JRX-PRO -The racer

[Johanp]

A vintage Losi on a local Swedish auction site!
I had to get it. Was prepared to bid high. But in the end I got if for a reasonable $120.

The carbon body is rough, but I just feel that I need to try to save it somehow.

Turns out to be an old racecar with lightened chassis and front shock tower.

It has the original Swedish importers name (Carrocar) and also decals from a local hobby shop (that doesn´t exist anymore) on the rear wing.
I contacted Carrocar and the founder answered. He didn´t recognise the car, but confirmed that the 3-spoke wheels and the esc was also from his company.

I will start the teardown and keep you updated on anything else interesting that I find.

[Mark Westerfield]

That's awesome. good deal. That is an actual carbon fiber body, correct?

[Johanp]

That's awesome. good deal. That is an actual carbon fiber body, correct?

Yes, pure carbon fiber.

It is for sure home made by some previous owner.
It is like one layer of carbon fiber that is laid up by hand inside an old Pro body and then cut out using very bad scissors.
My first thought was to put in my box of "not used parts", but now I feel I have to try to rescue it.

[Frankentruck]

I'm not really a Losi fan, but I would have bought that too just because of the cool CF body. It's also interesting that it came with a stick radio. That's a rare choice for an expensive racing buggy, but also maybe a sign that the previous owner knew what worked well for him/her and stayed with it.

[mikesofunny]

Very unique car. It's awesome that you were able to contact the company founder all these years later! Thanks for sharing.

[BattleTrak]

My favorite buggy.. I would’ve bought that just for the body too. Those 3 spoke wheels are awesome!

[Johanp]

I'm not really a Losi fan, but I would have bought that too just because of the cool CF body. It's also interesting that it came with a stick radio. That's a rare choice for an expensive racing buggy, but also maybe a sign that the previous owner knew what worked well for him/her and stayed with it.

My favorite buggy.. I would’ve bought that just for the body too. Those 3 spoke wheels are awesome!

Yeah...the CF body is rough and warped! However, I will invest some time in it and try to save it.

The car is now in pieces. It will need a good clean but the general condition is quite good.
The driveshafts are really worn, but running modified brushed motors without slipper does that to a drivetrain.

The chassis is milled out at the battery position. The milling is actually very nicely done.

It seems there is no white fiber glass layer in the chassis. And the bottom side has a texture from the carbon fiber weave. My JRX-2 is smooth on both sides.
Is this “normal” for the JRX-Pro chassis?

[scr8p]

Those cars didn't come with woven CF chassis. I don't recall any aftermarket ones either. So you may have an old team racers car or something along those lines. Prototype chassis? Testing different materials? Possible.

I do believe I've seen one before.

[Lavigna]

That milled out section looks so cool. Like you said it looks to have been done really well too.

[Johanp]

Those cars didn't come with woven CF chassis. I don't recall any aftermarket ones either. So you may have an old team racers car or something along those lines. Prototype chassis? Testing different materials? Possible.

I do believe I've seen one before.

Now I´m intrigued!
That is really interesting. Any idea where I can find more information about this?

Whatever the reason, this is definitely one to keep.

I have spotted some other modifications and I´ll look for more this weekend when the project continues.

[BattleTrak]

Maybe the former owner had carbon fiber skills and made the chassis too.. Some overall length, width and thickness measurements would be interesting to see.

[Johanp]

Maybe the former owner had carbon fiber skills and made the chassis too.. Some overall length, width and thickness measurements would be interesting to see.

That would be cool!

I took some measurements:
The width is 133,4mm (5 1/4").

The length is 343mm (13 1/2").

The thickness is 3,6mm (9/64", I had too google how to read a caliper in inches. Correct me if I´m wrong )

The width and length seems to be in inches since they are quite "sharp" readings in inches.

When looking at the edges of the chassis they seems to be factory made. And it seems odd to make and countersink the four holes for the 5-link supports on a H-arm car.

The very front edge of the kickup is in the picture below. Is that the "factory" way to machine the chassis?

kickup.JPG (27.62 KiB) Viewed 2234 times

kickup.JPG (27.62 KiB) Viewed 2234 times

[TRX-1-3]

^^^"Is that the 'factory' way to machine the chassis?"^^^

Yes, I believe so. The CF panels are layed up with the front "kick" angle and then routered or "machined" from there so that front edge is vertical and shows that kinda wedge/angle/taper as a result.

I would guess that angle would match the caster/kick up angle.

kickup.JPG.jpg (30.47 KiB) Viewed 2175 times

kickup.JPG.jpg (30.47 KiB) Viewed 2175 times

The black thing is the router bit and the little arrow is the spinny effect.

[Johanp]

and the little arrow is the spinny effect.

Love it! Thanks!

The more I look at the chassis the more I´m leaning towards it is factory made.

I have found some more interesting modifications.
I guess whoever raced this car lived by the Colin Chapman motto "add lightness"!

The attachement for the truck body mount is filed down.

The rear bulkhead has material removed.

The battery holder base is filed down.

The rear tower has the outer lower attachment points removed.

Some nice round holes in the front tower.

[TRX-1-3]

That rear battery nest notch-out may have been made to clearance a/the battery terminal/wire. I suspect the previous racer ran a laterally arranged pack.