View Full Version : J bar?

07-26-2010, 11:11 AM
What affect will lowering the j bar at the pinion make to a car and what affect will more rake on the j bar make. When the track is tacky our car is bad fast but when it slicks off we cant get out of the corner. The car dont seem to role on the rr as much as most im thinking this will help us get out of the corner correct me if i wrong. W run the bsb black package and when we use the lr slick shock it helps a touch but it is so stiff it throws the car everywhere if the track is rough at all.

07-26-2010, 05:54 PM
Someone has to have some info on adjusting a jbar

07-26-2010, 07:27 PM
It should tighten car up dropping it on the pinion. Usually 4-5 inches of rake works good but some run more and some run less. If your running a 9in, a good starting place is even with pinion or one hole below. Do a search on here on jbar, alot of good information in here.Good luck.

Tucker Motorsports
07-27-2010, 04:48 AM
Lowering the jbar at the pinion will give you more sidebite. The more rake you put in the jbar will help lift the car faster and turn the car in the center and drive off the corner. Try putting it 1 hole below the pinion with 6"-7" of rake. That should help the car roll over on the rr, turn it in the center and drive off the corner.

07-27-2010, 11:41 AM
Guys thanx alot for the we run a quickchange someone told me to go a inch below the pinion that sound rite?

07-27-2010, 07:25 PM
On a qc, try 1-1.5inches above center of pinion as it is lower than the 9in. Good luck.

08-09-2010, 03:40 AM
Just thought i would give a update... i mesured are j bar and it was 1 1/4 above the pinion and 7 1/4 rake so i left that alone. We had 200lb springs across the rear and we put a 150 on the rr and also moved the pull bar all the way to the left of the rear end housing and its allready as far to the left in the front as it can go. It seemed to let the car roll on the right side better and driver said forward bit felt better and this was the slickest i have seen the track all season.Just wondering what yall think about what we changed, and also wonder what the angle of the pullbar affects.Again thanks for the help

08-10-2010, 12:38 AM
Any info on the pull bar angle and how it chnages the car?

08-10-2010, 08:55 PM
In my particular situation my j-bar is in the bottom hole which is even with the pinion. It has 5" of rake right now. If i move it up on the frame will that have the same effect as moving down at the pinion?

08-11-2010, 12:05 AM
dont know for sure but from what i have seen on r car seems to roll easyer the lower on the pinion

08-12-2010, 11:28 AM
i think by putting the 150 in the RR you loosened the car on entry and helped it get turned sooner making it feel like you had better drive off. i would try putting the 200 back in and lower your jbar on the frame about to a 5in split(7 1/4 is alot) try to tune other areas if you feel its still not good enough i would say your crutching something with that much split.

08-12-2010, 10:54 PM
We have always had a problem with the car being tight on entry. that may be another reason the 150 felt like it helped. if i take 2.25in of rake out of the jbar what is that going to do the the car? also we r running the bsb black package slick track shock on the right front other 3 just reg. If u need me to post more info on the car let me know. We have just had a heck of a time getting the car to turn in and soon as we do it seems we loose all forward bite.

08-13-2010, 10:31 AM
it should free up entry a little and late entry as well. post the rest of your setup and maybe we can steer you in the right direction

08-13-2010, 07:09 PM
k here is what i got for springs LF650,RF550,LR200,RR150 and for wheel weights i have LF669,RF470,LR677,RR648 cross46.6,rear 53.8 and left 54.5
Shocks like i said bf is the bsb black package with the slick track shock on the RF. I dont have the bar angles or the ride heights with me let me know if u need them. It is a metric clip car with nova lowers 4/4 car LR shock in front spring behind RR coil over spring in front.also i think pinion is set at 7 or 8 cant remeber for sure. Let me know if u need anymore info

Lethal Threat
08-13-2010, 07:25 PM
put it in the center of the pinion and leave that mounting point alone and then adjust the rest on the frame side. moving it up on the frame side will give it more bite if its left side of frame. never go over 7 inches

08-13-2010, 07:51 PM
we r a inch and a quarter above the pinion bc we run a quick change and 7.25 on the rake guessing i will try taking it down to 5 what with that do the car?

Lethal Threat
08-13-2010, 07:58 PM
ah gotcha. it should give the car less side bite and make it looser

08-13-2010, 08:46 PM
What about foward bite will it change anything there

08-14-2010, 07:32 AM
Lowering the rake will lower the roll center of the rear and it could give it more side bite because it allows it to transfer the wt. better. It might have better drive because of the rear suspension working better. JMO and good luck.

08-14-2010, 12:02 PM
Thanx for the info going to change the rake to 5 in and change the spring back to a 200 and ill let u know how it does

08-16-2010, 01:51 PM
you may need to reduce ls% to induce roll once you lower that panhard bar on the frame

08-16-2010, 05:45 PM
So just thought i would give a update from this weekend driver didnt want to take the 150 out or take rake out the jbar so we left it. We run 2in offsets all the way around and i wanted to atleast go to a 3 on the rr but he wouldnt.In the heat on the last lap spun passing for the lead. Then in the featuer put a 3 on the rr came from 12th to 3rd. But he said the car felt better then it had all season and the track was more dry slick this weekend then ever. I still think im going to raise the upper lr bar for more forward bite. thanx for any help and ideas i got from yall.

Nick Tucker Motorsports
08-20-2010, 03:54 AM
How much angle is in the rr and lr lower bars?

08-20-2010, 07:48 AM
Reading some of this got me to go check my Jbar and it had 8 1/2" of split with it about 1 1/2 below the pinion, could this kill some of the forward bite?
Car feel good rotates good thru the turn but just needs more forward bite (don't they all).

08-20-2010, 08:50 AM
So just thought i would give a update from this weekend driver didnt want to take the 150 out or take rake out the jbar so we left it. We run 2in offsets all the way around and i wanted to atleast go to a 3 on the rr but he wouldnt.....

Tell your driver to keep trying the same things and see if anything different happens..... :)
A lot of this stuff is driver preference, and trial and error. He will never know what works good for him and the car, if he isn't willing to try different setups.

08-20-2010, 08:18 PM
How much angle is in the rr and lr lower bars?

Not sure dont have it wrote down i will chek tomorrow and let u know