Thoughts on acceptable street tyre wear rates

[Murray_Calavera]

Just now, Dose Pipe Sutututu said:

I used to run 4mm total toe in LOL...

this was actually also recommended by 2x different alignment shops (BT Motorsports in Smithfield and also Porters Suspension In Kirawee)

Yep, I'm not surprised. It's good advice. Some of the really big HP drift cars run up to 10mm toe in chasing outright grip in the rear. 

[Murray_Calavera]

6 minutes ago, Duncan said:

Nah, it's all poly in the back of the race car, rose joints not allowed. 

Also keep in mind that toe is static. Depending on how/if bump steer is set that becomes toe out under power with standard or standardish length upper front link.

All of my control arms/traction rod are stock in the rear at the moment. 

Does the factory setup toe out much on power?

[GTSBoy]

37 minutes ago, Murray_Calavera said:

Does the factory setup toe out much on power?

Yes. It's a combination of rubber bush deflection and bump steer. Bump steer is not outrageous on stock length arms, but it does exist. The rubber bushes deflect a lot.

Poly bushes trim that deflection down a bit. Still do it. Hard to say how much delta though. Spherical bearings almost completely eliminate it.

What this means is that listening to people's recommendations for toe-in settings on the rear (or on the front for that matter) really needs to be done while understanding everything that goes into that particular recommendation. If you try to run zero toe on a stock bushed car you are going to end up with quite a lot of toe out on squat (and another factor in the bush deflection is not just squat, but the reaction to the force pushing the car forwards - the wheel naturally wants to move forwards wrt the chassis in order to impart accel force of the chassis). If the recommendation came from someone with a lot less deflection available in their rear end, then their recommendation is not valid for your setup.

The opposite is obviously also true.

Bump steer is the biggest thing that people do not think about. The situation will be different in many ways for each car. Spring and ARB stiffnesses, damping, any geometry changes (ie adjustable camber arms without adjustable traction arms), static ride height, and so on, all impact the bump steer curve that will be experienced under accel/decel/cornering

[Murray_Calavera]

Reporting back on the NS2R 120 treadwear. I only got 6,400 KM on the rears, no track work and no shenanigans on the road. 

They were really nice while they lasted, even in the wet. I would really like to get around 10,000 km from my street tyres so I'm trying RS4 now. 

Initial thoughts on the RS4 are the dry grip levels feel similar to the NS2R, so if I can get 10,000 km out of them I'll be really happy and probably won't bother trying any other street tyres and I'll just stick with them. 

[The Bogan]

2 hours ago, Murray_Calavera said:

Reporting back on the NS2R 120 treadwear. I only got 6,400 KM on the rears, no track work and no shenanigans on the road. 

They were really nice while they lasted, even in the wet. I would really like to get around 10,000 km from my street tyres so I'm trying RS4 now. 

Initial thoughts on the RS4 are the dry grip levels feel similar to the NS2R, so if I can get 10,000 km out of them I'll be really happy and probably won't bother trying any other street tyres and I'll just stick with them. 

If your car doesn't come out to much in the wet Toyo R888R's last well, I got about 10k km out of them before putting RS4's back on, the R888R still had a few mm left from the tread wear markers when they came off, so probably another few k km's

The R888R's were the best "fair weather" street tyre I have ever used, BUT, they didn't like pools of standing water

I do alot of Hwy driving, rain, or shine, and whilst the R888R's were exceptional in the dry on the street they really didn't inspire confidence when hitting pools of water on the Hwy doing 110 kph

If my car was just a sunny Sunday cruiser I would definitely still be running the R888R's, the difference between dry grip between the R888R's and RS4's is large, as you would expect 

From my experience with the RS4's you are likely to easily get 10-15 even 20k km out of them on the street if you aren't doing lots of skids or track work

[Murray_Calavera]

42 minutes ago, The Bogan said:

If your car doesn't come out to much in the wet Toyo R888R's last well, I got about 10k km out of them before putting RS4's back on, the R888R still had a few mm left from the tread wear markers when they came off, so probably another few k km's

The R888R's were the best "fair weather" street tyre I have ever used, BUT, they didn't like pools of standing water

I do alot of Hwy driving, rain, or shine, and whilst the R888R's were exceptional in the dry on the street they really didn't inspire confidence when hitting pools of water on the Hwy doing 110 kph

If my car was just a sunny Sunday cruiser I would definitely still be running the R888R's, the difference between dry grip between the R888R's and RS4's is large, as you would expect 

From my experience with the RS4's you are likely to easily get 10-15 even 20k km out of them on the street if you aren't doing lots of skids or track work

My street tyres really have to be able to hold up to everything. I just drove down to Sydney for WTA, if a crazy storm hit on the way back up to QLD, I still want to be confident with the way the car handles and feel that I can safely get home. 

That's good news for the RS4's, I was a little concerned when I measured the tread depth at just under 6mm, I would be over the moon to get 20k out of them. 

I'm surprised how much life you got out of the R888R's as they are rated at 100 treadwear.

[The Bogan]

1 hour ago, Murray_Calavera said:

My street tyres really have to be able to hold up to everything. I just drove down to Sydney for WTA, if a crazy storm hit on the way back up to QLD, I still want to be confident with the way the car handles and feel that I can safely get home. 

That's good news for the RS4's, I was a little concerned when I measured the tread depth at just under 6mm, I would be over the moon to get 20k out of them. 

I'm surprised how much life you got out of the R888R's as they are rated at 100 treadwear.

Fair point on needing all round tyres, that's why I went back to the RS4

As for how long the R888R's lasted, I was surprised as well, although I pretty much just cruise around like Nana 90% of the time, it did rack up most of the km on lots of trips up and down the Hwy to Goulburn and back, I got the R888R's initially to try and get some traction from the dig, and while they were much better than the RS4's they still had traction issues, thus they were replaced with some drag radials for the strip and rolls

The RaceTCS has helped massively with the RS4's on the street with traction though, both in the dry and more importantly wet conditions 

Happy travels

[Kinkstaah]

+1 (+2?) on RS4s. I recently replaced mine after about 19,000kms but they were heavily doctored, as in running higher pressure on the street, taking care of them etc, but they did see track work and some spirited hill stuff. It's definitely doable.

That said, I have to use a NS2R if I want to go into widebody tyre fitting in the future, so maybe I'll opt for the 180TW for the road and go AR1 for track days in a world where I have enough money to say things like this sentence without laughing.

[SKYMAGGOT]

Anyone notice much grip difference between 235 & 265 with same sort of compound?

Also running 235 front 265 rear compared to 235 or 265 all round?

[Duncan]

Easy question, but hard to answer

Generally, in road use, you would not notice the difference in the same tyre but 20% wider.

In flat out use like racing, absolutely, particularly in hot weather and more than 1-2 laps.

[Murray_Calavera]

6 hours ago, SKYMAGGOT said:

Anyone notice much grip difference between 235 & 265 with same sort of compound?

Also running 235 front 265 rear compared to 235 or 265 all round?

At a very general level -

On the street, going wider you'll notice more tramlining and tendency to hydroplane in standing water. (On the street, one would hope you aren't doing anything to cause a tyre to overheat, however if you are the below also applies). 

On the track, going wider improves the tyres ability to handle heat which improves grip levels and wear rates. Wider tyres generally means larger tread blocks, this again improves the tyres ability to handle heat.  

[GTSBoy]

Actually it's the shape of the contact patch that makes wider tyres "handle the heat" better. It's not that they actually handle the heat better, but that they don't heat up as much.

A narrow tyre has a long contact patch. That is flat on the road interface and the whole body of the tyre/tread face has to deform every time it hits the road, passes under the centre and then departs the road surface.

A ~65 profile tyre has a square contact patch.

A wider, lower profile tyre has a wide contact patch. There is less deformation as it goes under the centreline every rotation. The reduced deformation causes less internal frictional heating. In serious (is track) tyres this means that you can actualy use softer compounds on these wider tyres, which is what gives the tyre better all round traction. If the compound is not optimised for the heat input rate, then you will either struggle to get it up to temperature, or you will give away some possible grip. All the usual shenanigans that come into choosing the absolute optimum tyre, which is too many variables for me to hold in my head.