No heat in RF tire?

[drtrkr244]

Thats the fun of dirt racing. Deciding what will make those four little rubber contact patches work better.

Its not always cut and dry.

Knowing when to increase/decrease load on a particular corner is the hard part.

Why is one or more corners of the car not working? Is the load on that tire too much or not enough? Is the spring too stiff thus shearing the contact patch? Is the tire too soft or too hard?

Deciding on whether a tire needs more or less load for a particular track condition is the trickiest part.

[leadfoot_35]

Thats the fun of dirt racing. Deciding what will make those four little rubber contact patches work better.

Its not always cut and dry.

Knowing when to increase/decrease load on a particular corner is the hard part.

Why is one or more corners of the car not working? Is the load on that tire too much or not enough? Is the spring too stiff thus shearing the contact patch? Is the tire too soft or too hard?

Deciding on whether a tire needs more or less load for a particular track condition is the trickiest part.

I don't mean to high jack the thread but you guys have me thinking. What is your opinions on tire temps? For instance, the LR tire is hotter than the RR. Would you say the RR is working more or less than the LR?

[Egoracing]

drtrkr244 you are dead on, there are SO many variables. Is it pushing becasue the front is overworked and giving up OR not working enough and the rear is working harder OR the RF or LR has a bent shock which is not allowing the suspension to work, OR the LS weight is so high that is is letting the right side slide and keeping weight from transfering. You have to kind of take what ANYONE tells you (even the chassis mfg) and think about what your car is doing and if the adjustment will make it do what you want it to do.

leadfoot, A tire gets heat due to 2 things, weight load causing it to work and if it is spinning and the friction is causing the heat. Many times a colder tire is that way because it is working better and not spinning, you have to look at the tire wear and see what it is telling you.

[Egoracing]

Weight transfer is just like changing your cars left and rear percentages.

The only way to change it is by moving lead or components.

Softening Rf spring only cures tight entry while on throttle, ie. decreasing wedge.

Are we to assume you think Joe Garrison doesn't know what hes talking about in his setup info?

There is a reason that the WOO and Lucas drivers are winning races against locals, the books and adjustment guides are 2-3 year old or older info NOT the best but they wont get you into trouble. If you get the first 2 GRT books there is information in them that directly contradict each other. The information on Integras site is the best I have seen for a LONG time.

A softer RF will allow the weight centerline of the chasis to gain leverage on the top of the spring and it will load the spring more it will also allow the LR suspension to extend during weight transfer to the RF(the cars work corner to coner across the chassis not LF to RF and LR to RR). This will allow the car to already be in an attack position when you get onto the gas and it keeps the car from falling off of the bars going into the corner until you pick up the gas.

If the car is going to transfer 800 lbs from LR to RF and you are running a 600 lb RF it is going to compress the spring 1.5 inches. Not alot of movement in the RF and probably not enough to get the spring lower than the weight centerline as it raised during acceleration. NOW same setup with a 200 lb spring is going to compress the spring 4 inches which is going to allow the LR to unload more and raise the weight centerline as the chassis goes up. The added compression and added lift will allow more transfer.

Out your car on scales with a stifff RF and jack up the LR until it adds 5-800 lbs on the RF. Now put a soft one in and jack it up until you transfered the same weight and look how much higher the LR is and how much lower the RF is once you get the weight the same.

[missile07]

Will transfering my weight over on the right front hurt trying to transfer the weight to the right rear? It doesn't seem to get weight transfer to the right side at all. The car is tight in on throttle and tight in off throttle. Forcing me to stab the brakes to get it to turn and resulting in poor exit forward bite.

We were rained out so I haven't been able to try anything.

[Dirtrunner35]

Has your car always been like this or is this a different car ?? Since your rained out look for anything binding.

[Egoracing]

I f it is something new I agree with dirtrunner, something is off. When you are going thru the corner is the LF on the ground and where/when is it off the ground if at all? You need to address the corner just as you drive thru it, entry, middle then exit as correcting one will alot of times fix other areas.

If you are picking up the RF then the only thing loading the RR is the force of weight transfer and the suspension thru the traction device. If you put the car into a state that the lf is unloaded on the scales the RR is also unloaded. (If you put it on a jack and jack it up that is a rigid LF not an unloaded one. We did alot of strapping, and twisitn of a car once to see why we had a push and when we go the car in the on track attitude we found that over 80% of the cars weight was on the LR tire. It was smashed WAY down BUT that is also how it was on the videos of the car. We found some things binding and made a few changes and got the car to 60% weight on the LF and it ran MUCH better.

A stiffer spring will catch more weight decelerating or on the brakes causing the car to naturally want to turn towards that spring. A lot of times if the car was pushing going in BUT had been right before we would add a spring rubber to the LF or go to a stiffer spring. On late models it is not odd to see a 650 LF and a 250 RF now if you figure in the different leverage the mod front has on springs that can be as high as 1100-1200LF and a 450-600RF depending on the suspension.

[missile07]

The LF does not come off the ground. The car has always been very hit or miss. This is the third year I have ran it and it has always seemed to be tight in.

I tried a straight panhard bar last season a few nights and had really good bite coming off but was still too tight getting in and in the center.

We dont have alot of opportunity to practice so I am looking for ideas I can change at the track.

I started the season out with all GRT specs as far as what is on their website. The numbers you see on the first page are where the car seems to be the best.

[washeduptoo]

Did you plumb the brakes or some else, had that happen this year, was biasing the brakes the wrong way. Guess you have tried lowering the jbar on frame? Less fuel or rear percent? Sticking the rr out some? A heavier spring in rf, trailing rr more, more stagger, lighter rr spring. Does your rr b/c have more the one hole on the bottom, you could lower it there to loosen if you've tried raisen it up on frame. You've tried most of these, just passing out ideas. If your running a limiter on lr for the drop, you could shorten it. You could put a nail or screw in rf brake line to see if that helps.Best of luck.

[missile07]

I have tried the following:

-lowered j-bar on frame
-reduced rear percentage from 57.5-58 to 56-56.5
-put a 650 spring in RF

I am trailing 1/4 now how much could I go before it hurts forward bite? I am currently in the bottom hole on the RR birdcage but I can go up more on the chassis.

I run a Afco 90/10 on the top of the rearend and I have seen results where some ppl take it off to loosen it in?

[washeduptoo]

I would take the 9010 off and see how you like it, alot of guys aren't running them including us. You can run a dummy shock if you want some kind of protection for breakage or cable of some sort. Taking it off, appears to have gave us more bite and loosened it up on entry but we use it on a rough track. More angle in rrb bar will help on entry but I would try the 9010 first to get the feel of it. Best of luck.

[Egoracing]

90/10 will tighten a car up. I would not go more than a 1/4 inch trail on the RR and you can get a spring rubber or 2 and put them into the LF, if you do not like it then pull them out, we have done it under cautions you just need to make sure that it does not end up high enough in the frame that you can not get to it.

[Dirtrunner35]

I have tried the following:

-lowered j-bar on frame
-reduced rear percentage from 57.5-58 to 56-56.5
-put a 650 spring in RF

I am trailing 1/4 now how much could I go before it hurts forward bite? I am currently in the bottom hole on the RR birdcage but I can go up more on the chassis.

I run a Afco 90/10 on the top of the rearend and I have seen results where some ppl take it off to loosen it in?

Lowering the j-bar will give you more body roll but less weight transfer in the rear, making the rear tighter and the front looser.

Is your RRL bar level or up hill a little in the bottom hole ?? Go up another hole to try to free it up on entry more.

Has the car always had that 16 inch spring and always tight ?

[missile07]

I havent tried a lower or higher LF spring yet. Pullbar is barely to LR on the rearend end.

I honestly wonder if my front end roll center is located too much to the right. My upper a-arm angles are about the same when at ride height & from what I can gather if it is too far right then there is not enough leverage to move the weight to the RF.

I am thinking about purchasing the software from Autoware to find out more about my front end. I didnt buy the car new, so I dont know if things were moved.

[missile07]

no to the 16 inch spring....i have 13 inch springs I can run in its place in most rates but couldnt tell much difference.

Yes to always being tight. Last year we had some sprint car shows at our local track and the car was really good come feature time because of the tightness, but it finally rubbered down.

I would rather the car be good coming off the bottom, so a little tight on the throttle is ok. Just having to use to much rear brake getting in

[Dirtrunner35]

Stagger ?? Raise the RRL bar up a hole. A friend I know on here has a leaf mod and moved his RR back a 1/2 inch and car was a ton better. And moved it back a little more . His car was always tight.

[drtrkr244]

GRT recommends 1/2" longer on rt side bars.

Are you tight on or off the gas? That could be why we are giving different answers.

That is one problem with the online adj. guides.

[Dirtrunner35]

My tire temps after last night
LF- 83 RF- 100-95-100

LR- 120 RR- 136-120

Track was really slick, so I was running the top with my RR in the cushion.

[missile07]

I think my post was high jacked....

I was able to race this weekend and here is what I done:

-decreased j-bar rake from 6 1/2 to 6
-moved RR lower bar up one hole & increased bar lengths (LRU 16 LRL 13 1/2 RRU 16 3/8 RRL 13 3/4

The car was better getting in but still tight & my drive off the corners was horrible. Honestly I think I would rather have excellent forward and be a little tight. Any ideas?

[Dirtrunner35]

Did you check your tire temps ? And why did you lengthen your lower bars 1 1/2 ? Does anyone video your racing ?