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Author Topic:   dw9 4L/ZL help (tight in)
sulley
Dirt Roller

Total posts: 9
posted May 21, 2004 05:53 AM  
I am looking for some advise on things to try on my DW9 loosen it up entering the corner and in the middle. It is a 4link left and Zlink Right with the left spring clamped in front of the rear end and the right on top of the housing. I have been running the short panard bar that mounts to the left of the gear. The springs are the following.

LF 650 RF 700
LR 200 RR 250
L=51.5
R=57.5
C= 49 to 51 depending on the amount of LR

Afco pull bar w/1050 spring mounted at the driveshaft loop.

I have tried running any where from 10lbs of LR to 100lbs of LR. I have raised the panard bar to the top hole on the rear end and about 10 degrees of angle in it. Still tight in the center.

This problem of being tight in, tight middle seems to be the worst on a heavy track. I have been on one dry track this year and it handled like a dream.

Any help would be appreciated.

Thanks

NJantz
Dirt Forum Champ
Total posts: 755
posted May 21, 2004 06:27 AM  
Here are somethings to try:
-Increase your leftside weight %
-Lead the left rear
-Put more rear brake in.
-If your car has a brake bar on the RR lower it.
-Put a tiedown shock on the LR.
-Soften the LF spring rate.
-Get into the corner harder.

Just remember that what you do to the car to fix its corner entry problem will also effect how the car comes off the corner.

sulley
Dirt Roller

Total posts: 9
posted May 21, 2004 07:14 AM  
Thanks for the input.

I have tried putting a ton of rear brake in the car but doesn't seem to help that much.

The one time I got the car to turn I had the LR about 1/2" in front of the RR. I also put more angle in both upper and lower LR bars to get more rear steer in it. It would then turn as long as I was on the gas, but I lost forward bite coming off.

Foward bite is the one thing that this car does have when it I have it tight going in. It felt like I had just put a bandaid on the car with that much LR lead and rear steer in the car so I have been searching for the correct fix.

The percentages that I gave were without a driver in the car.

Thanks again for your help.

sulley
Dirt Roller

Total posts: 9
posted May 21, 2004 07:50 AM  
I have made a few changes to the car that I am going to try this weekend. Let me know what you think.

I put a long panard bar behind the rear end. The center of the hiem end is about an inch below the center line of the rear end and the frame end is about 6" higher.

I changed the front springs to LF 700 and RF 650. The rear are the same.

I have about 20lbs of left rear in it as of right now.

I am kind of searching right now so once again any input would be helpful.

Thanks

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted May 21, 2004 07:56 AM  
can I ask how you ended up at those spring rates? Is that the way DW reccomended or did someone else?

2nd2none
Dirt Forum Champ
Total posts: 755
posted May 21, 2004 10:16 AM  
Just looking at a 250 RR spring and a 200 LR spring, the 250 RR will tighten the car up getting in and up to the point where you start to get on the gas.

EMOD1
Dirt Full Roller

Total posts: 26
posted May 21, 2004 10:35 AM  
What shocks are you using sometimes a 95 on RR will help turn on entry. Also removing 90/10 shocks will unhook car on entry. Getting the car to set easier on entry fixes the push in the center. Emod1

dirtracr
Dirt Maniac

Total posts: 199
posted May 21, 2004 11:28 AM  
switch the rear springs..

nvracer
Dirt Maniac

Total posts: 127
posted May 21, 2004 11:58 AM  
I would change the rear spring split,
Depending on the track. I run a 200# LR and 175# RR. But the LR is behind the axle on the birdcage.
Also you can also Lower the RR Z-link on the chassis which will create roll steer.

sulley
Dirt Roller

Total posts: 9
posted May 21, 2004 01:26 PM  
I started with the following springs.

LF 650 RF 750
LR 200 RR 200

I put a 700 in the RF because about everything I read says to soften the RF for a push getting into the corner. I put a 225 in the RR to try to keep the car from rolling over so bad. Then I went to a 250 on the RR because it was still getting over on the RR. Enough that the tire was into the quarter panel. The RR spring sits inboard and is angled towards the center of the car at the top. So it is at a mechanical disadvantage.

Maybe the stiffer spring wasn't the thing to do but I wasn't sure what else to do to keep the car from falling on the RR. I had the short panard bar as high up in the car as I could get it with my mounts.

Hope this helps explain my situation.

Thanks for all the input.

[This message has been edited by sulley (edited May 21, 2004).]

dirtracr
Dirt Maniac

Total posts: 199
posted May 21, 2004 02:54 PM  
we run an 8 and never have that problem..we run lf 700, rf 750, lr 250, rr 175...i run the 1050 also...might look at your brake bias, stagger or if it is a heavy track, you might want to give it a little more "set" when you enter or go down one on the left lower bar....that's all i can think of, we've never had to adjust the panhard bar the way you have..good luck..

nolimit92
Dirt Forum Racer

Total posts: 97
posted May 21, 2004 06:16 PM  
Your spring rate is way messed up. Depending on how you drive you car into the corners is alot of how these 4 bar Zs handle. Softening the RF will only make the push worse. Put the 750 RF and 650 LF back in. Then forget about how much the car is rolling, cut the wheel well out more to keep it from rubbing. Change your rear springs back to the way DW says to run them. We tried to reverse our springs last year and what I noticed is that is did fix one problem we were having but really hurt us in other areas (ran it that way a total of 1 NIGHT!).175 or 200 RR and 225 LR put around 75 pounds of LR bite in the car and make sure to get your front split as close as you can (we run 25 pnds LF heavier to keep the LF close the the ground). I have noticed that I can drive these cars alot of different ways and make a huge difference in handling.

Alot of people have alot of different off the wall ideas on how to make a car fast but for the time being I would listed to the general concensus on here, there is alot of really smart set up people on here!!!

Hope this helps.

Mike Pruitt
No Limit Racing http://home.att.net/~nolimit92/wsb/html/view.cgi-home.html-.html

nvracer
Dirt Maniac

Total posts: 127
posted May 21, 2004 08:39 PM  
If you are rolling over that far, and are tight. I would start to raise the panhard bar up to loosen up the car. I would also take out some angle. See if it loosens it up some. I bet it enters and goes through the corner better.

sulley
Dirt Roller

Total posts: 9
posted May 23, 2004 08:52 PM  
Just thought I would give an update of how racing went with the changes I had made. The track was very heavy and wet (we had a ton of rain). I had the long panard bar behind the rear end. I think this made the most difference in loosening the car up going in and in the middle of the corner. The car actually felt loose going into the corner, in the middle and coming out. I didn't ever think I would get that thing to feel loose on a heavy track.

The reason I had the springs in the car that seem to be messed up in most everyones view was because everything I have read says that if the car is pushing going in and in the middle of the corner to put a softer RF spring in the car and another fix is to put a stiffer RR spring. Once again I think most of the problem with the corner entry and middle could be related to the short panard bar that I had in the car. I think I will go back to a more traditional spring set up for this week and try that with the long panard bar.

Thanks for everyones help, this is a great place to get help when you are struggling.

Once again, thanks everyone.

[This message has been edited by sulley (edited May 23, 2004).]

2nd2none
Dirt Forum Champ
Total posts: 755
posted May 23, 2004 10:06 PM  
RR gets you in LR gets out out. Stiffing the RR will tighten you going in and loosen you coming off because there is more spring rate on that wheel. Stiffing the LR will loosen going in and tighten coming off. Soften up your RR to a 200# spring and put a 225# on the LR. We run the same front springs as you 650 LF 700 RF with a DW9 4bar with the sliderless setup under it.

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted May 24, 2004 06:19 AM  
I dont know whether it helps you any but we switched our front springs to 750LF/700RF (opposite as last week) this past weekend and the driver said it rolled through the corner a lot better may think about going to a 650RF. Also a pair of 225 across the back and getting about 3" shock travel front and rear with the 12" panhard bar. Our track is usually really dry though.

[This message has been edited by dirtbuster (edited May 24, 2004).]

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