50 PSI in (stock) yokohama A550H 225/55/R16 tires
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50 PSI in (stock) yokohama A550H 225/55/R16 tires
What will 50 psi do on stock tires? MAX 35 PSI. I am asking this because I didn't notice it was at 50 PSI until today's accident on my way to the autocross track (rear swung out on wet street and did a 90 degree turn into a guard rail). I didn't even give it much gas (15-25% throttle on exit of a wide turn). Wasn't even trying to make a fast turn at the intersection. Anyways, I have always noticed that the car kinda skips/jumps on small bumps, rolls alot on the high way, and I guess has a rough ride when the car is stock. I lowered to 35 PSI for the track and it was as if I was driving a totally different car. I am an idiot. Well what do you guys think that has been the cause of all my poor handling?
Anyone got a used 95 front bumper?
Anyone got a used 95 front bumper?
#6
Lexus Champion
If your tires are overinflated, they could be damaged more easily when running over potholes or debris in the road. Higher inflated tires cannot isolate road irregularities well, causing them to ride harsher. However, higher inflation pressures usually provide an improvement in steering response and cornering stability up to a point.
Tire footprint and traction are reduced when tires are overinflated for the loads carried. In particular, tires with aggressive tread patterns may contribute to over steer or "roadwalk" (exactly what you complained of) if inflated beyond the specified inflation pressure. Over inflation also increases the chances of bruise damage.
When a tire has too much air in it, the center of the tread bears most of the load and wears out faster than the outside edges. In effect, the tire bulges out in the center and you are riding on less tire. This is why your car rode so skittish and smacked a wall easily.
Finding the right tire pressure is key for any application. What I do is put the recommended pressure and then get my car to peel out. I then inspect the tread marks on the ground and note if it is flat or not. If it is mostly evident on the outside of the tire mark but uneven in the center then I increase tire pressure. If the center is too heavy and the sides light then I decrease the pressure. Since this is a rwd car and depending on the SC may not have enough power to burn two tires you will have to use results from one or possibly two tires to estimate the pressure needed for the fronts. This is thrown out the window though if your fronts and rears are different tires/sizes.
Tire footprint and traction are reduced when tires are overinflated for the loads carried. In particular, tires with aggressive tread patterns may contribute to over steer or "roadwalk" (exactly what you complained of) if inflated beyond the specified inflation pressure. Over inflation also increases the chances of bruise damage.
When a tire has too much air in it, the center of the tread bears most of the load and wears out faster than the outside edges. In effect, the tire bulges out in the center and you are riding on less tire. This is why your car rode so skittish and smacked a wall easily.
Finding the right tire pressure is key for any application. What I do is put the recommended pressure and then get my car to peel out. I then inspect the tread marks on the ground and note if it is flat or not. If it is mostly evident on the outside of the tire mark but uneven in the center then I increase tire pressure. If the center is too heavy and the sides light then I decrease the pressure. Since this is a rwd car and depending on the SC may not have enough power to burn two tires you will have to use results from one or possibly two tires to estimate the pressure needed for the fronts. This is thrown out the window though if your fronts and rears are different tires/sizes.
Last edited by Hermosa; 07-11-04 at 08:14 AM.
#7
Lexus Champion
Okay I remembered an easier method
1. Park on level ground.
2. Ensure that your car is pointed straight ahead.
3. Draw a chalk line completely across the tread on each tire.
4. Pull ahead 2-3 tire revolutions or until the chalk starts wearing off.
If the chalk is worn off equally across the width of the tread, the inflation pressure is correct.
If the chalk is worn off more in the center than at the edges the tire is overinflated.
If the chalk is worn off more at the edges than in the center the tire is underinflated.
Yeah, yeah but peeling out is fun too.
And try to do this test at normal tire operating temperatures.
1. Park on level ground.
2. Ensure that your car is pointed straight ahead.
3. Draw a chalk line completely across the tread on each tire.
4. Pull ahead 2-3 tire revolutions or until the chalk starts wearing off.
If the chalk is worn off equally across the width of the tread, the inflation pressure is correct.
If the chalk is worn off more in the center than at the edges the tire is overinflated.
If the chalk is worn off more at the edges than in the center the tire is underinflated.
Yeah, yeah but peeling out is fun too.
And try to do this test at normal tire operating temperatures.
Last edited by Hermosa; 07-11-04 at 10:11 AM.
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#12
Former Sponsor
Inflation
Always follow the inflation pressure recommended on the inside of the door jam and never inflate beyond the max inflation pressure listed on the sidewall of the tire. Always check tire pressures cold (first thing in the morning).
Last edited by Brandon@TR; 07-12-04 at 09:14 AM.
#13
Lexus Test Driver
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Re: 50 PSI in (stock) yokohama A550H 225/55/R16 tires
Originally posted by chitwnsazn
What will 50 psi do on stock tires? MAX 35 PSI. I am asking this because I didn't notice it was at 50 PSI until today's accident on my way to the autocross track (rear swung out on wet street and did a 90 degree turn into a guard rail). I didn't even give it much gas (15-25% throttle on exit of a wide turn). Wasn't even trying to make a fast turn at the intersection. Anyways, I have always noticed that the car kinda skips/jumps on small bumps, rolls alot on the high way, and I guess has a rough ride when the car is stock. I lowered to 35 PSI for the track and it was as if I was driving a totally different car. I am an idiot. Well what do you guys think that has been the cause of all my poor handling?
Anyone got a used 95 front bumper?
What will 50 psi do on stock tires? MAX 35 PSI. I am asking this because I didn't notice it was at 50 PSI until today's accident on my way to the autocross track (rear swung out on wet street and did a 90 degree turn into a guard rail). I didn't even give it much gas (15-25% throttle on exit of a wide turn). Wasn't even trying to make a fast turn at the intersection. Anyways, I have always noticed that the car kinda skips/jumps on small bumps, rolls alot on the high way, and I guess has a rough ride when the car is stock. I lowered to 35 PSI for the track and it was as if I was driving a totally different car. I am an idiot. Well what do you guys think that has been the cause of all my poor handling?
Anyone got a used 95 front bumper?
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