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Author Topic:   high lr bite setups ??
rpm20
Dirt Freak

Total posts: 338
posted June 05, 2005 04:23 PM  
what are the advantages or disadvantages of the high lr bite setups i hear so much about,
how are the setups acheived and when would it be best or better to run it.

lets say i run a 200 lr and a 175 rr
and i am at zero bite,

what changes would i make to get to the type setup i just described?

i have heard of some folks lately running as much as 250 - 300 lb lr bite
why would a racer do that and what other effects could be expected?

also , what other changes would be needed to balance this setup

[This message has been edited by rpm20 (edited June 05, 2005).]

midmod34
Dirt Maniac

Total posts: 119
posted June 05, 2005 04:58 PM  
all the j cars run 340+ lbs bite they are all fast. loose in fast on the gas

PinThunderStang
Dirt Forum Racer

Total posts: 89
posted June 05, 2005 05:23 PM  
If you have a lot of lr, it makes you loose in and tight from center off. This is what I personally like. I like to be able to throw her in there and mash it from the center off while steering underneath the people that are sliding to the top coming off.

dirtee1
Dirt Full Roller

Total posts: 28
posted June 05, 2005 07:12 PM  
J-cars with the rayburn style swing arms on both sides run the 340 bite.

MOD MAN
Dirt Roller

Total posts: 21
posted June 05, 2005 08:21 PM  
quote:
Originally posted by dirtee1:
J-cars with the rayburn style swing arms on both sides run the 340 bite.

Whats a j car

WPP
Dirt Freak

Total posts: 451
posted June 06, 2005 04:29 AM  
What spring rates on the front and rear the j-cars run

rpm20
Dirt Freak

Total posts: 338
posted June 06, 2005 05:07 AM  
so back to my original question,
how are these setups acheived........is it a lot heavier lr spring?......lots more turns on the sliders, coilovers etc.

what creates this setup and what balances it.

if its seriously loose going in , then they must be on the gas a lot harder when most are off the loud pedal, making them a lot faster in the corners,
hows this setup work on the straight aways?

rpm20
Dirt Freak

Total posts: 338
posted June 06, 2005 05:08 AM  
does this setup cause a lot of 3 wheeling in the car?

wfoondirt
Dirt Forum Champ
Total posts: 505
posted June 06, 2005 07:07 AM  
One thing I discovered using a high wedge setup is that if you run enough rear spring the car will typically tighten up as the track slicks off. If you use enough front brake and drive into the corner fairly straight the car can actually be pretty good on entry. I wouldn't use it on a setup with alot of antisquat because it will be too tight on exit.

I worked with this setup on our swingarm mod for a couple years and have continued with a similar setup on our l/m. You'd laugh if you knew how much rear spring I have in our l/m now.

Changing springs won't add bite, you have to either add ls% or crank a bunch on the adjusters. On our l/m for example we are at ~57% ls(with driver), 57% cross and ~400lbs bite.

[This message has been edited by wfoondirt (edited June 06, 2005).]

N4cer5
Dirt Roller

Total posts: 13
posted June 06, 2005 07:47 AM  
If you want more lr and maintain your same ride height you have to turn on your jackbolts on all 4 corners, just like pinthunderstang was saying, the more lr in your car will losen you going in and tighten you on the gas and carry you down the straits with forward bite. Most of these fast guys today are running at least 200lbs of lr bite and gettin the car to turn with more stagger then you would normally run.

dirtee1
Dirt Full Roller

Total posts: 28
posted June 06, 2005 08:19 AM  
A j-car is specialty fabricating out of fargo, ND. If I remember right the springs are 800lf 900rf 300lr 250rr. They run 56% left side weight.

[This message has been edited by dirtee1 (edited June 06, 2005).]

rpm20
Dirt Freak

Total posts: 338
posted June 06, 2005 08:29 AM  
its my experience that as you decelerate in the corner entry the car actually gets looser with more lr bite.

so then with high lr bite pulling the lr tire as you decellerate, the car gets looser, so then power needs to be applied to tighten it and keep it from spinning out in the corner thus helping the car not pin the rear so hard and making it turn while being tight in the corners..............correct ??

rpm20
Dirt Freak

Total posts: 338
posted June 06, 2005 08:31 AM  
krom , xtreme, zero ?

what do you guys say, i know your reading this, you are all always helpful in my ponderings

riffraff
Dirt Roller

Total posts: 11
posted June 06, 2005 09:01 AM  
How do you go about determining what your left rear bite is? I always here people talking about it, but I dont know the formula to get it. Thank You

rpm20
Dirt Freak

Total posts: 338
posted June 06, 2005 09:08 AM  
lr bite is the weight carried by the lr tire minus the weight carried by the rr tire.

say on the scales you have 600 lbs of weight suppported by the lr and , 500 carried by the rr then you bite would be 100 lb. lr.

or if the rr is more than the left then you have rr bite.

quote:
Originally posted by riffraff:
How do you go about determining what your left rear bite is? I always here people talking about it, but I dont know the formula to get it. Thank You


Kromulous
Dirt Forum Champ
Total posts: 796
posted June 06, 2005 09:35 AM  
Your right on RPM20, more LR bite will do exactley what you describe.

I watch Mod's run 2 nights a week, and about 99% of the cars i watch are entirely to tight on entry. The thing is, that most forget, is if your tight on entry you ruin exit, aka you got to slow down so much to get it to turn.

I would think that a high wedge set up you wouldnt want to let off all the way. Just roll off the throttle a little get it turned and off again. Smooth on throttle is the key, you cant have poor throttle control and drive this set up, just like a LR clamped set up, drivers who like to pound the throttle dont do well with them.


rpm20
Dirt Freak

Total posts: 338
posted June 06, 2005 10:49 AM  
my left rear bite with driver is about 100 and i can tell you that comin in as i let off i can really feel it pull the car down and turn me, then when she is turned as much as i like , i have to apply more throttle to keep it rollin good, i just cant imagine what 300 lb of lr would feel like.....it must feel like your groin got left behind..lol

wissota3x
Dirt Forum Racer

Total posts: 86
posted June 06, 2005 03:17 PM  
j cars are 900 lf 900 rf 250 rr 350 lr 56.5 left 56.5 cross, 59 to 60 rear. motor is 2 inch's left and low.rayburn swing arm wit alot of angle both sides on the short swing.Had 2 of them and they are still hard to beat. Also 3 to 4 inch's of stagger and 21" behind panhard.

wfoondirt
Dirt Forum Champ
Total posts: 505
posted June 06, 2005 04:07 PM  
quote:
Originally posted by Kromulous:

I would think that a high wedge set up you wouldnt want to let off all the way. Just roll off the throttle a little get it turned and off again. Smooth on throttle is the key,


And alot of front brake. If can get to where the front wheels are slowing the car as much as the rear then you minimize the oversteer effect that alot of cross creates.


Kromulous
Dirt Forum Champ
Total posts: 796
posted June 07, 2005 07:08 AM  
Were gravitating to high wedge set up with our 4-Z deal. I am just a wee bit leary of running 200lbs of LR bite, but we been easing it up since we started out last year.

Although were getting a very slow start this year, but i imagine we will keep on increasing LR bite.

I wish i could drive one of them J-cars with that much LR bite. I cant stand a race car that pushes, when i move the wheel 1* i want to feel a response. Gonna have to bite the bullet and crank that LR down and find out what happens.

zeroracing
Dirt Forum Champ
Total posts: 1875
posted June 07, 2005 08:33 AM  
As far as wedge goes it depends on how I want the car to handle. I classify a low wedge set up as 0-120 lbs and on a high wedge setup 130+. Most the time I start out with 130 lr bite, and for my regular track has ran as high as 190. The car is very easy to turn in traffic and has good forward drive on exit. Also on that track i run aloto f rr bar angle, and not much lr to make the car driveable and freeed up.
My advice on a lr behind car especially start out like 130 and if you want it freer and a little more drive off, add some more lr bite. go up about 30 a time till you go too far then start to back it down a little bit. On a swing arm car since the springs are on the arm and experince no indexing, most the time I would not be afraid to keep going up and up on it. Have ran a swing arm and been happy with it with as much as 250 lr bite.

CLBaker25
Dirt Maniac

Total posts: 193
posted June 07, 2005 01:01 PM  
You guys have talked about the reaction going in and comming off the corner but what is the reaction in the middle when you first get on the gas? How does a high bite setup react in the middle of the corner or when you first get on the gas?

Thanks,

Corey

Still Learning
Dirt Roller

Total posts: 21
posted June 07, 2005 03:06 PM  
On this same subject... do you get more forward bite as you decrease the left rear bite?

wissota3x
Dirt Forum Racer

Total posts: 86
posted June 07, 2005 08:26 PM  
I have to agree with Zero. Not much bar angle in the LR and more bar angle RR to create some loose roll steer and bite.We are at 180 pounds of LR bite.Impala chassis with 900 RF 800 LF 275 LR behind on the cage 225 RR on the front B cage.58.5 rear 56 left.3 to 4 inchs of stagger on hoosiers.With the added LR bite the car tends to be loose going in.WE added some more panhard angle and it helped with side bite and forward.THe car is a point and shoot.DRive it in deep and pivot off the LR until she's pointed staight and stab the throttle.JMO.

KK17
Dirt Freak

Total posts: 229
posted June 08, 2005 07:48 PM  
As stated previously with the j-cars you run crossweight the same as your ls % which is around 56% or 300+ pounds of bite..that's with the short swingarm setup..I run a j car with a 4-z setup and run about 125lbs of bite which again is more than most 4-z setups...the thing with both these setups is to get enough roll to create some rear steer to help turn mid corner....the only thing I didn't like about the high cross is if you have to make a right to avoid a car/accident, the left rear really made the car hard to control especially if you jumped off the gas , otherwise Jay's cars pretty much drive themselves..

Racer17V
Dirt Full Roller

Total posts: 34
posted June 09, 2005 12:04 PM  
Great post guys. Quick question. I've read a lot about the swing arms, what would you advise for a simple 3 bar with sliders? I used to run 250-275 with the swing arm, but with a 3 bar set-up, can I get away with 200 lbs LR? Do I need to take angle out of the LR bar and add it to the RR like you guys are trying? Thanks.

rpm20
Dirt Freak

Total posts: 338
posted June 10, 2005 04:25 AM  
this has been a good topic and i am glad i posted it, lots of good information.

i am running about 100lb lr with me in the car right now and it seems good, i may take it a little further and then try to drive in a lot deeper before i get out of the gas, allowing me to get back on sooner. i think it really helps corner speeds, at least if your not driving on glass...lol

nelson1m
Dirt Roller

Total posts: 15
posted June 19, 2005 11:54 AM  
i have a 4link/z link and only have been running 50 to 80 pounds or lr bite do you think it would come out of the corner better on a dry track with more lr bite like around 120 or 150?

devil wrench
Dirt Maniac

Total posts: 178
posted June 19, 2005 12:12 PM  
what the high wedge setups have done, is to change the timing of your laps, basically to get the car to pivot earlier, and get on the gas sooner. depending on the track, this can be good or bad. this type of set-up is straight from late models, specifically Mark Richards at Rocket... he was he originator.

OppendikeRacing29
Dirt Maniac

Total posts: 135
posted June 21, 2005 09:45 AM  
do these set ups take more left side % to work properly? and do you normally lose some side bite?

Larry Lundin
Dirt Full Roller

Total posts: 45
posted June 22, 2005 09:00 AM  
For 17V, are your sliders/springs still mounted on the swing arms? I run a 2-link now with the slider still on the LS swing arm. I'm running a 225lb in that position with a 175 on top of the RR. If your still using the swing arms on both sides, you'll most likely have to stay with the stiffer springs. There is a very good calculator in the Tool Box above that will convert and calculate spring rates for you. Give it a try and see where you're at. It will take all of the guesswork out of trying to determine your actual spring rates and point you in the right direction.

devil wrench
Dirt Maniac

Total posts: 178
posted June 23, 2005 12:55 AM  
quote:
Originally posted by OppendikeRacing29:
do these set ups take more left side % to work properly? and do you normally lose some side bite?

Definitely...

gould
Dirt Forum Champ
Total posts: 730
posted July 26, 2005 07:38 PM  
What about a high rr setup?

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