PDA

View Full Version : Tight in center help needed



RJ16
10-14-2012, 09:40 PM
I’m looking for some advice. I have been fighting a problem with the car pushing through the middle of the corner when I start to pick up the throttle. I’m sure some of it’s me due to this is the first year I’ve drove any type of dirt car. I drove asphalt for 12 years, so I understand that most of the problem is me. I’m having a hard time getting used to throwing the car into the corner when the track is tacky. I was wondering, if there are some adjustments that I could make to assist me with being more competitive while I continue to learn to drive. The car is an older leaf spring Dirt Works that someone converted to a 4-bar car on both sides. Any driving advice or chassis suggestions to help me get through the center would be greatly appreciated.
Springs: LF 550 RF 600 LR 175 RR 200
Bars RRU 20 RRL -3 LRU 26 LRL 0 has 6” drop on LR
Weights without me: Cross 48.9%, Left 53%, Rear 55%
Caster Left 2deg. Right 4deg. Camber Left +3.5 Right -6
Stager 3 ½ rear 1 ½ front
No LR brake Floater
In addition, I don’t know it matters, but we run UMP chassis rules with a 362ci steel head Holley 4412 gas only motor rule.

HEAVY DUTY
10-15-2012, 08:51 AM
I would start by chaining the LR to 4 to 4 1/2 " drop and then add some lrl bar angle. ( 5 or 6 degrees up in front) You shouldnt have to throw the car in. If you are you probably need to free up entry some by raising the rr lower to about 5 or 6 degrees up. Those 3 changes should make a huge difference. Asphalt to dirt is a big change and will take awhile to get used to. I started racing on asphalt and havnt been on it for 30 years, but still have bad habits learned on asphalt.

jsf74
10-15-2012, 03:49 PM
I've struggled with the same problem all year also. It wasant until the end did I realize my entry was tight causing everything out to be junk also. Loosen entry and you will be better everywhere else.

smirk
10-15-2012, 03:50 PM
Raise both bottom bars to start with. Right side level left side up at least third hole. Prob all youll have to do.

racinjj
10-15-2012, 10:03 PM
I agree with smirk, raise the lower bars to get some roll steer, trail the RR a half inch if that doesnt help enough. I made the switch to dirt 4 years ago after 8 years on asphalt, its tricky at first, you need to learn to trust the car when you throw it in.

RJ16
10-16-2012, 02:36 PM
Thanks for the advice, I will try it this weekend. Thanks again.

Dirtrunner35
10-16-2012, 02:45 PM
If you are driving it in and smashing the gas , it will push.

powerslide
10-16-2012, 03:23 PM
I see a few things that are questionable.
-6in drop in LR. If this is measured around the birdcage its far too much. Cut it down to 4-5inches.
-Other thing is someone cut the car up and put 4bar brackets on it. What length bars center to center is each bar? How much trail in the RR? If the Right side is shorter than the left it will promote a tight car.
-Stiffer RR spring than LR promotes a tight on entry car. Swap those around
-Agree w/ everyone else that the bottom bars need some up hill angle.

Where is your panhard bar mounted? Straight or J?

RJ16
10-21-2012, 06:57 PM
I would like to thank everyone for your help, the car preformed the best it has all year with raising the bottom bars and reducing the drop to 4”. Although, it has lost some forward drive off the corner. Thanks again!

frontrunner
10-22-2012, 04:10 PM
switch ur front springs also.....

oldtrackchamp4x
10-22-2012, 07:12 PM
You didn't say how much LR bite you have but by looking at how low your cross is, i'm guessing it's probably 20-30 lbs, i would think if you went up to 60-70 lbs of bite it would give you the drive off that you are lacking, but it will also loosen entry a little more. At least it worked real well on the DW i had. JMO

RJ16
10-22-2012, 09:52 PM
You are correct, my left rear bite is 30. I do have a question about adjusting bite. Do you use the wedge bolts to adjust it or add weight to the left rear?

oldtrackchamp4x
10-23-2012, 06:25 PM
You stated this is a 4bar car, so all you should have to do is put 1 turn in RF 2 turns in LR 1 turn out of LF and 2 turns out of RR -- If you have coarse threads on the front screws and fine threads on your LR slider and your RR coilover your ride heights should stay close to the same, with your bite being close to the 60-70 lbs. I would have car on scales while doing this to make sure what your final bite is. JMO

RJ16
10-23-2012, 07:03 PM
Thank you, I played around all day with the car and took notes to see how much moving the jack bolts changed percent’s, bite, and ride heights for future reference at the track. I left everything the same except I increased bite to 70lb, which changed my cross to 49.5%. If I continue to have forward bite issues would it be advantages for me to continue to increases bite or look in another area?

oldtrackchamp4x
10-23-2012, 08:45 PM
There are always things you can do, but don't worry about it until you have that problem.