Looking for set-up help on 3/8 mile banked track

[rocket28z]

My home track is a 1/4 mile and pretty flat with little banking. 
Our other track is a 3/8 very banked track and we can't seem to nail down a set-up. 
Any ideas on changes?  Thanks!

[Gimpster]

 What are you trying for a set-up now ?

~G~

[VMS Motorsports]

Asphalt or dirt?

[rocket28z]

We're running asphalt
Current set-up:

LF: 250 spring
RF: 300 spring
LR: 120 spring
RR: 150 spring

[Gimpster]

Chassis acts like a plow going around the corners ?

~G~

[rocket28z]

On the 3/8 banked track, yes, terrible.
On the flatter track it handles pretty well for the most part.

[Gimpster]

My feeling is your front springs are way to heavy. Hence the plow comment. All the weight reaction is forced back from the front on the chassis. I can see why it turns on a tight track because it is carrying all the load up front. With that much spring split front to rear, it is balancing the chassis on the rear. I will give you a tip.. on asphalt,none of the fast guys now days are running over 100 lb spring weight on any corner of the car. The old stiff spring set-ups of the past aren't what is winning these days. They are not limiting the chassis and letting the roll center move around more for total chassis use. Caster is another thing that is binding you up. On a pedal bike, is the top of the front forks ahead of the wheel mounting point ? Foreward caster on this light chassis is giving you too much rolling resistance.

~Gimpster~

[rocket28z]

Thanks for giving such thorough response, greatly appreciated!
Your spring suggestion makes sense and I'll give some softer ones a try.
I'm a little confused about the caster situation but your example  makes sense, are you talking about both fronts tires or the RF?
If you don't mind me picking you brain a bit more, what do you suggest for softer springs and are the splits I'm running reasonable?

-28z-
 

[Gimpster]

Well, don't go buy a bunch of springs under 100 lbs. Something else has to be done before you do that. To get used to your chassis and figure it out, I wouldn't go over 200 up front. Maybe even start with a couple 200s up front to figure out how your chassis responds with less weight forced on the rear of the chassis. Where and how the chassis unloads will be more subtle, controlable. With your car as it is on your shop floor, have it in neutral and move it ahead by pushing on the back of the car with a few fingers. Now loosen the jam nuts and crank the caster back quite a ways, go behind your car again and push it ahead with the same fingers... it will roll easier (takes less hp to move the car foreward from your engine) Also view 2 invisible lines, the same length coming off the upper ball joints and where they would point on the chassis, this is the influence factor your steering has on the chassis and it's roll center. Also, a softer rear spring on the right rear than the left will allow the left rear control arm to drop more than the right, thus shortening the wheel base on the left side through radius swing giving you rear steer. Also, with different caster settings and the car on the scales, watch how the numbers change when you turn the front wheels right and left while on the scales... this should put you more in touch with driver input per reaction manipulation of the chassis.. LOL you have to know where you are at before you start adjusting !!!

~Gimp~

[Gimpster]

.. By the way, on dirt I don't run any more camber than 4 on the right and 2 on the left.... I think your camber is too much but then again, I don't know your traed cut angles. Just sayin

~G~

[rocket28z]

LOL trust me I'm not going to start off by throwing 100 pound springs on the front, I'm going to ease into it haha.
Might not ease into the caster situation, I'll do that little shop experiment and see how that goes.
As far as the spring situation goes, I'll probably do the 200 across the front and do trial and error from there and probably like you said, soften up the RR.
I'll start thinking about camber once all this is figured out lol.

[Gimpster]

Yeah, relax that chassis just a little. Extreme changes will confuze the hell out of ya when you get to the track

~G~

[rocket28z]

Yep, been down that road before haha,
Thanks a bunch for the help!

[Gimpster]

 No problem, hope I opened some doors of thought instead of giving you a set-up that don't work for your driving style. Like I advised, let that chassis move around on it's axis a little more and it will be more responsive to driver input.. good luck my friend

~Gimp~

[Gimpster]

 Before I forget... When going softer spring on the right rear, over a 25 pound spring split on the rear, the chassis gets goofy when it settles in after it's unload point in the corners

~Gimp~