My JRX2 restore/race build

[ChocoTaco73]

Hey all, I picked up a JRX2 a couple weeks back originally with the intention of just restoring it but now I’ve decided to get her running in the local 17.5 class. First, a little backstory about myself: I started racing off road Production class with my box stock RC10 in 1986 (IIRC) here in Las Vegas at the long gone Circus Hobbies. It just so happened that Losi driver Jack Johnson lived and raced here with his pre-prod JRX2 so I was able to see it in action long before it was released. As soon as it was released my parents bought one for me (the original white box w/JRX2 logos) and away I went. My parents were both very supportive of my racing with my dad in particular going above and beyond. Driving me to races out of town, charging batteries, cleaning tires, doing everything he could to help out. He passed away unexpectedly just over 11 years ago and his birthday was just a few weeks back. I’ve been out of racing for about 20 years and thought about getting back into it now and again over the years but just never took the plunge. A couple weeks back I was watching old RC vids on YouTube, got really nostalgic and decided to pick up and restore a JRX2 and dedicate it to my dad. That quickly turned into restoring and racing, I think dad would approve. I’m still waiting on some parts to really dig in but thought I’d post some pics of what I’m starting with. There is much more to come and considering the local track (702 Raceway) is carpet, this could get interesting lol

[coxbros1]

Nice car and cool back story!

[ChocoTaco73]

So I thought my shocks were locked up but turns out that wasn't the case. Also, picked up a JRX-Pro SE for parts, cracked open the diff and found white/yellow diff gears. Were they standard on the Pro SE? They don't ring a bell, thanks!

[ChocoTaco73]

Well after some more digging I think those diff gears did come with the Pro SE. It's been so long I completely forgot lol

[ChocoTaco73]

Still waiting on a few odds and ends but made some progress. I picked up a stainless steel screw kit because I wanted to see what the weight difference would be for the screws low on the chassis. Front bulkhead, rear bulkhead, 5 link side mounts, etc. The SS screws added approx 10 grams, not sure if it'll make much of a difference on the track but figured it was worth a shot. Rebuilt the diff with vintage MIP goodness:

[ChocoTaco73]

Does anyone remember using the Losi under bulkhead bumper to get more kickup/caster out of the JRX2? Here is a pic of the kickup for a JRX2 chassis and a JRX Pro SE chassis, IIRC 20 degrees and 30 degrees respectively. We used to cut the bumper behind the front mount holes, stick it back under the bulkhead and cinch everything back down. That would get you pretty much 30 degrees, I just used the rear holes of the bumper as I'm not going to cut it up...yet

[ChocoTaco73]

Had a so-so looking bulkhead laying around so decided to drill it and the rear hinge pin mount for a couple screws. The 5 link has a decent amount of slop in it anyway and the inner hinge pins never seemed tight enough so we would use a few screws to basically lock the inner hinge pins in place.

[ChocoTaco73]

Getting there:

[mikesofunny]

Looks like it's coming along nicely. Awesome that you found those old MIP rebuild kits! I have sourced a few of those myself. Look forward to seeing progress.

[ChocoTaco73]

Quick update, my Brasso came in today so I polished up my hinge pins and shock shafts. And then this happened:

[ChocoTaco73]

Decided to run modern hex wheels in the back so I used the revised rear axles, a thin 1/4" spacer and an AE 7mm hex. No rubbing on the 5 link now Also went with a B4 spur so I could run the big dual slipper pads. Miscalculated how far it would stick out lol Back to a lexan cover. Waiting on some RPM ball cups to come in to replace all the old ones then it will be time for some electronics

[BattleTrak]

Looking good! That RPM #7308 gear cover allowed for a 93t spur gear and some early slippers like the A&L Power Clutch. They also made a bigger version for the Losi slipper and Hydra-drive...but are hard to find now. A reproduction lexan Hydra-drive cover is probably your best option.

[ChocoTaco73]

Yeah, I actually have a couple lexan hydradrive repops that will do the trick, just need to mount one up. Was looking forward to rocking the RPM cover but of course I got a bit ahead of myself when ordering lol

[ChocoTaco73]

Since front carpet tires are so narrow I had to give my B4 wheels a trim, my RC10B6 rears came in and look great. The Losi 22 rears fit just fine but the recessed center doesn't give me the room for the nut driver to tighten them down properly. Good to go now. Also spaced the lower link on the hub carrier to gain a bit more clearance. Getting closer.

[ChocoTaco73]

It was a good day: