Suggestions for Improving 3-Link Handling (Dirt Mod)

[CC57]

As I start to prepare for next season, I’m looking for some advice/opinions.

 

Some of the handling traits I’ve experienced are:

; seems a bit tight going in, and loose off. (That maybe in part to the following: first time in Mod (ran a Limited late model and a metric chassis with stock 4-link Southern Sport Mod in prior dirt experience); first time back on dirt in 4 years; ran 2 seasons on asphalt before returning to dirt. And I may not be pushing the car hard enough).

 

; doesn’t seem to rollover as much as I expected. Could this be from set-up (see below), or the fact I’m running a long panard bar, behind the axle, tied to chassis on left, axle housing on right? Or combination of both?

 

; doesn’t have has much bite I need, or would expect. Running a coil spring torque link. And for some reason I don’t have the spring rate noted, but I could get the rate if necessary.

 

Here are some background notes:

 

’01 Harris 3-link (Chevelle stub), all set-up data with 215# driver, full fuel cell (32 gal alky) included.

 

Left side: 52.6% Cross (RF – LR): 49.3% Rear: 59.7%

Total weight: 2,530#s

 

2” offsets everywhere but RF, which is a 3” offset (recommendations of original car owner)

 

Springs: LF: 650 RF: 700 LR: 175 RR: 200

(Based on the cable ties on the rods on the shocks, I’m using all available travel)

 

With the above in mind, a couple of questions:

 

1) Harris recommends to start with 3” offsets on LF, LR, RR, with a 2” on the RF. If I change to this configuration, what would it do: would it transfer weight to the right side; thereby, reducing left side percentage?

2) Reducing L-side percentage should help the car rollover more, correct?

3) My understanding is its good to run higher rear percentages when running alcohol (to offset the weight reduction experienced in features), but is my current set-up a bit too high on the rear percentage? Also, I’ve heard that with to high a rear percentage, handling traits are going in tight, coming off loose.

 

Anyway, would appreciate any and all input, suggestions, etc. I’ve, of course, some time over the offseason to do some research and study. And then prepare to experiment going into the start of next year.

 

Thanks all

[Wayne Walker]

Need alot more info. What are the bar angles and lengths? How much angle do you have in the panhard bar? How high is it mounted? What are your starting air pressures? Where are the rear springs and shocks mounted? Where is your ballast mounted? Low or high? What shocks are you running?

 

Based on what you have given, go down on the LF spring to a 600. Start with 85 pounds more LR than RR.

Start with 5 degrees in the panhard. Have the center of the hiem on the housing 1 inch from the bottom of the axle tube. The RR bar should be 0-5 degrees up hill to the frame. The LR bar should be 18-20 degrees up to frame. The LR sping should be mounted in fount of rearend. RR sping can be either in front or on top of rearend. LS wieght should be around 52-52.5% WITHOUT driver. I would drop the rear % down to around 57.5-58%

We run 3-off wheels except the RR which is a 4-off. The #-off on the RF will help the car get over on that corner a little easier and help it turn in and through the center. The softer LF sping will help the car entering the turn and shouldn't affect it anywhere else. The 3-link car we had seemed to prefer the long bar over the j-bar. The long bar is more stable and consistant.

 

Caster plays a BIG role in how a three link car enters and drives through the turns. We were running LF 0.5+degrees and RF 6+degrees.

 

Swap the rear springs.

 

If you have any questions, feel free to call.

 

Wayne Walker

512-856-2132

[CC57]

Thanks for the reply.

 

I'll have to get back with you on some of your questions.

 

In the mean time, I'm compiling the input from here and other sites where I received input. Then I’ll identify similar suggestions and probably ask a few more questions.

 

One question though. I was on the phone with Harris tech support. After being dressed down by the Harris employee because I didn’t have the Harris recommended configuration on the car, I came away with one question from our “discussion”. Does anyone know where I could find the dimension of the spindles used on the mid-80’s Impala and 1980 Camaro? I need to see if they’re the same or not.

 

Thanks again

[Wayne Walker]

I don't know without going and measuring them at a junkyard. All we run is the IMCA stamped Pinto spindles. I don't mean to bad mouth Harris but they build thier cars for the tracks up north. The info I gave worked very well at Texas Thunder Speedway in Killeen. We had the only three link that could run up front consistantly and won a few.

[claybuster]

Are those percentages with you in the car?

[CC57]

Are those percentages with you in the car?

 

Yes they are

[speed demon 7]

Cowboy,

 

Add one more 7 to the side of the car and it will go faster!!!