HOT rr tire

[rcstreet1]

stockcar driver- if you think my bite is about right what do you think would cause the rr tire to get hot..but thanks every one for your suggestions i made some changes and were gunna see what happens to night.

[rcstreet1]

thanks every one!!!!put more bite in car and it help alot

[Ricky76]

What causes the rr to get that much hotter though ? Is it because it's just spinning, sliding more across the track, or doing more work than the lr ?

[buterbaughb1]

how much hotter are you talking? I have never had my lr as hot as my rr, and talking to fellow competitors, they seem to feel the same, at least with the metric cars. We run late model tires in our area, with 2bbl carbs. i run 240# of bite and a 200lb rr spring, am i out to lunch?

[Ricky76]

I know I should have checked the temp difference, but after we go through tech and I get to the trailer it would change a lot. I've felt of them by hand after the feature and I'd say maybe 10 degrees difference ? This may not be too bad, just wondering ? Thanks, Ricky

[rcstreet1]

i would say 10 deg difference is good. when i was sayin my right rear was gettin hot it was about 50-60 degrees hotter . i put more bite in it and that problem went away so i guess the right rear was doing to much work..

[Ricky76]

O ok. Thanks for the information.

[Ricky76]

I know this is an old thread, but we had play day yesterday and my car was terrible. We moved the weight off the rear of the car an put it closer to the rear end and just in front of the fuel cell and the car car much better. I checked the rear tires and they were about even as far as temps, but the car didn't have enough forward drive and was snappy loose in the center of the turn. I added three rounds of left rear and changed from a 200 lb rr spring to a 175 and the car got better, but the rr tire was much hotter than the left rear tire after these changes. The car felt much better, but the tire temps changed a lot after these changes ? It seems that adding the lr bite, the rr got much hotter ? I know the rr isn't spinning more than the left rear because it's a Ford 9 inch with a full spool so they're going to spin the same. Maybe this will help with people's questions about tire temps ???

[merc123]

Here was my 3-link setup

1200# / 75 shock. -- 1000# / 75 shock
275# / 94 shock -- 250# / 95 shock

53.5 left
54 rear

Bite: 80

We had 120 to 140 at one time but pushed and car would not drive right. Dropped it down and worked great.

Was going to try a 1000 / 800 spring but moved up to a new class

Could the j-bar be causing part of the issue? Maybe it has moved or the length was set right.

[72Dubya]

I know this is an old thread, but we had play day yesterday and my car was terrible. We moved the weight off the rear of the car an put it closer to the rear end and just in front of the fuel cell and the car car much better. I checked the rear tires and they were about even as far as temps, but the car didn't have enough forward drive and was snappy loose in the center of the turn. I added three rounds of left rear and changed from a 200 lb rr spring to a 175 and the car got better, but the rr tire was much hotter than the left rear tire after these changes. The car felt much better, but the tire temps changed a lot after these changes ? It seems that adding the lr bite, the rr got much hotter ? I know the rr isn't spinning more than the left rear because it's a Ford 9 inch with a full spool so they're going to spin the same. Maybe this will help with people's questions about tire temps ???

If you soften the spring up on the RR, it will allow more weight to sit on the RR, allowing the RR to have to do more work and heat up more. It will also take some weight and drive off of the LR, not letting it do as much work, so it will not be as hot as before. It would be best to rescale the car, as well as check the ride heights.

[junebug]

Ok...im a modified guy and haven't messed with stock car stuff forever but u said your loose on entry...which everyone knows to fix entry first then gradually work to exit when tuning on your car...not arguing at all but if ur loose in I thk u need to take away bite....make the car not slide getting in...cars only have so much grip and if u give up 50% by sliding on entry then u only have 50% left on exit...if u can keep the entry looseness to a minimum then you will have more traction left when its time to pick up the throttle...providing the car isn't pushy

[ss74]

Junebug is right on. Your RR is spinning because it's not biting the surface, or getting grip. More LR bite will free you up on entry. And driving style makes a huge difference on ones setup. If you like to sling the car sideways on entry to get the car to turn then your screwed coming off. It will feel free and spin the tires terribly. You need to focus on getting a better balance in your car. Get the car to rotate naturally and then your mid turn and exit will improve. remember, you can't win the race getting off the corner until you win the race getting in. Balance, balance, balance. And one more thing to consider, the old ways of a stiffer RF spring is long gone, especially on metric cars. At a minimum start of with the same rates across the front, and as you get better adjusted to the charactoristic of the car you will eventually want a much stiffer LF spring then RF. The you will be able to start getting a greater spring split in the back which will greatly enhance you corner exit. Look at what the Late Model guys are doing. Some run as much as a 700 LF and a 250 RF. I know the chassis are different but the dynamics are the same.

[frontrunner]

Has anybody asked ya if ur on the gas or off the gas on entry if ya got to be on the gas on entry & slinging the car on entry thats heating up the rr tire so if ya got to sling the car on entry or run it in to turn car that means to much L/R in car just saying... The next thing is run 1 1/2 stagger all the time on rear & 1/2 on front next change L/r to a 225 & go to a 800 Lf and a 900 RF..Next if ya can pull the rr back 3/4'' or move the lr forward eaither way do that and then add l/r bite in the car if its alittle loose after you try this....

[frontrunner]

That should keepthe heat out off the rr tire...

[junebug]

Not sure what to think of that post up there...if ur rr is hot its usually because the car is tailed out really bad and sliding the rr...i have never burnt up a rr when my car was straight...so im thinking 3/4 trail would burn the rr clear down to the chords...if it was me id keep trail 1/4 from zero all the time so either a 1/4 fwd or 1/4 back...any more them that feels funny to me...i would try 900 lf 750 RF 200 lr 250 rr
4 lf 3-7or 8 RF 8-2 lr 4 rr shocks
1/8 rr lead 30-50 lbs of wedge
54 or so left side %
Jbar 1" below pinion center 5" rake
Bar angles 17-20left 3-8right
1 1/2- 2" stagger in rear
1" in front
3/4" toe out
2-4 caster 3-5 camber
All that should be a very neutral drivable setup...if u have problems from there start checking for binds or other issues possibly...but at least that's be a good starting point

[Ricky76]

If you run a rf spring that soft, how do you keep it from bottoming out the shock or the frame hitting the a frame ? I run stock mount shocks on the front and we can't run pull bars, j-bars, and no 3 links. I've also never ran a stiffer rr spring than a lr spring ?

[junebug]

There's a few answers to that question...one thing u can do is put a bump stop on the shock shaft...but in my opinion the car bottoms out the RF less with the soft spring...i know that sounds stupid but here's why....if u have a soft spring with the RF tied down the car will not lift off the spring meaning u keep the spring compressed so when u enter the corner there is...lets say 4 " of RF compression...where the stiff spring popped back up and maybe only has 1-1.5"...so a 750 @ 4" has 3000lbs of load...even if u have a 1200 @ 1.5" of compression that is only 1800 lbs...thats why in my opinion the soft RF with a 3-8 will bottom out less that a stiffer spring...
In simple terms the stiffer spring gets more of a running start at roll the softer one just kinda lays there

[speedbuggy]

Also, with a softer RF, more front weight will transfer to the LF on entry and more right side weight to the RR through the turn.

[frontrunner]

All i was saying is if ya have a tight car ya got to sling in into the turn and that heats the rr tire becouse the driver has to break it loose to turn.. And by pulling the rr back will let the car turn itself by having the car freed up.. my car was so tight buring the rr up in one race so kept pulling the rr back & now no prob.. & then i pulled the rr back till car gets loose & then now i add lr if i need to tighten car back up..and yes i was afraid to try it till i did it and car was like a whole diff. car nice & free and now i can ajust it if i need to and im back on the rr 1 1/4'' now and car is great and i can run a whole race without heating up the rr....

[Driver88]

A friend of mine used to run his car with the RR trailing better than an inch. It worked for him. Two track championships in a row and was working on a 3rd when the track closed. I tried it and couldnt get it off the corner it would head straight for the wall. I'm not sure what he did different than me but it sure worked for him, and sure didn't for me.