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Old 06-09-2010, 11:53 AM   #1531
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Wow, a lot to think about! Thanks,Don
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Old 06-10-2010, 03:09 PM   #1532
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John

Raising the nerf wings up has worked a treat. They no longer rub the track and handling is much improved in the fast sweeper. I have yet to play around with the body shell position at the front as it does scrape sometimes but shouldn't be much of a problem to sort out.

I have also tested the Associated gold springs on the rear of my JS Pro. I ended up using the rears from an RC18B as they are longer and stiffer than the front ones. As I am using the rear springs on the front associated shocks it does not allow for any ride height adjustment due to the spring being to long and fully extending the shock. Fortunately though it sets the ride height of the main chassis to 8.5mm exactly where it needs to be to clear the bumps on my track. I run the rear pod around 7.5 and adjust the rear axle as the tyres wear which in turn keeps the main chassis at the correct level.
I needed to add a bump stop to stop the chassis bottoming out on the fast corners so have done this by inserting some fuel hose to the shock piston. It works well, the softer springs soak up the bumps better and the fuel hose acts as a damper when suspension is loaded up on the sweeper.
I have thought about cutting the springs down a little so that it gives me some adjustment on the shocks to get rid of some tweek but ill see how it goes this weekend before i do this.


Regards .....
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Old 06-12-2010, 08:53 PM   #1533
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Jim-Thanks for the post.

Body Cutouts
I thought I would address this from my perspective and invite discussion at the same time. First I will list ROAR rules on the subject. These may be different than IFMAR rules but often are mirrors of each other.
I found discussion under general body rules and then specific discussion under electric TC body rules.

General Body rules
6.1.10 Openings in the body other than those appropriate to full-size vehicle openings such
as grill, scoops, air vents, etc., must be kept to a minimum. Specifically servos,
receivers, batteries, and servo savers are not allowed to protrude through the original
body shell.

Electric TC
Body rules:
Bodies must resemble 2 or 4 door cars that have raced in a Touring Car series.
See Global Body Specifications below.
Wheel arch cut-outs: Maximum 9.5 mm over tire diameter.
The rear of the body may not be cut higher than 55mm above the measuring
surface with the chassis resting on 20mm blocks.
No windows may be cut out.

Firstly. No windows in electric TC's may be cutout. That is pretty clear. This is universally followed but often misread to include the whole bod.

"Specifically servos,
receivers, batteries, and servo savers are not allowed to protrude through the original
body shell."
That is pretty clear. Nobody does this except me on ocassion for experiments when I stick the speed control cooling heat sink above the body. I can live without that.


"Openings in the body other than those appropriate to full-size vehicle openings such as grill, scoops, air vents, etc., must be kept to a minimum." Now this clause gives us reason to peforate out wide pan bodies in a variety of places. I will list those that have been recommended to me. with appropriate photos.
Nissan, Perforation at top of the front fenders, Perforation along a drop in the hood line, both to increase front down force.
McAllister Nissan, Peugeout 905 B, Toyota GT1, Perforations below the rear spoiler, these reduce rear downforce. And the last picture a very smooth and vent free Porsche 962

continued on next post.
Attached Thumbnails
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-associated-nissan-gtp-body-001-resized.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-mcallister-nissa-nnpt90.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-toyota-gt1-body-cutouts-001-resized.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-porsche-962-body-001-resized.jpg  
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Last edited by John Stranahan; 06-12-2010 at 09:03 PM.
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Old 06-12-2010, 09:00 PM   #1534
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Now a full size Peugeot 905 B showing the huge air intakes on the sides of the canopy top. There is also an engine air intake on the top of the body just out of view. My interpretation on the Protoform 905 B model follows.
Here is picture of a open mod TC used in 110F weather with the long track at 150F. I got histerical responses from the local racers. The grill opening acutally fed a large tube that jetted air on the speed control. I say these both follow the rules. The wide pan mods certainly have precendents. Anyway discussion is invited. I like it when the speed control does not catch fire.
John
Attached Thumbnails
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-peugeot-905-b-duct-611672995_4d9c16567d.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-body-cutouts-001.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-grille-fed-cooling-air-duct.jpg  
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Old 06-13-2010, 07:06 AM   #1535
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John, you are racing in some serious heat over there, im surprised you don't have more problems. The temp system on my new SPX8 has not flashed over one flash so far so I'm happy. However, I had a motor bearing failure on my X12 yesterday. After fishing out the debris I managed to change the bearing and all was ok with no other damage apart for some minor scratches to the rotor. Do you use modified bearings or just the stock ones?

I have also tested the Corally foams on the JS Pro. They feel really good in low grip conditions due to them being a thicker tyre than the Jaco's but the front wheels do need some sanding on the insides to clear the kingpins.
I also found that the rears did catch the nerf wings on occasion due to their increased thickness and due to my higher nerf wing setting. This can be cured by either cutting the tyres back or adding some length to the links.
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Old 06-13-2010, 03:33 PM   #1536
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Quote:
Originally Posted by John Stranahan View Post
I like it when the speed control does not catch fire.
John
Words to live by there!
We are lucky that down here the temperatures don't get up too high, so cut-outs aren't a big deal.
I say "lucky" because or national rules state no cut-outs above the bumpers or door sills except for body posts, antenna, and transponder!
I'd like to be able to cut up the body a bit, just to get a bit of air flow over the esc of my touring car. Won't be an issue with the GenX as I only run 13.5 2S, so the esc is just ticking over with a 2wd
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Old 06-15-2010, 11:17 AM   #1537
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Thanks for the posts.

The pinion side motor bearing takes a beating with powerful motors in a wide pan. Oil it each session to help prolong its life. I use the steel motor bearings.

JS pro 10 king pins can be shortened a little on the top by sanding. Just leave enough metal to hold onto the snapring. You can also recenter it and gain some clearance using thinner kingpin shim.

You can sand the back of the Nerfwings to gain a little clearance. Do this outside with the drum sander on the Dremmel.
John
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Old 06-18-2010, 04:20 PM   #1538
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Quote:
Originally Posted by John Stranahan View Post
Thanks for the posts.

The pinion side motor bearing takes a beating with powerful motors in a wide pan. Oil it each session to help prolong its life. I use the steel motor bearings.

JS pro 10 king pins can be shortened a little on the top by sanding. Just leave enough metal to hold onto the snapring. You can also recenter it and gain some clearance using thinner kingpin shim.

You can sand the back of the Nerfwings to gain a little clearance. Do this outside with the drum sander on the Dremmel.
John
Do you ever use ceramic bearings anywhere on the car or are they too fragile?
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Old 06-18-2010, 08:36 PM   #1539
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When I close those 3 little vents in the summer on my wide pan even the SPX8 will thermal. The Tekin RX8 does not.

Slsspark-
Ceramic Bearings.
What we mostly have available to us are Hybrid bearings. These have Ceramic Balls and Hardened Steel races. So the question is does the harder ball make the bearing last longer or shorter. If the bearing undergoes impact damage then I think the answer is shorter. Impact damage is like when a wheel bearing is getting a hard hit when the wheel hits the boards. The bearing will brinnel. It gets a series of evenly spaced divots coinciding with the balls position at time of impact. If you hold the outer race and put a pencil on the inner race and spin it by hand you feel the bearing ratchet. I feel that the harder ceramic ball would make this problem worse. This is how our wheel bearings die. So I use no ceramics in wheel bearings.

Motor bearings die from a combination of grit damage combined with High RPM and brinneling when the heavy armature slaps the motor bearing race in a crash. That little O-ring in the LRP motors probably helps prevent the brinelling damage to the pinion side bearing bearing. A ceramic bearing would be better here but probably not twice as good as you still have a steel race being damaged by the grit. So for cost effectiveness I use the steel bearings here as well. On an outdrive bearing impact loads are very low. Use ceramics here, but then the Original equipment bearing hardly ever fails so I don't replace it. I get years of use here unless you run it without a seal.

I like rubber sealed or teflon sealed full contact seal steel bearings in grease (that keeps out the grit) for longest life.

You might run a little faster with non contact oil filled bearings for a single session, but by the next session or two the grit will have slowed the car over a rubber sealed bearing. You won't be able to measure the difference on the time sheet, though.

John
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Old 06-19-2010, 01:56 AM   #1540
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My baby finally finished and ready for tomorrows race meet (weather permitting).
I had some spare time so stripped it and rebuilt it, and came across a few interesting things. Firstly, my front suspension wasn't having a smmoth action. THe kingpins were very smooth, but the bottom pivot wasn't. I ran the shaft of my hex driver through it (almost perfect fit) for a minute or so, and everything was fine. I'm sure it would have worn-in over time, but it's nice to have it smooth from the get-go.
Also, my rear shock was sticking. After pulling it apart and playing, I noticed the piston was VERY tight in the can. I sanded a bit off the outside and it's now very smooth acting.
Just a few things. I'm sure they have been covered before.
Can't wait to race!
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CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-p1030294.jpg  
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Old 06-19-2010, 05:25 AM   #1541
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Quote:
Originally Posted by JR007 View Post
My baby finally finished and ready for tomorrows race meet (weather permitting).
I had some spare time so stripped it and rebuilt it, and came across a few interesting things. Firstly, my front suspension wasn't having a smmoth action. THe kingpins were very smooth, but the bottom pivot wasn't. I ran the shaft of my hex driver through it (almost perfect fit) for a minute or so, and everything was fine. I'm sure it would have worn-in over time, but it's nice to have it smooth from the get-go.
Also, my rear shock was sticking. After pulling it apart and playing, I noticed the piston was VERY tight in the can. I sanded a bit off the outside and it's now very smooth acting.
Just a few things. I'm sure they have been covered before.
Can't wait to race!
Just watch yourself with that shell
I tried one and it failed to turn mosty corners unless I backed off or brakes, also had to turn the steering lock right up to get it to turn which then made it hook coming out of a corner.
I tried it for 2 meetings and gave up, went gone back to the Corvette and set a new personal best race time.
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Old 06-19-2010, 10:38 PM   #1542
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Tell me, has anyone put a CRC front end on an Assoc Rc10R5?
I can get a cheap R5 chassis (used), but has not front end, and I happen to have a spare for my GenX.
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Old 06-21-2010, 11:24 AM   #1543
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2011 JS Pro 10 Status.

The hand-built prototype parts are finally tuned up. They worked as well as the previous versions with some weight, cost, and durability improvements. Machine cut prototype parts are being fabricated. Here are some notes on testing that will apply to any JS Pro 10; some of them apply to pan cars in general.

Minimized top plate
I tested the new pod with both my minimized battery top plate that allows a top loaded battery, and a regular long top plate that requires bottom loading. Lap times were identical. As you strap in the battery with the O-ring, the battery actually becomes part of the structure and minimizes banana type bending of the chassis along its long axis. This keeps the antisquat effective. I had some concerns here. See the pic below.

Setting antisquat
As the parts were new up top I had to reset antisquat. Raising the rear of the top link and lowering the front of the top link increases antisquat. I got more forward traction as I did this. When I went too far the car started to lift the front end and make it dive toward the inside board late in the corner as I added throttle. A snap spin. Reducing antisquat just a little resolved this issue.

Setting front roll center
I used up my supply of mid-size front tires that seem to work the best on pan cars and put on a new BSR front purple. I had too much steering. The car was undriveable. I raised the upper A-arms outer pivots one spacer to raise the front roll center and this helped a lot. I reduced front droop a tad with the screws and the car settled in. Now it really took 3 heats and the wear of 2mm of rubber before the car came in really well and produced low lap times. If you have a truer just true a couple mm off the diameter. Get a set of Associated Kingpin shims to fine tune the roll center.

Setting rear droop
On the way to a good setup I was having some cornering problems. The car seemed to corner in straight line segments. I suspected a problem at the rear. Reducing rear droop just a little by adding more spring preload solved the problem. The rear droop is now zero with body off and 1 mm or so with body on. This solved the problem and produced nice smooth round cornering.

Rear Chassis Height
I had the chassis too low and was losing cornering power on the sweeper. I adjusted it up with the axle ride height spacers and this was solved. I have my Nerf wings shimmed with washers so that when you move the car fully down in bump, the rear tips touch at the same time as the rear of the chassis. this means the rear of the Nerf wings are shimmed up. I also have them shimmed so the outer edge touches the ground at the same time as the edge of the chassis. The outer ends are shimmed up for roll clearance. Any rubbing reduces cornering on the sweeper.

Bump stops
The rear suspension with stock setting works like this. As the chassis goes down in bump, the shock pistons touch the rubber bladders at the top of the shock and provide a soft bump stop at almost full down. Additional small movement causes the links to hit the bottom of the side plates providing a hard but still springy bump stop. This tends to keep the chassis off the ground even on high speed bumps if your ride height is high enough. I am at 7-8 mm on the rear of the chassis and 6-7 mm on the bottom of the pod. This works really well for me and allows me to use 2lb/inch springs for better rear performance through the bumps.

The car was really fast this Sunday and put 3/4 lap on a fast mod touring car during a run.

John
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CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-prototype-pro-10-2011-001.jpg  
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Old 06-29-2010, 03:33 PM   #1544
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John, the SPX8 is holding up great. It works really well in a 10th application.

Your car has really started to perform now that the summer is here and I have cured the bottoming out of the chassis on the sweeper, although I am running the chassis a little high than I would like it is still awsome.

I can also coat the complete front tyre with additive which is something that I could not do with the standard GenX10. The car has so much traction and does not spin out due to to much front end grip. I have noticed however that motor temps increase by around 25-30 degrees (c) and the ESC's temp LED flashes 6 times instead of 1-2 times with the front tyres completly treated!

The Corally foams work so much better than the Jaco's and do not seem to chunk at all. They fit great with a little sanding of the front king pins and some adjustment to the rear links. I will be using Corally foams from now on.

I have had a couple of minor failures so far -

A lightened diff ring on one occassion has sheered it's way around the fixed points of the outdrive. I had to replace the outdrive but just used the one from my old GenX10 so was not to much of a problem. I'm not sure if this was due to high traction and the fact that I had to run the diff very tight to stop it slipping up? If it happens again I may go back to using standard diff rings.

I have replaced the rear shock top ball studs with ones that have a longer thread as also on one occassion one did fall off in mid corner causing me to crash. This was mainly due to it not having sufficient thread lock but having longer threaded ball studs adds more reliability.

Up to this point the car has developed zero wear in any of the components and the only thing that requires a small amount of attention (apart from the norm) is the tightness of the panhard bar which is very easy to do. Not even the tiny RC18 shocks have started to weep fluid but I am going to replace the seals soon anyway as they are cheap.

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Old 06-29-2010, 04:01 PM   #1545
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My JS Pro 10 has also been working really well. This is my rookie season in Pro 10 (and I'm no better than "inexperienced" in R/C overall), yet I'm holding down 4th place in points behind some serious talent. The car gets better every week, and can carry some amazing cornerspeed.

And after some 26 indivdual races plus practice, I can confirm the durability of the car - as a rookie, I've had some spectacular incidents, but the car is great. It tweaks a lot less than a standard pan, simply because the suspension components are beefier. I haven't really had to touch anything in a month or so, aside from cleaning.

For the Panhard, I really recommend carefully drilling the mounting hole in the motor bulkhead deeper, then tapping it for the use of a much longer screw. The metal is thin under the pinion hole but even if you break through, there is a lot more thread to hang on to. Blue Loctite (or red if you want a permanent mount) on the screw and you're golden. My Panhard hasn't ever come loose.
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