As of lately, I have been doing a whole lot of reading regarding vintage (80s) Jeep racing. I have also wanted to get more involved in the Autocross scene in the area once I sold the Miata. This type of research is proving to be somewhat difficult since I have never actually never given a second thought to, gasp, lowering a Jeep.
I am after something comparable to these fine machines:
Although I am simply in the idea stage of this possibility, I am trying to better understand how the suspension characteristics of a lowered vehicle compare to a lifted vehicle. I also want to better understand how these suspension systems should be built based on stock configuration. My target truck is the 1991 MJ I bought to build as a krawler on 37's. Luckily the only work I have been able to do to it was getting the 4.0 to fire and the floors replaced.
Front end:
Maintain the stock 5 link suspension. Use a shorter coil spring (approximately 2") to set the ride height. Run a stiff shock and thicker swaybar. Replace the stock control arms with home built arms of DOM and rod ends. I imagine using rod ends vs bushings would firm up the response. The stock steering linkage would be replaced with GM one ton tie rods in a, inverted T/crossover style. I believe the ridiculously flat nature of the draglink would eliminate that "dead spot" due to TRE roll so many people have with the inverted T steering on a lifted vehicle. The trackbar/panhard mount would need to be raised by at least an inch to make clearance for the front differential (yes, 4wd!)
Rear end:
Maintain the leaf spring suspension with medium/firm shock. Replace the stock MJ shackles with shorter XJ aftermarket units, resulting in 1" drop. Remove one overload leaf from the spring pack resulting in about a 1/2" drop. Weld heavy duty spring plates to the bottom of larger axle for another 1" drop. Retrofit a rear sway bar and links.
The drivetrain:
4.0L engine attached to a manually shifted AW4 automatic. Run a 242 transfer case (2Hi- 4Hi - AWD - N - 4Lo). The Dana 30 front axle will replaced with a low pinion variety to keep the driveshaft out of the motor mounts and would be fitted with CV axle shafts to replace the 'bucking bronco' effect u-joint axle shafts have on hard surfaces. The rear axle would be a Ford Dana 61 full floater. Disc brakes all around and a 4.10 gear ratio.
Problems I can see:
- The front axle has a 5x4.5" bolt pattern while the rear has a 8x6.5" bolt pattern. I could run spacers up front (meh) or run two of the same style wheel with different bolt pattern. This would cause some issues when it came time to rotate the tires, carrying a spare, or having a flat
- Minimum of a 16" wheel to clear rear brakes
- I don't know how to pick a tire
- Parts are heavy but should be indestructible on the street
- It is a 4wd Jeep, lowered, for street use
- I don't know what I am doing
What does AR say? Have I lost my marbles?
