4 Bar mod loose center off Help

[want2bafast1]

I have a 4 bar mod with Chevelle stub it enters corner good but has very little traction from the center of the corner and down the straight on throttle. Here is some info on car. 650LF-650RF 175LR floated behind on cage -200RR floated in front on cage 45 degree LR upper @ full drop 30 degree LR lower @ full drop 18 degree RR upper @ ride height 1 degree uphill RR lower @ ride height 15 inch lowers 18 inch upper bars RR has no trail its straight with LR 52 percent left side 56 percent rear with out driver, driver weighs 215 lbs 30 LBs left rear bite pull bar at 20 deg. angle 1200 lb spring 2.5 inches of stagger in rear J bar 1 inch above pinion on quick change 4 inch rake up to frame UMP Hooser tires Car has multi hole 4 bar mounts should I try like 13 inch lower and 16 inch upper bars. Any tips would be great this thing is getting very discouraging we have been getting whooped for 2 months. Thanks For the help in advance

[Canon47]

What are your left side bars at ride height? I would not be afraid to give it more LR bar angle or lengthen the chain a bit and go to 47 degrees. Also when you check your bar angle on the LR your car should be at ride height with tires on and only jack LR in front of tire on frame until it hits chain. If you are at 45 degrees with the car up and rearend hanging you are losing traction.

[oldtrackchamp4x]

I would try at least 60-70 lbs bite. It will loosen entry by will give you way more forward drive. Also only try one change at a time and write down the results. JMO

[JustAddDirt]

1st thing I would do is take out stagger.
2nd lower RR lower bar
3rd. put longer bar on RR lower bar
4th move j-bar or down on pinion. My baseline is at pinion center, and go down from there
If you add wedge like mentioned, lowering j-bar on rear end will compensate for that.

This is what I would do, you will get a different opinion from every poster.
You will just have to figure out what works for you, and your car

[want2bafast1]

Thanks for the tips guys.With car jacked up in front of LR tire tell chain gets tight is when LR upper is at 45 degrees. It is at 26 degrees at ride height and LR lower is at 13 degrees at ride height.

[charcoal01]

I would say drop your left rear lower first before you try anything else.

[mudeater18]

I would say drop your left rear lower first before you try anything else.Exactly what I was thinking.

[ryoung99]

While I have never driven a mod before (I am monitoring this site as I just bought one). In my midget when I have had this condition, most often my problem was that I was tight going into the corner and had to over drive entry which caused me to be loose on exit.

With a problem like this in a mod, what is the probability that the problem is the car is too tight on entry?

[want2bafast1]

Ok guys we are way better after trying you sugestions. Dropped LRL bar hot lapped car was better but not enough traction on exit, put more wedge in for heat better but entry seemed to loose, dropped J Bar on pinion for feature, holly crap raced the guy hew lapped me last week, for the Leed for 15 laps. Car seemed to get loose on exit after about 12 laps maybe from fuel burn off? Car enters and goes trew center very good. Should I add a little rear percentage to tighten car towards end of race? Not getting greedy but if this thing gets a little better I think we might be able to win one. I can't believe the improvement. Thank you .

[Modlitefan0]

By no means trying to bash anyone here, but what is it with you UMP guys running so much stagger. I know you guys know your cars better than I do, but we only run anywhere from 1/8 to 1 1/4 on our IMCA car so I am just trying to figure out why there is so much of a difference.

[Confused?]

They run the stagger because they can. If we could get that much stagger with the IMCA tires, we would run it also. Stagger really helps the car turn through the center.

[charcoal01]

Softer tire and big blade makes for a tighter car, stagger helps it roll the center I'm guessing.

[JustAddDirt]

Are you on Alky or gas?
Does it feel like your RR tire is giving up, and you are getting loose?
What were rear tire temps after feature?
Answer those questions and we can proceed more from there.

My first thoght is take out stagger.
I run 1.75" stagger max.
Back out 1/2 at a time, or just take the jump to 1.5"
are you running 27.5 rr and 26.5 on sall other 3 corners?

[want2bafast1]

Yes I am on alky sorry I didn't get tire temps but RR did feel hotter to the touch, we do run 3-26.5 and 1 27.5 tires. It did seem like the RR went away and it got loose on exit. I have tried less stager in the past,car seamed to exit better but seamed to tight in the center of the corner real hard to pass in traffic. I will try to go down a 1/2 inch on stagger? Thanks

[JustAddDirt]

I run 4 26.5 tires.
the 27.5 swells out so much in the center, and it gets the center tread hot and the tire will go away quicker.
you have to watch chalk marks, but you can get 1.5" of stagger with the A's pretty easily.
If you run D's it is a different story.
I almost need a 27.5 A to match a lot of the 2.65 D's. they seem to always be about 85"

Just a suggestion