ok Im going to give this a shot.

[stock car driver]

00000000000000000

[charcoal01]

Have you tried indexing out of the rr spring a little bit?

Also, what length bar are you running on rr lower.

I've been fighting something similar and have tried a few things with some success recently.

[DaveBauerSS6]

No on the RR bars, will cause more indexing.

Some suggestions,
J bar 1 inch below the pinion with a 6 inch split.
Heavier RR spring, same bite.
Hang 25 # chunk over RR.
Split right side bars on frame. About 20* up on top and 0-5* up on lower.
Only if the track is dead smooth, chain the RR; 1 inch below normal ride height, no driver.

Any videos of the mod races??

[RRR_Products]

Rr floater

[charcoal01]

Try 2 degrees out of the spring on the rr. I think that should be one turn in on top bar and one turn out on bottom but I'm not sure because of your bar placement on birdcage. It should soften the rr rate up a bit until it comes past center. You can also try just dropping both right sides bars a hole. Most guys I know who run out here in the Arizona slick are around 16 to 18 degrees on the top rr and 0 to 2 degrees up on the rr lower.

[charcoal01]

Btw 4.5 inches from center of axle is what is considered standard for most cars and bird cages.

[RRR_Products]

7" j bar split minimum or more rr floater angle.

[charcoal01]

175 on a slick track is pretty standard but depending on tires and rules you hear of some pretty crazy springs both directions working. You being on imca rules a 175 is a pretty good bet if you want to feel the car get on the rr better. I think you'll be able to feel the indexing pretty well though. If you like it but need more I think you can get up to around 5 degrees out before it starts causing other issues. Your chassis builder should be able to tell you that number.

[LM14]

I have been getting the comment from several 4/4 mod drivers that they loose the feel of the RR. Most came from swing arm style mods or stock cars. I think it had partially to do with the additional roll steer in a mod compared to their former cars. Several guys that drove Late Models told me when they drove mods it was worse in a mod as far as feel because of the HP vs smaller tires. We dealt with it and never found a good answer. We went up and down on spring, played with bar locations, changed J-bar angle and length, moved the rear to the left, different offset wheels and different amounts of bite. Never got "comfortable" in the car.

Good luck, I'm sure you will figure a way to get the feel you need.
SPark

[xxxmod]

Lowering the J bar (both ends) will create more roll.Are your rear brake pads
giving up in the feature causing the car to go tight.. If so install better pads.Consider installing more aggressive pads
on the left front than the right front for better turning.

[mod88s]

Where do you have your jbar located on the pinion and how much split do you have? What are you running for a LR shock? Are you running a LR brake floater? What are you running for left side %?

[clbaker25x]

Jeff,It has been hard at Eagle with entry to 1 being so rough consistently this year. We tried a 3 compression, 6 rebound shock racing at another track to keep the car on the right rear, but hard to do that when the track is so rough.

[DaveBauerSS6]

Is the April race a crate motor?

[DaveBauerSS6]

I have a Bms by Dmr I don't think they have a clue, I have a Grt coming.

I dont think any of them have experience with the crate in a IMCA mod. The program is still new. The theory of how a adjustment effects a car is the same, but what a crate likes is different.

Can you post corner weights?? I understand your game plan for the weekend; just something for me to think about.

[Dirtrunner35]

you said a slower track, you mean a slick track ? And wouldn't lowering your rear roll center give you more roll but less side bite ?