Tire Talk Megathread

[Gossypiboma]

Originally Posted by rhyary

Bartledoo ,
As I mentioned above
The 265 tire has max load of 1609
The 275 has max load of 1521 and cost more.

This is not the same on the 30 aspect ratio:
The 285 has less max load than 295.

Why would it be? What does it mean?
Which one is faster?

You can attack me all you want and treat me like an idiot if it makes you feel good. After all it is a sign of the time to attack the person, rather then deal with the question.

But for those who are curious like me, it is still interesting to find out the answer.

I dont see how a tires max load rating is going to effect grip? FYI I'm a decent bit faster on the 295/30 than the 275/35.

I also disagree with the statement that utilizing a square setup doesn't end up with a cost savings. It absolutely does. Being able to rotate from left to right and front to back certainly prolongs the life of a set of tires.

[Bartledoo]

Originally Posted by rhyary

Bartledoo ,
As I mentioned above
The 265 tire has max load of 1609
The 275 has max load of 1521 and cost more.

This is not the same on the 30 aspect ratio:
The 285 has less max load than 295.

Why would it be? What does it mean?
Which one is faster?

You can attack me all you want and treat me like an idiot if it makes you feel good. After all it is a sign of the time to attack the person, rather then deal with the question.

But for those who are curious like me, it is still interesting to find out the answer.

I’m not attacking you dude. Just trying to prevent bad advice from getting pushed onto people who are new to this stuff. Sorry if it seems like an attack on you, but it’s really just an attack on the “information” you provide. You’re probably a great person. I have no doubt.

[rhyary]

Originally Posted by Bartledoo

I’m not attacking you dude. Just trying to prevent bad advice from getting pushed onto people who are new to this stuff. Sorry if it seems like an attack on you, but it’s really just an attack on the “information” you provide. You’re probably a great person. I have no doubt.

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Bartledoo
Are you saying that stuffing a 295/30/18 is a good advice for people new to this sport?

Are you saying that running 285/30/18 square is a good advice to new people?


Are you saying that 265/35/18 front and 275/35/18 rear is a bad advice?

On the basis of what do you say that I am giving a bad advice?

I am just curious to know since I have hands on tried most of the setups I am talking about (granted in 19” not 18”) and work with novice drivers multiple times a month and on multiple tracks.

Your main claim to not listen to me is that I don’t know how to drive. Perhaps. I am not claiming to be an extrodenary driver.

What I do see on the track is a lot of people compensating for slow driving with equipment. Specifically when people want to go faster, they buy bigger tires and than stickier tires. And they do go faster. But if they continue to drive the “skiny tires” and get better with managing traction they will be faster anyway.

A bigger tires will also give you one faster lap with less effort. I can see it when I am next to the new Corvettes. They have huge tires. They don’t have to take advantage on what the track gives them. They go anywhere any line and still have the traction to pull it off a bad line.

When you are on less fortunate tires, you have to find and be in the camber, you need to be aware when you losing camber, everything matter. And it is more enjoyable to try to be more precise.

And remember, just because you say something is bad advise, does not make it so.

“Just trying to prevent bad advice from getting pushed onto people who are new to this stuff.”

Wow, Internet humility is not your strong point, but I am sure you are great guy in person like we all are. :-)

[Bartledoo]

Originally Posted by rhyary

.
Bartledoo
Are you saying that stuffing a 295/30/18 is a good advice for people new to this sport?

Are you saying that running 285/30/18 square is a good advice to new people?


Are you saying that 265/35/18 front and 275/35/18 rear is a bad advice?

On the basis of what do you say that I am giving a bad advice?

I am just curious to know since I have hands on tried most of the setups I am talking about (granted in 19” not 18”) and work with novice drivers multiple times a month and on multiple tracks.

Your main claim to not listen to me is that I don’t know how to drive. Perhaps. I am not claiming to be an extrodenary driver.

What I do see on the track is a lot of people compensating for slow driving with equipment. Specifically when people want to go faster, they buy bigger tires and than stickier tires. And they do go faster. But if they continue to drive the “skiny tires” and get better with managing traction they will be faster anyway.

A bigger tires will also give you one faster lap with less effort. I can see it when I am next to the new Corvettes. They have huge tires. They don’t have to take advantage on what the track gives them. They go anywhere any line and still have the traction to pull it off a bad line.

When you are on less fortunate tires, you have to find and be in the camber, you need to be aware when you losing camber, everything matter. And it is more enjoyable to try to be more precise.

And remember, just because you say something is bad advise, does not make it so.

“Just trying to prevent bad advice from getting pushed onto people who are new to this stuff.”

Wow, Internet humility is not your strong point, but I am sure you are great guy in person like we all are. :-)

I’m not trying to convince you of anything, anymore. That ship has sailed. We have all tried many times. The humility, as you say, is not there when it comes to performance driving, and accepting logic when it comes to driving and equipment. You will interpret your data to confirm your own theories, and that will be that.

But, if you just start spamming good threads will senseless stuff, it will be unfortunate.

In re equipment, though, do you not have a supercharger and giant aero?

I’ll let it fizzle here…

[leftfootbr8king]

Bartledoo can’t help but feel like providing a facts and or/experience based counterpoint for readers to weigh, without the confrontation, would have produced a productive result.

Is this how you would converse standing in front of him at the track?

[DRLane]

Originally Posted by leftfootbr8king

Bartledoo can’t help but feel like providing a facts and or/experience based counterpoint for readers to weigh, without the confrontation, would have produced a productive result.

Is this how you would converse standing in front of him at the track?

You’ll have to read through the existing thread. Unfortunately, it’s too much to bring every new account up to speed.

https://www.m3post.com/forums/showthread.php?t=1685308

[leftfootbr8king]

I’ve read that thread in it’s entirety.

[Bartledoo]

Originally Posted by leftfootbr8king

Bartledoo can’t help but feel like providing a facts and or/experience based counterpoint for readers to weigh, without the confrontation, would have produced a productive result.

Is this how you would converse standing in front of him at the track?

If we had been through the same bs hundreds of times already, yes. Several of us have spent plenty of time trying, previously.

It’s not like I’m an asshole in person. I socialize quite a lot at the track, and I help every single person who wants or needs a moment of my time. But, I also won’t stand by listening to someone at the track talking nonsense at a group of people. Nor would I expect anyone else to listen to me do the same.

It would be a lot easier to sift through this if we were all at the same track together.

Back to tires. When is the new CR-S available?

[BoilerUP]

Originally Posted by Bartledoo

Back to tires. When is the new CR-S available?

A few sizes are already available.

https://philstireservice.com/product...-cr-s-v2-2023/

[DrFerry]

Originally Posted by BoilerUP

I've got two track days with 10 sessions and three ~120min drives between my house and NCM on a set of 275/35R18 front and 295/30R18 rear RE71RS. Cadillac ATS-V Sedan so similar to a M3. Camber -3.0 front, -2.0 rear, pressures 29l/30r cold first session, bled down to 30psi before subsequent sessions.

Okay, I'll bite and throw my hat into the ring. For 10 track sessions and three ~2hour drives between your house and NCM your tires don't look too bad. However, there are some things that are obvious to me when "reading the tires" from the photos and their wear pattern(s).

Some housekeeping items first: The OEM fitment for the ATS-V coupe is front size = 255/35ZR18 (94Y) XL and rear size = 275/35ZR18 (99Y) XL. The 275/35R18 RE-71RS is 0.6in taller than the OEM fronts diameter. The 295/30R18 RE-71RS is 0.6in shorter than the OEM rear tire diameter. So 1.2in of rake has been introduced which might affect weight distribution - slightly. Not a big deal, but something to be aware of. Additionally, the load index of the OEM rear tire is 99 whereas the load index of 295/30R18 RE-71S is only 94.

The best practice is to set pressures and camber using a pyrometer and measuring data when the tires are up to operating temperatures (approximately 200F to 210F) depending upon product and manufacturers approach to the tread compounding rheology. The goal is to achieve uniform tire temperatures across the face of the tread +/- 10F from inside shoulder to outside shoulder. This is achieved primarily through alignment settings and corner balancing with pressures acting as a fine tuning tool. This topic is covered in more depth in the files attached.

General recommendations -> if keeping the same tire sizes and brand as pictured:
1) Get a pyrometer and take tire temperature and pressure data by coming "hot" into the pits. Then make adjustments as mentioned in the attachment examples etc.

2) Increase the front and rear negative camber by -1.0 degree in the front and -0.5 degrees in the rear.

3) Use a higher starting cold inflation pressure of about +3.0psi from whatever pressure was used for the 10 track sessions mentioned (~33psi cold). Aim for uniform pyrometer readings across the face of the tread both front and rear axle positions (+/-10F).

4) Aim for a hot pressure ceiling of +6 to +7psi over the cold starting pressure towards the end of the session. IF you see a hot pressure gain higher than this recommendation, then increase the cold starting pressures. This is because if the cold pressures are too low excessive carcasse and belt flexing will increase the hot pressure. Not to mention the tire's shoulder will roll under the rim causing wear. Think of repeatedly bending a coat hanger - it gets hot due to fatigue doesn't it - same for rubber, steel and polyester.

Please see the edited photos with comments and the other files attached with pressure and alignment rules of thumb examples. PS: Load index is not an indication of a tire's grip potential. UTQG Treadware rating is 'perhaps' a better indicator than load index.
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[slcook54]

Originally Posted by Bartledoo

If we had been through the same bs hundreds of times already, yes. Several of us have spent plenty of time trying, previously.

It’s not like I’m an asshole in person. I socialize quite a lot at the track, and I help every single person who wants or needs a moment of my time. But, I also won’t stand by listening to someone at the track talking nonsense at a group of people. Nor would I expect anyone else to listen to me do the same.

It would be a lot easier to sift through this if we were all at the same track together.

Back to tires. When is the new CR-S available?

I bought them last night from elite performance, local shop. Just shy of $1600 shipped. 285/30/18. Will mount them on my new e88s when they get here. Still have another set of 295/30 71RS to get through first.

[b4hand]

Originally Posted by rhyary

.

What I do see on the track is a lot of people compensating for slow driving with equipment. Specifically when people want to go faster, they buy bigger tires and than stickier tires. And they do go faster. But if they continue to drive the “skiny tires” and get better with managing traction they will be faster anyway.

When you are on less fortunate tires, you have to find and be in the camber, you need to be aware when you losing camber, everything matter. And it is more enjoyable to try to be more precise.

I can agree with this. I have been using a less known tire, the Maxxis Victra RC-1, 275/35/18 and most people have said I need to get on a faster tire, or a "better" tire. But I have been wanting to focus on me as a driver, vs going with a defacto fast tire. I am actually conquering some fears with getting to the limit of the tires, and understanding how to be faster. Still have a long way to go.

[rhyary]

In the spirit of keeping this thread alive
4 fronts and 4 rears for ~$1200.00

Too bad I have too many tires already waiting for a car.

[slcook54]

285/30/18 CRS (Left) vs. 295/30/18 RE71RS (Right). Both on 18x10.5 wheels.

[rhyary]

Originally Posted by slcook54

285/30/18 CRS (Left) vs. 295/30/18 RE71RS (Right). Both on 18x10.5 wheels.

Can you spray some water on the tires, role them on some flat surface and measure the actual tread width?

Be insteresting to see the contact patch difference

[DrFerry]

Originally Posted by rhyary

Can you spray some water on the tires, role them on some flat surface and measure the actual tread width?

Be insteresting to see the contact patch difference

For a contact patch size or shape measurement to be meaningful, the tires would need to be under load (same load) with the same pressure. There should be a noticeable difference in outer diameter. The Tire & Rim Association (T&RA) as well as the ETRTO allow a tire design “window” with recommened tolerances for section width and diameter. In summary a “fat” tire on the far end of the design window can overlap a “skinny” tire on the narrow side of the window - in the next size up or down - if different manufacturers are using different design philosophies.

Example: One manufacturer seeks to minimize weight (for lower rotating inertia or cost reasons?) while another seeks to maximize grip by widening the tread and section widths.

In this streetable category of tires the difference shown in the photos is surprising, though I’ve seen it before. When tire manufacturers are seeking to reduce tooling costs or perhaps sharing mold parts among similar sizes they sometimes exploit the T&RA design window.

[BoilerUP]

Closing the loop:

After my 13th session on the RE71RS, I saw my left *rear* 295/30R18 RE71RS tire had corded. At this point, the tire had 4-4.5hr of track time.



I threw my street 285/35R18 rear PS4S on and drove three more 20-25min sessions; my front left 275/35R18 71RS was completely toast after that:



Conclusions confirming other posters upthread: The RE71RS needs more than -3.0 front camber my 3800lb sedan, and I likely was running the tires at a bit too low pressure.

I threw another sent of Conti ECFs on the car, my first set of those got 32 sessions and while they don't have nearly the pace they're hard to kill. Feel ready to try DH scrubs but will probably do a set of RRs next.

I like you Bimmer folks, most V owners are scared of turns

[Tommysalami]

Originally Posted by rhyary

In the spirit of keeping this thread alive
4 fronts and 4 rears for ~$1200.00

Too bad I have too many tires already waiting for a car.

Doesn't 265/35-19 rub a lot up front?

[rhyary]

Originally Posted by Tommysalami

Doesn't 265/35-19 rub a lot up front?

yes big time.
It is not a size for garage queens.

[e92BMW///M3]

Originally Posted by BoilerUP

Closing the loop:

After my 13th session on the RE71RS, I saw my left *rear* 295/30R18 RE71RS tire had corded. At this point, the tire had 4-4.5hr of track time.

Conclusions confirming other posters upthread: The RE71RS needs more than -3.0 front camber my 3800lb sedan, and I likely was running the tires at a bit too low pressure.

Appreciate it is a different platform, but what were you running pressure wise that you thought was too low? I've run the RE71RS 285/30/18 on my mostly stock weight (full interior) M3 targeting ~35psi hot which typically means about ~30psi cold. Currently around 2.7* front camber (from memory).

[BoilerUP]

Originally Posted by e92BMW///M3

Appreciate it is a different platform, but what were you running pressure wise that you thought was too low? I've run the RE71RS 285/30/18 on my mostly stock weight (full interior) M3 targeting ~35psi hot which typically means about ~30psi cold. Currently around 2.7* front camber (from memory).

I had a couple sessions - after lunch - where I went out at 28psi (started 30psi cold, got up to 35 hot, then sat for a while and I neglected to check prior to suiting up).

I think 30psi cold is totally fine, but 28psi is likely fine for time trials, but for a 25-30min session 28psi cold is probably a bit too low.

[danvitmon]

There was a previous message where a guy asked

"Anyone have some suggestions on a tire for 100% HPDE use? Dedicated wheel set so no street use, I'm running a 275/35/18 now which fits nicely so if I can stick with that size it'd be great.

Needs in order of importance:

Long life/hard wearing
Cost effective
Great dry grip
Decent wet grip"

A few people chimed in and said V730, NT01, or RS-4. I am in the same boat in terms of cost effectiveness since I just finished my courses at 22yrs old, and I don't really have 1-2k to drop on tires that will last 3 days but are insanely fast (A052/RE71RS/CRS).

I have heard lots of good things about the V730 from guys with lighter weight cars but haven't heard a whole lot from E9X M3 guys, so what are your guys' thoughts on them? I would run a 265/35/18 or 275/35/18 on a 10.5 square, and the $900 shipped cost for V730s is irresistible. I am a fiend for used tires though since that is as cost effective as it gets, but if worse comes to worse, I would buy a new set of V730s.

Speaking of used tires, if anyone has a used set of 200tw 265/35/18 or 275/35/18 tires in the bay area or is within a 7hr radius, let me know