Track tires for E92 M3 Coupe ?

[syncros]

Hello all,
According to you what's the best option for a track setup wheels and tires for a E92 M3? I would like to run 18" wheels and get wider tires on all 4 corners. I've been told that I was better with keeping a staggered setup as I would need to modify the camber to run on a square setup.

My plan this summer is to go at 4-5 events and would like to have a set of track tires who can hold for this summer.

Thanks, Vincent

[Andrei]

With stock suspension?

Stock tire sizes, especially if you are starting out which I am guessing from your unwillingness to change camber.

In stock form M3s are great for beginners. Past that things need to be modified.

Why did you get advised to modify camber for square setup? Was that to fit the wider rubber under the fenders?

With stock springs it doesn't matter that much which camber setting you have up front. The car will roll so much in the corners it will chew up the outer edges of tires unless you drive very slow.

[Emre]

My plan this summer is to go at 4-5 events and would like to have a set of track tires who can hold for this summer.It really depends on whether you're looking for a separate set of wheels/tires exclusively for track use vs. running the same wheels/tires both on the street and one the track.

If you want to run DOT-R tires, the Michelin Pilot Sport Cup seems to be the hot choice for larger wheels. I have no experience with them, as I run 15" wheels on my track car. Others can give you more detailed info.

But, if you're looking for one set of summer tires to do double duty on the street and track, I would strongly recommend the Yokohama ADVAN Neova AD07. They offer phenomenal grip in the wet and dry. They hold up exceptionally well on the track, even with a heavy car. Turn-in is almost as crisp as a lower end R-compound tire (comparable to something like the Falken Azenis RT-615). Really tough to beat as an all-around street/track tire.

[Emre]

I'll also mention two other tires that everyone seems to rave about. Keep in mind that, unlike the Yoko ADVAN Neovas, I have zero real-world experience with these tires! I'm just passing on what I've read and heard on various forums and such.

When it comes to larger tire sizes, I'm mostly in touch with the Evo and STi crowd. Most guys with stock brakes are running 17x9" wheels with 255/40-R17 rubber. In that community, people really seem to like the Bridgestone Potenza RE-01R and the (significantly less expensive) Dunlop Direzza Sport Z1 Star Spec.

[kenneth]

FWIW, for the Dunlop Direzza star spec, the e9x crowd is also raving about them!

[Andrei]

E92 M3 comes stock with Michelin PS2 tires. Those are great but expensive. Keep them on. Even if they are 19".

Stay away from r-compounds on stock suspension. Not only you will destroy the outside edges faster (more lateral g thus more lean in the corners) but you will fry the brakes so fast that a full day of driving will require lots of fluid bleeding.

[Silverblades181]

Stock tires are pretty good.

[syncros]

I'll keep the stock suspension.
All I want is a set of wheels and tires dedicated for the track that will last for the complete year (4-5 events). My only other mod will be brake pads as I've told that the OEM ones are very weak on the track.

I'm ok with changing the camber as long as I can ride on the street with the camber level as I don't want to modify this every weekend.
Stock tires (PS2) can't hold too long on the track according to posts on m3post.com

What should I do then?

Thanks for your advise.
Vince

[mayor]

+1 on AD07 - fantastic tire, though expensive!

Other than pads (probably), +1 on suspension being the next to-do mod.

[Andrei]

PS2 will not wear out any faster than a tire with equivalent treadwear rating.

You still didn't say what level are you starting at. Are you a beginner or not?

If it is going to be your first time then the only thing you should do is change the brake fluid to something better (RBF600 or equivalent) and leave the DSC on for the whole first event.

After the first event, if you liked it, you can start changing things.

Brake pads, dedicated wheels, etc., etc. comes after you do your first event no matter what you read on M3post.com. People spend too much time tinkering with stuff, often having very little idea of what they are doing, instead of driving.

You will save a whole bunch of money and time and will learn a lot better if you modify things on the car only after experiencing the need for modification first hand. Are the stock pads junk on the track? Of course, but in the first day you'll be more worried about knowing where the next corner is going to and how to drive in track traffic then about braking from 230 km/h. If you feel the pads getting mushy during the second day it would be great. That means that once you put race pads in you will appreciate the difference.

And no matter what anyone says there is no such thing as dual purpose brake pad. There are street pads and there are race pads. Some race pads are more tolerable than others on the street but they are still not optimal. All those "dual use" pads are junk on a heavy car like the E92 M3. They could work on an underpowered and light E30 but E30 guys never get to go above 200km/h.

Start driving, not tinkering.

[Gregster]

+1 on AD07 - fantastic tire, though expensive!

Other than pads (probably), +1 on suspension being the next to-do mod.

Looking at the new suspension in the rear of the E92 M3.. I feel bad for the owner that wants to change sway bars for a DIY on M3post.com.

[Andrei]

Looking at the new suspension in the rear of the E92 M3.. I feel bad for the owner that wants to change sway bars for a DIY on M3post.com.

Come on, dropping subframes is almost as fun as unbolting the diff.

[Silverblades181]

The E92 M3 is plenty of car stock. Learn to drive first. I learned on a basicly stock E30 318is with H&R Sport springs and Bilstein sport shocks as the only mod for 2 years and I had PLENTY of fun. 100whp is cool, your at WOT most of the time, plus you don't need to lift when you give point-bys.

[syncros]

I've been tracking for the past 4 years now and I know the Tremblant Track real good. What's different this year is that I've never tracked an M3 (this is my first M). Never drove a 416HP car and such an heavy car before. I intend to be really careful as this is my day car too.

I intend to change brake pads for track weekend and replace them by stock ones otherwise. I also prefer to have a set of dedicated track wheels (lighter wheels and better tires). I'm open to change the camber if I can find a suitable solution for track and street setups.

FYI: All of my posts and replys but get approved by a moderator so I can reply at the proper speed...

Anyone know if Toyo will still provide a 40% discount for the club members in 2009?

Thanks again for your input.

[Gregster]

Come on, dropping subframes is almost as fun as unbolting the diff.

Maybe you don't have to completely drop it.. I have to see a new M3 on a lift to figure it out :o.

I like the new 5 link rear end though
http://www.realoem.com/bmw/diagrams/w/d/234.png

very modern.

[Emre]

I also prefer to have a set of dedicated track wheels (lighter wheels and better tires).Again, the whole question comes down to whether or not you want your track tires to be R-compounds. If you want to run R-compounds, the Michelin PSC's are the most popular in your size. You can also try the Nitto NT-01 or new Toyo R888. If you want street tires, you're not going to find anything better than the Yoko ADVAN Neova AD07.


Anyone know if Toyo will still provide a 40% discount for the club members in 2009?I believe the deal is still good. I'll double check.

[kenneth]

There will be a few novice drivers with M3 at Tremblant! I've recommended they change nothing to their car for now.

As the OP has track experience, the square setup may be the way to go, as those staggered OEM fronts take quite a beating. Mine will be finished in a couple of track days!!

[Andrei]

If you have that much experience you will find the stock suspension way too soft.

To keep the car streetable I'd go with something like PSS10 kit (I have no idea if it's available for the car yet but it should be). Then you can install camber plates and get a reasonable compromise camber setting. I don't think there is much room to change camber without any camber plates. But camber plates on stock springs are a waste of time. The car will lean so much that no amount of camber will help you. In addition to the suspension and camber plates you'd need a good set of sway bars. Get the thickest you can find.

I have no idea if a square setup is easily possible but from previous M3s the flared fenders usually make it doable. But it is definitely optimal to get same size wheels and tires. You will possibly need spacers for the rear as the rear wheel offset is always more aggressive on the M3 to give it wider rear track. If you get 9.5" wheels you could run 265 rubber all around. Maybe even 265/35/18 PSC that is very easily available (rear Boxster S size).

If you know your way around Tremblant then the stock pads are mostly to have a laugh about how many laps it will take to fry them. Get race pads. Hawk HT-10, DTC-70. Pagid RS-19, RS-29 if available. Some people like Carbotech but I fried them in a two day event. Don't get Hawk Blue or whatever "track/street" pad. The M3 is too heavy for those.

If you continue to track the M3 you will either need a brake cooling kit (cheaper and cruder) or a big brake kit (much more expensive, but oh so cool), or even both (crude and expensive, proper crazy track guy setup).

For the first event take the car on stock rims and learn the car. Do not mount r-compounds if you are not stiffening up the suspension. With less grip the outer edges of the tires will not get as much of abuse.

For setup tips you may want to check bimmerforum.com which I believe has more track guys on it some of who have E90/E92 M3s.

Your posts are no longer subject to moderation. Only the first one was. That is an antispam measure. Otherwise the forum will be overrun with offers to sell you WoW experience points. If you continue to have trouble with that, PM me and I will investigate further.

[syncros]

Thanks guys.
I will continue my investigations on possible setup and let you know before I do anything. Thanks again for the input.
I'm really anxious to put it on the track as I really enjoy the noice of the engine in this car (it gives me such a smill everytime).
Vincent

[Silverblades181]

Thanks guys.
I will continue my investigations on possible setup and let you know before I do anything. Thanks again for the input.
I'm really anxious to put it on the track as I really enjoy the noice of the engine in this car (it gives me such a smill everytime).
Vincent

I get a big grin everytime I roadtest an M3. It is simply an awesome driving experience. I might say "The Ultimate driving experience"

[Gregster]

I get a big grin everytime I roadtest an M3. It is simply an awesome driving experience. I might say "The Ultimate driving experience"


Any car that runs mid to high 12s stock is ok in my book...

[bmwqc]

Any car that runs mid to high 12s stock is ok in my book...

Any back to back performance comparison between the current M3 and the E46 M3?

[Gregster]

Any back to back performance comparison between the current M3 and the E46 M3?

Only between a C6 and E92 M3

http://www.youtube.com/watch?v=OA_W_edeB8M

:p

However from what I've seen the 05-06 E46 M3s are stiffer suspension wise.

[syncros]

Never drove a E46 M3, but my understanding is that the E46 where more tailored for track usage (lighter and stiffer suspension). But the 420HP should be fun when exiting any curve.
The C6 is faster but is largely modified!

[Gregster]

The club should have a meet at Napi on 5$ Tuesdays just to have some fun and get some 1/4mi times :)

[Emre]

The club should have a meet at Napi on 5$ Tuesdays just to have some fun and get some 1/4mi times :)A few years back (maybe 2003 or 2004) I had looked into booking Napi for a day. The price isn't all that high. We were talking about maybe doing a joint event with the new BMW CCA--Green Mountain Chapter. Those guys were really interested in drag racing. There wasn't really enough interest to pursue it on our end, so we dropped it.

Personally, I think there's some potential there. It would be relatively easy to get sponsorship, host a show-n-shine, etc. Would make for a fun day.

[bmwqc]

A few years back (maybe 2003 or 2004) I had looked into booking Napi for a day. The price isn't all that high. We were talking about maybe doing a joint event with the new BMW CCA--Green Mountain Chapter. Those guys were really interested in drag racing. There wasn't really enough interest to pursue it on our end, so we dropped it.

Personally, I think there's some potential there. It would be relatively easy to get sponsorship, host a show-n-shine, etc. Would make for a fun day.

Emre,

Is there anything else there besides the drapstrip? (i.e. any large piece of open tarmac)?

[Emre]

Is there anything else there besides the drapstrip? (i.e. any large piece of open tarmac)?I've never been there in person. Greg and especially Eric would know better: Eric used to host events there many years ago.

I know that they run some sort of "drift" events out there. So there must be something besides just the 1/4 mile track.

[sebdavid]

If there's anything else than a long straight piece of tarmac and we can use that, then I'm in. Otherwise I see no point in destroying my clutch and gearbox. Straights are the boring parts between turns as far as I'm concerned. If we were a Mustang Club I could see there being an interest but I'm not sure that many people from our club would be interested. I may well be wrong though.

[Emre]

I'm not sure that many people from our club would be interested. I may well be wrong though.Like everything else, it depends largely on cost. Let's say we can rent the track for an evening for $500 (it's probably less than that). You get sponsors to cover $200. Charge people $20 for basically unlimited runs. You'd need 15 people to break even.

Between BMW Quebec and Green Mountain Chapter, I bet you could find 15-20 people who'd be into it. I know I'd go, even though my car is S-L-O-W in a straight line.

[sebdavid]

Yes, I didn't want to sound all negative or anything, I just wanted to express my opinion. Maybe a poll would be in order when we find out the cost.

My thinking is even at $20 I wouldn't go, because I can't afford the abuse on my drivetrain ($20 is only the tip of the iceberg), and because I don't see the fun in accelerating from a standing start over and over again in a straight line, in a car that was not meant for this.

But I'm sure more than 20 people would be interested. And if you charged a bit more for non-members that would open up a world of possibilities, I know several people who would go.

Now if we had the parking lot to do some gymkhana or un-timed autocross or car control exercises, that would be awesome.

[kenneth]

You should get 15-20 members easy. It will mainly depend on the date, so one option is to get a few dates and ask those interested to vote for the date!

I have an O/T question on tires. I have a staggered OEM setup (255/35/18 R and 225/40/18) Bridgestone RE 050A runflats. My fronts will eventually need changing, and I have a set of "almost new" Yokohama Advan Sport non-runflat. What do you folks think of running the Bridgestone runflat on the rear and the non-runflat up front?

Is that a no-no?

Thanks!

[sebdavid]

http://www.youtube.com/watch?v=fSEkUV7torQ&feature=related

yeah.

[Emre]

http://www.youtube.com/watch?v=fSEkUV7torQ&feature=related

yeah.Wow. The guy in that video is such a monumental douche-bag it's truly staggering. You slept with your therapist. You are so cool :rolleyes:

If you can sit through 8.5 minutes of assorted douche-baggery and lots of posturing/preening, he basically says that he tracked the car extensively (which also puts lots of wear and tear on your drive shafts) then he launched the car using a high-rpm clutch drop. Not the smartest thing to do, even without old, worn-out parts. Being a total douche doesn't help either.

You don't have to launch the car on the strip if you don't want to. You can take off normally and just run through the gears.

[sebdavid]

A lot of us DO track our cars extensively, and going to the drag strip you would expect to do high-rpm clutch drops. Isn't launching aggressively the whole point of being on a drag strip?

Launching a car just doesn't feel right to me, maybe I have too much mechanical sympathy.

I'd rather go through the gears on a road course where there's a curve waiting for me at the end of the straight.

But again, this is just my opinion and I'm sure lots of people disagree.

[Emre]

A lot of us DO track our cars extensively, and going to the drag strip you would expect to do high-rpm clutch drops. Isn't launching aggressively the whole point of being on a drag strip?It doesn't have to be. If the goal is to get the lowest possible times, then you'd launch it. If the goal is to have a fun evening screwing around with a few buddys then going out for beers afterwards, there's no need to do a 5K rpm clutch-dump.


Launching a car just doesn't feel right to me, maybe I have too much mechanical sympathy.Me neither. I never launch, although I did try it a couple of times just for the heck of it when the clutch on my Evo was about to be replaced. I can see why people break trannys and transfer cases on these things: the grip off the line was amazing.


I'd rather go through the gears on a road course where there's a curve waiting for me at the end of the straight.No doubt. It would only be worth doing something like this if the cost were really, really low. Like under $500 all in.

[Gregster]

A lot of us DO track our cars extensively, and going to the drag strip you would expect to do high-rpm clutch drops. Isn't launching aggressively the whole point of being on a drag strip?

Launching a car just doesn't feel right to me, maybe I have too much mechanical sympathy.

I'd rather go through the gears on a road course where there's a curve waiting for me at the end of the straight.

But again, this is just my opinion and I'm sure lots of people disagree.


If you launch at 5k you'll just spin or worse axle hop it. You can launch at 2k and just slip the clutch out. No abuse... You don't drive a Honda that you need to launch off the rev limiter.

You only start breaking stuff at the strip if you are running super sticky tires and massive amounts of HP.

Drag racing night might end up like this.. :p
http://www.youtube.com/watch?v=49K-RGdkfVg

[Andrei]

You should get 15-20 members easy. It will mainly depend on the date, so one option is to get a few dates and ask those interested to vote for the date!

I have an O/T question on tires. I have a staggered OEM setup (255/35/18 R and 225/40/18) Bridgestone RE 050A runflats. My fronts will eventually need changing, and I have a set of "almost new" Yokohama Advan Sport non-runflat. What do you folks think of running the Bridgestone runflat on the rear and the non-runflat up front?

Is that a no-no?

Thanks!

Don't ever mix different brand tires. Would you run slicks with normal tires? That is the same but less extreme.
This doesn't mean that you won't get away with it if you do mix tires but if something bad an horrible happens don't be too surprised.

[kenneth]

Thanks! You know that means I will need to get a square setup. :o

[Chow Mein]

I helped out with 4 tech inspections last year, and I often check if the front and rear are the same model tire. I wouldn't let a car go on the track if the front and rear were different models.



Don't ever mix different brand tires. Would you run slicks with normal tires? That is the same but less extreme.
This doesn't mean that you won't get away with it if you do mix tires but if something bad an horrible happens don't be too surprised.

[Chow Mein]

The tech inspection form should be changed to prevent this scenario. Imagine LCMT turns 1-3-4-6-7 with a shady tire setup, or the Sanair tri-oval apex before the back straight.



I helped out with 4 tech inspections last year, and I often check if the front and rear are the same model tire. I wouldn't let a car go on the track if the front and rear were different models.

[sebdavid]

Wow! I'm surprised that this matters so much guys. I'd think that a car with different tire model front to rear wouldn't be worse than a car out of alignment or with different wear on the front and rear tires, or different size tires (square vs. staggered setup comes to mind), etc. Obviously that's not the case, from your responses, but why?

I mean, I understand slick vs. normal tires, but this is a lot less extreme, isn't it? Just makes the car different in its reactions, more understeer or oversteer, but it'll be consistent, not a sudden surprising reaction from the car resulting in a big moment, no?

I'm just trying to understand and learn here, you guys know a lot more about this than I do, obviously. I just wouldn't have expected such a radical response!

[Chow Mein]

It matters to me anyway, especially since the club emphasizes safety. If we believe everyone's car on the track should be in excellent mechanical condition, the tires on all corners should be the same, worn or not.




Wow! I'm surprised that this matters so much guys. I'd think that a car with different tire model front to rear wouldn't be worse than a car out of alignment or with different wear on the front and rear tires, or different size tires (square vs. staggered setup comes to mind), etc. Obviously that's not the case, from your responses, but why?

I mean, I understand slick vs. normal tires, but this is a lot less extreme, isn't it? Just makes the car different in its reactions, more understeer or oversteer, but it'll be consistent, not a sudden surprising reaction from the car resulting in a big moment, no?

I'm just trying to understand and learn here, you guys know a lot more about this than I do, obviously. I just wouldn't have expected such a radical response!

[LagunaM3]

I know an instructor who got a flat on one of his track tires. Not wanting to throw the rest of the event away, he put 2 street tires on. He put the streets on the front and the rcomps in the back. He knew full well that this would lead to some serious understeer (which is preferable to the reverse, wicked oversteer), and he drove accordingly. He had fun and drove the car for the rest of the event without incident. Granted, he's a very experienced driver who knew what he was doing.

[sebdavid]

Of course safety is paramount. My point is that I would expect mismatched tires front to back to change the handling, of course, but:

1) not more than having worn tires at one end and new tires at the other
and
2) in a consistent fashion, something you would be able to adapt to, i.e. more under- or oversteer, as opposed to a patched tire (which can go flat or explode) or crappy alignment (which could make the car swerve under braking), which bring about sudden and unexpected reactions from the car.

To give you another example, I'm sure my mom's WRX with mismatched tires would still be easier to drive around a racetrack than a stock GT3 on perfect rubber.

No?

:confused:

[Chow Mein]

every tire has a different limit for traction, IMO it's a nono for a HPDE since you're learning. Instructors on the other hand, are exempt for inspections.

[Andrei]

Look, we have rules and regulations at HPDE to make the event safer.

Sometimes it is more practical to have a strict rule that is very black and white as enforcement becomes easier. A more nuanced approach could work but the event is run by volunteers who are already very busy trying to make it all work. Yes, sometimes a reasonably safe situation is still against the rules. Forcing people to make judgements will lead to mistakes in judgement.

Look at the German inspection system. No good shop would even mount the tires on your car unless they have been TUV approved for your particular car. Same with wheels. A very blanket prohibition that often prevents you from using wheels/tires that are perfectly fine. But it also prevents you from having to guess how far you can push it with modification. There is a clear line and that's it.

The same goes here. Only a complete set of tires of the same brand. That's not even as restrictive and German road rules. If you don't like the restrictiveness of our HPDE you can drive on the track with other less restrictive groups. I certainly do that. I also come to BMW Club events and follow the rules of the club as I understand that the goals are a bit different.

[sebdavid]

Look, we have rules and regulations at HPDE to make the event safer.

Sometimes it is more practical to have a strict rule that is very black and white as enforcement becomes easier. A more nuanced approach could work but the event is run by volunteers who are already very busy trying to make it all work. Yes, sometimes a reasonably safe situation is still against the rules. Forcing people to make judgements will lead to mistakes in judgement.

Agreed. The thing is, this isn't a rule I've seen before, and it certainly isn't in the tech inspection form.


If you don't like the restrictiveness of our HPDE you can drive on the track with other less restrictive groups. I certainly do that. I also come to BMW Club events and follow the rules of the club as I understand that the goals are a bit different.

I'm sure you didn't intend it that way, but I don't like the sound of this.

I never implied I thought the (non-existent) rule was stupid or excessive, I was simply trying to learn and understand better. I love our HPDEs, I get as involved as possible with the Club given my frequent absences and (very) limited budget. I have no desire to dispute rules, and I stand behind the Club's various decisions and rules 100%, as I already stated.

I simply saw this issue crop up, I don't think we have a rule about this, and I was trying to further a discussion with (I think) valid points that, if we make this a rule, WILL be brought forth by potential members or attendees to our events. I think it's only fair we try to address them; I obviously don't have the knowledge to do so myself (or I wouldn't be asking the questions in the first place) but I sure hope somebody here will help me (and others) understand.

[Emre]

every tire has a different limit for traction, IMO it's a nono for a HPDE since you're learning. Instructors on the other hand, are exempt for inspections.Just to clarify: instructors are absolutely NOT exempt from inspection. Instructor cars must be inspected. The difference is we allow instructor "self-tech."

The reasoning is that instructors are very experienced track guys and very anal retentive about safety and maintenance. We have to be: we're carrying passengers at comparatively high speeds. Our maintenance regimens and pre-event tech inspection routines are generally much more extensive than what you see on the tech inspection form. So it would a bit silly to insist that instructors take their car to a shop for a quickie inspection after it's been gone over with a fine-toothed comb.

[Emre]

Of course safety is paramount. My point is that I would expect mismatched tires front to back to change the handling, of course, but:

1) not more than having worn tires at one end and new tires at the other
and
2) in a consistent fashion, something you would be able to adapt to, i.e. more under- or oversteer, as opposed to a patched tire (which can go flat or explode) or crappy alignment (which could make the car swerve under braking), which bring about sudden and unexpected reactions from the car.Ultimately, we need to have straightforward rules that make some kind of sense. More important, we need to enforce those rules consistently. You can always find some exception that tests the limits of the rule. But we can't have on-site tech inspectors (volunteers who are taking time out from their own driving school that they're paying for) spending 30 minutes on each car dealing with unusual circumstances and being forced to make unilateral judgment calls about what's safe and what's not. And it's the instructor's job to focus on your driving, not inspect your car.

In practice, no one is going to be able to control this anyway. You can drive up on street tires with a set of r-comps in the trunk. You can mix and match them...who would know? One of your tires could be corded or one of your pads could be down to the backing plate or you could have blown off torquing your wheels...who would know? We rely on the driver to respect the rules and not do anything crazy. It's an honor system to a large degree. Your instructor is putting his/her life and health in your hands.

[johnmdanskin]

I have a total lack of understanding of the concern about different front and back tires. Anyone with a staggered setup is going to end up replacing fronts and backs separately unless they have don't care money. Now you are running semi-cooked fronts (rears) with brand new rears (fronts). So what. It's like changing a sway bar setting. If I take front from all the way loose to all the way tight and do the same for the rears, that will make more difference than different fronts and rears. The difference between brands isn't bigger than the difference between cooked and uncooked tires. I can see serious issues with side to side mismatches but front to back? Give me a break.

[kenneth]

I sure am glad to have asked this question :D

Didn't know it would have caused such discussions! But discussions are good. Please carry on.....

[sebdavid]

John, to me what you're saying makes sense. But we could be missing something. I want to understand what it is, and if it is a concern, I think we should add it to the inspection form and rules.

[Chow Mein]

IMO, this is exactly why it should be included in the rules, as this thread has shown there is quite a difference of opinion when it comes to mixing tires brands/models. It should be written and clear to everyone whatever the final ruling is.

The rules should cover how things should be when you arrive at the track. I know things can happen during the course of a 1-3 day track event, and comprimises are necessary sometimes which would be a grey area, in order to not write-off the rest of a track day due to an unexpected occurance.



I have a total lack of understanding of the concern about different front and back tires. Anyone with a staggered setup is going to end up replacing fronts and backs separately unless they have don't care money. Now you are running semi-cooked fronts (rears) with brand new rears (fronts). So what. It's like changing a sway bar setting. If I take front from all the way loose to all the way tight and do the same for the rears, that will make more difference than different fronts and rears. The difference between brands isn't bigger than the difference between cooked and uncooked tires. I can see serious issues with side to side mismatches but front to back? Give me a break.

[bmwqc]

IMO, this is exactly why it should be included in the rules, as this thread has shown there is quite a difference of opinion when it comes to mixing tires brands/models. It should be written and clear to everyone whatever the final ruling is.

The rules should cover how things should be when you arrive at the track. I know things can happen during the course of a 1-3 day track event, and comprimises are necessary sometimes which would be a grey area, in order to not write-off the rest of a track day due to an unexpected occurance.

I will consult the tracking committee on this topic

[sebdavid]

Well, can we bring this discussion to a conclusion?

Is running mismatched tires front to back a serious security hazard or not?

[bmwqc]

Well, can we bring this discussion to a conclusion?

Is running mismatched tires front to back a serious security hazard or not?

I have already posed this question to the tracking committee.

[PassatVR6]

running mismatched tires front to back is really not a hazard given the driver is compenent.

[PassatVR6]

The tech inspection form should be changed to prevent this scenario. Imagine LCMT turns 1-3-4-6-7 with a shady tire setup, or the Sanair tri-oval apex before the back straight.

LCMT turns 1-3-4-6-7 was done with a shady tire set up and the car was being pushed close to its limits (playing catch up with car in front), there was no danger.

I don't understand why would not let the cars go. Different tires can be no different then a bad alignment or a bad suspension set up.

[Andrei]

running mismatched tires front to back is really not a hazard given the driver is compenent.

Even Schumacher screwed up once a while. He was way more than "competent".

Everyone makes mistakes.

Deciding if the driver is competent is very subjective. Having a simple bureaucratic rule is much simpler and doesn't really pose that much of a burden. And it's easy on the organizers who are busy enough. The chief instructor is harried enough during the event and deciding on relative safety of different tire setups is forcing him/her to make snap decisions.

Yes, we can't really check that a suspension setup is bogus unless it is something completely absurd. That doesn't mean we should stop checking the things we can check.

Why would anyone want to run different brand tires front/back? If it's an emergency I can understand an exception being made (within reason). But coming to an event with already mismatched tires is just goofy.

[johnmdanskin]

Why would anyone want to run different brand tires front/back? If it's an emergency I can understand an exception being made (within reason). But coming to an event with already mismatched tires is just goofy.

Why would anyone want to run different size tires front/back? Coming to an event with already mismatched tires is just goofy.

Adding rules adds bureaucracy and red tape. More reasons to send people away unhappy for no real reason.

Maybe I've decided that I like toyo r888s in front for crisp turnin but I like toyo ra1s in back for predictable breakaway. Maybe I'm trying to switch from michelin psc2 to toyo r888 without tossing two perfectly good tires. Why not? How is this different than running some weird staggered setup or blowing it with my alignment. You can't check everything but why add this bureaucracy and second guess someone who may know what they are doing

[Emre]

John makes some good points.

As I mentioned in post #50 (http://www.bmwquebec.ca/forum/showpost.php?p=30969&postcount=50), this is the kind of thing that we really can't control anyway. No one is going to sit down and compare front and rear tire brands/models/condition. Nothing would stop someone from entering the tech inspection line with one set of tires and swapping tires as the event goes on. You can't expect the in-car instructor go walk around and do a mini inspection before each run. It's an honor system.

Personally, I think this is the kind of thing that can be suggested, but not really made into a rule (at least not a rule that could be enforced). We can say, "we strongly recommend you run the same brand/model/condition of tires front and rear." I don't htink we can do more than that. I do think that mixing r-comps and street tires is generally a bad idea. If it makes people happy, we could specify that.

Realistically, I think this is a non-issue.

[sebdavid]

Say your model of tire isn't made anymore, and you have to replace only two (due to wear, road damage, whatever). You're not going to replace all four and waste a pair of perfectly good tires.

What if you want to change tire brands/models, but two of your tires are up for replacement before the two others?

What if somebody gave you 2 good tires? (this actually happened to me)

Plenty of reasons why you could end up, even temporarily, with mismatched tires. Kenneth is in the situation right now. Most of us don't have crazy budgets so we need to watch expenses.

I still don't see an argument saying mismatched tires could really bite you in the ass unexpectedly (unless it's Canadian Tire cheapos in the rear and slicks in the back, but that's a bit extreme) if it's just different brands/models of the same type of tires. I still have a suspicion that it wouldn't make more of a difference in the handling as adding an LSD, changing suspension settings (even undramatically), alignment, tire pressures, brake pads front to rear, driving style, staggered vs. square, or changing cars.

In Kenneth's case, for example, you tell him not to use two different tire brands front to rear, but that means he's going to go with a square setup vs. his stock staggered one. I'm convinced that will make at least as much of a difference as if he used mismatched tires.

There must be something I'm missing here, and I'm sure I'm not alone.

[Andrei]

Ok ok. I might be a little paranoid but as an instructor getting into someone's car if I notice different brands of tires I might infer something sinister about the general maintenance of the car. I'm not going to flip out but it's just kind of ghetto to me, that's all.

And having different size wheels front to back is only crazy if "ze german engineers" didn't mean to make it that way. If someone shows in a 911 with a square setup, I'd be puzzled.

How about this: I you are just starting out don't be mixing tire brands and what not. And if you are solo, then please make sure the cords are not showing.

But I think we can all agree that NASCAR style COTM crabbing alignments are right out, right?

[johnmdanskin]

But I think we can all agree that NASCAR style COTM crabbing alignments are right out, right?

which track?

[Gregster]

If the tire model has been discontinued (around every 5 years) and you can't get replacements then I suggest getting 4 new tires. Tires get old and hard... This reminds me of those people who show up to the track with 6 year old Hoosiers because they needed to have track tires or changing the oil but not the filter...