Did the first autocross of the year yesterday - raced with the BMWCCA. Finally had a chance to try out my new Azenis RT-215 tires. The tires were mounted on the stock 15 inch rims. I drove rougly 50 miles on the tires before arriving at the autocross.

Did 6 runs on a 70 degree, sunny day and drove away not all that impressed with the performance. And this is trading up from the pathetic Continental 175/65/15 crap tires.

Right off the bat I noticed that the steering feel/sensitivity was a little worse with the Azenis than with the crap Continentals. This really surprised me considering how stiff the steel sidewalls on the Azenis are - I was expecting immediate and extremely crisp response from the car during turnin. That was not the case. The level of overall grip is definitely much better, but not dramatic or anything. Maybe a lot of my observations were just illusions, but having autocrossed an entire year on Continental tires I feel like i am in a decent position to compare the two tires.

I am thinking the reason for less than dramatic transformation in handling performance is the fact that the stock rims are barely wide enough for the 205 tires. In fact, it is such a tight fit that the tire shop charged me another 30 dollars of labor for the suffering they went through to put the suckers on. The sidewalls are nowhere near vertical/flush with the wheel, the tire bulges bigtime and then the sidwall angles back inside towards the lip of the rim. This must have some substantial negative impact on sidewall integrity and therefore turning, steering feel and grip.

To remedy the problem I pushed the front pressures up to 45psi with the rears running 38. I used chalk on the sidewalls, and even at 45psi it seemed the tires were rolling quite a bit - the chalk was all but gone after the 60 second lap.

Am I the only one experiencing this problem or is this expected when you put a wide tire on such a narrow wheel? I would love to hear what others have experienced.

mine is a 2004 MC with SS+

Thanks.

 

Briefly, I would certainly guess it was the narrow wheel. Because I can tell you this, the Azenis don't roll onto the sidewalls easily at all. When we ran the 205/50R15 on a 15x6.5 in 2003, we could run as low at 30psi in front without rolling over onto the sidewall. Also, people have run the 205 on an 8" wheel without problems, so they clearly like a wide wheel.

There is a vast amount more grip in the Azenis than the Continental, although a fresh set of Contis are an excellent rain tire.
I would highly suggest getting some wider wheels, and I'm actually quite shocked nobody steered you against mounting the 205 Azenis on the 5.5" wheel. It's not an R Compound, so it's not the same as squeezing the 205 V710 on there (which does perform well).

Brian

 

Brian,


So you attribute the problems I am having to the narrow 5.5inch wheels? Would I be getting much better handling if i had mounted the 205/50 tires on a 6.5inch wheel? This is a consideration for me since I race with BMWCCA where wheel changes won't push me out of my class.

Which budget 15x6.5inch wide wheels would you recommend? I really like the Flik Blast-c - relatively light, look nice and should have the proper offset.

Also, I was considering trading up to race rubber next year (either Victoracers or Toyo RA-1s, since they last a long time and are more budget). Would mounting these tires (or other race tires) on 5.5 inche stock wheels be an option? As in, will the lack of width on the wheel have the same level of detrimental effect on handling? Also, in your opinion, which race tires are best for mounting on narrow wheels?

Sorry for the barrage of questions. I am a little unhappy to have invested all this money into marginal improvements.

Thanks!

 

Brian can speak much more to the subject than I can but I have the Azenis (not the brand new new ones) on 16x6.5 inch wheels. I am not the fastest one in class out there (HS) but my lack of speed has little to do with the tires. I love the tires. I do not notice the turn in problems that you note. They weigh a good bit more than regular tires, you are looking coming from a lighter tire where as I am looking at them coming from a runflat. When I went to a school last year, Marshall Cone, liked the feel of the tire (for a street tire mind you) on the car. I was running about two more lbs of air in the rear over the front to help with car rotation. 34 to 36 lbs front for 70 deg days, 40 for when the air temps hit 90 (all in bright sun). I might be running the tires with a bit to much air. I am still learning the feel of the car.

I have less than a year of autocrossing under my belt so please consider that when comparing it to anything else you read.

Oh yes, I own a 2003 MC with SS+, and to weigh the car down a little added the sport and touring packages when I picked out the options.
(I switched to the Monza wheels 16x6.5, still running factory struts all around and factory pipes out the back.)
John

 

Vano, heck, if the wheels aren't going to be Stock legal, get 7" or 7.5", not 6.5". 15x7's are much more common. If you're on a budget, get anything cheap and light, don't get a 15" wheel that weighs more than about 13lbs.

I can't think of any other reason the tires wouldn't work for you, so it's got to be the wheel width. That, and the Falken is a very stiff (and heavy) tire, so squeezing it on that rim can't be helping. But it's different from an R Compound.

Marshall Cone and Anthony Difiore both did very well this past weekend (Atlanta Pro, Anthony WON!) on 205/50R15 V710's on the 5.5" wheels, so they must work some.
The Hoosier R3S04 will work well also, and may even give you more runs...

Brian

 

Thanks for the replies guys.

Brian, I will start looking into either 6.5 or 7 inch wheels to replace the stock 5.5s next year.

I have read a bunch of threads regarding good offset (good meaning proper fit and good performance). In your opinion what is the offset I should be looking for in 6.5 and 7 inch wheels? (I guess if I get a 7 inch wide wheel, one day I might go from 205/50/15 to 225/45/15 tires - i heard if you don't have the right offset, they will rub). I don't have any plans to lower the car, but may add camber plates in the future.

Thanks.

 

Oh man... That is interesting.

I have been wondering about why I bought 16x6.5 SSR's and V710s for them when I already had 4 sets of 15x5.5" wheels.

If the 15" V710 is that fast, I may actually run them next year and sell the big money wheels. I'm no national champion, I think I'd rather have the $$$ in my bank account

 

Satay, Mike Potaki was on 16's with Hoosiers and came in second. It's still the driver and Anthony had some smokin' runs.
It doesn't mean one is faster than the other, but that weekend was brutal on timing the tire choices.
Want to sell those V710's? I still would like to run them side by side.

Vano, 42-46mm on 6.5", 38-42mm on 7".

Brian

 

Na, I will keep 'em. Although maybe I'll sell the wheels next year, depending on things. But I guess I am lucky that I bought the tires when I did!

 

Hey Guys,

The 710's on the 5.5 wheel seems to be a desend setup. I liked then anyway. (they got me the win right) I am going to be running a set of 205/50/15 flakens this weekend on my car. I will report back what I think of them.

Anthony
Philly region
64 HS

 

I'm definitely sure you won't like them after coming from the V710's

I do feel that it must be something to do with the small wheel though. Like I said, we could run down to 30psi on the Azenis on the 6.5" wheel, no problem, and no roll on the sidewall either.

Brian

 

Hey conedodger,

I would really like to hear what your experiences this weekend were. I wonder if you find the azenis on 5.5 inch wheels more responsive than I did. Also, what tire pressures worked best for you. I am starting to think that, given that the tire's sidewall integrity has been compromised, pressure plays a bigger role than if they had been mounted on 6.5"+ wheels.

 

Here is a quick impression of the tires. The day was mid 40's +/- drizzle on and off all day. Just enough to make the line wet most of the day. These things are no 710 that is for sure. I did think they worked better than the crappy contin.... I never auto-xed the contin. but I could feel the falkens are more responsive (street use vs. Auto-x.) We could not get the car to want to rotate at all though. I think we ended up with 35 front 23 rear for pressure and my co-driver got it to rotate a little. I was pushing to hard for the street tire. I wanted it to hold grip like the 710 and stop like the 710, not going to happen.

Probably not much help, but there you go.

 

Personally, you were way off with your pressures, especially in the wet. I would have run around 30-33psi in the front and 35-40psi in the rear, depending on the rotation you wanted. With 23-25 in the rear, you probably had a perfect contact patch on that tire, not loosing any grip THAT way, that's for sure.

For this post and others, here's my logic on rear pressures:
Anytime you run the same pressure front/rear on the MINI, you're technically overinflated in the rear since it's such a front bias car. So, you start there and keep going up until you get the rotation you want, by decreasing your rear contact patch. By starting very low, you'll create more friction, heat, then grip, as long as they don't overheat.

In the rain, the Azenis have phenomenal grip, especially if you get a little heat in them.
Anthony, I just think you got some great heat (relative) and good contact patch in the rear, never lending itself to rotation.

Brian

 

Hmm... sounds like I was running the wrong pressures too. I had 45f / 38r at the end of the day. I gradually cranked up it up to 45f to control the front tires' tendency to roll. But i didn't really notice much improvement with rolling between 38psi and 45psi... instead i was getting a fair amount of understeer and probably not letting the front tires heat up and grip enough.

Going to the M-Club autox next week - I will start with 35f and 45r and see how that feels. The tires should be nicely broken in this time around - at the first autox they only had 50 highway miles on them.

 

Sorry guys, let me be more specific with my experience...

What I said applies more to my experience on 15x6.5 wheels with the 205/50R15 AND camber plates and 16x6.5 wheels with 215/45R16's without camber plates. If you guys are rolling the 15's over on the 5.5" wheel, you have no choice but to increase pressure.

With camber plates on the 15x6.5" with 205/50R15 we ran as low as 30psi without rolling over. We determined what pressure between 33 and 40psi to run by how quickly we wanted them to heat up. If it was cold, we ran lower to create heat quicker. If it was hot, we ran higher pressures to keep the temperatures down.

Obviously, the camber plates control a lot of the rolling. But, on my Stock car, with 215/45R16 Azenis' as my everyday tire, I've never had rollover problems either with a rare autocross, but otherwise very 'spirited' driving.

Sorry I wasn't more clear earlier.

Brian

 

Brian,


Thanks for the clarification. Is running much higher pressures in the back the only way to get the car to rotate? Should I even consider doing pressures like 40f 50r? or should I keep the fronts at around 45 and keep dropping the pressure in the back until the rears roll really easily and create some rotation?

I am now starting to really see my mistake with the 5.5 inch wheels. Starting to look around for cheap 6.5 and 7 inch wheels to use once this set of Azenis is worn out. (The shop had so much trouble putting the tires on the narrow wheels that they told me they would charge me 30 bux just to take them off).

Anyone know where I can find Flik Blast 15x7 wheels? Edge Racing only has 15x6.5.

 

One thing you also need to look for is a new place to get tires mounted. Unmounting these tire will be a piece-o-cake.

The shop that mounts my 225/45-15 Hoosiers on a 6.5" rim has a system.
One guy works the machine
One stands on the tire
Sometimes I push down on one spot

Removal is just a one man operation, just like a properly sized tire.

If your in the Chicago area I HIGHLY recommend K.O. Tire in Elk Grove (tell them Mark sent ya)

 

Increasing the pressure after you've found the ideal contact patch will always decrease the contact patch, essentially making the tire skinnier. You can cause a lack of grip by running too low of a pressure, but I prefer not to because it's harder to read and the car feels more "sloppy".
I would start at whatever pressure is needed to keep the front tire from rolling over. Start the rears at the same pressure. If you don't get the rotation you want, up the pressure FIVE psi. If you still don't get it, go up another FIVE psi. I stress the 5psi number because you need to initially make bigger changes to see their effect, then you can back off if it's too much.

Perhaps you will end up with 40f/50r, it wouldn't surprise me.

Brian

 

I did the M-Club event at the Meadowlands this Sunday so I had a chance to test the Azenis out again and play with pressures a little bit more.

I went with 40f / 50r... WHOA!!! So much better!

The understeering tendency of the car went from moderate to minor. While the car would still push with the gas pedal down, the second I backed off even a tiny bit the tail would come in and go right around the corner. The car was SO EASY to control - i would go from understeer to neutral to oversteer on demand. There was a point on a long 40mph sweeper where I had to do counter steering because the car was about to spin. Didn't know a stock Cooper would ever exhibit that characteristic.

What all that translated to was pretty good lap times, considering my mediocre (at best) skills. I was consistently running 2.5 seconds slower than the fastest Mini Cooper S drivers on Azenis tires (no MCs to compare to - i was the only one). The course really favored the MCS as it started off with a 70mph straightaway - I was bouncing off the rev limiter in second gear. I probably lost over a second right there to any MCS at the event.

I am much happier now with the tires - the change in pressures really brought them to life and made the car easy to drive fast and rotate around cones, though I am still getting rolling on the front tires.

 

I am still thinking about getting wider wheels for autocrossing. Trying to find an inexpensive wheel that is relatively light in 15" size.

I had narrowed it down to the Flik Blast 15x6.5 40mm offset and the Falken Hanabi 15x7 42mm offset.

I liked the Hanabi better because it is 1 lb lighter and .5 inches wider, so in the future I can fit wider tires on (such as 225/45/15). Then I read a post by mtwlawson about the hanabis rubbing with 225/45/15 hoosiers on. Now I am confused as to what the offset should be. If i am going to go with a 15x7 wheel and run a wider tire, then the offset should be 36 - 39mm, otherwise it will probably rub. Or was this problem because of how wide hoosiers are?

The offset for the Blast wheels is 40mm. Can I use these wheels and mount 225/50/15s on without any fear or rubbing?

Thanks.

 

Barring anything unusual, the Blast with a 40mm offset and 225/50R15's should fit fine. The Hanabi is going the wrong direction, you want a 7" wide wheel to be 40mm or less (38mm would be good as well).

My Rota Slipstreams are 16x7, 40mm and with the 215/45R16 Azenis there's plenty of room.

Brian

 

Vano,

I know you said you race with BMWCCA, but if you ever try and do SCCA H Stock events those wheels will not fly. To be legal with a 16" rim, you need a 6.5 x 16 with a max offset of 44.

There are few rim choices out there. Stock V-Spokes (R89's), AK Monzas and SSR's come to mind.