Any tips or hints for an XJ off-road racer?

[tchase]

As some of you may know I've started racing my old '91 XJ. After being quite competitive in the 2 events I ran this season we're really hooked now. Here's the class rules for the class I'm currently running:

4 & 6 Cylinder Stock Class
-Anything that is factory built stock, full stock body, stock running gear, or any combination of stock components, must be located in stock location.
-Body lifts allowed for tire clearance.
-Box must have all steel construction, including headboard and floor. Made and removed as one unit. Must have exterior OEM panels or replacement OEM panels.
-May run open exhaust.
-No aluminum carburetor intakes except for OEM fuel injections systems.
-Factory OEM aluminum heads may be used in conjunction with factory OEM fuel injection.
-Shocks must be OEM mounted.
-No after market add ons except carburetors and headers (ex: no fuel pumps or ignitions)
-Street DOT tires, no cut tires

I'll probably stick with that class for next year but will eventually step up to the following:

4 & 6 Cylinder ProLite Class (Combined)
-Full stock body or fully caged.
-No nitrous or superchargers, induction systems or boosters.
-May run open exhaust.
-Street DOT tires, no cut tires.

Over the winter we plan to cage the beast so the first question is this; I've got an old 2wd shortbed commanche that's beyond saving for street use, would this be a better candidate for a racer than the XJ body? Is the gain in wheelbase worth re-wiring the whole truck for the HO drivetrian? I scored a '93 country last week that is tremendously rusty but has a great drivetrain including an 8.25. I also have a buddy who has an old 258 he said I could have so I'll be building a stroker if I'm gonna step up to the pro-lite class. Budget is tight but we have some sponsorship and more would be available if we can build a competitive rig for pro-lite. I'm currently going over the great thread on pre-runner type suspension but any other input and tips would be greatly appreciated.

 

[Yucca-Man]

Since they allow body lifts if needed, I'd guess this isn't a Cherokee-specific race? Check out JeepSpeed for more info on racing XJs.

 

[tchase]

No it's not brand specific at all. Xj's aren't even all that common especially in the stock class since everyone else can lift but we can't. Typical competition is Ranger/BroncoII's, S-10/Blazers, and one Pathfinder thrown in for good measure this year. The JeepSpeed stuff will be helpful if we step up a class but not much help for the stock class. Even then it's a bit different than JeepSpeed as the courses are only about a mile long. More like the tough truck competitions held in arena's. Usually 3-4 jumps and lots of tight turns, longest straight-aways are maybe 500ft, usually less. Anyone here know anything I could do to be faster and still conform to the stock class rules? I'm currently running a '91 4.0/AW4/D30/D35/4.10's and open diffs. I know the diffs would be a good place to start but what else? Right now my top priority is tires as 235 BFG A/T's with 50% tread just ain't cutting it.

 

[Dirk Pitt]

Remove all the interior???

 

[Skullver]

convert to a stroker motor, if there are fuel regs then this is not a good idea as the strokers need the higher octane.

 

[woody]

Id 2x the advice to check out Jeepspeed forums... Giti Gowland is one of the smart ones to read from...

Best advice given the class rules... get the best shocks & bumps you can afford. Also look at a XJ 44 geared up (like 4.10ish) and install a full spool and brace the housing/tubes.

 

[RyleyF]

Throw some retreads on there, trim the hell out of the fenders, and truss the axles REALLY good, you'll be good to go.

 

[tchase]

Thanks for the tips guys. As for the interior, alot of it is already gone and the rest will go when the cage goes in. Stroker isn't class legal for stock, niether is fender trimming. My current question I guess is in regards to the 44. I don't deal with extremely high traction surfaces (sand, loose gravel, mud) and even if I step up a class I want to stay as low as possible so I'll probably never run a real big tire. I'm currently running a non c-clip 4.10 35 and have a couple more of those laying around plus a few other ratio 35's. I know where I can get a relatively cheap XJ 44 but it's not 4.10 (of course), so I'd have the added cost of buying new gears. I abused my original 35 for a lot of years and it never did fail (anyone want it? c-clip, 3.55, 9" brakes. Didn't think so). Is heavily trussing and spooling/locking the 35 a major waste? The added cost of the 44 would buy my tires and then some.

 

[CRASH]

convert to a stroker motor, if there are fuel regs then this is not a good idea as the strokers need the higher octane.

What the hell are you talking about?

CRASH

 

[CRASH]

Lots of good suspension advice here:

http://www.naxja.org/forum/showthread.php?t=25592

 

[old_man]

Single biggest performance increase you can get would be to go to 4.56 gears. Use the high altitude CPS. They were both offered stock. Definately get busy trussing the axles but also work on strengthening the unibody. It won't take a lot of pounding from jumps. Especially if you do a nose first landing. I would also upgrade the motor mounts.

If clearance over obstacles isn't an issue, why the heck would you want to lift the vehicle. A higher CG will cause you problems in the corners. Keep it as low as will work. Work on your spring rates and shock rates for handling. Horsepower only a small portion of the equation. Tire selection may be one of your biggest overall issues if cornering is of prime concern.