Tire Talk Megathread

[Gossypiboma]

Originally Posted by slcook54

What size? I’m happy with 4 days, not 2.5.

295/30/18

The rest of the tire looks like it could go another 4 days. The outer edge wear is significant for some reason. Didn't have this issue with NTO1s or RRs.

[BoilerUP]

What cold/hot tire pressure were those RE71RS run at, and were they rotated side-to-side at all?

I ran them 35ish hot at NCM on my ATS-V sedan with -3.0 camber up front and while I've only got one day on them they look fine.

[Gossypiboma]

Originally Posted by BoilerUP

What cold/hot tire pressure were those RE71RS run at, and were they rotated side-to-side at all?

I ran them 35ish hot at NCM on my ATS-V sedan with -3.0 camber up front and while I've only got one day on them they look fine.

35 psi hot in my case and I did rotate.

[slcook54]

Originally Posted by Gossypiboma

35 psi hot in my case.

36 here.

I didn’t rotate side to side but will on this current set.

[spxxx]

Originally Posted by slcook54

36 here.

I didn’t rotate side to side but will on this current set.

I'm running mine at 33-34psi hot and they seem to wear pretty evenly.

[e92BMW///M3]

I have staggered rims (18x9.5 +22, 18x10.5 +23) and was looking at the RE-71RS. Initially I was thinking of trying 285/30/18 front and 295/30/18 rear, but then got the itch to try a square setup. I currently run 275/35/18 front and 285/35/18 rear and on the Lime Rock Park autocross (pretty tight setup), I feel a bit front-grip limited.

Any practical downside to running 295/30/18 all around on my current rims? The plan would be to swap the front rims to match the rears in the future if I liked the square setup, but didn't want to have the expense of 2 new rims for an experiment. If I didn't like the 295/30 on the front I figured I could always dismount and use them on the rear in the future and figured I could test fit the fronts as well. I appreciate this isn't conventional and that it wouldn't be a true square setup given the difference in sidewall support, but assumed it would be a reasonable proxy.

[Bartledoo]

Originally Posted by e92BMW///M3

I have staggered rims (18x9.5 +22, 18x10.5 +23) and was looking at the RE-71RS. Initially I was thinking of trying 285/30/18 front and 295/30/18 rear, but then got the itch to try a square setup. I currently run 275/35/18 front and 285/35/18 rear and on the Lime Rock Park autocross (pretty tight setup), I feel a bit front-grip limited.

Any practical downside to running 295/30/18 all around on my current rims? The plan would be to swap the front rims to match the rears in the future if I liked the square setup, but didn't want to have the expense of 2 new rims for an experiment. If I didn't like the 295/30 on the front I figured I could always dismount and use them on the rear in the future and figured I could test fit the fronts as well. I appreciate this isn't conventional and that it wouldn't be a true square setup given the difference in sidewall support, but assumed it would be a reasonable proxy.

There is a very good chance you will have worse front end pinching 295/30 on the 9.5” front.

It always depends, but here is a fun test tirerack did on the matter.

https://m.tirerack.com/tires/tests/t...y.jsp?ttid=296

[e92BMW///M3]

Originally Posted by Bartledoo

There is a very good chance you will have worse front end pinching 295/30 on the 9.5” front.

It always depends, but here is a fun test tirerack did on the matter.

https://m.tirerack.com/tires/tests/t...y.jsp?ttid=296

Thanks, interesting article. It makes sense that the 295/30 might be worse short term than the 285/30 on the 9.5 rim and based on the article the 285/30 might also not be ideal on the 9.5 rim either.

[slcook54]

Originally Posted by e92BMW///M3

Thanks, interesting article. It makes sense that the 295/30 might be worse short term than the 285/30 on the 9.5 rim and based on the article the 285/30 might also not be ideal on the 9.5 rim either.

I think 285/30 or 295/30 on a 10.5 is going to be the sweet spot. I have 295/30 mounted on my RIAs, going to try 285/30 next.

Separately the new Nankang CRS are getting positive feedback over the RE71RS. May give that a shot.

[rhyary]

I drove an E92 M3 track preped on 285/30/18 square at PMP last week on RE-71RS. 10” RIMs. I drove an E46 M3 track prepped on 275/35/18 square at LRP on 10” rims.

In my opinion a setup to try will be 265/35/18 front and 275/35/18 Rear.

I do not belive that the 30 series tires will be faster than 35. I also think but not tested that the 265/35/18 front - 275/35/18 rear will be more balanced setup.

My .02

[tsk94]

Originally Posted by rhyary

I drove an E92 M3 track preped on 285/30/18 square at PMP last week on RE-71RS. 10” RIMs. I drove an E46 M3 track prepped on 275/35/18 square at LRP on 10” rims.

In my opinion a setup to try will be 265/35/18 front and 275/35/18 Rear.

I do not belive that the 30 series tires will be faster than 35. I also think but not tested that the 265/35/18 front - 275/35/18 rear will be more balanced setup.

My .02

Why?
Both why would 30 series tires be slower, and why the 265/275 would be more balanced. Not saying you're wrong, just curious on your thinking.

[rhyary]

Originally Posted by tsk94

Why?
Both why would 30 series tires be slower, and why the 265/275 would be more balanced. Not saying you're wrong, just curious on your thinking.

.
The 30 series tire have less tire wall. If we agree that the tires are part of the suspension then the 35 in relation to the width have more ability to obsorb the imperfection. This is the theory. In my experience the 30 tires below 300 width are sliding more than digging in. When starting a turn, there is a small steering input that puts the car on the outside springs (loading the suspension) . Then you add steering to actually turn. I find the 30 to be more sliding than digging in.

In general, the 35 will take more air and the 30 will ride on the stiff side wall.

The OEM setup 245/35/19 and 265/35/19 has not only staggard setup in width. The rear has more sidewall and the tires providing rake. I would say that BMW has a reason to do so.

I would think that the 265/35/18 and 275/35/18 will have some of that idea.

[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.

These tires were right side first day (5 sessions) then left side second day (5 sessions)


These tires were left side first day (5 sessions) then right side second day (5 sessions)

[rhyary]

[QUOTE=BoilerUP;30172235]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.

Can you show us the outside edge?
Take a picture 45* from above so we can see the outside and part of the middle to the outside.

Cambar numbers look good. can you do -3.0 with stock suspension or aftermarket?

-2.0 rear is very good.

For your next set change the rear to 275/35/18 and see if you will be any slower. My bet is that you are just as fast as 295/30/18 on the same tires.

[Gossypiboma]

[QUOTE=rhyary;30172500]

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.

Can you show us the outside edge?
Take a picture 45* from above so we can see the outside and part of the middle to the outside.

Cambar numbers look good. can you do -3.0 with stock suspension or aftermarket?

-2.0 rear is very good.

For you next set change to 275/35/18 and see if you will any slower. My bet is that you are just as fast as 295/30/18 on the same tires.

295 vs 275 square is definitely faster. Maybe im not understanding correctly, but are you saying otherwise?

[rhyary]

Researching the RE-71RS specs as provided by Tirerack

The 265/35/18 max load is 1609
The 275/35/18 max load is 1521
The 285/30/18 max load is 1433
The 295/30/18 max load is 1477

The interesting point is that the 265/35/18 has the highest max load. No sure what all this means, and as you all know my experience is more with the 19” size. My fastest setup is 265/35/19 on the front, and I would dare to say I think the 265/35/18 will also be a good choice.

While drivers like the rotation idea, this idea has not carried any savings. Just before I corded the front, on number on ocassions and accross mutiple tires types and sizes, I went the fastest lap on the setup. Once I corded a front, there is no point putting it on the rear.

So I would advise to focus on what best for your car/setup and not strive for a square setup.

What the front need is not what the rear need. so optomize the setup to be mediocre on both ends is not very satifying.

Perhpas someone here can shed light on the max load factor. But guesing here, if max load on the 265/35/18 is higher than I want that tire on the front to take the abuse a front tire go thru.

when someone conclude that they don’t have enough front grip with 275/35/18, so the next thing to try is 285/30/18 or 295/30/18, then I would say this away over simplification of front grip.

Perhaps it is counter intuitive to look for more grip by “downsizing” to 265/35/18, but I think it has enough merit to give it a try.

When I went to a ridicules size of 235/35/19, the grip was amazing on the RR, but the tire did not last long. And that should be also a consideration.

All of the above is me thinking. unfortunetly I can’t speak from first hand experience yet. Working with number of students to optimize setup and perhaps later in the summer I will have something more hands on.

Once my car is together, I will be mostly on 275/35/19 rear and 265/35/19 front. I do have to burn some 305/30/19 and 295/30/19 I have in stock.

[Bartledoo]

I’m sorry rhyary but your experience is counter to reality in too many cases to be taken seriously. In the past you’ve gone from old street tires to slicks and not found the appropriate lap time corresponding to the difference in tire; and then claimed at certain tracks sticky tires are not faster than old street tires. You just don’t know how to get the maximum performance (or near to it) out of a set of tires.

Not trying to be mean, but I feel irresponsible just letting someone advise people based on left field opinions.

[DRLane]

Originally Posted by Bartledoo

I’m sorry rhyary but your experience is counter to reality in too many cases to be taken seriously. In the past you’ve gone from old street tires to slicks and not found the appropriate lap time corresponding to the difference in tire; and then claimed at certain tracks sticky tires are not faster than old street tires. You just don’t know how to get the maximum performance (or near to it) out of a set of tires.

Not trying to be mean, but I feel irresponsible just letting someone advise people based on left field opinions.

I know this is the common narrative, but friendly reminder he’s working a lot with professional coaching (probably more than almost anyone on here) and has tons of data acquisition (again more than most in this regard too).

At LRP on those 300 tw mismatch setups he’s within 1 sec of f8x on RRs (60 seconds). I’ve sat shotgun for a day and I can confidently say he’s driving the car.

Could he push harder on slicks? Probably but he’s not as Willy Nilly as it seems.

[BoilerUP]

My ATS-V has Vorshlag camber plates; all I could get stock was -2.0 front.

I'll probably try 275 squared at some point as that opens up a bazillion tire options for 18" wheels, but with 600whp on E48 and no rear aero I'd be tiptoeing into high-speed sweepers in respect of snap oversteer.

Regardless, I'm far from maximizing the available grip of the 71RS and appreciate sharing experiences with this tire on chonky sedans.

[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.

[BoilerUP]

Here's some pictures of one of my front 275/35R18 RE71RS as requested

[Matt Fojtik]

Has anyone here tried the AD09’s yet?