04 MCS with h-sport springs going to run 15" kosei K1 TS in SM on street tires. Got the wheels but having difficulty in tire decision. I want to go as wide as possible for a larger contact patch but don't want to have to trim fender wells.

Anyone see any challenges with running 225/45/15 and then which one.

I think I will likely run the Falken RT 615's 205/50/15 and remain in Street Tire category. Then again I'm thinking about going to the Kuhmo V710's and running in Open.

Unfortunely, I'm not overly competetive in either because of M3's and STI's not to mention my driving skill . Still having a blast though.

Your thoughts..........

 

225/45-15s should fit just fine with no rubbing. I'm using that size Avon Tech Rs on 15x7 Kosei K1-Rs, and am very impressed with them so far.

Scott
90SM

 

I'm running 225/50/15 Victoracers on K-1's. There is a touch of rubbing but the big problem turned out to be that the wider tires + camber was too much for the stock struts. I added Koni yellows which caused wicked oversteer. I just put on the H-Sport front sway bar and am doing a little adjustment on the strut dampening. Hopefully this weekend I'll have a nice, neutral car.

 

It looks like from my inept performance yesterday that my money will be better spent on driving school rather than expensive tires. My car is plenty fast but the pilot is a little to impatient. Just can't grasp "slow in fast out" for some reason. Not like this was my first event .

The open class on race tires would be a total waste of time so I think I'll stay on street tires until I have half a clue. As just about all the regions are seeing, I would imagine, the Mini is having a difficult time competing in SM and Arizona is no exception. In the stock categories they seem to be doing okay.

I have my mind set on the Falken RT615's but they only come in a 205/50/15. Would like to be a little wider as I am currently running 215/45/17 Yoko's. The new Kosei K1 TS 15 X 7" wheels and whichever tire will be dedicated track and autocross tires so the stickier the better. Not worried about wearing them out.

Any thoughts on steet tires? Already signed up for one driving school at Leguna Seca in December and a local driving school a week or two before that one. Seat time baby. Need the seat time. It'll be okay....

 

Whether in 15" or 17", good street tires worth considering would be-
Bridgestone potenza S-03 or
Goodyear Eagle F1 GS-D3
from tirerack.com, talk to alex.

These tires work fine in dry or wet for street or track. They don't wear forever but for one tire that does a heck of alot you should check them out.

 

I'm riding on TOYO Proxies T1-S
~$125/ea for 205/50/16

they're great in wet, and even better dry.

 

Ended up going with the Falken Ziex 512 225/45/17 for the street mostly for thread wear and the Falken Azenis RT-615 205/50/15 for the track. We'll see.

Thanks to all those that helped.

 

Falken is supposed to have a 215 next year (1st qtr 06). I may hold out.

 

If you want an accurate speedometer reading on your street tires, a 205x55x15 Michelin PE2 is the right diameter. They give me 1% high speedo reading (the fewer-tickets direction) with my 15x7" SSR Comps.

 

This is the track package. We get to test it out in a couple of weeks. Yippee

 

What did you have to do to fit 225/45/17's. This is the tire size I want and I will be getting h-sport springs too. How bad are you rubbing?

 

by looking at the pic, i don't think he has rubbing issue

 

Yeah thats what I was thinking too but I don't know how that is possible. Even with stock suspension you get a little bit of rubbing with 225/45/17's and his is lowered.

 

Those tires say Azenis. They are 205/50/15. I think the words track and street got switched.

 

Sorry guys, haven't been watching this thread.

I think that the Falken street tires Ziex 510 in 225/45/17 is a little rounder than a lot of the more performance oriented tires that have a more square shoulder. I believe that's why they don't rub, at all. I will classify that statement by saying they don't rub on the roads in Arizona. My most recent trip to California indicated otherwise. Arnold, put some of that tax money into the freeways. I will say that these tires are better for cruising. Less noise, better ride etc. But they are terrible if you try to do any DRIVING on them. They don't like turning and don't grip hardly at all. But, they are doing what I want them to do. Hush up and last long.

On the other hand, the Azenis RT615's 205/50/15 (pictured in this thread)which I used at Laguna Seca a couple of weeks ago, ROCK!!!! They went and stayed where I wanted them and no arguing. I was and am pleasantly surprised that after 37 "hot" laps which unfortunately was actually about 15 there is little or no sign of wear. These also are doing exactly what I wanted them to do. Stick baby!!!!

Falken gets my vote.

 

How do you figure.....Your mph is measured thru the wheel sensor so it wouldnt matter if you had different size tires or wheels.

 

1FSTMINI,

Sorry, but you are mistaken. The speedo gets its input from the sensor as you describe, which is why it will always indicate the same speed for any particular engine rpm and gear selection combo (say 3000rpm in 6th). Note that I said indicate.

The actual vehicle speed will vary depending on the rolling diameter of the tires installed. If the outer diameter of the tires is the same as stock, the indicated speed will be the same. If the diameter is smaller than stock, the actual speed will be slower than the indicated speed. If the diameter is larger than stock, the actual speed will be higher than the indicated speed.

A wheel speed sensor is mounted at a fixed distance from the axis of rotation, say 4" from the centerline of the hub (I made that distance up, just for the record). Again, using hypothetical diameters because I don't feel like looking up specific numbers, assume the stock tire is 24" in diameter and the replacement tire is 25" in diameter. Visualize a point on the outside outside of the tire where it is contact with the pavement, at the very bottom of the tire. Rotate the wheel forward 1 full revolution, or 360 degrees. When the same point has once again come in contact with the groun the replacement tire will have traveled a slightly greater distance than the stock tire due to the larger circumference of the replacement tire. With either tire, the wheel speed sensor has seen only 1 revolution, and thus indicates the vehicle speed that it was calibrated to (which is based on the stock tire diameter).

Scott
90SM

 

Ummm ok...You just schooled us on how the sensor works which we already know.

So your telling me when i put my 205/50/15 tires on my speedo wont read the same as when i have the 215/45/17 being we have a wheel sensor that measures wheel speed.

 

Your speedo will read the same as it always has. It just won't be right. Your car "has no idea" that you've changed the diameter of your tires.

Scott
90SM

 

To use the tire sizes that you've listed,

With the 215/45-17 tires, your speedo says 60mph when you are traveling in 6th gear at a particular engine rpm.

Switch to the 205/50-15 tires, and in the same gear and engine rpm the speedo will still read 60mph (because the input to the wheel speed sensor hasn't changed) but the actual vehicle speed will be 6.26% slower. That is because the 215/45-17s rotate 845 times per mile and the 205/50-15s rotate 902 times per mile due to the difference in their circumference. Your still rotating the wheel the same number of times per minute, but a point on the outside diameter of the tire isn't traveling as far for each of those rotations.

Get it?

Scott
90SM

 

You know everytime I tell someone I switched wheels and tires and that I get a small gearing advantage and how the performance is improved they want to change the subject and talk speedo error. I don't care that the speedo is slightly off. I bought the car for good performance. If a slight speedo error is what I get in return for improved performance so what. I didn't buy the car because I wanted an super accurate speedo. It is close enough. If want to calibrate my speed I use a GPS. I wish people wouldn't always change the subject. It is about performance.

 

Well, since the discussion had taken a nearly 3 month break, I just responded to the most recent post.

The same basic geometery that drives the speedo change also changes gearing by the same percentage, and thus impacts acceleration. Going to a 15" combo frequently also lowers the weight and inertial effects, which also helps, but for acceleration I've personally found the gearing impact to be more noticable. I haven't had a stock diameter (or width for that matter) tire on my MCS for the last 75K+ miles for all of those reasons.

That's exactly why many autocrossers use smaller than stock diameter tires, and bingo, here we are in an autocross forum. Will wonders never cease?

Scott
90SM