52LikesTeam Losi JRXS Type-R
08-22-2009, 09:00 AM
Wow... there's nothing left of that top deck! 
Let us know what you think.
Let us know what you think.
08-22-2009, 10:37 AM
08-22-2009, 12:21 PM
Just as a personal note. I have tried playing with the scale tweak system on more than one occasion, even for a couple of hours at last years nats while waiting for the rain to stop. Heaps of us all in the A-finals all chucked our chassis on the scales and got all sorts of weird results. Interestingly enough was that the best car on the scales (within 5g on all four corners) was way slower on the track than some of the fast guys inc myself which where over 30g out in some corners. I understand the theory but I have never seen proof that it converts to on track speed. I have always found the best tweak measurement to be lifting the chassis off the ground in the center with correctly set droop. This gives you a car that tracks straight on and off power.
after all these years I m still sticking with my MIP tweak station. KISS rule
08-22-2009, 12:23 PM
What you are looking at there is chassis tweak, not weight balance. To do weight balance you check the left/right and front/rear vs each other off the chassis itself, not the suspension. Try this....
*Place all gear on you assembled chassis lightly held in place so it won't move around.
*Use two points or a round object up the center of the chassis (the center is marked with a small hole at each end) to balance on.
*Add weight on either the left or right to get it balancing right.
*Now get out your scales (at least 1kg) and a similar size solid object like a car stand. You will also need two objects to place the chassis on (I use my tools with a flat edge).
*Place the objects on the scales and base and adjust so the tools or what ever you use match the wheel base of your chassis.
*Now zero the scales and place the chassis on both objects making sure the axles are straight over the balance points (tools or whatever). Note the reading.
*Now switch the chassis around and repeat for the other end.
*You now have your front rear ratio so add weight to get it right. You can also move the weight you used for left to right balance forward or aft to help as long as it is the same distance from the center of the chassis.
Generally a balanced chassis is faster than unbalanced and light. The losi seems to like A 52/48% F/R balance.
Also here is a pic of the upper deck I just killed to try out tomorrow. I picked what parts to cut so I could also secure all the wiring neatly. I doubt there would be much in it anyway but the chassis is very flexy now.
*Place all gear on you assembled chassis lightly held in place so it won't move around.
*Use two points or a round object up the center of the chassis (the center is marked with a small hole at each end) to balance on.
*Add weight on either the left or right to get it balancing right.
*Now get out your scales (at least 1kg) and a similar size solid object like a car stand. You will also need two objects to place the chassis on (I use my tools with a flat edge).
*Place the objects on the scales and base and adjust so the tools or what ever you use match the wheel base of your chassis.
*Now zero the scales and place the chassis on both objects making sure the axles are straight over the balance points (tools or whatever). Note the reading.
*Now switch the chassis around and repeat for the other end.
*You now have your front rear ratio so add weight to get it right. You can also move the weight you used for left to right balance forward or aft to help as long as it is the same distance from the center of the chassis.
Generally a balanced chassis is faster than unbalanced and light. The losi seems to like A 52/48% F/R balance.
Also here is a pic of the upper deck I just killed to try out tomorrow. I picked what parts to cut so I could also secure all the wiring neatly. I doubt there would be much in it anyway but the chassis is very flexy now.
looking good, look like middle X part can be a really good pivot point of flexing, let us know how you liked it!
08-22-2009, 12:54 PM
Da john wee,
I browsed thru your blog and like the addendum to the shock building video.
One question that I have is what length do you set the rod.. When using a caliper, measuring the distance from the bottom shock cap to the top edge of the shock end. I figure this to be 12mm, what setting do you use?
thanks
I browsed thru your blog and like the addendum to the shock building video.
One question that I have is what length do you set the rod.. When using a caliper, measuring the distance from the bottom shock cap to the top edge of the shock end. I figure this to be 12mm, what setting do you use?
thanks
08-22-2009, 03:39 PM
Da john wee,
I browsed thru your blog and like the addendum to the shock building video.
One question that I have is what length do you set the rod.. When using a caliper, measuring the distance from the bottom shock cap to the top edge of the shock end. I figure this to be 12mm, what setting do you use?
thanks
I browsed thru your blog and like the addendum to the shock building video.
One question that I have is what length do you set the rod.. When using a caliper, measuring the distance from the bottom shock cap to the top edge of the shock end. I figure this to be 12mm, what setting do you use?
thanks
hey max
Thanks for visiting my blog.
I dont measured that way, I measured from top of the shock cap to botoom of the rod end to be I think 63mm (it s been long time since I measured that)
08-22-2009, 06:40 PM
PRS goes up to 128, i have a 120 from them. I run a 115 robinson just about everywhere and i can get fdr up to about 5.8 - 5.9 with it. I don't think you need kevlar.
If you were talking about 6.5 and lower i may agree but i don't think 10.5 generates the torque that the hotter winds to.
08-22-2009, 07:18 PM
PRS goes up to 128, i have a 120 from them. I run a 115 robinson just about everywhere and i can get fdr up to about 5.8 - 5.9 with it. I don't think you need kevlar.
If you were talking about 6.5 and lower i may agree but i don't think 10.5 generates the torque that the hotter winds to.
If you were talking about 6.5 and lower i may agree but i don't think 10.5 generates the torque that the hotter winds to.
I always liked the Losi Kevlar from the day realeased, Beilive me I had every brand machined gear on my cars, that incld some of very rare Japanese machined spur gear mchained to moon,
my sugestion came from what if all this speedo company coming out with new "timing boost" version, I heard Novak having a new ESC on work, LRP have a SPX that dominating Asia, GM rocking in europe, with all this newer high RPM ESC, we will need yesteryears small/normal size spur/pinions
for myself I digged out all my "normal size" pinions from 29-40T yesterday, few missing so I ordered few "normal size pinions" too along with a 118T spur.
I was only carrying 43-52T with my LRP TC, BTW
IMO we bought the PRS adaptor to fits 104-108t spur, not because we hated Kevlar spur, IMO if Losi ever realised a 108T Kevlar Spur, PRS never had a chance to sell that many adaptors, then upgarade version came out which was Flyingfox shaft.
if any one makes topsahft fits Losi spur w/Flyingfox quality, I 'll switch to Losi spur anytime, with a TEKIN RS of cos.
Last edited by SweepRacingUSA; 08-22-2009 at 11:36 PM.
08-22-2009, 09:27 PM
I had to order a few PRS spurs myself. I took out 2 110s this week just by tapping a barrier rounding corners too tight. There is so much torque in the RS/17.5 Redline. Tekin really did a nice job. I'd recommend it to anyone running 17.5 in their JRX-S Type R.
08-23-2009, 02:54 AM
Ok guys... Started my track day out well... 10am and my brother comes in and asks me if I am still racing today!?
Well missed out on practice and 1st run so dropped car on track for 2nd Q. It felt really planted but lacked an form of mid to high speed steering. Old tyres on it so may have been 1/2 the reason. Anyway 17.4
Third Q with new tyres and car was better. Basically pulled away from the other two guys with little trouble. Have no idea on lap time cause some moron kicked out the loop after 3 laps.
Added 2mm rear droop and 1mm fron to see if I was limiting roll but lap times didn't improve much down to 17.2
Well had to stand around and marshall noisy cars so after that had another 2 runs to test. 1st change was minimum ackerman which usually makes the car a little loose to drive. Manual timing said there was nothing in it but the car did have more steering everywhere. 2nd time out changed to fxII but with no warmers (no more power) and was easily faster than the other quick mod car which was now doing 16's.
Notable difference all day was lack of high speed steering that was the most notable trait of this chassis when I 1st got it. However the car was planted and glued to the track all day never setting a foot wrong. The potential to tune in more performance is there. I am guessing that high roll centers may be a better balance with this kind of low speed performance so next weekend I'll be doing back to back runs with high and low roll centers and we will see where its at. Also I run 90% steering lock always... I could have easily turned this up today with a well behaved car. Another benifit was the loss of quite a bit of weight so all in all the upper deck mod has changed the car quite a bit with mayb a slight increase in lap performance but run performance is definatley better.
The bearing I removed is an axle bearing I mounted on the rear left upper deck support I ran the front over this bearing to give more wrap around the layshaft pulley and therefore less belt skip under brakes (mod brakes are crazy these days). I will have to put it back in sometime but without bolting it between the upper and lower decks the chassis flex is moving the belt off the bearing and it ends up flipping. When I get it back in I'll post some picks.
Well missed out on practice and 1st run so dropped car on track for 2nd Q. It felt really planted but lacked an form of mid to high speed steering. Old tyres on it so may have been 1/2 the reason. Anyway 17.4
Third Q with new tyres and car was better. Basically pulled away from the other two guys with little trouble. Have no idea on lap time cause some moron kicked out the loop after 3 laps.
Added 2mm rear droop and 1mm fron to see if I was limiting roll but lap times didn't improve much down to 17.2
Well had to stand around and marshall noisy cars so after that had another 2 runs to test. 1st change was minimum ackerman which usually makes the car a little loose to drive. Manual timing said there was nothing in it but the car did have more steering everywhere. 2nd time out changed to fxII but with no warmers (no more power) and was easily faster than the other quick mod car which was now doing 16's.
Notable difference all day was lack of high speed steering that was the most notable trait of this chassis when I 1st got it. However the car was planted and glued to the track all day never setting a foot wrong. The potential to tune in more performance is there. I am guessing that high roll centers may be a better balance with this kind of low speed performance so next weekend I'll be doing back to back runs with high and low roll centers and we will see where its at. Also I run 90% steering lock always... I could have easily turned this up today with a well behaved car. Another benifit was the loss of quite a bit of weight so all in all the upper deck mod has changed the car quite a bit with mayb a slight increase in lap performance but run performance is definatley better.
The bearing I removed is an axle bearing I mounted on the rear left upper deck support I ran the front over this bearing to give more wrap around the layshaft pulley and therefore less belt skip under brakes (mod brakes are crazy these days). I will have to put it back in sometime but without bolting it between the upper and lower decks the chassis flex is moving the belt off the bearing and it ends up flipping. When I get it back in I'll post some picks.
08-23-2009, 12:12 PM
OK so I finished the build of the JRXS and things went pretty smoothly. Had a few issues with the wrong hardware being included in the kit. Somebody at Losi needs to inform the packers that 5-40 screws and 4-40 screws are not interchangeable. I had issues building the front carrier and steering knuckle as the long screws that go through the top of the carrier were 5-40s not 4-40s.
I have one issue that needs to be resolved. When using the plastic Lipo tray I can't get my packs to fit. Since the tray has the fingers on the front that have to slide in first the angle I have to use rotate the pack in place the thickness of the pack hits the rear edge of the battery slot. In looking at the steel tray, which I'll most likely need any way, I noticed that there seem to no fingers on the steel tray. That would allow me to drop the whole tray/battery package straight in, fixing my problem. Is that the case? Does the steel tray drop straight in versus having to pivot in like the plastic tray?
I have one issue that needs to be resolved. When using the plastic Lipo tray I can't get my packs to fit. Since the tray has the fingers on the front that have to slide in first the angle I have to use rotate the pack in place the thickness of the pack hits the rear edge of the battery slot. In looking at the steel tray, which I'll most likely need any way, I noticed that there seem to no fingers on the steel tray. That would allow me to drop the whole tray/battery package straight in, fixing my problem. Is that the case? Does the steel tray drop straight in versus having to pivot in like the plastic tray?
08-23-2009, 12:34 PM
I have the steel tray using a thunder power 5000 40c fits with no mods.
08-23-2009, 12:43 PM
Lol that topdeck has to be a joke right?
08-23-2009, 12:49 PM
08-23-2009, 01:18 PM
