Tire pressure
#17
Pro
Thread Starter
I will recheck them tonight after driving home. However, the interesting information is that after just having the alignment done, the inside edges of the tires are not getting as warm as the middle and outside. I will report back tonight.
#18
Pro
Thread Starter
Here is the temps after my 30 mile drive home Lf 118,118.5,120 Lr 155.5,121,130,5 Rr 113.5,112.5. 105.5 Rf 114, 117.5, 117
Not surprising the tire near the exhaust was the hottest. I have a stoplight to stoplight drive of over two miles off the freeway. Probably I should do a highway stint and check them just off the exit. I think the tires hear up from the exhaust and the fans on the drivers side.
Not surprising the tire near the exhaust was the hottest. I have a stoplight to stoplight drive of over two miles off the freeway. Probably I should do a highway stint and check them just off the exit. I think the tires hear up from the exhaust and the fans on the drivers side.
#19
Rennlist Member
Those temps are a lot warmer. See the difference in your front tires, the outside is cooler this time. When the inside and outside don't match, the middle temp should be in the middle between them.
Wether the inside or outside is hotter or colder will be the difference between driving straight, and making a lot of turns. If consistently hot on inside or outside alignment would be suspect. Autocrossing the outside is almost always a little hotter because of all the turning. it also wears the outside corner off the tires.
How accurate is your tire gauge? Looks like left rear is low. The middle of the tread is colder and the overall temp is higher. or you were doing non-limited slip burn outs
Wether the inside or outside is hotter or colder will be the difference between driving straight, and making a lot of turns. If consistently hot on inside or outside alignment would be suspect. Autocrossing the outside is almost always a little hotter because of all the turning. it also wears the outside corner off the tires.
How accurate is your tire gauge? Looks like left rear is low. The middle of the tread is colder and the overall temp is higher. or you were doing non-limited slip burn outs
#20
Pro
Thread Starter
I'm going to check again Tommorow same route in reverse. But this time I plan to stop immediately off the freeway and check the tires. My thought is the left rear inside is closest to the exhaust and is effected temps tire.
#22
Pro
Thread Starter
Here is my latest data.
SKMBT_36314110316000.pdf
From this data it seems:
a. the inside of the front tires is cooler than the center and outside.
b. the inside of the rear tires are warmer than the center or outside
c. the left rear tire is heated by the exhaust.
Anyone else wanna chime in?
SKMBT_36314110316000.pdf
From this data it seems:
a. the inside of the front tires is cooler than the center and outside.
b. the inside of the rear tires are warmer than the center or outside
c. the left rear tire is heated by the exhaust.
Anyone else wanna chime in?
#23
Rennlist Member
Have you tried adjusting the pressures and see what happens to those temps?
What I call inside and outside is about 2 inches from the edge of the tire. Far enough in you are reading tread area that contacts the road. Center, of course is center.
When Adjusting the pressure an accurate gauge is important. Also it's best to overfill the tire by at least 3 psi, then bleed it down to the desired pressure. While it doesn't take but around 1 or 2 psi to zero in on getting even temps or at least linear across the tread, it takes plus or minus 3psi to change the handling feel of modern radial tires.
What I call inside and outside is about 2 inches from the edge of the tire. Far enough in you are reading tread area that contacts the road. Center, of course is center.
When Adjusting the pressure an accurate gauge is important. Also it's best to overfill the tire by at least 3 psi, then bleed it down to the desired pressure. While it doesn't take but around 1 or 2 psi to zero in on getting even temps or at least linear across the tread, it takes plus or minus 3psi to change the handling feel of modern radial tires.
Last edited by RKD in OKC; 11-04-2014 at 02:52 AM.
#24
Rennlist Member
Here is my latest data.
Attachment 883610
From this data it seems:
a. the inside of the front tires is cooler than the center and outside.
b. the inside of the rear tires are warmer than the center or outside
c. the left rear tire is heated by the exhaust.
Anyone else wanna chime in?
Attachment 883610
From this data it seems:
a. the inside of the front tires is cooler than the center and outside.
b. the inside of the rear tires are warmer than the center or outside
c. the left rear tire is heated by the exhaust.
Anyone else wanna chime in?
b] probably to be expected if mostly straight line highway driving
c] an interesting observation but then your model does have the exhaust hanging around in that area. Still I would not have anticipated that might happen.
Regards
Fred
#25
Pro
Thread Starter
The weird thing is that although I've had my alignment checked several times in the past.... the inside of my front tires are worn quite a bit. These tires are also only 1 year old. Guess the Summer heat just kills them.
#26
Rennlist Member
You have a problem
#27
Rennlist Member
Sounds to me like the toe is set incorrectly. inside tire wear is typical of excess toe out. the toe changes significantly with ride height and is the primary reason not to allow the alignment shop to lift the car prior to having the alignment performed.
#28
Pro
Thread Starter
Yeah when I replaced my rack I had it aligned shortly after. Drive it about 500 miles and realigned it again. But to install the rack it was lifted and could t drive it far before the alignment. I gave a copy of the workshop manual alignment instructions to the alignment shop. I even mentioned the part about pulling the suspension down. I guess that's why they didn't charge for the second alignment.
#29
Rennlist Member
Yeah when I replaced my rack I had it aligned shortly after. Drive it about 500 miles and realigned it again. But to install the rack it was lifted and could t drive it far before the alignment. I gave a copy of the workshop manual alignment instructions to the alignment shop. I even mentioned the part about pulling the suspension down. I guess that's why they didn't charge for the second alignment.
Fred
#30
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
I ended up building a couple laser-level holders that attach to the wheels for checking toe. There are some excellent guides by others that tell you how to use strings, tape measure, stuff like that to check your own. Earl Gillstrom has a step-by-step that's easy to follow and get's the job done.
I'd been to a local highly-recommended-by-928-owners shop. They let me sit under the car with the tech as adjustments were made, and according to the Hunter machine it was perfect. In less than 2000 miles, the inside front ribs on the new tires were corded. The car was well-settled when it went onto the rack. I took it back to see what was wrong, and they graciously put it back on the rack and again it showed everything fine. So even the best techs on the highly-regarded machines don't necessarily do great alignments. They may be acceptable for the station wagon but too expensive (in tires) on the 928.
Needless to say I strongly encourage folks to learn how to do their own alignment, even if just the camber and toe-in settings. Folks in or near central Oregon are welcome to come by for an alignment clinic. I need the practice it seems.
There's a thread here on RL someplace that describes some DIY alignment methods. Takes some care and patience but the results are worthwhile.
I'd been to a local highly-recommended-by-928-owners shop. They let me sit under the car with the tech as adjustments were made, and according to the Hunter machine it was perfect. In less than 2000 miles, the inside front ribs on the new tires were corded. The car was well-settled when it went onto the rack. I took it back to see what was wrong, and they graciously put it back on the rack and again it showed everything fine. So even the best techs on the highly-regarded machines don't necessarily do great alignments. They may be acceptable for the station wagon but too expensive (in tires) on the 928.
Needless to say I strongly encourage folks to learn how to do their own alignment, even if just the camber and toe-in settings. Folks in or near central Oregon are welcome to come by for an alignment clinic. I need the practice it seems.
There's a thread here on RL someplace that describes some DIY alignment methods. Takes some care and patience but the results are worthwhile.