981 GT4 Unusual Left Front Tyre Wear
Discussion
Has anyone experienced unusual wear on the left front tyre? These are Michelin Pilot Sport Cup 2. The wear is experienced on the second tread in from outer side. The wear across this second tread is uneven and is worse towards the outer. The tyre in the photo had only been used at two trackdays at Brands Hatch, which is mostly RH circuit.
After the first day at Brands, we got Hunter Laser alignment checked and minor adjustment was made to the toe. Then at Silverstone recently, the Pirelli team at the track recommended switching front right and left to even out wear. Even after swapping tyres at Silverstone, there was again obvious wear to the front left. The Pirelli guys hadn't seen this type of wear before and thought it might be alignment (checked ok), tyre pressures (checked ok) or perhaps suspension alignment, which we haven't checked yet.
Any advice would be very welcome.
After the first day at Brands, we got Hunter Laser alignment checked and minor adjustment was made to the toe. Then at Silverstone recently, the Pirelli team at the track recommended switching front right and left to even out wear. Even after swapping tyres at Silverstone, there was again obvious wear to the front left. The Pirelli guys hadn't seen this type of wear before and thought it might be alignment (checked ok), tyre pressures (checked ok) or perhaps suspension alignment, which we haven't checked yet.
Any advice would be very welcome.
GT4Ian said:
I wonder whether there is a different Geo set up that minimises wear?
Iirc it's kind of thought to be the relatively soft front spring rate that is causing the issue. Geo alone I don't think had that much improvement in wear (or lap times for that matter) as you can't easily put on sufficient camber without adding more bits to the car anyway. Geo probably will ultimately help but not by as much as one might hope I'd suspect.GEO set up within Porsche spec. They’ve checked it. Experience is about 8 track days to date, two at Brands Hatch on these tyres so far with mostly RH bends. We have ARDS instructor with us every time, so we are pushing car. My son drives as well so we are doubling up. We did 160 miles at Silverstone and 140 miles at Brands last two outings.
Front left will always wear more in particular, on clockwise circuits, so good to swap side to side after each to extend the life a little.
As 911r says could be a bit to do with steering inputs.
But largely, the kind of wear you are seeing looks normal to me if you are running OEM hardware and OEM settings on the car.... you will burn up that second tread.
A geo setup for fast road or track will certainly help manage that a bit better.
Cup2 will always wear unevenly across the width of the tyre as it’s dual compound, outer is softer for cornering grip, inner harder, for steering.
As 911r says could be a bit to do with steering inputs.
But largely, the kind of wear you are seeing looks normal to me if you are running OEM hardware and OEM settings on the car.... you will burn up that second tread.
A geo setup for fast road or track will certainly help manage that a bit better.
Cup2 will always wear unevenly across the width of the tyre as it’s dual compound, outer is softer for cornering grip, inner harder, for steering.
Edited by TDT on Saturday 12th September 20:56
Not sure an ARDs instructor adds or takes away anything regarding pushing or tyre wear.
But oem geo you are totally screwed with just -1.5 camber.
You should feel the tyre go greasy after about 5 hot laps, so are you staying out too long ?
You will hit tyre grip levels very early on with the Porsche geo, so you are just increasing heat and if anything the tyres a bit low, so that would also add heat.
You need min -2.2 camber, some rear toe links and a track geo and I would try 31 psi up front.
do 2 laps and bleed air out down to 31psi.
Many people you see at track days take 10psi out and wait for the heat and tyre to get back. That’s bad news.
I let about 3 psi out at track on arrival tyres already hot from getting there so high , do 2 sighting laps to check track, curbs and any other changes so slowish laps.
Bleed down to 31 psi, then go straight out and do 3 faster laps, then bleen down to 31psi again. (32/33 psi rear)
On cups that is normally is ok for the day.
Then I keep laps to only 4 or 5 and come in as I feel the tyres go greasy (hot) so not worth staying out.
I normally drive with the PSM and traction off also to try and keep the systems screwing up your rear disks.
I would say the cars being over driven on the oem geo, PtV is messing with the rear and the front lefts scrubbing while too hot and too low psi (29 psi is BELOW recommend levels for this tyre hot)
Cup2 are NoT sided, they are designed for the left side of the car, so you DO need to swap tyres side to side to even wear.
So to recap
1: buy rear toe links
2: get a geo
3: try 31/33 psi hot (ASK TDT this )
4: don’t talk to Pirelli
5: hire a current pro race driver for track tuition.
6: maybe try cup connect tyres in the future it’s a faster tyre and will tell you what temps and psi to set your tyre too and tell you to come in if you are trashing them on the app.
But oem geo you are totally screwed with just -1.5 camber.
You should feel the tyre go greasy after about 5 hot laps, so are you staying out too long ?
You will hit tyre grip levels very early on with the Porsche geo, so you are just increasing heat and if anything the tyres a bit low, so that would also add heat.
You need min -2.2 camber, some rear toe links and a track geo and I would try 31 psi up front.
do 2 laps and bleed air out down to 31psi.
Many people you see at track days take 10psi out and wait for the heat and tyre to get back. That’s bad news.
I let about 3 psi out at track on arrival tyres already hot from getting there so high , do 2 sighting laps to check track, curbs and any other changes so slowish laps.
Bleed down to 31 psi, then go straight out and do 3 faster laps, then bleen down to 31psi again. (32/33 psi rear)
On cups that is normally is ok for the day.
Then I keep laps to only 4 or 5 and come in as I feel the tyres go greasy (hot) so not worth staying out.
I normally drive with the PSM and traction off also to try and keep the systems screwing up your rear disks.
I would say the cars being over driven on the oem geo, PtV is messing with the rear and the front lefts scrubbing while too hot and too low psi (29 psi is BELOW recommend levels for this tyre hot)
Cup2 are NoT sided, they are designed for the left side of the car, so you DO need to swap tyres side to side to even wear.
So to recap
1: buy rear toe links
2: get a geo
3: try 31/33 psi hot (ASK TDT this )
4: don’t talk to Pirelli
5: hire a current pro race driver for track tuition.
6: maybe try cup connect tyres in the future it’s a faster tyre and will tell you what temps and psi to set your tyre too and tell you to come in if you are trashing them on the app.
GT4Ian said:
Thanks, good advice. A recommendation we had from another site was to use Centre Gravity to check alignment and suspension set up. Worth a try I guess.
No point checking it, you have had it checked, you need a proper set up which also means buying a few parts.The shocks are not adjustable so nothing to check bar if they are nackered lol
But yes Cof G will help you put a more focused geo set up on the car.
TDT said:
Front left will always wear more in particular, on clockwise circuits, so good to swap side to side after each to extend the life a little.
As 911r says could be a bit to do with steering inputs.
What psi do you run, I forget my setup, sure I ran about 31 psi front. As 911r says could be a bit to do with steering inputs.
Edited by TDT on Saturday 12th September 20:56
All sensible advice from 911R. Tyres will still look like that after a good spanking even with better tack focused geo. Its normal.
31psi hot is maybe a touch high for fully optimum performance in my experience. Not sure about swopping tyres from side to side. I tend to change the highly loaded tyre pair more often than the other side on all the toys.
31psi hot is maybe a touch high for fully optimum performance in my experience. Not sure about swopping tyres from side to side. I tend to change the highly loaded tyre pair more often than the other side on all the toys.
Porsche911R said:
TDT said:
Front left will always wear more in particular, on clockwise circuits, so good to swap side to side after each to extend the life a little.
As 911r says could be a bit to do with steering inputs.
What psi do you run, I forget my setup, sure I ran about 31 psi front. As 911r says could be a bit to do with steering inputs.
Edited by TDT on Saturday 12th September 20:56
I’ve found that changing side to side does help even the wear across the set of tyres, so that when you end up replacing the set, you get new boots all at the time all around, all hopefully similar age.
Track connect is a very good suggestion and funnily enough, I’m bolting a set of these on next week, to try out, along with the TC module.
This will take guess work out of the equation, and will even recommend if you need to run different pressures left to right based upon which circuit you are at. Apparently the track connect also has a slightly different compound which is a step on again from Cup2 N1/N2.
Edited by TDT on Saturday 12th September 22:00
TDT said:
A geo setup for fast road or track will certainly help manage that a bit better.
interesting. if I remember correctly lasource went for some full on track geo initially at 2.5 camber with his if not more but in the end went back to more or less oem but at the max of the range and found little different in either tyre wear or lap time tbh...Gassing Station | Boxster/Cayman | Top of Page | What's New | My Stuff