My Vintage Losi Stash & Build Thread *5-Link Build No.3!*

[DerbyDan]

That is a good looking buggy. Is there a "Dutch" version body shell?

Haha no - its just that the bodyshell on this car is one that came with a bunch of parts I brought from a seller in Holland

Cheers Sludgeguts - I'm glad you've been inspired by this thread

Must get a quicker motor hooked up (8.5) & get a new body ordered (Is Mr Lexan still selling the JRX2 shell?)

[urpaldan]

Great to hear the jrx2 ran so well!

How would you compare it to its sibling the XX?

[CGMike]

This is awesome! I would love to do something similar with my GTX (have one runner and one that looks prestine). My only issue with having a runner that is old is trying to find parts when and if it breaks. Ive also thought about buying a LXT or something similar and converting it to brushless to race it but again finding parts seems very difficult. Please keep us updated!

[DerbyDan]

Great to hear the jrx2 ran so well!

How would you compare it to its sibling the XX?

Difficult to say really given that I was only running a 13.5 in the JRX2 - but running a 6.5 in the XX, I dare say that once i've stuck something more 'speedy' in the JRX2 it may reveal some interesting handling characteristics?

That said a flat indoor track with rather defined man-made ramps & bumps is probably going to be less of a test for an off-road chassis - especially when there is plenty of grip on offer, to a certain extent anything with the correct tyres & a sensible damping/spring/ride height set-up is going to go OK? The real test would be on a more natural surface like a grass track - or even an outdoor astro surface where ripples & ruts occur.... this is the kind of surface that the XX revelled in!

[DHC6]

Great thread and very nice cars guys. It inspierd me to buy some more parts for my Losis. Just picked up a set of Robinson Racing Fiberglass 5 link suspension side bulk heads. It was always the weak link in the suspension , so I pick up originals and upgraded parts when ever I see them. I just wish there was a track anywhere close by where I am, but still enjoy building and maintaining them.

[DerbyDan]

So after the initial shakedown run with the 13.5 motor I managed to source a cheap (relatively) 2nd hand 8.5 Orion Vortex brushless motor (It was agreed amongst the vintage racers that an 8.5 would be our fastest allowed motor wind) with this installed into the JRX2 last Tuesday, I set off to race at the same club/track where I did my shakedown run two weeks previous. I was hoping that a few of the other guys had managed to get their vintage cars ready so that we could have a heat of our own but unfortunately I was the only one, so had to join in with the rest of the 40-odd 2wd racers (we just run 'modified' open class - no stock class here )

Anyway I am please to report that the car yet again ran faultlessly throughout the meeting. I made a couple of changes during the night - the first was to go up again on the rear spring rate - to Losi blues, when I first ran the car with the 13.5 on pink springs (that I would normally run on my XX) It rolled alot from the rear causing front inside wheels to lift during cornering, swapping to red springs cured this, but the extra speed of the 8.5 mean't that I was going into corners faster & the rear end 'roll' re-appeared - the blue spings stiffened up the rear yet again & stopped it from rolling so much that it lifts front wheels! I also added yet more lead weight on the front end - theres approx' 50g-60g now stuck either inside or on-top of the front bulkhead! To try & tame the on-power understeer.

I did the rear spring swap just before my first heat & didn't have time to adjust the ride height which mean't that it sat a little high at the rear causing a couple of grip-roll moments - for the rest if the night I ran the car lower & I must admit it handled really sweetly especially considering that it is running all the original JRX2 geometrys - it even has the stock pistons inside the shocks with 30wt oil front & rear.

I ended up qualifying 18th out of 40 (or 8th in the 'B' final) which I was really pleased with. With my modern car I would normally expect to qualify somewhere in the middle to the bottom of the 'A' - although on this particular night we had three of the UK top drivers all battling it out for top-spot (Darren Bloomfield, Tom Cockeril & David Poulter)



Onto my final & starting lower down the grid sometimes is an advantage as you can sit back & try to avoid the usual first corner/lap carnage - which is what I managed to do, working my way up to 3rd & managing to hold onto that position until the end!

Here's a little video that my mate took with my phone of my car in the B final - he's not the greatest cameraman & the phone doesn't give the clearest picture, but you get the idea!

[youtube]FsUl8F8V730[/youtube]

[SFC K]

That is pretty cool looking buggy and I really like the trailning arms for the rear. It looks really low and fast. That track looks cool as well and they all looked really fast.

[losiXXXman]

That's a quick track and the competition is steep! Awesome that you can hold your own out there! Just more proof that these cars never really got outdated, we just perceived that they were....or just gave in to the pressure to have the "newest" thing going. Driving skill trumps chassis once again.

[minreg]

Amazing that is a JRX2 flying by in a real race and with a mod motor too. Cant believe how well it handled. Guess you just make it look easy. Good job!!!

Would love to see it run on a clay dirt track.

[DerbyDan]

Amazing that is a JRX2 flying by in a real race and with a mod motor too. Cant believe how well it handled. Guess you just make it look easy. Good job!!!

Would love to see it run on a clay dirt track.

Yes it went well - my main problem though was the double jump (not really visible on the video) I had the slipper backed off & with the 8.5 motor on zero timing I just didn't have quite the 'grunt' to clear the 2nd ramp so I settled for driving it safe. The optimum motor for 2wd on most UK tracks seems to be either 7.5 or 6.5 depending upon the motor's characteristics & your ESC - so most of the other cars in my race I would assume would have either of these wind motors installed & were clearing the double jump with ease, my estimation was that I was loosing up to 1sec a lap just on this one obstacle!

I too would love to run this car (or any car for that matter) on a dirt track, but here in the UK wiith our wet weather, it just isn't feasible - unless someone can put the funds together necessary to build one indoors. There is one outdoors dirt track at Robin Hood Raceway, but I don't think it gets used much. On such a surface I'm sure the rear motor layout would give me an advantage over the mid-motored cars (that normally really 'shine' on high grip astro turf) but I also fear that ruts & undulations in a more natural track surface may show up the older cars shortcomings?

I kinda find it curious why 'stock' racing seems so popular in the States, over on this side of the pond there is just 2wd or 4wd (& the occasional SC or Stadium Truck) but the motor limit is open (modified rules) which means that these days you can buy more power than you need over the model shop counter... which means you never have any arguements over cheating with illegal super-fast motors or batteries. I read discussions on here saying about running brushless motors in vintage cars & guys saying not to use anything more powerfull than a 13.5 & perhaps sticking with a 17.5 is best to be on the safe-side. For sure these BL 3 pole motors generate more torque (& at low RPM high load conditions) which is what can destroy transmission/drive trains, but I find running these slower motors boring & I want to keep up with the 'bigger boys' & so far I haven't any problems running lower wind motors in my vintage cars.

[minreg]

Never run LIPO or brushless so no idea what that is like. Did not realize it was so wet there hence the indoor tracks. I remember my JRX2 did seem to "Push" a lot. Not sure what else to call it. But on a dirt track I think there would be more issues than astro turf. Least it would seem that way to me. Maybe I could not see the bigger jumps but I remember some big ass jumps and table tops back in the day.

I had to run stock cause I'm just not that talented to run mod or 4 wheel. Plus mod motors were expensive and you needed a very good matched NICD pack. Believe it would have been 1400, 1500 or 1700 mAh at that time.
I bought a JRX2 mid motor conversion car that used to belong to a member here.

[vintagercaddict]

Awesome collection of vintage jrx parts. How long did it take for you to source all that stuff out?

[vintagercaddict]

seeing all of your losi parts you've accumulated..makes me want to start doing the same thing! Luckily yesterday I went to my LHS and found on the back peg a losi jrx bulkhead in white with the newer header card.. Had to have it!

[DerbyDan]

Ooops!



So after a good summer season of running my JRX2, the diff gear finally gave in to the torment of the Orion 8.5 Brushless motor. It happened during the last buggy meeting for the year at my local club (its a touring car club normally, but once a month we have been running a buggy heat during the normal meeting) & will probably be the old Losi's swan-song for a little while as I have plans to run something else next year. Luckily the stripped gear happened in the last race/final of the evening & I managed to hold onto my built up lead to take the final win

The highlight of racing this car so far has to be during the 'JAE' car show where our club put on a display of R/C racing on a nice traditional (for the UK) grass track - we ran regular demonstration races throughout the event, I alternated between cars for each race between my modern TM2 2wd racer & the JRX2... neither car were unbeaten despite the 'out of the hat' grid position for the start of each race. Ultimately the TM2 was a whole lap quicker over a 5 min race but the older car was supreme in the early morning wet conditions (from rain during the night) before the track dried... despite the less than ideal tyres fitted to the car.

[DerbyDan]

Fixed the transmission over the weekend - decided to use the Thorpe gears that I aquired in a small lot of parts from the US which I brought mostly for the Robinson Racing trailing arm side brackets that are used on this car.... I didn't think I would use the Thorpe parts!



I decided to install both the nylon layshaft gear along with the aluminium diff gear as it didn't seem wise to run the standard steel layshaft with the Thorpe diff? But as the below image tried to show, the Thorp layshaft gear fitment is different & I had to shave the gear down in its width to get it to fit (the opposite way round) onto the slipper clutch layshaft.