Street Tire Pressures At The Track?

[RYU]

Thanks Billy. This is helpful. I had it set at about 2 full turns of the spring perch past 0 load for more preload. This equated to about 1/8" worth of compression on the springs (9k/11k).

Can you help me understand in what situations one might want to adjust more/less spring preload?

I can believe a 10-12psi swing. A lot depends on the tread design and tire size. Also if their is water in your tires from condensation it will cause large tire pressure changes. 47psi is WAY too high and I would expect it to be skiddish.

Outer front tire wear might indicate the need for more front camber.

I would loosen the spring perch to just barely touch the spring (no preload compressing the spring) -or even back it off 1/4"so there is a slight gap between the spring and the collar (to increase droop travel). From there use the bottom adjuster with the threaded shock body to set your ride height.


Billy

 

[stuntman]

Thanks Billy. This is helpful. I had it set at about 2 full turns of the spring perch past 0 load for more preload. This equated to about 1/8" worth of compression on the springs (9k/11k).

Can you help me understand in what situations one might want to adjust more/less spring preload?

On that style coilover, preload reduces and can eventually eliminate droop travel. A lac of droop travel negatively impacts ride quality especially over bumps. Any little bump can make the tire lose contact with the ground. This is a topic of debate for some tuners but the shift has been toward more droop travel in racecars.

If you move too far in the direction I said, you will reduce compression travel and bottom out over bumps. The trick is to lower the spring perch as much as you can (for more droop travel) without bottoming out the shock over bumps. This will improve ride quality, predictability, and performance.

Billy

 

[RYU]

I can confirm. There is a particular stretch of flat straight road near my area but it's filled with small tiny bumps right before each stop. No doubt from years of heavy trucks braking and likely compressing the asphalt.

I was braking about 65% from full hard and the front end was skipping around a bit (no doubt also due to the tires). I wasn't expecting that.

I'll try what you said and add about 1/4" of additional droop. Fun stuff. I can't wait to dial it all in. My current setup is already light years better in terms of aggressive driving.

On that style coilover, preload reduces and can eventually eliminate droop travel. A lac of droop travel negatively impacts ride quality especially over bumps. Any little bump can make the tire lose contact with the ground. This is a topic of debate for some tuners but the shift has been toward more droop travel in racecars.

If you move too far in the direction I said, you will reduce compression travel and bottom out over bumps. The trick is to lower the spring perch as much as you can (for more droop travel) without bottoming out the shock over bumps. This will improve ride quality, predictability, and performance.

Billy

 

[NSXDreamer2]

wow, it's been side tracked again, and I'm sure the OP is more lost than before he posted :tongue:

Billy, I did remember when my first year tracking stock suspension and oem size tires (it's the Kumho MX back in the days). We tend to run lower psi, of course those poor tires all look like a "crisp creme" by the end of the days.

OP, just play with the pressure, I'm sure with your driving skills, you will find something you like, it's just part of the fun... Sooner or later, you will start modding the car, either for chasing your friends, specific car; or minimize wear and tear, (As I mentioned before, I probably spend less money on my NT01 than if I running any street tires.)

Enjoy sliding down the slippery slope:wink:

BTW, if you have any tire installer equipped with Nitrogen; take advantage of it.

 

[Sylvan]

wow, it's been side tracked again, and I'm sure the OP is more lost than before he posted :tongue:

Billy, I did remember when my first year tracking stock suspension and oem size tires (it's the Kumho MX back in the days). We tend to run lower psi, of course those poor tires all look like a "crisp creme" by the end of the days.

OP, just play with the pressure, I'm sure with your driving skills, you will find something you like, it's just part of the fun... Sooner or later, you will start modding the car, either for chasing your friends, specific car; or minimize wear and tear, (As I mentioned before, I probably spend less money on my NT01 than if I running any street tires.)

Enjoy sliding down the slippery slope:wink:

BTW, if you have any tire installer equipped with Nitrogen; take advantage of it.

Hehe thanks, don't worry my original question was answered so I don't mind seeing the discussion take another turn. You may be right about the mods, we'll see....

 

[stuntman]

I can confirm. There is a particular stretch of flat straight road near my area but it's filled with small tiny bumps right before each stop. No doubt from years of heavy trucks braking and likely compressing the asphalt.

I was braking about 65% from full hard and the front end was skipping around a bit (no doubt also due to the tires). I wasn't expecting that.

I'll try what you said and add about 1/4" of additional droop. Fun stuff. I can't wait to dial it all in. My current setup is already light years better in terms of aggressive driving.

I'm not sure if I would agree that the majority of your issue is a lack of droop travel. Increasing droop might help but since the front is loaded during braking, I don't think its your biggest issue.

 

[RYU]

I'm not sure if I would agree that the majority of your issue is a lack of droop travel. Increasing droop might help but since the front is loaded during braking, I don't think its your biggest issue.

i'll give it a shot and report back. hope to be able to make some adjustments in a couple of weeks.

 

[sparky]

stuntman what are tyre stagger and camber stagger ?

-1.5 F / -2/5 R
2mm out front toe
2 to 4mm in rear toe (tradeoff is rear stability vs tire wear - higher toe in more wear).

...and higher toe gives less or more stability?

And by stability do you mean the tendency for rear to move around, e.g. under heavy braking or rapid steering inputs?

 

[sparky]

stuntman by ''tyre stagger'' and ''camber stagger'' do you mean the tyre patch-on-road size and negative camber increases from front to rear?

-1.5 F / -2/5 R
2mm out front toe
2 to 4mm in rear toe (tradeoff is rear stability vs tire wear - higher toe in more wear).

...and higher toe gives more stability?

And by stability I assume you mean less tendency for rear to move around, e.g. under heavy braking or rapid steering inputs?