LegendsRacer - Legends & Bandolero Racing Forum
LEGENDS => Setup and Handling => Topic started by: rocket28z on July 07, 2013, 11:04:16 am
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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!
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What are you trying for a set-up now ?
~G~
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Asphalt or dirt?
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We're running asphalt
Current set-up:
LF: 250 spring
RF: 300 spring
LR: 120 spring
RR: 150 spring
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Chassis acts like a plow going around the corners ?
~G~
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On the 3/8 banked track, yes, terrible.
On the flatter track it handles pretty well for the most part.
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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~
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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-
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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~
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.. 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~
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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.
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Yeah, relax that chassis just a little. Extreme changes will confuze the hell out of ya when you get to the track
~G~
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Yep, been down that road before haha,
Thanks a bunch for the help!
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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~
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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~
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I am sure that you understand that they are two different tracks and banking. Going to be different on set up for both tracks.
Spring rates will differ. Tire pressures. Stagger. Etc.........Gearing may be different. Lots of stuff to take into account when running more than one track.
Lots of notes and set up sheets are the order of business. There are a few good "general" set ups on the site. They are still going to need "tweeking" to each individual trak and driver style.
Steve
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Gimpster, I just want to make sure I understood you right. You said the "fast guys" are running springs rated under 100 pounds? How high does the car need to be so it doesnt bottom out the shock? I have close to the same springs as Rocket has and I push that little green thing on the shock all the way up every run. Im curios as to how to make 100 pound springs work thanks in advance.
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The Ol' Gimpster likes to run his cars and set ups very soft.
NOT for everyone.
Steve
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I've heard similar things about soft springs being the way to go from multiple drivers.
Cruzin, I have similar results with my stiffer shocks, little green tattletale is all the way up after a run - so good question!
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I will PM you in a sec...something is keeping me from sending pms
~G~
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Yup Steve, rough tracks don't upset the chassis and driver input can manipulate the roll center ;D
~Gimp~
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Not every track is smooth. Pavement requires less shock travel than dirt tracks (for the most part).
There are paved tracks that have rough transitions from straights to turns. Very soft springs are going to bottom and cause the car to be twitchy.
I like your thoughts on starting with (say) 200# springs on the front. See how the car handels, or feels to the driver. The left and right front springs are going to vary according to track configuration. Rear spring selection will vary also.
Steve
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Just relaying input from techno chats with asphalt friends who have raced it for years, and they are saying the old stiff spring ways are being beaten in the past few years by softer spring wars. They are trying to keep up with the changes.. lol not all based on my dirt preference
~G~
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lol! I know... I get it Gimp.
A lot of these guys are new. It may cause more problems for them than good.
Good food for thought though. ;)
Steve
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Hi guys I am reading this and have several questions but mostly what is a set up with the springs that the "FAST GUYS" are running. on a 3/8 mile banked track??????
We are running LF-250, RF- 280, RR 200 and LR 190. We run 3/8 and 1/4 mile tracks, high bank asphalt up here in Michigan. I have noticed that my shocks are fully compressing and was going to go to heavier springs to try and slow the roll of the car...........I read this and cant figure how we can go light if the shocks are bottoming out already??????? I am thinking that if we use lighter springs we will be dragging on the track.......please tell me where I am wrong?
Please advise,
Barry
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Something to try.
LF 275 RF300
LR185 RR200 (225 if coupe)
Get the left wheels as close to the frame as legal. 6 1/8 on the LR to the drum. LF control arm from center of ball joint to center of heim should be around 14 7/8 - 15 inches. Right is 17 3/16.
47.5% cross
Max length on left, 72 7/8 on right side.
Get rear end as close to front of the car as possible (measure 5 1/2 from the back of the tube to the back of the upright frame piece in the back. Both sides.
LF Lower control arm should angle towards the front of the car by tenth of an inch (1/2 inch spacer). RF Lower should be the same distance across the cross member (1/4 inch spacer).
Camber LF 3.5, RF 5 7/8
Caster LF 1.75, RF 4.25
Tire pressures
LF19 RF25.5
LR16.5 RR 25
Good Luck. Have had great success with this setup.
OZZIE
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Ozzie gave you a great starting point but one thing to remember is how heavy is your driver. We have four cars and springs change a little from driver to driver because some of us are better eaters than others..... ;D
Use that as a starting point but don't be afraid to change some things
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any ride heights? don't know how you guys get low cross to work we can't 47.5 but 50.5 works for us..[sedan]
joe
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LF 3 5/8 RF3 7/8
LR3 7/8 RR4
We are running a Sedan. We run 47.5 we good weather 65-80 degrees and run up to 48.4% when hot and muggy. I have a 185lb driver. This setup seems to work on a 3/8ths pretty banked track....also works on 1/4 mile track but we lossen it up for that track by putting 3/4 turn in RR.
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CASTERS ARE BOTH POSITIVE ?
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Ozzie'
Your total ball joint width is 32 1/8th plus. with your camber settings, the total width should be illegal. What tracks are you racing? Just trying to figure your set up out, thanks!
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Ozzie'
Your total ball joint width is 32 1/8th plus. with your camber settings, the total width should be illegal. What tracks are you racing? Just trying to figure your set up out, thanks!
Was wondering the same. i think he meant 16 3/16th on the right.
Also why run a 1/2 spacer on the LF if you are going to run max wheelbase at 73 1/4
It would be better to run a 1/4 spacer on LF and have it parallel with RF and you would get wheel base at 73 1/8 LS.
When i run a 1/2 on the LF lower it is to make LS shorter 72 7/8.
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I'm pretty sure the LF was 14 7/8. The RF could be 17 1/16 to 17 1/8. I think the total was 32 inches. LF camber is 3.18 and RF is 5.87. Fit through hoop. The rear end I got from US Legends barely fit through the hoop. When I measure toe with plates, the measurement is approximately 59 3/8.