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Team Losi JRXS Type-R

Old 11-20-2008, 03:42 PM
  #8506  
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Originally Posted by RCGaryK View Post
Have an odd setup issue that I think I have figured out but just checking for some other feedback...

I last raced my Type R at the USVTA Nationals. Carpet track using the HPI tires and inserts and all. Anyways my car worked really well for the first 2-3 minutes. It was fast, smooth, basically a monkey car. The last 2-minutes or so the rear end would get looser and looser to the point the car was un-driveable. To this point I had thought of a few possibilities:

1) The front tires were taking that long to come up to temp
2) The rear tires were getting overheated by that point
3) There was air in the shocks and it was taking that long to affect the handling
4) The tires were picking up crap from the track, causing a build-up problem.

Going back to a conversation that I had with Billy Fischer back at the Horizon Hobby Shootout, I think I may have found the issue
5) The diff lube was breaking down and causing the diffs to overly diff-out.

I was using the brown Losi grease on the thrust bearings and the clear Losi stuff on the balls. I just rebuilt the diffs with AE Stealth and Black grease on the balls and on the thrust assembly. I also replaced the thrust washer assembly by tossing the thrust cages and using a total of 8-thrust balls on each diff in lieu of the standard 6. I won't be able to test this till Sunday, but I ran the exact same tires/tire dope on a different chassis 2-weeks ago and it never happened. It's not a tire deal, it's gotta be a chassis/setup deal. Any thoughts?

OH, and me sucking as a driver IS a valid explanation too
This can happen, but not usually with the losi brown, You can use this on the diff balls as well. One question? What motor are you running? Usually this only happens with mod of maybe a 10.5. The diff may have just not been tight enough too. It felt good when it was cold on the bench, but was just loose enough that when you get going on the track it than heats up and slips.

Let us know what happens.

RedRocket
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Old 11-20-2008, 03:48 PM
  #8507  
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Originally Posted by a_main_attendee View Post
Definately break in the diff after a rebuild, clean the tires really really well and apply something like jack the gripper to them afterwords (a major help for me when combating buildup with jaco blues at my local track), perhaps take some weight off of the front, such as stiffer spring, more front downtravle, etc.

I have never ran with hpi vintage tires though, so it seems as if it may be a tire issue.
I used JTG and cleaned the tires after each run with Lighter Fluid. Don't think it's tire though because like I said, I used the exact tires on a different car 2 weeks ago and the grip was consistent from 15-seconds in until the 8-minute mark. If I would have had the same results with both chassis, and the other was not a JRX-S Type R, I would totally agree it's probably tire. But since the other car was consistent to drive the entire run I gotta think it can't be tire.

Originally Posted by RedRocketRacing View Post
This can happen, but not usually with the losi brown, You can use this on the diff balls as well. One question? What motor are you running? Usually this only happens with mod of maybe a 10.5. The diff may have just not been tight enough too. It felt good when it was cold on the bench, but was just loose enough that when you get going on the track it than heats up and slips.

Let us know what happens.

RedRocket
I was running a 4-cell 17.5 configuration.
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Old 11-20-2008, 03:54 PM
  #8508  
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Originally Posted by TJames987 View Post
has anyone else had their high dollar front one way bearing fall apart? Unfortunatley you have to buy the entire oneway tube for 45 bucks and can't find the oneway bearing to just replace it. Has anyone else had this happen?
Yes, 3 of them,each lasted no more than a week each
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Old 11-20-2008, 03:57 PM
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I might as well post my setup, see if anyone spots anything....

Front:
5.5mm ride height
4-degree caster
0 arm sweep
Standard Ball Stud (No JR Link)
Long arm
Diff
45wt oil
#57 Piston
20lb spring
#1 hole in steering rack, #1 in steering arm
.050 sway bar
Shock in hole #2 on tower
Diff High
Arms centered
High Roll Center

Rear-
5.5mm ride height
2 1/2 degrees rear toe (3 degrees inboard but 1/2 hubs installed R on L and L on R)
Low roll center
Arms spaced to the rear
Camber Link- 5/A
35wt Oil
#55 piston
12.5 spring
Shock mounted in 3/outside
Diff High

Setup changes between then and now:
Before ran a 17.5 Brushless w/4-cell placed in the middle. Now running 21.5 with LiPo. Car is equipped with the Steel LiPo tray.
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Old 11-20-2008, 05:15 PM
  #8510  
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What does ride height do the setup?
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Old 11-20-2008, 06:38 PM
  #8511  
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Originally Posted by RCGaryK View Post
I might as well post my setup, see if anyone spots anything....

Front:
5.5mm ride height
4-degree caster
0 arm sweep
Standard Ball Stud (No JR Link)
Long arm
Diff
45wt oil
#57 Piston
20lb spring
#1 hole in steering rack, #1 in steering arm
.050 sway bar
Shock in hole #2 on tower
Diff High
Arms centered
High Roll Center

Rear-
5.5mm ride height
2 1/2 degrees rear toe (3 degrees inboard but 1/2 hubs installed R on L and L on R)
Low roll center
Arms spaced to the rear
Camber Link- 5/A
35wt Oil
#55 piston
12.5 spring
Shock mounted in 3/outside
Diff High

Setup changes between then and now:
Before ran a 17.5 Brushless w/4-cell placed in the middle. Now running 21.5 with LiPo. Car is equipped with the Steel LiPo tray.


Looks to me like your rear end is too soft. Go up to 56 pistons, 40 wt and 15-17.5 lb springs see if that works. The rear end of the car might be rolling too much and breaking traction.
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Old 11-20-2008, 07:00 PM
  #8512  
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I'll try that, but if that's what it was wouldn't it be occurring immediately and not later in the run?
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Old 11-20-2008, 07:09 PM
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Originally Posted by RCGaryK View Post
I'll try that, but if that's what it was wouldn't it be occurring immediately and not later in the run?
Probably whats happening is up front the car feels good cause the tires are cold and have alot of bite. As the run goes on the tires build heat the rear traction goes away cause your over working them.
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Old 11-20-2008, 07:52 PM
  #8514  
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Originally Posted by RCGaryK View Post
I'll try that, but if that's what it was wouldn't it be occurring immediately and not later in the run?

I know its sound weird, but yesterday, my tires were squeeling. I had 17 front and 15 rear springs. I went to 15F/12R and my car became loose after about 2 minutes. I had the impression that softer springs would give me more overall traction but apparently not. I went back to my stiffer setup and the car was good for the entire race. The squeeling went away once the track got hotter.
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Old 11-20-2008, 07:57 PM
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Originally Posted by [email protected] View Post
I know its sound weird, but yesterday, my tires were squeeling. I had 17 front and 15 rear springs. I went to 15F/12R and my car became loose after about 2 minutes. I had the impression that softer springs would give me more overall traction but apparently not. I went back to my stiffer setup and the car was good for the entire race. The squeeling went away once the track got hotter.
I've had that happen myself. The old Pit Shimitzu S-slicks would bark every corner and Tamiya A-compound tires will squeal if you're hustling the car as well.
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Old 11-20-2008, 07:57 PM
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This setup was awesome for vta, give it a try Gary
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Old 11-20-2008, 07:58 PM
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Originally Posted by [email protected] View Post
I know its sound weird, but yesterday, my tires were squeeling. I had 17 front and 15 rear springs. I went to 15F/12R and my car became loose after about 2 minutes. I had the impression that softer springs would give me more overall traction but apparently not. I went back to my stiffer setup and the car was good for the entire race. The squeeling went away once the track got hotter.
When we run sorex tires they squeal like crazy, don't worry as long as the car feels good.
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Old 11-20-2008, 08:07 PM
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Originally Posted by rcracingkid View Post
This setup was awesome for vta, give it a try Gary
If thats the setup form the gate I'd say its better then awesome
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Old 11-20-2008, 08:07 PM
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Originally Posted by rcracingkid View Post
This setup was awesome for vta, give it a try Gary
Will do. Setup looks close to Matt's setup he gave me when he ran 13.5 @ the Plex. Only question is that this is for a high-bite track. Where I run is relatively low-bite. I figure at most maybe just drop a spring rate and 2 1/2-5 on the shock oil to increase bite?

How does the Trinity oil compare to Losi?

Are you running the JR link or no?
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Old 11-20-2008, 08:47 PM
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Originally Posted by Jeff Crosson View Post
What does ride height do the setup?
higher give you more bites and easier driving experience.

set it at 5mm for indoor smooth track or 5.5 for outdoor track and forget about it then... keep practicing~
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