A&Q about Lotus
Q:
4,500 miles, a few spirited drives.
I noticed that the outer edge on each one doesn't have much dirt. Are they over-inflated?
A:
Low in the middle...underinflated. And why are the sides of your tires getting chewed up?
A:
It's called camber. Go fast around the corners and you'll get the outsides dirty. It's supposed to look like that.
A:
Originally Posted by LARRY
Low in the middle...underinflated. And why are the sides of your tires getting chewed up?
IMHO, they don't look chewed up enough.
A:
I think these cars come with a hair too much negative camber in the rear and not enough in the front. Tire probing at 3 track events in two weeks shows the outside of the rears almost always cooler than the middle and inside. I might try pulling the 1 remaining shim on each side in the front and adding it to the rear.
A:
Originally Posted by ZJChaser
I think these cars come with a hair too much negative camber in the rear and not enough in the front. Tire probing at 3 track events in two weeks shows the outside of the rears almost always cooler than the middle and inside. I might try pulling the 1 remaining shim on each side in the front and adding it to the rear.
I had that problem after lowering the rear and changing to Hoosiers. Added one shim to the rear and the temps were within 2 degrees across the tire.
BTW, I believe the shims are different (F/R).
A:
I thought they might be but then I thought that knowing lotus they'd keep it cheap and just use the same shim all around, I hadn't actually checked though. oh well.
A:
Originally Posted by ZJChaser
I thought they might be but then I thought that knowing lotus they'd keep it cheap and just use the same shim all around, I hadn't actually checked though. oh well.
The ones I picked up at the shop were thinner than most of the ones in the rear but did the trick.
A:
Originally Posted by MyElise
It's called camber.
+1
A:
Originally Posted by benles
4,500 miles, a few spirited drives.
I noticed that the outer edge on each one doesn't have much dirt. Are they over-inflated?
Looks almost unused to me. My "street" tires at 4,500 and a couple of track days were worn well into the wear bars in the middle. I talked with one of the Yokohama reps at the LOG track day and he told me that the Lotus-recommended street pressure (AD07s) was too high for the track. Their target for the track is to warm up to around 35 psig at the rear, and to avoid overinflation when fully warm start at ~25 rear, 23 front.
These tires look more under-used than underinflated. I think the rear camber (and front, for that matter) are nearly perfect for track use on non-LSS cars. My wear from side to side is perfectly uniform. Evidently, I've just been using too much pressure for the track and the center of the tread is way down. Same with my so-called track tires -- also AD07s -- only more so. I have a new pair on order (fronts are A-OK and have probably twice that mileage still left) and will adjust the pressures accordingly.
I'd go for more extreme negative camber if I were autocrossing the car (greater side-loading than track use), but for occasional track days, it's just about perfect. Alastair McQueen seemed to think so. He was very smoothly putting my car into attitudes on the track that I've seldom been able to master with speeds and lap times, of course, far better than mine.
FWIW, all the Elises and Exiges I was able to closely observe at the LOG track days had the outer camber on hard turns about perfectly vertical to very slightly negative (top of tire inwards), both front and rear. Seemed to be about ideal for the circumstances. Texas Motorsport Park (course two) is medium-fast to fast, and has several high-speed turns including one equal-radius combination pair. Several are off-camber and a couple (the "Rattlesnake") are quite tight and slow (mid-second gear).
I'll post some pics of the well-worn rears as soon as I get home from this week's business in Cali. Straight off the track, the tires looked and felt liked treaded racing tires -- marbled tread rubber, nice and shiny, good and sticky.
A:
haha.. here's mine just at 6k
A:
Originally Posted by lotusport
Texas Motorsport Park
It's MSR C (Motorsports Ranch Cresson) the other is in Houston..
A:
Well I've got a track pack equipped exige running 2.3 degrees negative camber for each rear tire. The result is they're 7-10 degrees hotter on the inside, so I'm planning to add one shim back in and retest. However, I want to make the point that I'm a pretty beginner level track driver. If I was as fast as some of you out there, I might be working the rear tire over more.
xtn
A:
Originally Posted by lotusport
FWIW, all the Elises and Exiges I was able to closely observe at the LOG track days had the outer camber on hard turns about perfectly vertical to very slightly negative (top of tire inwards), both front and rear. Seemed to be about ideal for the circumstances.
I hope you didn't use mine as a frame of reference. Mine is set up as close to where I want it as possible without machining stuff. (Still not quite perfect, IMHO.)
I'll pretty much leave the car where it is for now - my next few seconds will come from working on me.
A:
Originally Posted by codymac
I'll pretty much leave the car where it is for now - my next few seconds will come from working on me.
Damn that's gonna take a bunch of work. You'd better hire a team. I know for most people they say effort/money is better spent on the driver than on the car, but for you? Fuhgedduboudit.
A:
My right rear tire is worn quite uniformly and nearly slick after last weekend. Time for a new pair of rears. Left rear is just really worn.
Thanks for the info on track pressures. After a 3 mile cool down lap, I would come off the track and then set pressures to 24f/26r. As the day warmed up, I was bleeding off about 2lbs after each session. I was just thinking that 25 might be a better target for the rear....
But, I think I'll keep the front at 24, because I could use a little less grip up front. More drift, less spin, I hope.
Thanks again for the info.
A:
Originally Posted by xtn
Damn that's gonna take a bunch of work. You'd better hire a team. I know for most people they say effort/money is better spent on the driver than on the car, but for you? Fuhgedduboudit.
I wonder what Schumie is doing...