Tire Talk Megathread

[Bartledoo]

Originally Posted by rhyary

This is interesting to me.
I have never had an issue in the rear wear wise.
At times I had a grip issues but not wear.

I would love to understand this better if you don't mind to elaborate. What wears out? center? Sidewall? How do you setup the car to wear the rear?

You increase the rear roll stiffness relative to the front, and set the car up with actual neutral balance. Most people are just running crazy soft rear relative to the front. For example, I’m running 628f and 1120r spring rates, front and rear hotchkis bars both on soft setting.

[rhyary]

Originally Posted by Bartledoo

You increase the rear roll stiffness relative to the front, and set the car up with actual neutral balance. Most people are just running crazy soft rear relative to the front. For example, I'm running 628f and 1120r spring rates, front and rear hotchkis bars both on soft setting.

My spring rates are 800f (coil over) and 1200r (divorced). It does not feel lazy setup to me.

[Bartledoo]

Originally Posted by rhyary

My spring rates are 800f (coil over) and 1200r (divorced). It does not feel lazy setup to me.

Bar settings?

[rhyary]

Originally Posted by Bartledoo

Bar settings?

Fixed from H&R
I used to have Hotchkis

[bigjae1976]

Originally Posted by Kelse92

Tire rack should have a test out in the new Yoko slick in a few weeks. They're testing it vs the R7
If you're ever in Dallas or don't mind paying shipping we get lots of 250/265 18 scrubs off a GT4 usually $50-100/tire depending on heat cycle count

Interested. Sending a PM.

I've used the Z214s on my E46. They are really grippy for a day or two and then fall off pretty fast.

[b4hand]

I think I'm going with Maxxis RC-1. Only about $50 more per tire than RS4's

[alpine2530]

Has anybody tried Vitour Tempesta semi slick tires?

[spxxx]

Originally Posted by alpine2530

Has anybody tried Vitour Tempesta semi slick tires?

Sound sketch. I like it.

Someone please tell me they're good.

[bigjae1976]

I heat cycled my first set of RRs, skipped it for the 2nd.

I feel like I got more fast sessions and the tires lasted longer with the heat cycling. I feel like it is well worth the $60.

Onto my 3rd set of RRs...forgot to check the heat cycle box. Damnit!

[b4hand]

Originally Posted by bigjae1976

I heat cycled my first set of RRs, skipped it for the 2nd.

I feel like I got more fast sessions and the tires lasted longer with the heat cycling. I feel like it is well worth the $60.

Onto my 3rd set of RRs...forgot to check the heat cycle box. Damnit!

How long did the heat-cycle'd set last?

[slcook54]

Is 295/30/18 square is doable on stock front fenders? I'm running -3.5 camber and a 3mm spacer. I'm on 18x10s but open to moving to 18x10.5 or 18x11 (if that will work).

[leftfootbr8king]

Originally Posted by slcook54

295/30/18 square is doable on stock front fenders right? I'm running -3.5 camber and a 3mm spacer. I'm on 18x10s but open to moving to 18x10.5 or 18x11 (if that will work).

3mm spacer on what wheel backspace

[leftfootbr8king]

Originally Posted by leftfootbr8king

3mm spacer on what wheel backspace

11" square is going to be a difficult fit. No/trashed fender liners, probably will need adjustable control arms up front to adjust track width.

11" in the back is no issue.

295/30 on 10.5" square gets you the most with the least extra effort. I've done it, and know personally other cars that do with an effective backspace of -15 thru -20 depending on helper springs or not.

[DRLane]

295/30/18 isn't a problem on the front across any of those widths. I'm in 11'' in the front with et 19. No damage to the fender but definitely worn the liners in spots over the years.

That said, moving to 10.5 square with intention for 27/65-18 Mich slicks vs current 315/295 Hoosiers.

[DrFerry]

Originally Posted by DRLane

That said, moving to 10.5 square with intention for 27/65-18 Mich slicks vs current 315/295 Hoosiers.

Data below from the Michelin Racing Tire Catalog should you need it..
.

[DRLane]

Originally Posted by DrFerry

Data below from the Michelin Racing Tire Catalog should you need it..
.

Yes, they have a robust catalog! Not sure if you're referencing their 11" wheel width?

It's common front tire on Porsche cup

[DrFerry]

Originally Posted by DRLane

Yes, they have a robust catalog! Not sure if you're referencing their 11" wheel width? It's common front tire on Porsche cup

I was just wanting you to see that different compounds were available (and rains) in the size you mentioned. An 11" wide rim is ideal, but the size will fit on a 10.5" wide rim. However, you may lose a small amount of cornering power at larger slip angles. When comparing machine test (bench) data versus the same tire, at the same load, and same pressure, mounted on an 11 inch wide rim versus a 10.5 inch wide rim the loss is about 3 to 5% if I recall correctly (area under the curve = cornering power). The design application rim (the recommended rim) is best IF it can fit under the fender - which I realize with the E9X isn't always possible without fender liner removal etc. up front.

[DRLane]

Originally Posted by DrFerry

I was just wanting you to see that different compounds were available (and rains) in the size you mentioned. An 11" wide rim is ideal, but the size will fit on a 10.5" wide rim. However, you may lose a small amount of cornering power at larger slip angles. When comparing machine test (bench) data versus the same tire, at the same load, and same pressure, mounted on an 11 inch wide rim versus a 10.5 inch wide rim the loss is about 3 to 5% if I recall correctly (area under the curve = cornering power). The design application rim (the recommended rim) is best IF it can fit under the fender - which I realize with the E9X isn't always possible without fender liner removal etc. up front.

Great share, thx!

[Bartledoo]

Originally Posted by DrFerry

Data below from the Michelin Racing Tire Catalog should you need it..
.

The michelin slicks are interesting. Their shape seems as if they were designed around maximum allowable tread widths, but wheel width was not a limitation.

[DrFerry]

Originally Posted by Bartledoo

The michelin slicks are interesting. Their shape seems as if they were designed around maximum allowable tread widths, but wheel width was not a limitation.

The 'generic' Michelin Racing Slicks are designed for a nominal (application) rim width with a recommended width tolerance (+/-) due to their use in motorsports arenas where maximum rim width is either unknown, or not governed by sanctioning body rules. Their molded and inflated pneumatic shape is designed to maximize lateral stiffness and cornering power. In layman's terms that means 'straight up and down' sidewalls rather than a rounded inflated profile. At the back of the Michelin Racing Tire Catalog recommendations are given for rim width applications, pressure, camber ranges, etc. for each size produces (and compounds). See the extract below for 27/65-18 which shows the nominal application rim width = 11.0 (+/- 0.5 inches).
.

[Bartledoo]

Originally Posted by DrFerry

The 'generic' Michelin Racing Slicks are designed for a nominal (application) rim width with a recommended width tolerance (+/-) due to their use in motorsports arenas where maximum rim width is either unknown, or not governed by sanctioning body rules. Their molded and inflated pneumatic shape is designed to maximize lateral stiffness and cornering power. In layman's terms that means 'straight up and down' sidewalls rather than a rounded inflated profile. At the back of the Michelin Racing Tire Catalog recommendations are given for rim width applications, pressure, camber ranges, etc. for each size produces (and compounds). See the extract below for 27/65-18 which shows the nominal application rim width = 11.0 (+/- 0.5 inches).
.

The sidewalls are flat but extremely canted on the correct rim width.

[DrFerry]

Originally Posted by Bartledoo

The sidewalls are flat but extremely canted on the correct rim width.

Good observation. This canted sidewall shape you mentioned is also known as 'trapezoidal' inflated shape. It's a design strategy for gaining cornering power for 'free' so to speak. Up to a certain point, a wider rim width is better and serves to allow the tire a 'more stable foundation' especially under cornering loads. Hence, in this example a 27/65-18 can also be mounted on an 11.5 inch wide rim per the Racing Catalog. Perhaps my layman's term straight up and down sidewalls choice of words is the not the best, but in comparison to the rounded passenger car or SUV tire inflated shapes we see on the street it suffices to convey the concept. Take a look at eighteen wheeler steer axle semi truck tires and you will see a similar strategy being employee due to the huge forces those tires must generate.