Tire Pressure How Much Impact?

97' CTD

97' CTD

FeFiFo-FoFeFeFi
Just curious on what is a good pressure to start at front/rear this will be on Interco STS's? Just wondering if their is some sort of run of the muck pressure to start with then tune in to the track condition's?
Thanks,
Brandon
 
50 psi in the rear and I run about 25psi or so in the front. This is with BFG AT. I even like to run the right front a hair more pressure than the left, trying to give the drivers side left a little more bite to overcome that fact that it is being lifted up from engine torque.
 
For me, it depends on the track/tire/weight combo. I'm one of those guys that hates putting all the weight on the front unless absolutely needed however some feel that's what it takes. It really is an art almost when it comes down to it at some tracks because if trucks are very evenly matched, the little things are what going to give it the advantage.
 
With the STS's I have gone all the way down to 18psi in the front and usually stayed between 40 and 65psi in the rears.

-Tom
 
I did 15 up front and 60-65 out back with my ProComp AT's last pull. Worked pretty good on that track, when I get weights on the front I might go to 20ish up front...
 
nwpadmax has told me that STSs are very pressure sensetive. He strugggled alittle at first then he got it figured and WOW!:st:
 
The best advice I was ever given was to start with 45 in the rear and 30 in the front, and work your way down.

65 in the rear is entirely too high on the 35-12.50-17. Spun the living daylights out of them once doing that. Never again!

I have the auto though and I can't say if it'll work with a stick, but the 45-30 is a great starting spot for both, it would appear; Worked fine for a CTD nv5600 truck that runs with us. He's lower than that now.
 
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I think rim width plays a huge part on the fronts, I still think a 10" wheel would be way better than the 8" that I have now. My tires seem to bow real bad and not flatten out at all. Something else I need to address.

-Tom
 
Tcolesanti said:
I think rim width plays a huge part on the fronts, I still think a 10" wheel would be way better than the 8" that I have now. My tires seem to bow real bad and not flatten out at all. Something else I need to address.

-Tom
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I agree, if you look at the prostock 4x4 gassers, they have very wide rims. The rim is almost as wide as the tire.
 
The STS's seem to have a real stiff sidewall which also hurts you if your rim is not wide enough. In comparison, a Pro-Comp A/T has a really flexy sidewall, not saying it is a good pulling tire just as a sidewall comparison.

-Tom
 
JFlagg said:
I did 15 up front and 60-65 out back with my ProComp AT's last pull. Worked pretty good on that track, when I get weights on the front I might go to 20ish up front...
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We still need to have a little chat about that LOL
 
GSM-01 said:
We still need to have a little chat about that LOL
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Why? You got some weights you can give me:hehe: The pull at Bloomsdale is where I adjusted tire pressure, the Belle pull I was at street pressures(55-60 front,45ish rear) Kinda backwards....But I had the RPMs I needed that time I didn't get at Belle, just not enough speed. Put those 2 runs together and it would be perfect:bang
 
JFlagg said:
Why? You got some weights you can give me:hehe: The pull at Bloomsdale is where I adjusted tire pressure, the Belle pull I was at street pressures(55-60 front,45ish rear) Kinda backwards....But I had the RPMs I needed that time I didn't get at Belle, just not enough speed. Put those 2 runs together and it would be perfect:bang
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I fore see some spare weights in the future.... Will know soon.
 
Tcolesanti said:
I think rim width plays a huge part on the fronts, I still think a 10" wheel would be way better than the 8" that I have now. My tires seem to bow real bad and not flatten out at all. Something else I need to address.

-Tom
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Totally agree.
 
Sledpuller said:
I general rule I always used, was drop psi until the tire spins on the rim, then add 2 psi, perfect.
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I used to do that, but have found videoing and/or looking at the "divots" (for lack of better term) at the end of the run tells me more and gives me a better indicator of tire pressures. One of the reasons is due to rim vs tire width as Tom stated, as running till the tires spins and adding 2 psi does not always give a good "footprint" on an oddball rim/tire setup......although it's not a "bad" rule of thumb.

As another member stated that usually means a couple of PSI difference in the front from driver's to passenger's side (on both my diesel and big block gasser).

FWIW

The other thing like Matt has found is that some tires are more sensitive to PSI changes (usually due to sidewall construction) and what works for a BFG will not work for a Bias tire. I have found Regular cab longbeds need different PSI's than the same truck that's a CC short bed with the same basic HP/TQ and tires (in a non hanging weight class) which is most likely due to the difference in weight distribution induced by the difference in wheelbase.
 
Sledpuller said:
I was kidding.....LOL
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The funny thing is, it's seems like I'm the only one at the tracks that bothers to mark tires or check tread contact patches. Most guys (which I used to be one of them) go by what "feels" good or what "seems" to bring the RPM's down the most (not always the best indicators) as they might have gotten it down more (better hooking) by changing another PSI or two (ever wonder why the Super Stock gassers screw their beads....we can't so we have to rely on PSI and bead pressure or risk losing power through the tire/rim).

How many of you even think to mark/check your tire/rim relationships?

One Caveat: I'm not talking about your everyday AT or MT tires that some guys "pull" with. I'm interested in those of you that run an agressive tread softer sidewall tire like a bogger or claw (most likely it will be a dedicated pulling tire not your DD tire) as that is what I'm referring to above (sorry if I was not clear in my first post) :kick:

I know your no newbie puller and probably have more pulls/years under your belt (and I respect that), but I'm no greenhorn either. I learn something new every day. $.02 :pop:
 
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