Michelin Cup 2 Shredded and Rolled

[tacthecat]

Touring Car rules specify rim size as 10"x18" maximum.

Sponsored

 

[metal_driver]

Now I'm at a cross road. Do I get the NSX wheels at 19x9.5 or get other 18x9.5 wheels? Most Type R folks are using 18", and Honda Performance Development chose 18" for its Type R TC and TCR cars.

https://hpd.honda.com/Articles/Touring/TypeR

What I like about the NSX wheels:

• The offset at +55 is very close to the OEM of +60. That should make the scrub radius close to OEM and reduce torque steer.
• Cup 2 tire is widely available for 19" wheels, but hard to find for 18", and I really like the handling of the Cup 2. It's the most widely used tire to break records at the Nurburgring.

Some questions:

1. How do the NSX wheels handle compared to OEM (e.g. responsiveness to steering input and precision)?
2. How bad Is the torque steer in 2nd and 3rd gear?
3. Did you need to modify anything to fit the NSX wheels, or they bolt right in?
4. How does the increased negative camber affect traction in straight line (hard braking and acceleration)?

Sam3, here are my answers to your four questions;

1. I had the 19" NSX wheels installed at the same time as I had the Hardrace lower camber adjust plates put on. I gotta to tell you it definitely felt a little different on the street probably due mostly in part to the increased camber (I added 1 degree plus a bit when I had the pins pulled). The driving feeling definitely was not as crisp but as I learned the increased camber is a must for the track.

2. With such a small offset change I did not notice a difference in torque steer.

3. The NSX 19" front rims simply bolt on. Only thing I added/used were centering rings as the wheel center bore is larger on the NSX wheel, but some say they are not required.

4. I went with a slightly wider tire (255) and they were Cup 2's so overall better traction.

Now having said all that, I was thinking alot like you when I first started out a little over a year ago - I was more concerned about keeping the offset close to oem.

This year, however I've decided to go with to 18x9.5 +45 wheels as I've come to realize what many were saying all along - the tire cost are lower with the 18's and you can get a wider tire on the wider rim. Also the track does not treat rims kindly and the NSX rims aren't exactly cheap so I've decided I save those for street use.
Although I haven't had a chance to try out the new Motegi Traclite 3.0's I just got in, I highly suspect that the change in torque steer will also be negotiable... as many have been saying. i'll let you know how it goes when I get a chance to try them out.

 

[Dave B]

I went to 18 x 9.5 with 45 mm offset with both 265 and 275 tires (bought 2 sets) and didn't notice any issue with torque steer or fitment on a stock suspension. Increasing camber with Hardrace ball joints helped a lot.

 

[dominican]

This is pretty common actually. It's an issue with not having enough negative camber, too much lateral forces on the sticky surface rubber when you are turning causes the rubber to start separating. In order to reduce this, you'll need to add negative camber to your suspension setup.

 

[Sam3]

Sam3, here are my answers to your four questions;

1. I had the 19" NSX wheels installed at the same time as I had the Hardrace lower camber adjust plates put on. I gotta to tell you it definitely felt a little different on the street probably due mostly in part to the increased camber (I added 1 degree plus a bit when I had the pins pulled). The driving feeling definitely was not as crisp but as I learned the increased camber is a must for the track.

2. With such a small offset change I did not notice a difference in torque steer.

3. The NSX 19" front rims simply bolt on. Only thing I added/used were centering rings as the wheel center bore is larger on the NSX wheel, but some say they are not required.

4. I went with a slightly wider tire (255) and they were Cup 2's so overall better traction.

Now having said all that, I was thinking alot like you when I first started out a little over a year ago - I was more concerned about keeping the offset close to oem. This year, however I've decided to go with to 18x9.5 +45 wheels as I've come to realize what many were saying all along - the tire cost are lower with the 18's and you can get a wider tire on the wider rim. Also the track does not treat rims kindly and the NSX rims aren't exactly cheap so I've decided I save those for street use.
Although I haven't had a chance to try out the new Motegi Traclite 3.0's I just got in, I highly suspect that the change in torque steer will also be negotiable... as many have been saying. i'll let you know how it goes when I get a chance to try them out.

Thanks Jeff for the answers! I'm torn between keeping my LE wheels/tires as I love them so much. I love the handling and the looks. The car feels so planted, precise, and turns in like a dream. They look so sharp on the Champion White. My biggest concern is the cost is untenable. At this rate I'd be changing tires every 2K to 3K miles. Much less when I start tracking it.

If I'm going to upgrade, the question for me is whether to go 19x9.5 or 18x9.5. I don't know if 265/35R19 would fit on stock suspension without rubbing. The advantage of the 19 is that you get sharper handling than the 18 (steering response and the shorter sidewalls flex less on hard corners). And you have access to more tire types (i.e. the Cup 2 are rare to find for 18). The disadvantage is they are heavier than 18 and tires are generally more expensive.

I may give added negative camber a shot before I change wheels/tires, but @djhartm experience is discouraging (removed guide pins to add negative camber and the stock wheels still murdered the tires).

I see on your build thread that you installed the 18. How does that compare with the NSX 19?

 

[Sam3]

I went to 18 x 9.5 with 45 mm offset with both 265 and 275 tires (bought 2 sets) and didn't notice any issue with torque steer or fitment on a stock suspension. Increasing camber with Hardrace ball joints helped a lot.

I'm seriously considering adding camber. But I want to do it in a way that doesn't compromise the handling characteristics of the car. I like that the car in stock settings doesn't understeer a lot when pushed early out of corners. Yet the backend is lively enough to rotate the car by sliding and tucking in safely without inducing a dangerous oversteer.

That's why I'm weary of changing front camber without also changing the back. Flying Gato on YouTube added negative camber to the front by removing the guide pins, then a month later had an uncontrolled oversteer and crashed into a wall. We can argue whether the added camber only to the front was the main contributor, or the worn-out tires, or the bumpy track.

Honda's HPD cars have camber adjustability for both front and rear (on TC and TCR). I'm considering RV6 rear camber arms (used by HPD), but they don't seem to have a front camber kit. I'm looking into the Hardrace for the front among others.

I need to decide how much front and rear camber I should dial in while keeping the handling spirit of the car intact.

 

[Deleted member 47337]

A while back, I had a spirited canyon drive on the Michelin Cup 2 with OEM cold tire pressure (35/F and 32/R), and on that hot day the car felt squirrely after about 20 minutes. So I thought the hot tire pressure is getting very high, resulting in the tire becoming rigid and losing its flex and grip. So for a subsequent trip, I decreased the cold tire pressure to 32/F and 30.5/R, especially that Michelin recommends running cold pressure of 25/F and 28/R (on a rear wheel drive car). See page 14 in this brochure:

https://www.tirerack.com/images/pdf/Michelin_Care_and_Feeding.pdf

That did not go well. The grip was definitely much better and no more squirreling. But the front left tire got shredded and big chunks peeled out of it down to the metal wires (you can see them in the pic). The tire also rolled (you can see some of the writing on the sidewall got chafed off). The tire has may be 4 thousand miles on it. The only thing of note is that I was taking an ascending right hairpin and on tracking out I gave it some throttle in 2nd gear. That caused a slight oversteer and the left front end hopped a bit.

Is that normal for the tire to roll and get shredded for a slight decrease in tire pressure? In performance driving schools, they set the tire pressure so low that the TPMS warning light is always on. I used a high quality pressure gauge (Longacre) right before heading out, so I didn't under-inflate by mistake. I also measured the tire pressure cold two days later and it's still at 32 psi, so the tire losing pressure to a puncture before that happened is ruled out.

Aside from the LE wheels and tires, the car is 100% stock (no tunes, no bolt-ons, no mechanical mods of any kind).

Has anyone had issues like this with the Cup 2 (or other tires) on the Type R?

Oh man, that sucks. Don't sweat it. Stuff like this happens and we all learn from it.

OEM recommends 35F and 33R for our cars (not 32R). Not sure if that was a typo.

Also, Cup 2 should look like that after racing. Is it normal? Yes. Is it good? No. It doesn't feel good.

I'm not going to get super technical, but in simple terms, it is the air pressure inside the tire that supports the weight of the car. Meaning, no matter what size tire, shape, brand, width, you are always going to need to use the stock OEM pressures to hold the car up, because that is the SAFE pressure to operate the car in most conditions. It is a safety thing, not a performance thing.

When you lower the pressure that much, 32F and 30R, you are lowering the amount of weight each tire can hold per corner, even thought your tire says XL or whatever it says for the load rating.

So, that just puts an enormous amount of stress on the tires, due to your cars weight.

As far as how your tires look, I see tires cooked like in the shop all the time...usually from people who race their cars on a track on a really hot day. (They also lower the tire pressure just like you did)

How long should the tire last while racing depends on how hard the driver gets on it, surface temp of the ground, and the amount of friction of the tire and road contact.

It's hot everywhere in the summer...judging from your tire pressures, that tire looks like how it should. It sucks though, I know. I've been there. I would of dropped the pressure maybe 1 psi lower...2 psi max for canyon driving. You went a bit too low.

But yeah, that's normal for the situation.

 

[Dave B]

I'm seriously considering adding camber. But I want to do it in a way that doesn't compromise the handling characteristics of the car. I like that the car in stock settings doesn't understeer a lot when pushed early out of corners. Yet the backend is lively enough to rotate the car by sliding and tucking in safely without inducing a dangerous oversteer.

That's why I'm weary of changing front camber without also changing the back. Flying Gato on YouTube added negative camber to the front by removing the guide pins, then a month later had an uncontrolled oversteer and crashed into a wall. We can argue whether the added camber only to the front was the main contributor, or the worn-out tires, or the bumpy track.

Honda's HPD cars have camber adjustability for both front and rear (on TC and TCR). I'm considering RV6 rear camber arms (used by HPD), but they don't seem to have a front camber kit. I'm looking into the Hardrace for the front among others.

I need to decide how much front and rear camber I should dial in while keeping the handling spirit of the car intact.

I have the Hardrace ball joints in the middle position for an average front negative camber of 2.6. The car still understeers but not as bad and no issue with street driving. I think that with a softer sidewall tire like the Yoko A052 I would need the full negative 3.6 but can live with negative 2.6 with a stiffer sidewall tire. My guess is negative 3.0 would be best but can't get there.

I think my next move would be a slightly stiffer rear sway bar.

Not sure what happened with flying Gato.

 

[BillyJRacing]

A while back, I had a spirited canyon drive on the Michelin Cup 2 with OEM cold tire pressure (35/F and 32/R), and on that hot day the car felt squirrely after about 20 minutes. So I thought the hot tire pressure is getting very high, resulting in the tire becoming rigid and losing its flex and grip. So for a subsequent trip, I decreased the cold tire pressure to 32/F and 30.5/R, especially that Michelin recommends running cold pressure of 25/F and 28/R (on a rear wheel drive car). See page 14 in this brochure:

https://www.tirerack.com/images/pdf/Michelin_Care_and_Feeding.pdf

That did not go well. The grip was definitely much better and no more squirreling. But the front left tire got shredded and big chunks peeled out of it down to the metal wires (you can see them in the pic). The tire also rolled (you can see some of the writing on the sidewall got chafed off). The tire has may be 4 thousand miles on it. The only thing of note is that I was taking an ascending right hairpin and on tracking out I gave it some throttle in 2nd gear. That caused a slight oversteer and the left front end hopped a bit.

Is that normal for the tire to roll and get shredded for a slight decrease in tire pressure? In performance driving schools, they set the tire pressure so low that the TPMS warning light is always on. I used a high quality pressure gauge (Longacre) right before heading out, so I didn't under-inflate by mistake. I also measured the tire pressure cold two days later and it's still at 32 psi, so the tire losing pressure to a puncture before that happened is ruled out.

Aside from the LE wheels and tires, the car is 100% stock (no tunes, no bolt-ons, no mechanical mods of any kind).

Has anyone had issues like this with the Cup 2 (or other tires) on the Type R?

You need more front camber.

 

[BillyJRacing]

Recently a buddy of mine made a fb post regarding his cup 2's delaminating

Mind you he has a 2018 M4

Maybe a common issue? Here's his fb post

"Michelin Cup 2 - Delamination
Track car issues

Front tires on my M4,
285/30/19 Cup2 ZP 94Y delaminating after 42 laps. Great wear assides from the delaminating.
Rear 305/30/19 98Y wearing beautifuly 0 issues.
I read about this being a common issue with CUP2s on track.
I ran them 32psi max hot f&r,
outside temperature ~26celsius.
Car settings:
Front
-4.1 Camber
0.02 degrees toe in per side
550 lbs springs
1" suspension travel before bumpstops
Whiteline sway bar full soft setting
Apex SM10 19x10 + 25
15mm spacer
Rear
-1.9 Camber
0.10 degrees toe In per side
750 lbs springs
1" travel before bumpstops.
Oem sway bar
Apex SM10 19x11 + 44
10mm spacer
Big Front splitter plus rear wing.
PowerStop track day pads F&R (excellent excellent pads,0 fade, great feel)
Quick glance of the car in the attached video.
Car is not under steering nor over steering it’s planted.
Started 28psi cold F&R
I do 2 warmup laps 70-80% pace before going hard on them for the rest of the session.
Any ideas? Or are these not suitable for sustained track race pace 20min sessions."

Can't really tell without seeing what the rears look like, but with a tire stagger and too much rear downforce, it could just be a chassis/aero imbalance that caused the excessive front wear. What track was this on?

 

[BillyJRacing]

Here are some VERY good, relevant reads:


Not all Michelin Cup 2 Tires Are Created The Same

https://motoiq.com/not-all-michelin-cup-2-tires-are-created-the-same/


How to PROPERLY select and size TIRES for PERFORMANCE

https://motoiq.com/how-to-properly-select-and-size-tires-for-performance/

 

[Champale]

Nice to see you over on the Tye R forums, BillyJRacing! Always enjoy your tech knowledge on the Mustang forums.

 

[Sam3]

You need more front camber.

I installed new RT660 275/35R18 tires on 18x9.5 ET45 wheels with -2.5 front camber, running about 32 psi hot pressure. I shredded the front left in one track day. In addition to my insufficiently smooth driving, that day they ran five 30-minute sessions and a sixth bonus EOD session. I used them all up and didn't rotate the tires at the track.

My instructor said I can use this tire in the rear for one more track day. What do you think?

 

[tacthecat]

Buy lots of insurance.

 

[BillyJRacing]

I installed new RT660 275/35R18 tires on 18x9.5 ET45 wheels with -2.5 front camber, running about 32 psi hot pressure. I shredded the front left in one track day. In addition to my insufficiently smooth driving, that day they ran five 30-minute sessions and a sixth bonus EOD session. I used them all up and didn't rotate the tires at the track.

My instructor said I can use this tire in the rear for one more track day. What do you think?

That's tough. I probably wouldn't because it's not worth the risk. It' might be fine, but i'd recommend adding more front camber and look into wider front wheels and tires instead.

Sponsored