JR007

Would there be any advantage or disadvantage to running this on outdoor asphalt?
I'm picking there is a little less travel, but probably not much difference, as the factory spring stacks up toward the end of the travel and a lot of the additional king-pin length is coiled spring.
I don't want to do things for the sake of doing them, and with one set-up of each, i'd rather have them both the same from the get-go

John Stranahan

iTrader: (27)

JR007-I was hoping someone who used the short springs would post. I have not. I suspect their value is for high traction carpet where they will stack up and become solid preventing traction roll. Current Nascar cars do some of this spring stackup with COT bodies to keep the dam off the ground. I don't like short springs out doors. Any bottoming is disastrous to cornering grip.


JS Pro 200 Battle Axe news, 2011 Model
Kenny Roberts has finished his testing of this car and has provided valuable feedback that I used to make changes in the car. Thanks Kenny. Both he (on the oval) and I, experienced some chatter or in my case axle tramp (with the wide pan) under some conditions with the old pod. (Note this is for 3-link rear end cars) I did some experiments and the condition is worse the more flexible you make the left side of the pod. It is especially bad with the plastic left minimized pod plate (the black one). On my wide pan, I could tune the axle tramp out with the minimized aluminum left pod plate by going to 2 lb springs and removing the center post. It was not really a big problem for me as it only occurred on spinning the tires forward faster than optimum. It is absent with the extended left side plate from the early Gen X 10s. This extended left side plate for the Gen X 10 is no longer in production. So what I have done is gone back a generation to the RC10L3T style pod plate which has a top plate and bottom plate, no back x brace but has the needed extended left side plate. I have tested this style of pod with the 3-link for a couple of years. Chatter and axle tramp are non existent. A molded extended triangulated left side pod plate is available still from associated and will work here. Additional benefits will be the motor plate will not bend on high speed bumps. It is braced by the top plate now. That upper motor screw will now be more secure preventing gear damage. These changes are already bing prototyped on my wide pan with good success. Wide pan Machine cut parts are now on the way for final approval. Oval parts will follow soon after.





I have made changes to the JS Pro 200 complete car to reflect recent improvements and this feedback.

• Completely new pod, top plate, side plates, and bottom plate.
• New style extremely rugged Panhard Bar. It no longer attaches to the motor plate but has an offset tab on the bottom plate. This style of bottom plate will be available with the add on kits in a month or two and will lessen the 3-Link rear end kit price by the price of a motor plate or $20.
• New Panhard bar with Dubbro #4-40 HD rod ends instead of their standard duty rod ends.
• Solid Rear Cross Plate with fine body post adjustment (this was included in the previous model pictured on the Web site).

Now SWtour, if you would like to test this car read your PM.
3rd pic shows left side pod detail compared to the minimized left pod plate.

SKJ

iTrader: (20)

Hi John
My JS Battle Axe never made it on to the velodrome. I was having some electronics issues. Since this car was using all of my extra electronics I did not have time to switch anything out and diagnos the problem. I am currently getting it ready for the carpet track this weekend.

I am sure Joe (SWTour) would love to try out the car. I will give him a call at lunch today.

Steve

JR007

I have been mucking around trying to get my front ride height set on my Gen X 10, and just can't get it.
At present it's about 4mm if I have the standard 5mm block, and no spacers. The tyres are hardly worn, so I assumed this would have been higher given it's the "factory" setting for 1/10 wheels.
Should I go to a 3mm spacer? This seems to go against how the tuning should be if you are supposed to use the fibreglass spacers as the wheels wear down.
I'm a tad confused! ha ha

NiMo

I have found that the more droop you run the lower the front sits to the road, so you have to compensate by reducing the ride height blocks

JR007

At the moment I have about 2mm of droop in the front. Ids this too much for a large outdoor track? Maybe I should start back at about 1mm?

NiMo

I found adding front droop changes how much front grip you have.
Personally on my own track I tried running front droop and found the steering very nervous, now (rightly or wrongly) I screw my droop screws right in on the front, in effect taking out all droop, this added that little understeer to the car, now I just happen to hold the track record at present for the 2s 17.5 / 4c 10.5 GT2 class, and have done since last October (probably forever now it has gone 1s 10.5 / 2s 21.5).
Try less droop and see how you like it
No droop does take steering away

JDavis

Forgive me for being off topic but it sounds like you guys know allot about the Gen X 10 cars. I just bought one for a carpet series at my local track and I was wondering since I have never seen a world gt car on the track before. If I use a 2s lipo with a 17.5 brushless will I be able to compete against other drivers that are still using the old 10l chassis with a 17.5? I would like to keep the car at 200mm but do you guys think I will need to buy the conversion to 235mm to be competitive? Any advice on 17.5 gearing would be great. I haven’t run a 10th scale pan car for over 20 years and I’m pretty excited about this car!

NiMo

Not run indoors, but ran 2s 17.5 successfully outdoors.
No modifications are required
All fits in direct

John Stranahan

iTrader: (27)

Thanks for the posts guys. I like about 1-1.5 m droop outside. For me this gives me excellent steering grip while still being responsive on the JS Pro 10. I use similar amounts on the Gen X 10 outside.

Steve-Good luck on the flat oval. Give us a report. Feel free to write me an e-mail if you have setup questions.

JDavis-Given sufficient motor power a 235 mm car will outperform a 200 mm car everywhere. With 2S 17.5 the lighter weight of the 200 mm car may offset its performance disadvantage. Run the 200 mm car indoors. If you ever get out on an outdoor asphalt track, change it to a 235 mm car. CRC as well as SRC has kits to convert the front and back ends to 235 mm.

New pod detail for the JS Pro 200 cars. It will be 3/16 wider on the left side though. Right hand pod in the pic shows the minimized left pod plate.


__________________

JR007

John, you spend far too much time tweaking your designs. You should get a hobby!
Nice looking cars BTW, do you have many people driving them on large asphalt tracks? One day when I win the lottery i'd put the JS10 near the top of the list

John Stranahan

iTrader: (27)

As the tires wear down you use a thinner #4 then #3 spacer to lift the chassis. If you need additional thinner spacer then I use a thick Associated #8 Aluminum Washer. One is 1 mm thick, two gives 2 mm. You may need a short set of #8 x 32 screws with these and may also need to remove one of the #4 suspension mounting screws at the end of the triangular tab on the chassis. You can use a stack of the plastic shims to get heights higher than 5 for uncut tires.
John

JIM1

OK guys, here are some pics of my new JS Pro10.

The car is a real improvment over the standard GenX10. I was having to fight to keep an 8.5 under control before but now I can run a 4.5 even using John's setup which is set mostly for high grip. I have clocked it at 58mph without really trying and that's getting on the power a third way down the straight due to the car feeling a little un-settled before I nail it (something which I need to sort out). Car feels stable at speed, I am using the HMS Group C P-Type body and it fits perfectly.
The track I use is pretty bumpy and medium to low grip and at this time of year is covered in pollen. The car handles the bumps so much better especially through the sweeper and on power, although I have had a problem with the left nerf wing scrapping the ground as a lot of flex is generated using a high downforce body.
Due to the fully dampened suspension it is now possible to hit the brakes pretty hard without it spining out, something that seems to be avoided with standard pans.


I took John's advice and went with the SPX8 as my SXX TC spec died. I was a bit concerned as to how smooth this 1/8th ESC would be as my Losi Xcelorin powering my 5s Losi 8ight is pretty poor at very low speeds (then again, the motor is much bigger and sensorless). I can say that the SPX8 works very well and is just as smooth as the SXX and far easier to set up due to fewer profiles. It doesn't even break a sweat in operation and as John stated before it allows you to concentrate on motor temps.
I have converted the rear axle to Acer Ceramic Nitride Pro Series bearings and diff balls, also using a thrust bearing for increased durability and smoothness and with the lightweight diff rings that John supplies the result is superb.


The only problem I have come across with the JS Pro10 is the scrapping of the left nerf wing going through our sweeper. Bearing in mind that our sweeper is very bumpy and banked higher than a velodrome it is expected. The body post bolt actually takes the punishment untill there is nothing left but this hitting the ground drastically effects the handling.
My possible cure to this problem is shown in the picture above but I have not had the chance to test it yet. It involves raising the nerf wings up higher using a carbon piece which also adds some support to the nerf wings to stop them flexing as much. The main chassis itself does not drag the track if set to 6.5mm front and 8.5mm rear. The rear pod on worn tyres sits at about 5mm and does not drag.

Regards......more to follow.

NiMo

So can I book you in for the next meeting JIM1 ?

Have to say that after seeing how JIM1 drove with the standard 235 CRC around my track and then to see him drive with this version does show how well the car performs over a standard version.
Our banking may not be steeper than a velodrome, but it is certainly tighter and bumpier, with Tourers running 6mm f and 7mm r, and my 1s 10.5 running 8mm rear just to ride the bumps.

I may have to look in to a 200 version, just a bit wary of the hefty import duty we are currently being asked to pay for items from America.

Have also been looking closly at my F109, not too impressed with it at present so not racing it, but think a similar idea would transform that car and stop this straight line stability problem it has?

JIM1

Haha, yes I'll be there soon. Just need a couple of more test outings to stop this nerf wing problem.

By the way Nimo, I thought I would softern the rear a little to see if rear end grip improves as our track is quite dusty at times. I am finding the corner before the main straight very slippery. The springs that John supplies are quite hard so I have changed them to some associated golds that are a lot softer. I may have to insert some rubber 'o' rings or fuel hose to the shock shafts to act as a bump stop to stop it bottoming out in the fast corners though. These springs may be too soft but we will see.

By the way, if I remember correctly, import cost was around £60 for John's car.