who has tracked w/ 225/45 15s?...

[JRKOUPE]

Im wondering if it was obvious that the tire is a wee bit short?..did you run out of revs often and go to the next gear?...



Im used to 225/50s....but am considering 225/45s..

tia


Jrk

[nando]

which tire you looking at specifically?

I haven't.. but I need new 15's. Probably not going to do serious track use for a couple years so looking for some "smaller" high performance street tires instead.

I don't think you'd really notice much difference though. The biggest thing I notice going down a tire size or two is the decreased weight.. I found that I actually enjoy my car more on bottlecaps/snow tires than 235/50-15 R888s. :|

[JRKOUPE]

which tire you looking at specifically?

I haven't.. but I need new 15's. Probably not going to do serious track use for a couple years so looking for some "smaller" high performance street tires instead.

I don't think you'd really notice much difference though. The biggest thing I notice going down a tire size or two is the decreased weight.. I found that I actually enjoy my car more on bottlecaps/snow tires than 235/50-15 R888s. :|

235/50s are huge...lol

Ill pm you....

[dude8383]

Joel, I'm on 225 45's with my euroweaves. I went from a 205 50 16 wheel. I've got more grip now but didn't really notice a change in the attitude of the car.

Going to LRP on the 22nd, you goin?

[JRKOUPE]

Joel, I'm on 225 45's with my euroweaves. I went from a 205 50 16 wheel. I've got more grip now but didn't really notice a change in the attitude of the car.

Going to LRP on the 22nd, you goin?

hey..pm sent..


about LRP....bring snow tires....ya never know.

[gverelli]

^Same, 225/45 on euroweaves, never hit 5th at Tremblant with my larger 55 series Z1's, and still never touch 5th with the rs3's and they were half inch shorter,

[jlevie]

The Spec E30 tire on 15x7 rims is a 205/50, but in Enduros I ran 224/45's there was very little difference in rpm/speed. Certainly not enough to be noticeable.

[JRKOUPE]

The Spec E30 tire on 15x7 rims is a 205/50, but in Enduros I ran 224/45's there was very little difference in rpm/speed. Certainly not enough to be noticeable.

thats good to hear...thanks all!

[dude8383]

hey..pm sent..


about LRP....bring snow tires....ya never know.

EEK! If it snows my RS3's will be useless!!

[Jean]

I've done most of the season on 225/50 and last few events switched the rears to 225/45....I did that mostly because my 225/50 were done, and 225/45s were free.

[Wh33lhop]

Im wondering if it was obvious that the tire is a wee bit short?..did you run out of revs often and go to the next gear?...



Im used to 225/50s....but am considering 225/45s..

tia


Jrk

This is an easy calculation to perform if you remember where you're at at the end of most straightaways (although obviously you are not staring down at the tach when you reach your braking point :p).

I run 225/45r15s, there is very little sidewall flex. I run a 3.73 and my overall effective gearing is about halfway between a 3.73 and 4.10 with stock tires. So it is there, but not super noticeable.

[Fooshe]

I just did a 3 hour enduro on 225/45/15 Nittto NTO1's and they were steller! I did the sprints on my 205/50/15 spec tires (toyo RA1's) and I will say this, Spec E30 really should embrace using this tire size. MUCH better tire for this car's track set up.

[VinniE30]

Does decreasing the overall wheel/tire diameter have the same affect as a shorter differential ratio or a shorter gear ratios in the transmission?

Is it better to increase your gear ratio through the transmission choice, differential choice, or wheel/tire diameter choice?

I'm guessing the only difference is more stress on the parts in the transmission or differential if it's a shorter ratio.. I'm just wondering terms of performance though, not considering how hard it is to find a certain ratio differential or use a different transmission (ZF vs getrag) or have an inaccurate speedo.

[Emre]

I've got a stock M20B25 in my E30 track toy. I run a medium-case 4.10:1 LSD and 225/45-R15 tires. Between the smaller tire diameter and the shorter rear-end ratio, the overall gearing is noticably shorter compared to stock.

On the highway, it sucks. But on the track, it really helps with acceleration out of the corners. The car really pulls hard in 4th gear. At Tremblant, Mosport, and Watkins Glen, my gearing is perfect: I'm well into 5th at the end of the main straights and the gearing is spot-on for all the major corners.

[Wanganstyle]

Does decreasing the overall wheel/tire diameter have the same affect as a shorter differential ratio or a shorter gear ratios in the transmission?

Is it better to increase your gear ratio through the transmission choice, differential choice, or wheel/tire diameter choice?

I'm guessing the only difference is more stress on the parts in the transmission or differential if it's a shorter ratio.. I'm just wondering terms of performance though, not considering how hard it is to find a certain ratio differential or use a different transmission (ZF vs getrag) or have an inaccurate speedo.

if a full rally support shop was at your disposal, you would pick best handling wheels/tire for weight/fit for the chassis, and gear the individual gears 1/2/3/4/5/6 and final drive to be perfect for the course. BMW went to a close ratio with 1:1 final in the ZF style gearboxes to be more efficient, cut down driveline losses.

Larger tires usually allow for larger area of tire (if you cut and laid flat a 18" 245/40 it would be more total area of rubber than a 245/40/17). usually the more tire mass helps with heat, but this can be accounted for be higher temp rating/higher grip tire.

differential does not really care about tire size or abuse as long as its not over its working zone. if you are breaking the ring and pinion on power its another story.

Overheating the stock LSD in stock config(i.e.going to a drift day) will make the unit = open diff quickly, I did this in my e36m.... oops :P