52LikesTeam Losi JRXS Type-R
01-13-2008, 06:28 PM
#6243
Tech Apprentice
Snappy Rear End
Hiya all,
I'm a racer in Singapore presently running the R for the last year and a half in mod asphalt. This year's race series has a 23turn handout motor instead of the mod class. And there's no weight limit anymore. I have a problem with a snappy rear end.
Mod setup : Front 15lbs 40wt, spool, .04" roll bar. Rear 12.5lbs 40wt, .06" roll bar. LRP SphereComp on 6.5 turn brushless with IB4200 batteries and Sorex 40R all round. Weight around 1500g
23T Stock : Front 17.5lbs,spool .04" roll bar. Rear 12.5lbs 40wt, .06"roll bar. LRP SphereComp on Xenon 23turn with Orion 4800 Lipo. Weight 1340g
The car suffers from on power oversteering. When I squeeze, the rear wants to switch places with the front. I have tamed it by lowering the punch control on the LRP, adding a harder spring. Losing both front and rear roll bars had no difference so i put them back.
I need someone to critique my thoughts below.
1) I'm guessing with the drastic weight loss from the Lipo, the car has less tendency to want roll through corners. Will softer 10.5lbs springs all round help? I prefer soft cars as i find them easier to drive fast.
2) Max out the droop in front, this allows the weight to transfer rearward and sit the car down on corner exit.
3) Stock motors have alot of engine drag brake when I release the trigger, mainly due to the bushings. Move all static weight to the front.
Hope you guys can help me out here.
I'm a racer in Singapore presently running the R for the last year and a half in mod asphalt. This year's race series has a 23turn handout motor instead of the mod class. And there's no weight limit anymore. I have a problem with a snappy rear end.
Mod setup : Front 15lbs 40wt, spool, .04" roll bar. Rear 12.5lbs 40wt, .06" roll bar. LRP SphereComp on 6.5 turn brushless with IB4200 batteries and Sorex 40R all round. Weight around 1500g
23T Stock : Front 17.5lbs,spool .04" roll bar. Rear 12.5lbs 40wt, .06"roll bar. LRP SphereComp on Xenon 23turn with Orion 4800 Lipo. Weight 1340g
The car suffers from on power oversteering. When I squeeze, the rear wants to switch places with the front. I have tamed it by lowering the punch control on the LRP, adding a harder spring. Losing both front and rear roll bars had no difference so i put them back.
I need someone to critique my thoughts below.
1) I'm guessing with the drastic weight loss from the Lipo, the car has less tendency to want roll through corners. Will softer 10.5lbs springs all round help? I prefer soft cars as i find them easier to drive fast.
2) Max out the droop in front, this allows the weight to transfer rearward and sit the car down on corner exit.
3) Stock motors have alot of engine drag brake when I release the trigger, mainly due to the bushings. Move all static weight to the front.
Hope you guys can help me out here.
01-13-2008, 07:08 PM
#6244
Hiya all,
I'm a racer in Singapore presently running the R for the last year and a half in mod asphalt. This year's race series has a 23turn handout motor instead of the mod class. And there's no weight limit anymore. I have a problem with a snappy rear end.
Mod setup : Front 15lbs 40wt, spool, .04" roll bar. Rear 12.5lbs 40wt, .06" roll bar. LRP SphereComp on 6.5 turn brushless with IB4200 batteries and Sorex 40R all round. Weight around 1500g
23T Stock : Front 17.5lbs,spool .04" roll bar. Rear 12.5lbs 40wt, .06"roll bar. LRP SphereComp on Xenon 23turn with Orion 4800 Lipo. Weight 1340g
The car suffers from on power oversteering. When I squeeze, the rear wants to switch places with the front. I have tamed it by lowering the punch control on the LRP, adding a harder spring. Losing both front and rear roll bars had no difference so i put them back.
I need someone to critique my thoughts below.
1) I'm guessing with the drastic weight loss from the Lipo, the car has less tendency to want roll through corners. Will softer 10.5lbs springs all round help? I prefer soft cars as i find them easier to drive fast.
2) Max out the droop in front, this allows the weight to transfer rearward and sit the car down on corner exit.
3) Stock motors have alot of engine drag brake when I release the trigger, mainly due to the bushings. Move all static weight to the front.
Hope you guys can help me out here.
I'm a racer in Singapore presently running the R for the last year and a half in mod asphalt. This year's race series has a 23turn handout motor instead of the mod class. And there's no weight limit anymore. I have a problem with a snappy rear end.
Mod setup : Front 15lbs 40wt, spool, .04" roll bar. Rear 12.5lbs 40wt, .06" roll bar. LRP SphereComp on 6.5 turn brushless with IB4200 batteries and Sorex 40R all round. Weight around 1500g
23T Stock : Front 17.5lbs,spool .04" roll bar. Rear 12.5lbs 40wt, .06"roll bar. LRP SphereComp on Xenon 23turn with Orion 4800 Lipo. Weight 1340g
The car suffers from on power oversteering. When I squeeze, the rear wants to switch places with the front. I have tamed it by lowering the punch control on the LRP, adding a harder spring. Losing both front and rear roll bars had no difference so i put them back.
I need someone to critique my thoughts below.
1) I'm guessing with the drastic weight loss from the Lipo, the car has less tendency to want roll through corners. Will softer 10.5lbs springs all round help? I prefer soft cars as i find them easier to drive fast.
2) Max out the droop in front, this allows the weight to transfer rearward and sit the car down on corner exit.
3) Stock motors have alot of engine drag brake when I release the trigger, mainly due to the bushings. Move all static weight to the front.
Hope you guys can help me out here.
01-13-2008, 07:33 PM
#6245
it's probably due to having too much weight in the rear from the motor. not too much you can do other then ballast the front with lead. The r is somewhat known for being less then ideal on asphalt as is, so when you take even more weight out of the front, it gets tail happy due to the motor swinging the rear around.
also, you could try stiffer rear springs to make the snap more predictable, and lower the rear roll center.
also, you could try stiffer rear springs to make the snap more predictable, and lower the rear roll center.
01-13-2008, 07:51 PM
#6246
When I used my R underweight (with LiPo) it cornered like a 1/12th scale. It was also the most twitchy, ridiculously unpredictable thing I'd ever driven. I'm guessing there's quite a bit of setup changes that would need to happen to really take advantage of a lighter car.
01-13-2008, 07:52 PM
#6247
Tech Apprentice
Rear : Inner suspension pin full low, arms forward for shorter wheelbase. Upper camber link #4A
Hope this helps
01-13-2008, 08:22 PM
#6248
whats the scoop with the steel lipo tray? I need one and cant find it
01-13-2008, 08:33 PM
#6249
01-13-2008, 08:40 PM
#6250
01-13-2008, 08:44 PM
#6251
01-13-2008, 10:53 PM
#6252
Tech Apprentice
it's probably due to having too much weight in the rear from the motor. not too much you can do other then ballast the front with lead. The r is somewhat known for being less then ideal on asphalt as is, so when you take even more weight out of the front, it gets tail happy due to the motor swinging the rear around.
also, you could try stiffer rear springs to make the snap more predictable, and lower the rear roll center.
also, you could try stiffer rear springs to make the snap more predictable, and lower the rear roll center.
01-13-2008, 11:06 PM
#6253
In regards to the steel lipo battery tray...
I have a guy making some and I will try and see if there is enough interest. PM me if you want one so I can get an idea of how many and see what price I can sell them for. It's not something that is easy to make so I'm guessing in the area of $35 shipped.
I have a guy making some and I will try and see if there is enough interest. PM me if you want one so I can get an idea of how many and see what price I can sell them for. It's not something that is easy to make so I'm guessing in the area of $35 shipped.
01-15-2008, 07:28 AM
#6254
Hi, there is hope for someone can answermy question:
In eventually, If i wanted to upgrade the tech chassis. So I would buy JRXS Type R kit. But I am very concerning that Horizon Hobby will stop to contuining make the LOSI JRXS type R kits in future, is that true?
In eventually, If i wanted to upgrade the tech chassis. So I would buy JRXS Type R kit. But I am very concerning that Horizon Hobby will stop to contuining make the LOSI JRXS type R kits in future, is that true?