Noob Question On Tyres

[stockhome]

I ran my first set of tyres (bridgesrtone potenza's) at the recommended Lotus pressures and they wore in the middle not the edges.

 

I have more wheels and tyres than I know what to do with

 

standard wheels have ad07's (don't really get used that much but I like to keep everything)

lotus sport oz have hankooks (for everyday)

team dynamics have 888's (for trackdays)

 

all are run at 22 24

 

think I might have a problem

[R.I.B.]

For me all it boils down to is....

a. the tyre wear is more equal at 22-24 which means they are not under or overflated which will in theory give you more contact to the road and...

b. it feel better (gives more feedback, seems quite balanced between oversteer and understeer whilst cornering)

 

But that's just what i'm happy with. My driving style with mikes geo setup might be completely different to how you drive and how your car is set up.

 

My mate has bought an Audi S3 and the recommended tyre pressures are 42 front and 33 rear and he was asking me why it understeers like wheel barrow, it's no doubt in my mind that audi try and set it up to tend to understeer to stop "less capable" people flying backwards into a hedge. I said if I was you I would try dropping the front tyre pressure a bit at a time until it feels more balanced.

[Meister]

For me all it boils down to is....

a. the tyre wear is more equal at 22-24 which means they are not under or overflated which will in theory give you more contact to the road and...

b. it feel better (gives more feedback, seems quite balanced between oversteer and understeer whilst cornering)

 

But that's just what i'm happy with. My driving style with mikes geo setup might be completely different to how you drive and how your car is set up.

 

My mate has bought an Audi S3 and the recommended tyre pressures are 42 front and 33 rear and he was asking me why it understeers like wheel barrow, it's no doubt in my mind that audi try and set it up to tend to understeer to stop "less capable" people flying backwards into a hedge. I said if I was you I would try dropping the front tyre pressure a bit at a time until it feels more balanced.

Once again thank you RIB for taking the time to reply - I appreciate it!

The only thing I suppose I can not get my head around, is the fact that Lotus and the tyre companies must have spent hours and hours on road and track developing the tyres and you would have thought that they would have spotted the fact that they wear in middle of the tyre and recommended lower pressures?

Although I think you may have a point, potentially, with the fact they may want to induce understeer rather than oversteer as this potentially easier to control.

Mark

[R.I.B.]

Don't forget air temp to further confuse the matter. If you set your cold tyre pressures at 26psi when it's 25 degrees outside that would a probably more like 22psi when it's 0 degrees ;-)

[Alex B]

This tyre pressure question come hand in hand with the what tyres you prefer. I have khumo ecsatis h4 or something like that on mine, CN put them on prior to my buying it.

I've tried various tyre pressures and settled on two settings 20f with 22r OR 22f with 24r.

After trying higher pressures I found these to be about right for my driving style. Much higher than these and the steering becomes "floaty" and the back end jumps about.

 

Once again thank you RIB for taking the time to reply - I appreciate it!

The only thing I suppose I can not get my head around, is the fact that Lotus and the tyre companies must have spent hours and hours on road and track developing the tyres and you would have thought that they would have spotted the fact that they wear in middle of the tyre and recommended lower pressures?

 

Mark

 

Surely the answer is obvious to this question... Uneven wear will see you replacing tyres quicker...

[stockhome]

Once again thank you RIB for taking the time to reply - I appreciate it!

The only thing I suppose I can not get my head around, is the fact that Lotus and the tyre companies must have spent hours and hours on road and track developing the tyres and you would have thought that they would have spotted the fact that they wear in middle of the tyre and recommended lower pressures?

Although I think you may have a point, potentially, with the fact they may want to induce understeer rather than oversteer as this potentially easier to control.

Mark

 

Lotus purposely built understeer into the S2 as people kept crashing their s1's backwards into hedges. This is why they have such skinny 175 tires up front, the overinflated pressure may be part of that.

[Meister]

Lotus purposely built understeer into the S2 as people kept crashing their s1's backwards into hedges. This is why they have such skinny 175 tires up front, the overinflated pressure may be part of that.

 

Thanks Sheldon.

[DeanB]

Sheldon is bang on, although presumably Lotus thought they could gamble on a less understeery set up on the Exige.

One issue I have with the skinny tyres is that they limit braking performance.

[Numbnutz]

The 175 fronts irritate me too. Braking is ok unless you need to stop quick. The under steer can be reduced by removing a camber shim or two, but only wider tyres will help the braking.

 

What is more annoying, is that the 5.5j front wheels are on the limit for 175 and although you can squeeze 195 on, there isn't much choice in rubber for ad07/08 and only leaves 195 r888 or a048, both of which don't go with ad07/08 rears.

 

This has led me to two sets of wheels, (oem and some wider rims) and two different tyres. I'm still undecided on the trackday/summer tyres. Ad08's or r888's?

[DanP]

Once again thank you RIB for taking the time to reply - I appreciate it!

The only thing I suppose I can not get my head around, is the fact that Lotus and the tyre companies must have spent hours and hours on road and track developing the tyres and you would have thought that they would have spotted the fact that they wear in middle of the tyre and recommended lower pressures?

Although I think you may have a point, potentially, with the fact they may want to induce understeer rather than oversteer as this potentially easier to control.

Mark

 

It's been said that the standard lotus tire pressures induce wear in the middle of the tyre (during road use?). How do people find the wear during track use? So far in my limited experience, the edges of the tyre are hammered much more, and the wear is much more on the edges of the tyre, and might be even worse if you used lower pressures?

[stockhome]

Sounds weird if its wearing the edges if anything you would expect trackdays to make it wear even worse in the centre. Is it both edges of the tyre or just one. Probably worth getting the geo checked

[Acehole]

didnt think my thread would reach the dizzy heights of this many replies.

i will add my comments having just put AD07s on.

even though i am nothing more than a tootler in my car due to lack of both talent and confidence i can feel the difference in the new tyres

the car does feel more stable than it did on the old ones i removed, again this may only be a mental thing in reality.

the tyres that came off were running at pressures of about 20-21 at the front and 22-23 at the back.

the front tyres showed very little wear indeed i assume through both mine and the previous owners lack of talent.

the rear tyres were however very well worn around the centre of the tyre, almost down to nothing, and as said i drive like a pussy.

hope this adds to the debate.

acehole

[DanP]

Sounds weird if its wearing the edges if anything you would expect trackdays to make it wear even worse in the centre. Is it both edges of the tyre or just one. Probably worth getting the geo checked

 

I've just measured the tread depth, an it is pretty even all over, with the tread near the outside wall looking shredded.

 

Front:

 

Rear:

 

 

[stockhome]

The standard Geo settings are here http://wiki.seloc.org/a/Geo_Setups it always worth getting them checked as elise's are very sensitive to how they're setup. And a few mm can make a massive difference to how they handle.

 

HTH

[R.I.B.]

The front tyres are hard to wear down because there is no weight at the front of the car and all the power is going through the rears. My bridgestones went hard before they had worn out!

My ado7 rears have just about hit the wear markers and seem to have "fell of the cliff" and suddenly lost all grip!!! Had a massive oversteer surprise yesterday around an island that was too easily provoked, at first I thought it might be these cool road temp or dust, but a couple of sharp pull offs proved I have no rear grip at the moment!

Anyone know the cheapest place for a set of Ad08 rears?