]

The high numbers of the day were 42's, the tops in my class were 44's. A guy in an e92 m3 was in the 46's, I ran a lazy lap the first time and got 53, followed by a 49.8 then a 48.6 and a flat tire end of my day. I was really hoping to get in the 46's by the end of the day, but I had fun even if the day was cut short.

[chris82]

Originally Posted by brocklanders

An lsd would be nice but after doing my shocks, springs, bushings, and sway bars my opinion is these front tires are entirely to skinny.

What size do you have? I find I could use some more. I have 215 in front.

[brocklanders]

I bought my car in March and now has 7k miles, I won't buy tires till these go bald which will be soon. So I have 215's also, what the hell was BMW thinking a sport compact car has wider tires then that. I had made a comment in an earlier post about plowing into corners, I think these front tires had a lot to do with it. I would like to buy two rear wheels and go with 245 square, but we will see when the time comes.

[JimD]

I went square with Michelin PSS tires when my rears wore out. I am happy with them but haven't done an autocross since.

Times on the BMW Performance Center (PC) course, laid out with cones to slow you down in an autocross, are around 90 seconds. The winning time each year I've done it has been a little under 90 seconds. The instructors fun rides, with 4 or 5 people aboard, are normally just under 90 seconds, within 5 seconds of the winning time. I was about 100 seconds the last time I did it. There are a lot of people between 90 and 100 seconds with only a few under 90. Occasionally somebody goes over 2 minutes.

Without cones in the big turn at the BMW PC we did about 100 mph at the M school I attended. That's about the fastest part of the course. Maybe you could go a bit over 100 in a straight. But laid out for an autocross, we peak around 70mph. One guy claims to hit 80 but I've run it several times at about 1:40 without using 3rd gear. That means I didn't exceed 60 mph (buyt I hit the rev limiter pretty hard). When I use 3rd in a couple places, I maybe get to ~70 mph (but don't necessarily pick up time, smoothness counts).

[Kgolf31]

You need some 245s in your life.

Still trying to figure out how to fit 255 RS3s.

Currently running 245 RS3s. Which the tread width is comparable to a standard 255 Tire.

[dans135i]

Originally Posted by brocklanders

I'm taking the uno to the autocross tomorrow. I finished sixth out of nine last month which was my first time, against mostly m3's. Last time my game plan was to not crash, this time I'm going to go for smooth and clean. Although I did get my best time when I was plowing into the corners.

Sounds like you had fun! Just a quick note: If you mean plowing as in pushing into the corners you are entering way too fast , that is actually slower and you are scrubbing off speed when you plow into a corner. Slow in, fast out. Someone mentioned ax isnt good to push? That is the best and safest place to push and determine the limits of the car and the driver. If you take out a line of cones and more than once , you get a talking to but thats it. The corner workers arent too happy either . Just my .02...

[brocklanders]

I was definitely entering to fast, when I say plowing I mean it in the literal sense, going so fast that at full turn the car is still going straight. That is where I made the best time though, that's why I believe the tires are my weakest point, not just the compound but the width.

[Kgolf31]

E82s in stock form are push pigs.

[scoobysnax]

Originally Posted by brocklanders

I bought my car in March and now has 7k miles, I won't buy tires till these go bald which will be soon. So I have 215's also, what the hell was BMW thinking a sport compact car has wider tires then that. I had made a comment in an earlier post about plowing into corners, I think these front tires had a lot to do with it. I would like to buy two rear wheels and go with 245 square, but we will see when the time comes.

It's definitely ridiculous the 135i came with 215 width front tires--I had those on my old IS300!

Here's how I managed to kill the front OE Dunlops in less than 10k miles. About a dozen autocrosses and a car control clinic later:

Front driver's side got the worst of it:

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Front passenger side:

View post on imgur.com

[JimD]

While on a hot lap with an instructor from the BMW Performance Center I commented that it seemed like he was sliding a little in the turns. He indicated he was and that maximum cornering comes with a limited, like 5% slipping going on. So they deliberately hit the corners hard enough to slide just a little. Cars are all M cars that they drive so they are more neutral than my stockish 128i.

So it's OK to slide (or plow) just a little and it will reduce your time to do so. But the amount of slippage I experienced in these rides (I've done the hot laps at least half a dozen times) was never enough the instructor lost steering control for more than a split second.

Those dunlops look like they needed more pressure - seems to be scuff marks well up on the sidewall.

I run 225s on the front of my e88. That is all that the stock front wheels can support. Wider would mean new wheels. For my casual, occasional, autocross, this seem OK to me. If I ever get the time to get serious, I may indeed need to look into new wheels and wider tires.

[scoobysnax]

Originally Posted by JimD

Those dunlops look like they needed more pressure - seems to be scuff marks well up on the sidewall.

Yeah, I had them at 44 psi hot at a couple of events, and they still rolled!

[Kgolf31]

Tires like that just aren't meant to take the abuse. Plain and simple

[scoobysnax]

Honestly, I think the OE runflats get a lot more crap than they deserve. They're not completely terrible like generic Chinese tires (low bar, I know), but I was getting some respectable times with them, which reinforces the point that the driver is the most important thing to improve first.

That being said, having upgraded to Direzza Z2's are night and day.

[DietTab]

All the pressure in the world wont fix the roll you get with no camber. I delamed a couple runflats before I went to 255 RS3s all around.

[JimD]

I didn't scuff up my sidewalls that bad when I ran on my run flats. But my times were not that great. But my Michelins are much stickier tires. I hope I don't chunk them but I plan to use them in an autorcross, hopefully soon.