Does tread width matter?

[Dreamer99]

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I'm comparing the AD08R and RE71 tires in 255/35/19 and 275/35/19 for my ZCP wheels and the Yokohama's tread width is almost an inch wider than Bridgestone. These tires are for track usage but also to commute to and from tracks that are over 100 km away. Car has stock ZCP suspension.

Thanks

[dparm]

Originally Posted by Dreamer99

I'm comparing the AD08R and RE71 tires in 255/35/19 and 275/35/19 for my ZCP wheels and the Yokohama's tread width is almost an inch wider than Bridgestone. These tires are for track usage but also to commute to and from tracks that are over 100 km away. Car has stock ZCP suspension.

Thanks

Yes, it absolutely matters -- you're literally getting more rubber on the road. Those Yokos basically run one width larger (285). If you look at the sidewall profile, you'll see that it's very squared off. That also means that it is a bit less forgiving at the limit versus something more rounded like a PSS.

Obviously, the wider tire will sacrifice some wet traction but it's not exactly like the RE71 and AD08R were designed for driving through torrential downpours at 90mph.

Here's a photo of 275/35R19 AD08Rs on the rear of my E90 sedan. You can see what I mean about the very square sidewall:

[ThunderMoose]

Matter? Compound trumps width in most cases and RE71r are as grippy as Nittos. I would go with RE71rs over Yokohamas even if they are slightly skinnier.

[thasuperdude]

RE71s are amazing. They don't last long, but the grip level is ridiculous. I did about 7 auto-x's and DD them for 10 months. They're happiest at 36psi on the M.

[macdude357]

Originally Posted by ThunderMoose

Matter? Compound trumps width in most cases and RE71r are as grippy as Nittos. I would go with RE71rs over Yokohamas even if they are slightly skinnier.

This. And that fact that those treadwidths are a good match for a 9" and 10" rim respectively. Yes, you would technically get more grip with a wider tread (given all other things were equal, which in this case they are not), but once you start going past the rim width, you won't gain as much and you'll start to lose responsiveness.

[Richbot]

All you're doing with wider tires is changing the shape of the contact patch, all things being equal

All things are never equal, but agree compound/good tire more important than just getting the fattest tire on the car

[Dreamer99]

Thanks for the reply's. I currently have the AD08R's with no complaints but it looks like the 275's are being discontinued so just seeing what is out there to replace them. Not much else in 19" tires that can take lots of heat from 20-30 minute lapping sessions.

[dparm]

Originally Posted by Dreamer99

Thanks for the reply's. I currently have the AD08R's with no complaints but it looks like the 275's are being discontinued so just seeing what is out there to replace them. Not much else in 19" tires that can take lots of heat from 20-30 minute lapping sessions.

If the tires won't be used for daily driving duties, you could go for PSC2, NT01, RE71, etc.

[Dreamer99]

I have a second set of wheels/tires for daily driving but some of the tracks I go to are up to 100kms away and being in the Pacific Northwest area there is always the threat of rain so some tread is needed.

[SYT_Shadow]

Originally Posted by Dreamer99

I have a second set of wheels/tires for daily driving but some of the tracks I go to are up to 100kms away and being in the Pacific Northwest area there is always the threat of rain so some tread is needed.

RE71 is perfectly doable

VIR is like 500 miles from me and it can be done just fine with RE71/NT01 with tread

The NT01 might make you lose your desire to live due to the horrible racket they make

[dogbone]

Originally Posted by DrFerry

However, wider tires yield (give up) some braking and acceleration grip - again assuming the same compound for this statement and comparison.

Your answer sounds like it comes from a technical background. However, the above statement is not my experience. I do not come from a technical background on this topic. I can only speak to what I've experienced on track. Perhaps you could clarify what you mean?

How do wider tires give up braking grip? And don't people put fat tires in the rear to aid in acceleration grip?

When I went from 265 Hankook TD to 295 TD in the front, I felt the stopping power of the wider tires was amazing, along with turn-in being much better, and holding the car in a long steady-state rounder was better. My lap times benefitted.

I have a set of 265 Pirelli DH square on 9.5" rims. They're fine, but they cannot do what my 305 Pirelli DH square on 10.5" can do.

Also in my experience, in general, the outer edges of the front tires get SEVERELY punished on an E9x M3. And narrow tires get more severely punished than wider tires. More negative camber can help the front tire survive longer. The more camber I add, the longer the tire lasts. (My Vorshlag plates top out at about -4º and that's where they are right now. I just go with max camber.)

When I was running Hankook TD 265/35/18 on the front at Buttonwillow 13 CW, the outer edge of the front-driver side tire would get DECIMATED after only two sessions. The rest of the tire would be almost new looking. When I tried putting on a 295/30/18 Hankook TD up front with everything else being the same, the edge wear was significantly slower. I'd run the tires in a square setup, and with diligent rotation around the car, I could get up to 5 days out of the tires. The narrow tires would wear out quickly on the edges, and I couldn't rotate them around the car because it was a staggered setup.

My friend has the same car as me with a very similar setup--supercharged, same JRZ, same AP brakes, same aero. He had been running max camber like me and was getting fairly even wear on his tires. He went to a high-end alignment shop that reduced his camber down from around -4º to -3.2º. His next track day, he had some new TD's. IMMEDIATELY, the outer edges of the tires were getting punished. During the middle of the day, he slammed the camber back to maximum and the wearing of the outer edge was slowed. We've seen this over and over again. Fat tires and max camber = better tire wear on an E9x M3. Obviously, a soft, grippy tires will show the edge wear more quickly than a 200TW tire. But even jack hammering the outer edge of a hard rubber compound is not ideal.

So for me, experimenting with wider tires resulted in tires that lasted a heck of a lot longer, which was great. Plus the braking grip of a wider front tire felt good and stable. And I did find wider tires to be faster than narrower tires of the same compound.

Being supercharged, I have found that fatter tires deal with the power better. Narrow tires seem to be overwhelmed more easily by the blower.

Don't wider tires deal with heat buildup better too?

All I know is that every time I move to a wider tire, they last longer, my lap times are faster and the car feels more stable and predictable.

If I am understanding this situation incorrectly, I am curious to learn the correct way of thinking.

PS. For reference, here are the tires I have driven on track over the last 6 years (in order of acquisition/use, and whether they were new tires or scrubs):

-Michelin PS2 (stock tire) (new)
-Hankook R-S3 265/285 (new)
-Hankook TD 265/295 (new)
-Hankook TD 295 square (new)
-Hoosier R6 295 square (new)
-BFGoodrich R1-S 285 square (new)
-Michelin S9L slick 270 square (new)
-Hoosier A7 295 square (new)
-Yokohama A005 slick 280/300 (new)
-Pirelli DH slick 275 square (scrubs)
-Pirelli DH slick 265 square (scrubs) (the 265 has a tread width that is 0.25" wider than the 275.....go figure....)
-Pirelli DH 305 slick square (both new and scrubs)

[ricardofors68]

Originally Posted by dogbone

Your answer sounds like it comes from a technical background. However, the above statement is not my experience. I do not come from a technical background on this topic. I can only speak to what I've experienced on track. Perhaps you could clarify what you mean?

How do wider tires give up braking grip? And don't people put fat tires in the rear to aid in acceleration grip?

When I went from 265 Hankook TD to 295 TD in the front, I felt the stopping power of the wider tires was amazing, along with turn-in being much better, and holding the car in a long steady-state rounder was better. My lap times benefitted.

I have a set of 265 Pirelli DH square on 9.5" rims. They're fine, but they cannot do what my 305 Pirelli DH square on 10.5" can do.

Also in my experience, in general, the outer edges of the front tires get SEVERELY punished on an E9x M3. And narrow tires get more severely punished than wider tires. More negative camber can help the front tire survive longer. The more camber I add, the longer the tire lasts. (My Vorshlag plates top out at about -4º and that's where they are right now. I just go with max camber.)

When I was running Hankook TD 265/35/18 on the front at Buttonwillow 13 CW, the outer edge of the front-driver side tire would get DECIMATED after only two sessions. The rest of the tire would be almost new looking. When I tried putting on a 295/30/18 Hankook TD up front with everything else being the same, the edge wear was significantly slower. I'd run the tires in a square setup, and with diligent rotation around the car, I could get up to 5 days out of the tires. The narrow tires would wear out quickly on the edges, and I couldn't rotate them around the car because it was a staggered setup.

My friend has the same car as me with a very similar setup--supercharged, same JRZ, same AP brakes, same aero. He had been running max camber like me and was getting fairly even wear on his tires. He went to a high-end alignment shop that reduced his camber down from around -4º to -3.2º. His next track day, he had some new TD's. IMMEDIATELY, the outer edges of the tires were getting punished. During the middle of the day, he slammed the camber back to maximum and the wearing of the outer edge was slowed. We've seen this over and over again. Fat tires and max camber = better tire wear on an E9x M3. Obviously, a soft, grippy tires will show the edge wear more quickly than a 200TW tire. But even jack hammering the outer edge of a hard rubber compound is not ideal.

So for me, experimenting with wider tires resulted in tires that lasted a heck of a lot longer, which was great. Plus the braking grip of a wider front tire felt good and stable. And I did find wider tires to be faster than narrower tires of the same compound.

Being supercharged, I have found that fatter tires deal with the power better. Narrow tires seem to be overwhelmed more easily by the blower.

Don't wider tires deal with heat buildup better too?

All I know is that every time I move to a wider tire, they last longer, my lap times are faster and the car feels more stable and predictable.

If I am understanding this situation incorrectly, I am curious to learn the correct way of thinking.

PS. For reference, here are the tires I have driven on track over the last 6 years (in order of acquisition/use, and whether they were new tires or scrubs):

-Michelin PS2 (stock tire) (new)
-Hankook R-S3 265/285 (new)
-Hankook TD 265/295 (new)
-Hankook TD 295 square (new)
-Hoosier R6 295 square (new)
-BFGoodrich R1-S 285 square (new)
-Michelin S9L slick 270 square (new)
-Hoosier A7 295 square (new)
-Yokohama A005 slick 280/300 (new)
-Pirelli DH slick 275 square (scrubs)
-Pirelli DH slick 265 square (scrubs) (the 265 has a tread width that is 0.25" wider than the 275.....go figure....)
-Pirelli DH 305 slick square (both new and scrubs)

All of this is understood, but am I correct to assume that the wider is better to a point? I ask this as I was thinking of going wider on the fenders to accommodate wider wheel/tire combo but was told that anything wider than a 295 will work against good order and discipline
Any particular reason for not trying out the NT01 as it seems like a very popular tire for track days?
I will use a square set up with NT01 for the track but will be driving to/from the track on PS2, stuffing the track stuff in the rear seat cavity.

[135]

Originally Posted by dogbone

...
here are the tires I have driven on track over the last 6 years (in order of acquisition/use, and whether they were new tires or scrubs):

-Michelin PS2 (stock tire) (new)
-Hankook R-S3 265/285 (new)
-Hankook TD 265/295 (new)
-Hankook TD 295 square (new)
-Hoosier R6 295 square (new)
-BFGoodrich R1-S 285 square (new)
-Michelin S9L slick 270 square (new)
-Hoosier A7 295 square (new)
-Yokohama A005 slick 280/300 (new)
-Pirelli DH slick 275 square (scrubs)
-Pirelli DH slick 265 square (scrubs) (the 265 has a tread width that is 0.25" wider than the 275.....go figure....)
-Pirelli DH 305 slick square (both new and scrubs)

How would you compare the TD, R6 and A7? Grip, confidence, life/wear (heat cycles), lap times, etc.

I'm not sure how many tracks you've been to, or if you have a regular / "home" track, but it would be good to see your PBs for each of the tyres you've run, more so from the TD through to your current Pirelli. Surely with the change in tyres came better lap times, although, improved driver ability over time will probably skew the perceived benefits over the progression of tyres too.

[135]

Originally Posted by ricardofors68

...
Any particular reason for not trying out the NT01 as it seems like a very popular tire for track days?

He jumped from RS-3 straight to TD, which was the progression within the Hankook range. Once using the TD, there's no use going backwards to an NT01.

[macdude357]

Originally Posted by dogbone

Your answer sounds like it comes from a technical background. However, the above statement is not my experience. I do not come from a technical background on this topic. I can only speak to what I've experienced on track. Perhaps you could clarify what you mean?

From my research, it seems that yes, even though the contact patch would have the same area there are other factors involved. The wider tire may enable less air pressure which would increase the contact patch area. Also, the wider tire will have a lower load factor so even if the contact patch area is the same, if the load factor is reduced, then there is more overall grip.

For DOT tires of the same brand, the wider tire will also be taller (35% of 275 vs. 35% of 265) which will also have an effect on load factor and overall shape of the contact patch (and of course, in the rear an overall effect in final gear ratio).

[dparm]

Originally Posted by ricardofors68

All of this is understood, but am I correct to assume that the wider is better to a point?

Yes. At a certain point, the added weight begins to affect handling and acceleration. Also, wider tires are harder to get up to temperature meaning you might not be able to hit the sweet-spot where they provide the most grip.

Also, think back to Physics 101: friction is independent of surface area. Wider tires do not give more grip solely on the basis that they are wider, though a lot of it comes down to tire load sensitivity and the fact that asphalt is not perfectly flat.
http://www.physlink.com/Education/AskExperts/ae200.cfm
https://en.wikipedia.org/wiki/Tire_load_sensitivity

Something else that has been mentioned is that a wider tire might actually yield a smaller contact patch; although it is a wider patch, you aren't pushing down as hard (weight is constant) so the length of the patch is less. You can decrease the air pressure to try and compensate but only up to a point since it will shift the weight to the outside of the tire causing it to overheat.

As you can see, you are entering the slippery-slope of chassis and suspension tuning and may want to get some books on the subject.

[dparm]

Originally Posted by DrFerry

WOW, dogbone that's a huge amount of info. I guess I am wrong. I stand corrected, or sit corrected. I'll edit my post since there are always seems to be exceptions.

Here are a few links that might help shed some light on the topic. Oh, and a photo of dragster.

The width of the dragster rear tires in the photo are not all that wide, because dragsters don't care about cornering, but they care about acceleration (longitudinal grip). Think of acceleration as the reverse of braking.

Those tires are big for heat capacity reasons. Same for F1 cars. In fact, look at the sidewall height -- it's huge by road car standards.

[dogbone]

Originally Posted by ricardofors68

All of this is understood, but am I correct to assume that the wider is better to a point? I ask this as I was thinking of going wider on the fenders to accommodate wider wheel/tire combo but was told that anything wider than a 295 will work against good order and discipline
Any particular reason for not trying out the NT01 as it seems like a very popular tire for track days?
I will use a square set up with NT01 for the track but will be driving to/from the track on PS2, stuffing the track stuff in the rear seat cavity.

From my experience, I would say wider is better to a point. Also, in my specific case, I have a supercharger so, in theory, I think I should be able to overcome certain weight and rolling resistance issues. Of course, at some point, you start running into limitations of what you can even fit under the car and actually run on track. I'm in a very happy place with the DH 305 square setup, but it has taken some work to get to this point.

As far as NT01---When I was looking to step up from the Hankook R-S3 to a faster tire, the NT01 was 1-2 seconds faster at Buttonwillow, but the TDs were 4 seconds faster than R-S3. We were able to get the TDs for around the same cost as the NT01, so I chose the faster tire. (As far as we know, the TD is out of production now.) The NT01 is definitely a very popular tire. It's just not a super fast tire.

[dogbone]

Originally Posted by 135

How would you compare the TD, R6 and A7? Grip, confidence, life/wear (heat cycles), lap times, etc.

I'm not sure how many tracks you've been to, or if you have a regular / "home" track, but it would be good to see your PBs for each of the tyres you've run, more so from the TD through to your current Pirelli. Surely with the change in tyres came better lap times, although, improved driver ability over time will probably skew the perceived benefits over the progression of tyres too.

I've been to all the tracks in California. I would consider my home track to be Buttonwillow 13CW.

I've never run a new set of TD's once the car was gutted and caged and had full aero at Buttonwillow, so unfortunately I can't give the TDs a fair lap time there.

Also, I have progressed quite a bit as a driver in the last few years. I've been tracking for 6 years. The first 4 years, I use MDM traction control. I have been running for about 2 years DSC-off. So let's use lap times since I was running DSC-off. And now the car is fully setup for the track with cage, gutting, aero, diff, AP, JRZ, supercharger, etc. so lots of stuff has been changing. But I think I can answer most of your questions.

First, I'll compare TD, R6 and A7.

TD - we've been told they're not making TD anymore. I see you're in Australia. Can you still get them? Anyway, as my first "fast" tires, I loved the TD's. The braking grip was amazing. The cornering grip was very good. Where these tires would fall short is once you went past the grip limit. They did NOT like sliding, and they would grind and chatter and vibrate desperately trying to get the grip back. TD's also had a funky characteristic where they DID NOT like to do a lot of hot laps in a row. They preferred one lap hot, one lap off, and repeat. You could DESTROY them in one session if you ran them for 30 minutes straight hammering all hot laps. The rubber would chunk and you'd be unhappy. They heated up very easily in one warm up lap. And if I ran them square, I could get 4 decent days, plus one not-grippy day on them.

R6 - I wasn't a big fan of R6. Believe it or not, the R6 was a slower tire than TD at Buttonwillow. My friend and I both confirmed this. The R6 did not brake as well as TD. But the driving characteristic of the tire was more elegant than TD. When an R6 went past the grip limit, it was a smooth experience. It would lose grip and slide smooth, and then you could get the car back smoothly. The R6 didn't mind multiple hot laps in a row. The longevity of R6 was not great. 10-12 sessions and they corded. They didn't take much work to warm them up.

A7 - *sigh* Hoosier. Interesting tires. Hoosier wants the tires to be 40 psi hot---start at 33 psi. I called them. A7 is a pretty fast tire. Needs absolutely no warm up at all. You look at them and they're already warm enough to go hot right away. But they would get greasy after two hot laps in a row. The third hot lap and the car was sliding all over the place. Very solid braking feel. Good in corners and acceleration. They also slide smoothly like R6. But they have a short life. Mine corded after 8 (short--remember only 2 laps) heat cycles....I don't think I ran them quite as hard as they could be run. I'm a better driver now, but I'm not running them again---too finicky.

I'm going to briefly talk about one or two more tires:

BFG R1S - love this tire. In my opinion, it is the fastest and best value DOT tire short of slicks. Very good braking. Good in the corners. Slides well. Can run a full 30 minutes of hot laps without any issues. Faster than TD, R6, as fast as A7. Lasts 14-16 heat cycles before first tire shows cording. But remember, this is not just 2 laps and get off the track. This could be full 20 minute sessions. Sadly, they raised the price to be the same as R7. They used to be $200 cheaper. These tires need more warm up than any of the previous tires. I say give them two laps on the first run of the day. Later in the day, one lap is enough.

Pirelli DH - phew. Amazing. Once you drive them, you will not want other tires. They hold the ground like crazy. I have 4 sets of rims. All 4 sets have DH on them right now. Need I say more? I find the DH to be 2-3 seconds faster than R1S when they're fairly fresh.

My lap times: Disclaimer: I am not a pro driver. I am not Mr. Automatic lap-after-lap. I'm an amateur/hobbyist driver that has learned as much as I can in 6 years. My lap times have gotten decent over the years, but there is still more time to be had. So, these times do not necessarily reflect the maximum ability of the tires. You asked about lap times and I'm giving you the info as honestly as I can, but these times are NOT the result of some scientific testing----air temps, track conditions, driver skill, car setup, etc are all variables that are different from day to day in these results.

-Buttonwillow 13CW - 1:47.2 (Pirelli DH) (new) (on this lap, the car auto-shifted into 6th gear…..this was probably a 1:46.9 lap……dang)
-Buttonwillow 13CW - 1:48.0 (Yokohama A005) (new) (these tires can do 1:47’s. Car had shifting issues.)
-Buttonwillow 13CW - 1:49.0 (R1S) (new) (I had a 1:48.xx on R1S in a time attack but had to stop on the front straight right before the finish line due to another car on fire)
-Buttonwillow 13CW - 1:49.3 (Michelin S9L) (new)
-Buttonwillow 13CW - 1:49.5 (A7) (new) (I believe these tires can go faster than this.)
I do not have a TD time with the car in the same modded state as these times. I would guess I would have done a 1:50-1:51 on fresh TD.

-Laguna Seca - 1:34.3 (Yokohama A005) (new)
-Laguna Seca - 1:35.3 (Pirelli DH scrubs and braking conservatively. I did a long post about this a couple days ago in my build thread. Scrub DH could have gone faster than new Yoko if I braked more aggressively. I showed the AIM chart.)
-Laguna Seca - 1:36.2 (R1S) (new)

-Chuckwalla CW - 1:53.6 (Pirelli DH) (scrubs)
-Chuckwalla CW - 1:54.9 (Yokohama A005) (scrubs)
-Chuckwalla CW - 1:56.0 (R1S) (scrubs)

-Auto Club - 1:43.5 (Pirelli DH) (scrubs)
-Auto Club - 1:44.9 (Yokohama A005 scrubs)
-Auto Club - 1:46.6 (TD)

-Sonoma Raceway - 1:47.0 (R1S) (new)
(I've never driven Sonoma with slicks. Slicks would be at least 2-3 seconds faster.)

-Thunderhill 3-mile w/Bypass: 1:54.7 (R1S) (scrubs)
(I've never driven Thunderhill with slicks. Slicks would be at least 2-3 seconds faster. I've only driven this config three times.....I don't get up to Thunderhill much...I could stand to learn the track quite a bit more.)

-Big Willow - 1:27.5 (R1S) (scrubs)
(I've never driven Big Willow with slicks. I want to soon. it's so hard on tires that you don't really want to bring good tires there. I'm not sure what the slicks advantage would be. Weird track.)

[ricardofors68]

thank you.

[Richbot]

Cliffs notes: The only way to find out what is better is a stopwatch

[dogbone]

DrFerry---I'm curious. I was looking at your signature with your car setup. I have a couple questions.

-You have SSP clutch discs for the DCT. Did you move to those because you wore something out? Or were you upgrading out of caution because you have a supercharger and wanted the 900ft/lbs capacity of the discs?

I talked to SSP a couple weeks ago and they said because of my supercharger, they would have to assemble a specific set of clutch discs that would be able to deal with the extra heat and slipping of the clutches, otherwise their discs would burn out too quickly. Did they assemble a clutch set for you specifically with the supercharger in mind? How long have you had them? Are you happy?

-I see you have 11" wheels. Is that 11" square? That would be a massive front wheel. I don't see any notes on suspension in your setup. Are you running an 11" wheel with a 12mm spacer on the front on stock suspension? And no camber plates? What size tire do you have up there?

-With a 3.45 final drive, supercharger and DCT.....your car must launch like a raging monster! hmmm maybe that wasn't a question.....

-Does your car ever see a track?

Anyway, just curious.