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Author Topic:   J bar or shorty bar
MOD75D
Member
posted January 01, 2004 10:16 AM
I have a swing arm and I am wondering witch panhard bar to run? What are the pros and cons of both bars? I was also wondering if you can three wheel a swing arm car and how to do it? Thanks for your help.


zeroracing
Member
posted January 01, 2004 07:35 PM
depends on your track, i run a short bar only but i will try a jabr on rought tracks this year.
as far as pros and cons
short bar- rolls the car over alot creating side bite, but if track is rough the car is up in the air to much to be easy to drive. the short bar makes the car react very fast some drivers like that others dont. short bar will increse side bite over j bar, well needed thing on a swing arm. best for dryslick and smooth they are unbeatable.
j bar- good on rough tracks, car runs more level, less side bite, car reacts slower, easier to drive. good for super rough tracks.
you can 3 wheel with a swing arm, just put it on a short bar, and run a 300 lr and a 200 rr and it will, also a short lr link and long rr link work good and let the lr get up fast, also the 3 wheeling makes the swing arm tighten up good. more angle in the short bar helps alot to.


MOD75D
Member
posted January 02, 2004 04:51 PM
Thanks Zero, I was also wondering what front springs I should have? It is a pro chassis with a metric stub. I was wondering how to three wheel because most of the time our track is dry slick and everyone becomes bottom feeders and play follow the leader. But there was an out of town guy I think it was John Louge not shure. Came to our track and three wheeled around the top and was wicked fast. He just drove around all the guys running the bottom and I would like to try it. Thanks again for all your help Zero.


zeroracing
Member
posted January 02, 2004 06:16 PM
on my car three wheeling just tightens it up. i will look in my shop i have my front springs wrote down, i am on a metric stub also.
what a arms are you using nova or metric? you want a different spring rate for the nova. i have them both wrote down. also it sounds dumb but most all the time i try not to run where everybody else is or set my car for a different part of the track, at one track we go to everybody was running low so we ran high, anther everybody in the middle and slide up so we run low.
if you look and change your car very little usually you cna find another groove in most all tracks, then you can usually run faster because you dont have to let up for other cars as bad, but watch out the only problem we have had is people catching on and not being able to hold the line and run into my lr alot, or they stick it in the wall.


MOD75D
Member
posted January 02, 2004 07:44 PM
They are metric lowers. I have a J bar on the car now but didnt know if I could get enough side bite with it to run on that dry slick. I am trying to run in more groves than the bottom where everyone else is. So I dont have to play follow the leader. I have 650LF and 750RF now and 200LR and a 175RR. I have the short swing arms on both sides and 23 in. rear bars on both. I was also wondering where I should start with the J bar settings and ride hight. Sorry for all the questions but this is my first year in a bar car. Last year was my rookie season and I ran a mono leaf car. I did finish sixth in points though. Just wanted to up grade to a bar car. I do thank you for all your help Zero.


zeroracing
Member
posted January 02, 2004 07:50 PM
the j bar i do not use much so you might ask somebody that uses them more so they would be more accurate.
with metric lowers i run something like 800lf and 900rf but i will have to check to make sure that is right. been along time since i have had the front spring out(well now they are out but put up with the rest of the car). on the rear you will want more lr that will make it roll alot more and make the lr bite better. also a short bar will really help with side bite on dryslick.
i will double check the spring rates tommorrow and i will also talk to some guys that runs j bars all the time.


boas51
Member
posted January 03, 2004 08:58 AM
i also believed that a stiffer spring would "lift" the car more.
it was explained to me
you have a certain amount of weight on a corner of the car no matter what the spring rate. for ease of explanation 1000 lbs.
if you have a 500 lb. spring it will compress 2 inches to hold the weight and maintain ride height. when cornering 500 lbs is transfered off that corner so it raises 1".
now you change to a 250lb. spring it will compress 4 inches to maintain ride height. when cornering you transfer 500lbs. and that spring will release 2".
made sense to me.


zeroracing
Member
posted January 03, 2004 12:40 PM
pretty much sums it up, it pushes the body up and the tires into the dirt. that is why with more lr spring the car will tigten up and will also raise more.


NJantz
Member
posted January 03, 2004 01:37 PM
According to Boas theory, wouldn't the stiffer LR-spring make the car raise less??

At a track I ran at last October, I could get into the corner harder than anyone else and have great bite in the middle, but on corner exit I just spun the tires and could not get any forward bite. We had done about everything, so we went to a lot stiffer rear springs. This caused the LR corner of the car to not raise up so high and the forward bite improved. So this kind of backed up what Boa was saying if I am understanding correctly?

[This message has been edited by NJantz (edited January 03, 2004).]

zeroracing
Member
posted January 03, 2004 07:52 PM
the spring pushes on it harder so it either will lift the body or push the tire in the dirt. one or the other, and once the tire is as far down as it is going to go it will push the body up more. and by raising the rear springs are you meaning both sides. because a stiffer rr will keep the body from roolling as much.
with my car i can run 250 lr and 200 rr and the car is fine, and the front tire is about 4 or 5 inches off the ground at most. with a 300 pound lr and 200 rr the car is tighter and faster(as long as it is not to rough) and the left front is about 9-11 inches off the ground.
also the car will not work with a 300 and 200 on a really rough track, it bounces to high when you get on the gas.
the way he is explaining it is that if the stiffer the spring the less it will compress, a soft rr is easier to get body roll than a hard rr.
on the lr when in the corner the car is loosing wieght there due to body roll so to simplify it the body roll will start and the spring will push it on over, a 200 pound spring will push it with 200 pounds of force, but a 300 wil push it with 100 more pounds of force so that will mean that the car will raise up more beacuse the way boas said it i took it as the softer the spring the more it sinks, so the stiffer lr will cause it to roll over more. same reason people run soft rr.


zeroracing
Member
posted January 03, 2004 07:54 PM
i double checked the springs and i have a 800 lf and a 1000 rf the left front is a true coil and the rf is a hypercoil.


MOD75D
Member
posted January 03, 2004 09:30 PM
Thank you so much for your help guys! I do have more questions though, (sorry) What are the effects of lowering the J bar and raising it? And where is a good starting point? Also what angle should I start with on the pull bar? I think it's a 1000 lb. spring on the pull bar. Not looking to win races. Just dont want to wreck my new car. LOL.

[This message has been edited by MOD75D (edited January 03, 2004).]

zeroracing
Member
posted January 04, 2004 09:46 AM
effects of lowering or raising the j bar, well depends on where you are talking about. if you just raise it onthe frame, it will cause it to be at more of an angle, and that will cause the car to roll over more, if you lower it on the frame it will lessen the angle and less body roll. if you move it on the pinoin, lowering it there will cause more body roll, raising will cause less.
as far as over all movement the higher both sides are the less the roll(raises roll center) and the lower it is the more roll.
also i looked under a friends car that is pretty fast and he runs his j bar where the flat part is like 2 inches from level.(it slopes up tward the frame like 2 inches)
i did not measure it just noticed it so it may be a little off.
angle in the pull bar depends on track, short stop and go needs more angle, and longer tracks with bite in them then you can lessen the angle, usually start about 15 deg for most tracks, we run ours at like 18 or 19 when it gets really dryslick.
also a 1000 spring may work well, i had a progressive, and now i am putting on a 1200. but that will be on a fourbar swing arm car. a straight swing arm needs a little softer usually so i would start out on the 1000 and see what it does.


Rollin Thunder
Member
posted January 04, 2004 09:53 AM
Zero, how many features did you win last year?


zeroracing
Member
posted January 04, 2004 08:05 PM
well, last year i was at school alot and work so i did not race much, also we were out of motors so had to stick in the old street stock one, no wins, but ran decent for a 1500 motor from top to bottom.
that and i did not know my alot about bar cars until this year when i really started messing with them.
why have i ran angainst you?


zeroracing
Member
posted January 04, 2004 08:09 PM
this year i hope to get some, i still am at school alot but have a little more money to spend under the hood. and alot more knowlegde on setups.


truthtalker2
Member
posted January 06, 2004 06:58 PM
go to www.wographics.com there is a place that says RACE CARS click it then click photos there is a purple B9 mod that is a swing arm car i have been all over to race and this car's setup is one of the best i have seen. left front about 3-5" off the ground left rear all rolled up if you like the pics i will try to get a email or phone of the kid that drives it for you


MOD75D
Member
posted January 07, 2004 04:33 PM
I really want to thank you for all your help. I think that my good season last year was due to all the help I get from this web site and you great drivers. Maybe with your help I will get this bar car around the track. By the way I race on a 3/8 mile track with med. banking most of the time. It can be dry slick by time our heats are going on the track and its pritty smooth. I was also wondering where I should start with shocks and what brand if you have any input. Thanks Mod75D


zeroracing
Member
posted January 11, 2004 06:56 PM
dryslick a smooth, well i would run bilstiens(i run most the time) or afco(very good shock). if it is smooth run split vavle shocks.
also i would stick to afco springs they have really good products.
also short bar it on smooth conditions.


MOD75D
Member
posted January 12, 2004 01:52 PM
Ok Zero,Thanks alot for your help!


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