Auto-x tires

[619E30]

I am trying to get into autox and was wondering if 205/55-15 on 15x7 wheels would be alright for autox? And the car still has the stock m20

[Jean]

Tire model/brand is more important than size....but size is almost important as you need to be familiar with the class you are going to run in.

Have you decided what class you'll run in? Is it BMWCCA or SCCA?

[619E30]

I was thinking bfgoodrich g-force sport or yokohama s drives and bmw cca class

[Jean]

I am not familiar with BMW CCA autocross classes, but in SCCA different classes allow for different modifications including maximum wheel and wire size.

Tires such as Falken Azenis RT615, Hankook RS2 were a year or two ago one of the top two autocross STREET TIRES. New tires come out every year, and although G-Force and S-drive are good street tires, they don't exactly make a great autocross tire.

Find out what class you'll be in, sometimes mods you have done to the car force you into a class where an average or good strett tire is not going to be good enough. Then you start looking at dedicated set of wheels and DOT R tires ...

[619E30]

Yeah I've been looking at more tires and noticed the falken azenis rt-615's and was wondering if the 205/50-15s would be good to run?

[Jean]

Once again, look at the class and then select wheel/tire.

These make good / affordable autocross tires.

http://www.tirerack.com/tires/tires.jsp?tireMake=Hankook&tireModel=Ventus+R-S3

http://www.tirerack.com/tires/tires.jsp?tireMake=Dunlop&tireModel=Direzza+Sport+Z1+Star+Spec

[Wh33lhop]

I still want to shoot Hankook for putting that stupid flame pattern in the tread of the RS3.

There are a few classes of tire in the realm of track/autox.

There's the street tire class: Too many to list, but some relevant decent ones are the Toyo T1R, Falken ZE912, BFG G-Force Sport, anything all-season or without big blocks of tread goes here.

There's the "sticky street tire" class: Kumho XS, Bridgestone RE-11, Z1 Star Spec, Hankook RS3, RT615. In the big picture, these are suitable for spirited street driving with the occasional autocross/track day. More road noise and harshness than regular street tires. Typically these are between 140 and 200 treadwear rating, they will probably last you around 10-15k miles if your alignment is good and you don't abuse them.

There's the hybrid track/street class: Toyo R888 or RA1, Nitto NT01 are the only ones you need to know for an E30. These are more half trackday/half street driving tire. They will be pretty noisy and harsh compared to others, but still bearable if you like the grip. These are generally around TW 100, and may last you 10k miles if you're lucky. You will have to warm them up before they grip well and they will heat cycle out. I found a cute little video of the R888:


There's the semi-slick class: Bridgestone D01J or D03G, Yokohama A048, Bridgestone RE55, etc. You won't see many driving with these on the street, they are primarily meant for the track and driving to and from the track. Very noisy and harsh, you can drive down perfectly paved roads and they will still pick up rocks and stuff and make a racket. Most come in different compounds. They probably won't last more than a few trackdays.

Then there's the full slick class: Kumho V710, Hoosier A6, Hankook Z214, blah blah... this is a whole different ball game.

The class of tire you choose will matter infinitely more than whether you go with a 195, 205, 225 or with a 15, 16 or 17" wheel. The bottom line, though, is that you can have just as much fun autocrossing or tracking your car with shitty tires as you will with good tires, especially as a beginner still learning the limits of the car. If you try tracking 800 TW rating grandma tires, though, they will probably chunk up as they're not meant to withstand that abuse. But you should probably be okay for autocross as it is just a few short stints.

[CincinnatiKid]

Grassroots Motorsports did a new tire test late last year with all good tires, I'd choose one of these.

Here is a summary of times from worst to first.

6th - Falken RT 615 Mean time: 35.302 Sec Quick time 35.125 Sec.
5th - Dunlop Direzza Sport Z1 Star Spec Mean time: 35.209 sec. Quick time 35.061
4th -Toyo Proxes R1R Mean time: 34.522 sec Quick Time 34.452 sec
3rd- Bridgestone RE-01R Mean time: 34.478 sec Quick Time 34.430 sec.
2nd- Bridgestone Potenza RE-11 Mean time: 34.266 Quick time 34.238 sec.
1st - Kumho ECSTA XS Mean time :34.170 Quick Time 34.030 sec.

All tires were shaved to 3/32 nd and test performed on an Autocross set up.

I'm trying the Ecstas this season

And if I recall, to stay in stock class you have to use the stock tire size which would be 195s if you go with a wider tire you'll be in st class or something similar.

[619E30]

Yeah. My friend races his 300zx and says the kuhmo ecsta xs are the shit

[Ace M3]

Kumho XS, Dunlop Star Specs, Hankook RS-3's are all GREAT tires.

Don't worry too much your first time out though.

[gearheadE30]

I have s.drives and I've been pretty happy with them, but they don't have the outright grip of some of the others and they can be hairy in the rain. I daily on these tires too, though, and they've been lasting really well. 2 HPDEs and 4 autox's on these with probably 10k miles including street driving and I still am at more than half my tread depth.

[z31maniac]

And if I recall, to stay in stock class you have to use the stock tire size which would be 195s if you go with a wider tire you'll be in st class or something similar.

Nope, just the stock wheel size.

So you can cram 225/50/14 slicks on weaves and run stock. But you can't change springs and I doubt you'll spend the $1000 per corner on shocks that have the compression damping setup super stiff to mimic stiff springs.

Still be at monster truck ride height, just can't see it being very fun.

[nando]

I think you can use adjustable perches in stock class though, not sure about spring rates.

[jrhaile]

I've raced on XS', S Drives, T/A2s, PS2s and StarSpecs. Out of those, the S Drives are the worst! The StarSpecs are without a doubt the overall best if you live in a cool/somewhat wet climate.

[JJ1]

I've raced on XS', S Drives, T/A2s, PS2s and StarSpecs. Out of those, the S Drives are the worst! The StarSpecs are without a doubt the overall best if you live in a cool/somewhat wet climate.

Where do the XS's fall?