J Bar Before and After

[Dirt_Buster]

So can anyone explain the effect of the j bar. What I'm basically trying to find out is if I'm headed in an unknown direction that many haven't tried but it's working for me. So I run a limited schedule and attend a few races a year but when we come out we usually are up front or win. We had a brand new car last year with a one off set up and it left the field. Pretty awesome night. But it worked only for the 1/4 mile track we ran and dry slick and smooth. Basically I had the RR to the left from the RF 5.5". The J Bar was 22.5" long and 8" split. The car got hard onto the rr and was hooked. So we went to a bigger track and didn't do well but it was because shock calving problems, caster setting, etc. But we returned where we dominated that first night and with a whole new set up. Now we're a 19" J Bar and 9-10" split as well as RR in from RF only 3-4" now. What I felt was the car doesn't roll onto RR like it did with the previous set up and we're getting less travel on RR cool over on the camera under car. My theory was were trying to use the j bar as like a top link bar on the LR. We also are only 54% rear and the car drives off harder than most other cars and is hooked up. So what's anyone's thoughts on this? I only use it dry and smooth slick tracks ONLY otherwise it would prob pogo. But I'm feeling rr tire isn't being worked as much or chassis rolling Onto it? Roll center is now inside the rr? I don't know... If anyone can explain what I've felt or what I'm doing make sense that would be awesome. TIA

[collateralDamage]

RF to RR offset 5.5" @ 22.5" jbar vs. 3-4" @ 19" jbar??? Assuming that is from static ride height, That isn't just a change, that it a completely different sport on a whole other continent!! Not saying either is the right or wrong just saying, there would be something very wrong if you didn't notice a difference!!

Maybe I am misinterpreting your information? At the very least I would expect the results you experienced.

In my experience you can feel 1/4" offset change and/or a 1" jbar length change. Never changed them both at once, let alone both together....

[Dirt_Buster]

Well, we did that change trying to end up with almost the same set up but done a different way. We're still turning the same lap times and winning with it. The only difference though was maybe a little more front brake. We changed the set up to be more neutral on bigger faster tracks vs the 1/4 mile one we are very good at. Well I'm just trying to figure out if I'm hindering the car getting onto the RR because of the j bar. I realize we're getting less weight on the RR after changing rear end location as well. But I'm thinking the j bar is taking a lot of that load off the RR? Thoughts?

[RCJ]

I think there is a point, that the jbar quits being a jbar and does act like a suspension link/lift arm.

[SaddleUpLock&Load]

J-bar has thrown me for a loop this year. Chassis basic starting point is 8 1/2 up frame/center of pinion. Opening night we flew and drove off. Got under the car and the j-bar came loose at frame and bottomed clean out. (not a nice word)(not a nice word)(not a nice word)(not a nice word) near flat. Driver never complained and drove off for win. That night we were at 8 1/4 at frame. Following night got on a track a whole lot slicker and I raised it 1/4 inch on frame and he was tight as hell. Blew my mind that 1/4 to high he hated but being down 3 inches never even got his attention.

[Aces&Eights]

J-bar has thrown me for a loop this year. Chassis basic starting point is 8 1/2 up frame/center of pinion. Opening night we flew and drove off. Got under the car and the j-bar came loose at frame and bottomed clean out. (not a nice word)(not a nice word)(not a nice word)(not a nice word) near flat. Driver never complained and drove off for win. That night we were at 8 1/4 at frame. Following night got on a track a whole lot slicker and I raised it 1/4 inch on frame and he was tight as hell. Blew my mind that 1/4 to high he hated but being down 3 inches never even got his attention.

Must've been close to a, "Tipping point" so to speak. That 1/4 inch just took you over the top.

[Dirt_Buster]

So my question would be this overall. I had to do quite a bit of front brake as I couldn't get the rr in the track as well as I had liked and had to really double foot the car brake and throttle to keep it on the bars still since less brake pushing into the floaters. So the brake floater was freeing me up but I had to crutch the car with less brake floater force to tighten entry. So basically should I do one of two things I'm thinking and open to suggestions as well. Move rear end over a little to the left or put 10" j bar into it or less j bar and back to 8" split? I was at 9" last race and car was fastest on track but I didn't have the rr grip I wanted like before having that rear end over 5.5" from the RF. Thoughts suggestions? Thanks!

[Aces&Eights]

So my question would be this overall. I had to do quite a bit of front brake as I couldn't get the rr in the track as well as I had liked and had to really double foot the car brake and throttle to keep it on the bars still since less brake pushing into the floaters. So the brake floater was freeing me up but I had to crutch the car with less brake floater force to tighten entry. So basically should I do one of two things I'm thinking and open to suggestions as well. Move rear end over a little to the left or put 10" j bar into it or less j bar and back to 8" split? I was at 9" last race and car was fastest on track but I didn't have the rr grip I wanted like before having that rear end over 5.5" from the RF. Thoughts suggestions? Thanks!

Why don't we just go back to the 22.5 jbar that worked so well and just changed the offset on the RR for bigger tracks. Quit moving the rear end around so much...

[Dirt_Buster]

Update: Somthe changes we made are as followed. 10" split j bar and didn't change length so it pulled rear end to the left. So we went into Saturday night pretty well from the start. Went from 4th to 1st in the heat in 2 laps and checked out. Car felt great but to me could be a little more in the track rr. The feature started 3rd row inside and fell back a couple spots then made them back up and got to 3rd. Had some well known out of town racers in that night and they had about 2-3/10ths on us in the feature. Finished 3rd but think we know what to change for this next race. Want to lower down Left Upper a hole and let some more chain out to hopefully get car into rr more, add cross, and some steer. Any thoughts on this?

[Aces&Eights]

Update: Somthe changes we made are as followed. 10" split j bar and didn't change length so it pulled rear end to the left. So we went into Saturday night pretty well from the start. Went from 4th to 1st in the heat in 2 laps and checked out. Car felt great but to me could be a little more in the track rr. The feature started 3rd row inside and fell back a couple spots then made them back up and got to 3rd. Had some well known out of town racers in that night and they had about 2-3/10ths on us in the feature. Finished 3rd but think we know what to change for this next race. Want to lower down Left Upper a hole and let some more chain out to hopefully get car into rr more, add cross, and some steer. Any thoughts on this?

Which jbar did u end up running?

[Dirt_Buster]

19" bar still in it. I fee we need to let out more chain and drop the upper so we aren't over indexing. Car beat all of the locals but the 2 out of town guys are very quick.