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View Full Version : Air Pressures vs. Stagger



tireman
04-25-2016, 07:17 AM
I know most teams get comfortable with a set air pressure in tires. Is it safe to adjust air pressures plus or minus a couple of lbs. to get stagger in tires closer to what you are wanting to run? I kinda have a rule of thumb of no more than + 2lbs or - 1lb. What do some of you guys think. In my years, I feel that if you can change a 1/4 to 1/2 inch of stagger that is more important than a plus or minus lb. of air? All depending on track conditions of course.

MasterSbilt_Racer
04-25-2016, 09:19 AM
I know most teams get comfortable with a set air pressure in tires. Is it safe to adjust air pressures plus or minus a couple of lbs. to get stagger in tires closer to what you are wanting to run? I kinda have a rule of thumb of no more than + 2lbs or - 1lb. What do some of you guys think. In my years, I feel that if you can change a 1/4 to 1/2 inch of stagger that is more important than a plus or minus lb. of air? All depending on track conditions of course.

Air pressure will affect the car more than the stagger, IMHO.

Lizardracing
04-25-2016, 09:45 AM
Last night my car was on scales and I switch RR to increase the stagger/rollout 2" and LRB changed 3lbs

Subtracting 2lbs in the RF and LR and adding 2lbs to the LF and RR changed the LRB by 60lbs.

tireman
04-25-2016, 11:04 AM
Last night my car was on scales and I switch RR to increase the stagger/rollout 2" and LRB changed 3lbsSubtracting 2lbs in the RF and LR and adding 2lbs to the LF and RR changed the LRB by 60lbs.I Can see that, and it correlates with the theory of adding stagger, which would free up the car. Im talking moreso adding a couple lbs. to the LR which decreases stagger and also adds to the percentage of cross, which should tighten car. Im just trying to determine if there is significant differences in working off of stagger or air pressure. Going over a plus or minus 2 Lb. of air is a tremendous no no for me. Of course I will not decrease my LR because its at minimal now.

Lizardracing
04-25-2016, 11:19 AM
I should have metioned my car is a USRA/USMTS modified but I think the theories hold true anyway. That being said, Why are you self limiting tire pressure changes?

MasterSbilt_Racer
04-25-2016, 11:19 AM
I Can see that, and it correlates with the theory of adding stagger, which would free up the car. Im talking moreso adding a couple lbs. to the LR which decreases stagger and also adds to the percentage of cross, which should tighten car. Im just trying to determine if there is significant differences in working off of stagger or air pressure. Going over a plus or minus 2 Lb. of air is a tremendous no no for me. Of course I will not decrease my LR because its at minimal now.

He just explained to you, that indeed, changing air pressure has a huge effect on the "system spring rate" at that corner. It effects wheel load quite a bit and also the spring rate of the system.

There is a lot more going on there than the simple stagger change from blowing up the tire.

The two changes are significantly different.

Kromulous
04-25-2016, 01:37 PM
Wow i never consider that 2 lbs of air cross cornered would make that much of an impact.

TheJet-09
04-25-2016, 05:30 PM
I have always been told to never adjust air pressure to change stagger. But while on the topic, I've never understood why we run so low of a PSI in the LR (realistically 1/2 as much) as compared to the other corners of the car, especially since it's the heaviest wheel weight?

RCJ
04-27-2016, 06:55 AM
I do everything I can to keep the right side air pressures consistent.I adjust the l/r up or down 2lbs to help change the balance of the car.I 've adjusted the l/f, bit it doesn't have a lot of influence on the car.

a25rjr
04-27-2016, 07:26 PM
I have always been told to never adjust air pressure to change stagger. But while on the topic, I've never understood why we run so low of a PSI in the LR (realistically 1/2 as much) as compared to the other corners of the car, especially since it's the heaviest wheel weight?

That's only statically speaking . On the track, the RR carries the most load followed by rf, lr,lf.