Tire compound vs. Suspension

[luvtadrive]

Hey to all: Question for suspension experts...How does tire compound effect a given suspension setup. If a tuner sets up a car's suspension to give the desired effect of neutral feedback in cornering, hi-speed straight line stability, curb thump absorbing rebound etc. in other words "PRIMO" for RC3 tires & enters a room where tires are restricted to SC2. The "PRIMO" goes out the "WINDOW". So what can you do to modify a suspension to react to varying tire compound demands of on line racing challenges. Also if tuners were to start with SC2 as their basic tire platform Instead of RC3 would this not improve the cars handing when upgrading to Race soft tires & minimalize the degradation of using Comfort medium tires? I mean I'am just asking.

 

[MTLclllutch]

less camber and maybe a tad softer

 

[CSLACR]

Hey to all: Question for suspension experts...How does tire compound effect a given suspension setup. If a tuner sets up a car's suspension to give the desired effect of neutral feedback in cornering, hi-speed straight line stability, curb thump absorbing rebound etc. in other words "PRIMO" for RC3 tires & enters a room where tires are restricted to SC2. The "PRIMO" goes out the "WINDOW". So what can you do to modify a suspension to react to varying tire compound demands of on line racing challenges. Also if tuners were to start with SC2 as their basic tire platform Instead of RC3 would this not improve the cars handing when upgrading to Race soft tires & minimalize the degradation of using Comfort medium tires? I mean I'am just asking.

That's actually an excellent question.

Generally, the main difference for me, is I set the suspension softer, and lower the camber for harder tires.
On sticky tires cars hold more G's, which means more centrifugal force, which makes them lean harder, so you need a stiffer suspension to compensate, as for camber, I've found it seems to work better slowly increasing it based on tire compound, presumably for the same reason.

But since all my races have tire wear, I never bother going higher then 2.0 with camber. (I am known to run 20.0 spring rates if I feel the need though )

 

[luvtadrive]

Okay, I think I understand the concept. Sticky tires more spring rate & less rebound. Hard tires vice versa but but what about roll bars? Do they factor in as to the car's weight distribution only as far as oversteer & understeer or are they a factor in grip as well?

 

[praiano63]

That's actually an excellent question.

Generally, the main difference for me, is I set the suspension softer, and lower the camber for harder tires.
On sticky tires cars hold more G's, which means more centrifugal force, which makes them lean harder, so you need a stiffer suspension to compensate, as for camber, I've found it seems to work better slowly increasing it based on tire compound, presumably for the same reason.

But since all my races have tire wear, I never bother going higher then 2.0 with camber. (I am known to run 20.0 spring rates if I feel the need though )

I agree with this totally with just a restriction. This can be applied to very well balanced cars ,with a good weight repartition ,that will not show some big oversteer problems with lower grip tires.
In this case, with comfort or sport tires ,you will have to use specials settings to correct the problems, like lower rear springs and dampers together with ride height ,rear TOE and camber . All or just any of them oriented to correct the bad tendency of the car with this tires.
When you use racing tires with the same car, the problems disappears and then your settings are no more oriented to correct the car, but sometime to induce some rear oversteer or front grip to have a more agressive car.
So ,to resume, only with well balanced car with a good weight repartition ,you can just increase yours settings proportionally from a sport tire to a racing tire for example.
This is my opinion based on own experience.
Have a good day everybody.

 

[CSLACR]

Okay, I think I understand the concept. Sticky tires more spring rate & less rebound. Hard tires vice versa but but what about roll bars? Do they factor in as to the car's weight distribution only as far as oversteer & understeer or are they a factor in grip as well?

Roll bars...
On low settings, the car is easier to drive over bumps, etc
On high settings, I like the way the car handles so much better, it doesn't even bother me how harsh it is over bumps.

Both need to be driven differently, so I guess it's just a preference thing. I tested low vs high at Suzuka and Laguna Seca recently, and found when I adapted my driving style to fit each setup, lap times remained exactly the same.

I agree with this totally with just a restriction. This can be applied to very well balanced cars ,with a good weight repartition ,that will not show some big oversteer problems with lower grip tires.
In this case, with comfort or sport tires ,you will have to use specials settings to correct the problems, like lower rear springs and dampers together with ride height ,rear TOE and camber . All or just any of them oriented to correct the bad tendency of the car with this tires.
When you use racing tires with the same car, the problems disappears and then your settings are no more oriented to correct the car, but sometime to induce some rear oversteer or front grip to have a more agressive car.
So ,to resume, only with well balanced car with a good weight repartition ,you can just increase yours settings proportionally from a sport tire to a racing tire for example.
This is my opinion based on own experience.
Have a good day everybody.

Yes.
One thing is that with harder tires, especially on higher powered cars, people generally prefer a bit more under-steer, because it makes it harder to break the wheels loose from wheelspin, and also makes it easier to catch.

Another thing is that you have to calculate the difference in setup numbers.
Meaning you can can't always just "proportionally" change the settings.
For example: Spring rate @ 20.0 / 15.0 can't always just be changed to 10.0 / 7.5 Sometimes that'll work, and sometimes it won't.

I hadn't thought of connecting it to weight balance of the car, but that could easily be the difference in when it works or if it works, good thought.👍