16 replies to this topic

[Flyntgr]

It has been suggested by another driver that increasing or decreasing cross weight will improve right hand turns on a track with predominantly right hand turns. So, assuming a change from 50.00% CW to a higher or lower CW, in which direction should I go: wedge (increase) or de-wedge (decrease)? Thanks.

[FTodaro]

If you download JD's set up guide it walks you thought the process. in order to do this you should have scales but I have made changes at the track on the fly and just try to get things close. If we assume that your car is at or close to 50/50 . you can make adjustments

The following is from the set up guide, download it .

NOTE: If a car has 49% of CW (cross weight) it is considered de-wedged. If it has 51% CW
it is considered wedged. De-wedge helps the car turn left while tightening up the balance on
rights. Vise versa with 51% wedge. I’ll explain it more later.
The fun begins! You are either REAL lucky and have a 50% car, it happens, or you see a car
that is wedged or de-wedged. Based on your CW %, you need to make adjustments to the
spring perches. The following procedure is crucial, a must. Keeping the ride height the
same is your friend on track and in doing this setup. Forget what your brain tells you, just do
what I say for this part.
If you are de-wedged (less that 50%) you need to do the following.
Up on the LR & RF
Down on the RR & LF
Make the adjustments in equal turns up and down (from whole turns to quarter turns). This will
increase the CW with hardly any ride height change. One round is about 1.2%, your car may
differ. Get it exactly 50%, not 50.1 or 49.9, 50.00%.

[High Chair]

If you use 50/50 you cannot go wrong. Anything other than 50/50 is a very fine adjustment that will only yield in a few tenths at most if you are already driving the car at 100%. I have won many races with the 50/50 on right hand tracks. If you are losing by a few car lenghts than make a change if not don't bother or you will just srew yourself.

[Flyntgr]

If you use 50/50 you cannot go wrong. Anything other than 50/50 is a very fine adjustment that will only yield in a few tenths at most if you are already driving the car at 100%. I have won many races with the 50/50 on right hand tracks. If you are losing by a few car lenghts than make a change if not don't bother or you will just srew yourself.

I am at that point. I've used 50/50 and now need a little better run on the front stretch. I have Jim's instructions memorized. By analogy, if de-wedge is good for turning left, then it figures that wedged-plus (50.something) will help turn right. So what I'm asking is: DOES RAISING THE CROSSWEIGHT A LITTLE HELP YOU TURN RIGHT?

[Caveman-kwebb99]

I am at that point. I've used 50/50 and now need a little better run on the front stretch. I have Jim's instructions memorized. By analogy, if de-wedge is good for turning left, then it figures that wedged-plus (50.something) will help turn right. So what I'm asking is: DOES RAISING THE CROSSWEIGHT A LITTLE HELP YOU TURN RIGHT?

The simple answer is YES. But there is no magical number, every track is different so try 50.5 and see if you go faster vs. the other guys not faster vs. yourself as the track conditions are constantly changing.

[Rob Gibson]

I wouldn't start with 50.5 CW. I'd go 50.25 at most. But just try it and see how it feels.

[Lee Tilton]

50.4 works for me. You may also want to stand up the right front tire a little; maybe a half degree less than the left front.

[Flyntgr]

50.4 works for me. You may also want to stand up the right front tire a little; maybe a half degree less than the left front.

Thanks, Kwebb, Rob and Lee. I'll try the 50.4-50.5 CW first, and if needed, I'll raise the right front wheel a turn. What do you think about raising the right rear wheel a turn at the same time as raising the right front?

Lee, good to hear from you. Best of luck in the East.

[Johnny D]

Remember it's a balance. Better rights will give you worse lefts.
I would do it at the track and record what's best (lap times/feel).
IMO,
J~

[AJ Roderick]

Thanks, Kwebb, Rob and Lee. I'll try the 50.4-50.5 CW first, and if needed, I'll raise the right front wheel a turn. What do you think about raising the right rear wheel a turn at the same time as raising the right front?

Lee, good to hear from you. Best of luck in the East.

Shouldn't you adjust all 4 corners to keep the ride height the same? Someone with more knowledge correct me if I'm wrong

[dmathias]

A very wise golfer once told me to think of it as a 4-legged stool, ie, if you raise the RF and LR 1/4 turn, you should lower the LF and RR 1/4 turn

[Johnny D]

Yes.
Please read Franks comments above at a min.
JD set up Guide (downloads up top)^^^ is best ot know.
J~

[Caveman-kwebb99]

A very wise golfer once told me to think of it as a 4-legged stool, ie, if you raise the RF and LR 1/4 turn, you should lower the LF and RR 1/4 turn

yes, adjusting all 4 wheels is the best way. 1/4 on each wheel is like 1 full turn on one corner (just as Denny said above). 1/4 turn all around should change the CW dramatically as a percentage. You may need to do just 1/8 all around.

[davew]

We have all sat in a 4 legged bar stool that wobbles. What you want is to make the legs so they do not wobble, but you do not want the seat to be tilted to one side.

So you are sitting on the bar stool and it wobbles left front to right rear. There are 4 ways to stop the wobble. You could lengthen the left front, lengthen the right rear, shorten the right front or shorten the left rear. All will stop the wobble, but you will end up with a tilted seat. So you need to determine which way the seat has to move, and adjust the coresponding leg length. 50-50 would be no wobble and a level seat.

For wedge/dewedge on a car you are purposely changing the wobble to level ratio. Which naturally changes with the amount of adult beverages consumed.

I'm suddenly thirsty
Dave

[Flyntgr]

yes, adjusting all 4 wheels is the best way. 1/4 on each wheel is like 1 full turn on one corner (just as Denny said above). 1/4 turn all around should change the CW dramatically as a percentage. You may need to do just 1/8 all around.

I agree that the up/down adjustments need to be the same/opposite to keep the car level. BUT A couple of experienced racers have suggested that raising the right front (or raising both the RF and RR) will help the car turn right better, although this will increase the right side height/weight, and might or might not mess up the CW. Raising RF and RR should keep the CW the same,while making the right side weight more equal to the left side weight, but not the ride height. They say that because the right side is higher and putting more weight on the RF and RR tires that this setup should help the car turn right. Is this right or wrong, desirable or undesirable?

[Johnny D]

I agree that the up/down adjustments need to be the same/opposite to keep the car level. BUT A couple of experienced racers have suggested that raising the right front (or raising both the RF and RR) will help the car turn right better, although this will increase the right side height/weight, and might or might not mess up the CW. Raising RF and RR should keep the CW the same,while making the right side weight more equal to the left side weight, but not the ride height. They say that because the right side is higher and putting more weight on the RF and RR tires that this setup should help the car turn right. Is this right or wrong, desirable or undesirable?

I think that's why we have test days.
J~

[Tom Hampton]

I agree that the up/down adjustments need to be the same/opposite to keep the car level. BUT A couple of experienced racers have suggested that raising the right front (or raising both the RF and RR) will help the car turn right better, although this will increase the right side height/weight, and might or might not mess up the CW. Raising RF and RR should keep the CW the same,while making the right side weight more equal to the left side weight, but not the ride height. They say that because the right side is higher and putting more weight on the RF and RR tires that this setup should help the car turn right. Is this right or wrong, desirable or undesirable?

You cannot shift weight right to left with ride height (well, you can, but its barely measureable)...so you can't put more weight on the right-side tires as they contend. The basic premise of their theory is wrong. If fact, the weight will move to the LOW-SIDE tires, not the high side. Think about a car sitting sideways on a sloped hill: Which side would have more weight on it...uphill or downhill?

I'm no expert, but I can't think of anything good that comes from having the car un-level side-to-side unless you are on a circle-track.