My Type-R was good enough to finish 4th overall at the USVTA Nationals this year. Had to chase setup all week looking for more corner speed, but in the end, didn't traction roll at all. A few of the pivot ball cars were flipping over during A2 and A3, but I kept the roll centers low enough to stay rubber side down.

Not at all surprised. Over the year a couple of us have ran our type Rs in that class against the newest crop and found it works quite well. Been a couple years for me but not like the other cars have changed any in that time period.

I only stopped running it because I didn't want to loose any rare parts. Now trying to decide if I should move them on to someone else to die fighting or keep it locked away on my shelf. LOL.

Really cool achievement Greg. I'm running mine in a national UK carpet comp over the next few months. What general set up were you running out of interest?

would anybody happen to know the number of teeth on the front and rear belts on the type r ? thanks

If you set your car up with the latest/smallest esc, servo, and lowest profile shorty battery pack, you will easily increase your corner speed without any sign of traction rolling...

2021 USVTA Nationals setup sheet
 

The biggest difference on this particular chassis is the use of modern short shocks from Xray (T4-21 ULP). I drilled new shock towers with the upper shock mounting hole in the appropriate locations for the shorter lengths. Besides that, having forward facing ball studs on this custom steering rack made more finite Ackerman adjustments possible which helped keep the old gal from being edgy on the super high grip, new CRC black carpet. I'll grab some pics of those two mods...


https://cimg1.ibsrv.net/gimg/www.rct...73f24abbc5.jpg

We ran a shorty pack at the ROAR Carpet Nationals where my hired gun, Josh Knight, won the VTA title with this car. However, we definitely didn't have the fastest powertrain. People smarter than me have found that the shorty packs don't have as much punch as the standard packs, so I tried a few brands and finally settled on the SMC Extreme V2 6000. Since that race I also updated the ESC from a cheap 60amp HW to this Orca Oe101 which was worth a good bump in punch and adjustability that helped keep me from falling out of the A-main. I still used the HW 25.5 though, which apparently isn't the go-to motor choice on large, free flowing tracks. The HW is very rev-happy, so it has good pop off the apex on shorter tracks like Coastal RC for the ROAR Nats.
https://cimg4.ibsrv.net/gimg/www.rct...ff88be2d1e.jpg
https://cimg5.ibsrv.net/gimg/www.rct...3856cda17d.jpg
https://cimg6.ibsrv.net/gimg/www.rct...2d373efdda.jpg
https://cimg8.ibsrv.net/gimg/www.rct...eff328eb8f.jpg

Very cool Greg. Gives me some inspiration for some future mods for more performance. I've been thinking about redesigning the front shock tower for a while for better body clearance. Hadn't thought about the rack though. Nice work and thanks for the info!

That's a quite unusual setup, at least in my opinion. My swaybars save my life, keep the chassis from dragging. How much suspension droop do you run?

At that event, 2mm front and 2.5mm rear. I kept lowering the roll centers as the grip came up, which did make the chassis drag more. The pivot ball cars were traction rolling later on mains day, so I knew it was only a matter of time before my car tried to flip over. By A3, the chassis had a fair amount of carpet drag marks, but it didn't traction roll. I had run swaybars earlier in the event, but they were preventing the final amount of chassis roll and maximum tire loading that it needed to stay near the leaders, so I removed them instead of going to the lightest bars. With limited testing on qualifying and mains day, making that big change was all I had time to test.

I would have had my car set up the complete opposite direction. I have no idea how you kept it shiny side up. On grippy carpet I was running the hardest swaybars, steel battery tray, hold the car flat, prevent traction roll with the sidewall glue. I also used a short lipo and ESC behind the battery in the tray.

https://www.rctech.net/forum/electri...tively-18.html has an image

In my experience, traction rolling happens because the tire reaches a maximum loading that is strong enough to yank the CoG up and over. So my thought process is to delay that maximum load (weight shift) as long as possible in any given turn by lowering the roll centers so the side loads go through the springs instead of the arms, and then use spring rates and alignment settings to tune some of the sluggishness back out of the chassis. Also, like you mentioned, glue, prodigious and strategic applications of glue. lol

A couple people have messaged me about the short shock towers, so here's a diagram about how I made them with a drill press and Dremel.
https://cimg1.ibsrv.net/gimg/www.rct...d37204281f.jpg

I like the way you manage to get good time with a 15 years old + car !!!!
I still have my type R and I will race it this year in the VTA class :)

I have never been a "Let it roll" driver. I hold the car flat, but one thing you may want to try is this:

https://cimg5.ibsrv.net/gimg/www.rct...e0455b7e2a.jpg
that's all the glue I need. Paint a paper thin, flexible coat on the sidewall, this way when the car tries to roll over, the glue will let the car slide a little instead of tipping. Also the thin glue let's the sidewall stay flexible and retain the predictable handling of unglued tires. Just an idea.

I have a JRXS and am not sure if it is a Type R, is there any way to tell by just looking at it? (certain parts it may have)

Good to know brother

Is there a difference between the left and right c-hub? To be honest I don't see a difference at all.
https://cimg1.ibsrv.net/gimg/www.rct...3b3c9f4662.jpg

the angle of the hinge pin hole will be different in each

JRXS are mid-motor layout, and Type-Rs are rear motor layout.

For Sale?
 

Hi all,

I’ve been out of racing for 10+ years and fancy getting a jrxs as a bit of a project. Does anyone have a type r they’d be up for moving on?

feel free to drop me a PM

I've seen a few pop up on Facebook Marketplace in my searches for some Items I'm looking for.

PM sent ! I have one that I don't use

The losi springs come with small stickers that tell you the tension. If these stickers are gone, is there a way to still tell what the springs are? Are there other springs that are a direct fit?

Here are a couple of links to videos I found on YouTube that might help. Might be worth a try, hope this helps.
Vid #1
Vid #2

Very helpful. Thank you!

https://cimg2.ibsrv.net/gimg/www.rct...dcd379454.jpeg
I still race my JRXS type R in USGT. Been racing it since 2008 at Hobbytown Hobbyplex in Omaha. Timeless chassis geometry.

I reduced over 100g changing to a Protek 6400mah HV shorty lipo a few months ago. I only can mount the battery in the middle front of the tray due to top deck design and not wanting to drill. I have 28g at the far back of chassis; weight balance is maybe 55% front, I’m still testing. Final race weight is 1376g. Chassis stiffeners in rear have been removed.

if only a gear diff would be available for that car :)

The car runs well with a fair front weight bias. I always ran mine front-heavy.

You probably can retrofit another car's gear diff or make your own...

maybe out of Vibranium

Not many can build their own or design a good retrofit gear diff like somebody here, but then again the jrx-s type R has a pretty weird diff design that only a seriously modified F1 gear diff can fit: not for rookies and certainly much harder than making chassis plates...

How would the arm length of the JRXS go on low grip asphalt? From what I have read, shorter arms are better for low grip as it reduces roll centre, but goes against all the current trends with the arms becoming longer, is that because current cars are being designed around tracks with high grip eg carpet. Thanks

It's really the opposite with long arms being preferred on low grip surfaces, but the actual length of the arm is not the end-all of the process. For the most part the effect is on how hard and how fast the car will react to changes in direction. Long arms are generally slower to react than short arms, but most tracks aren't made of switchbacks and for a touring car with maybe 5-7mm of suspension travel the performance may be equal because once you have the appropriate stiffness to control the weight of the car. The real reason new touring cars like the Xray and Awesomatix have long arms is there is no downside and the long arm lets them narrow the front and rear of their chassis plate and allow more chassis roll before the chassis starts dragging. On high grip surfaces I had to use extremely hard swaybars on my Type R just to prevent this chassis dragging.

If there was a magical arm length to have for a car, the original JRX-S would never have been built. The Losi Street Weapon is a far, far superior rally car to any JRX-S, maybe the best ever, and it has very long arms for a touring car and over twice as long as those used on the JRX-S, as it's based on the XX-4.

Same as you, I used to race it with a shorty lipo. The race was very good. However, the parts were very race to find. I had to buy some full car auction (that had extra part) in order to have a stock of spare part. Anyway, I still have it and I may give it a try this winter at my local track :)

Thanks for the feedback.

Long time lurker, first time poster. Bought my first Type R maybe 6-8yrs ago but did nothing with it, it's still sitting in a box.

I Got a Tamiya TA-06 and messed with that instead...


Well now I recently got another Type R which brings me here. Hoping I can get some answers/assistance.


MY car issues:

-Both my 42T pulleys have chips

-The 23t (non apur gear side)pulley has a chip as well.

-I also need new belts


Sorry if I missed some stuff already posted but I promise I have been searching myself.


fat500

I found that the 3 racing pulley fits so I'm going to use that for the damaged 23t(non spur gear side). But I was wondering what spur gears you are using and how you modified the belt side pulley to accommodate this(parts and pics if available)?


General public/audience

1. Has anyone found 42t variants that would work instead of the Losi ones?

My diffs had the "same" but different Losi Pulleys, one pulley was flat with no holes for bearings. The other pulley was as described in the setup manual with bearings but the bearings had long since chewed up the plastic holes on the pulley and were just imbedded in the plastic of the pulley itself.

I Do see there are still some 41t and 42t pulleys out there from Losi but they are getting scarce and expensive. What drawbacks will I have running the Pulleys without bearings?


2. Belts!!!! Where can I find the front belt or a variant for the car, I have seen rear belts on eBay but not front belts. As far as I can tell some of the specs may be the same as the JRX-S:

Front Belt: LOSA3301, Type R: LOSA3303

Pitch Length: 330mm, Type R: ?

Tooth Pitch: 3mm, Type R: Same ?

Width: 3mm, Type R: Same ?

Tooth Count: 110, Type R: ?

Does anyone have a 3rd party source for replacement or know specs so I may search for one?


Finally, I have seen some cars running without the front upper arm and swivel, instead they are running ball and turn buckles only like fat500s Type R posted above. I was thinking of making this change as well, what are the drawbacks? The benefit I see is weight savings and less complexity for parts to break and replace. Thoughts?


This is a long post I know. Thanks in advance!

Gosh I remember my first 569th post

Cute! I meant in this particular thread my man 🫠

Regarding this part of my post I think I may have the answers, measured and counted the old belts I have but one is surely not stock and I can't be certain if the other is. Also I never ran the car before breaking it down. The Diff Pulleys are both 42t and 23t.

Front Belt -
​​​​​​Belt JRX-S : LOSA3301; Type R: LOSA3303
Pitch Length JRX-S: 330mm; Type R: 490mm
Tooth Pitch JRX-S: 3mm; Type R: 3mm
Width JRX-S: 3mm; Type R: 3mm
Tooth Count JRX-S: 110T; Type R: 163T

Rear Belt -
Front Belt JRX-S : LOSA3302; Type R: LOSA3304
Pitch Length JRX-S: ?; Type R: 235mm
Tooth Pitch JRX-S: 3mm; Type R: 3mm
Width JRX-S: 3mm; Type R: 3mm
Tooth Count JRX-S: ?; Type R: 78T