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Old 01-29-2007, 06:24 PM   #901
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Inspgadgt-Thanks for the link. I think we have something better in the works.

Unequal length Front A-arm Track Report

Track had medium high traction today after I ran a pack. This was due to a big Nitro race yesterday. It took a little while for my car to clean the rubber marbles off the race line. Then it was really fast. Air temp 50F. No sugar.

Well the last remaining problem with the car is now cured at the higher speed I can develop with the 3-link rear end and the Novak Velocity 3.5 R motor geared 7.5 to 1. I made it a point to use every lane of the straight. I could accelerate hard from the beginning due to good traction. I attained the best top speeds ever. The car was completely planted on the straight. This is due to the new front suspension with shocks acting more directly on the wheels (like the Corvette). I can use full throttle now. I await a manufactured model of this pan car for sale. I know that some interest has developed at my track. I'll add some more track report detail below.

Front Roll Center Adjustment
On the first pack I had some understeer (push). I removed my ride height spacer under the Aluminum uprights and used the shock collars to get back my 6.5 mm front ride height. This has the effect of lowering the roll center while keeping the ride height the same. I then had steering traction to match the improved rear traction from the high bite track. I actually have a little too much. This along with 20% drag brake unsettles the car just a little entering the hairpin. Now really what I need to do is just start the turn a little later and faster or I can adjust the uprights up a small amount with some of the nice CRC plastic shims that come as a set in various thickness. This was a really easy roll center adjustment to make quickly.

Run Time and Motor Temp
I made two run time tests of the 3.5 R. Both times I went 10 minutes 40 seconds on a single MaxAmps 4000 mA-h pack that was maybe 95% charged . This compares to 12 minutes with the 4.5R using 3200 mA-h under similar conditions. Motor temperature on the 3.5R was only 130F after one of these runs, so I think it could be run continuously at 50F air temp.

Camber curve
After my first 11 minute run, I noticed that the inside front tire on the sweeper had a reverse cone on it (pointy side in). This is a first. This tells me that the inside front tire on the sweeper is now making contact and contributing to cornering on the sweeper. This partially explains my improved cornering traction there. This is due to the cars more supple suspension. I reduced the inside tire camber from 2 to 1.5 degree as a result. The outside (laden side) tire was worn very evenly with 3 degrees of static camber. This is a first as well as it usually cones pointy side out even with 3 degrees static camber. This tells me the tire has a better camber curve or is more rigidly supported. I think both are true. Things are looking good.

I noticed Cristian Tabush raced the last big Nitro race. We may get a driving report from him some time on this pan car. Good Finish.
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Old 01-29-2007, 09:06 PM   #902
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Roll Center
I was curious where my front roll center was now. The car has just a tad too much steering. Only took a few minutes to take some measurements and calculate the roll center. The roll center is at -.12 inch. This is below the ground. I can raise it a bit. This will kill a little steering traction. The ground is a nice place for the roll center on asphalt. Here is the input and output of a program that I wrote that will calculate the roll center for a twin A-arm or A-arm plus camber link car. If you would like a copy send me an E-mail to [email protected] It is a Microsoft Excel file so you would need that program for it to work. A private message will not work. I will see if I can make it downloadable later. The graph is also part of the output to visualize the instant center and the roll center. The roll center is where the line from the tire crosses the center vertical line in the center of the car.

Yes this will work on that RallyX car too unless it has struts.
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OK here is a link where you can dowload it directly from the Web
When I dowloaded it it went into quick view plus but I could go from there and save the file for editing by hitting the excel logo at top left of quick view plus. Note that the quick view plus is not able to display it quite right.
Roll Center Calculator

Measurements (inch) Car on blocks wheels off
0.79 Center of gravity height. This value is not used in the roll center calculations, but for roll moment.
0.256 Chassis height on tires ready to race
0.268 Chassis height axles on blocks tires off
6.875 Width of car outer surface of hex adapter to outer surface of hex adaptor
0.332 Camber Link outer hinge pivot center of ball stud horizontal distance from block
1.672 Camber Link outer hinge pivot center of pivot, height above floor
1.8 Camber Link inner pivot horizontal distance to center of ballstud
1.429 Camber Link inner pivot height of center of ballstud to floor
0.222 Outer A-arm hinge pivot horizontal distance from block
0.554 Outer A-arm hinge pivot height of center of pin from floor
2.315 InnerA-arm hinge pivot horizontal distance from block
0.39 Inner A-arm height of center of pin from floor

CALCULATED VALUES

ROLL CENTER -0.12 inch
Roll Moment Arm 0.91 inch
Roll Moment @1.5 g 4.63 pound-inch
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-roll-center-graph002-resized.jpg  

Last edited by John Stranahan; 01-29-2007 at 09:44 PM.
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Old 01-30-2007, 03:04 PM   #903
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Porsche 962

I bought this body which I thought was a Hot Bodies Toyota turned out to be a Hot bodies Porche 962. It is a wide pan body. Wherever there is a shell there is a mold and more can be made. I'll put up a pic when I get it painted. This car was raced at Lemans as a GTP car and also in IMSA. They actually made a road version of it that you could buy and run on the street! Here is a Wikipedia picture from the Porsche Museum. Looks like mine is goint to be the Andretti white. It will be good competition for Tony's 200 mm MoMo (Serpent) Porche 962.

"After a post-'87 "dry spell", Porsche customer Jochen Dauer got the 962 re-classified as a road legal GT1 car under a loophole in the new ACO regulations for the 1994 24 Hours of Le Mans. The Dauer-Porsche 962 took its final overall victory there, surprising the world and proving the viability of the 10 year old design."

John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-porsche-962-imsa-cropped.jpg  
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Old 01-30-2007, 05:42 PM   #904
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Porsche GT1 Wide Pan Body

Here is a pic. It was a good fit. I will have a 2" spoiler chord after I add the spoiler. The color looks a little different up close. I have used a pearl white undercoat. About 1/2 can. This paint is almost clear with tiny pearlescent flakes. It mutes the sprint white undercoat and adds some sparkle outside.
John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-porsche-962-body-001-resized.jpg  

Last edited by John Stranahan; 01-30-2007 at 10:30 PM.
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Old 01-30-2007, 06:15 PM   #905
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Make sure you round off the edges on the tire wheel wells. It helps prevent tires from chunking in a crash.
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Old 01-30-2007, 09:35 PM   #906
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Quote:
Originally Posted by John Stranahan
Porsche 962 Wide Pan Body

Here is a pic. It was a good fit. I will have a 2" spoiler chord after I add the spoiler. The color looks a little different up close. I have used a pearl white undercoat. About 1/2 can. This paint is almost clear with tiny pearlescent flakes. It mutes the sprint white undercoat.
John
very nice John
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Old 01-30-2007, 09:59 PM   #907
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Thanks.

Note that I do round off my wheel arch corners. Thanks for the tip. I usually do a second trim at the track after I listen to the car go around corners and over bumps. Then I round of the corners. I also taper the back of the rear wheel arch back. This keeps it from getting stuck on top of the tire after a rear end collision. I trim the body posts down also.

Rotational Inertia Reduction
My custom 1/10 pan chassis is good now. The new front end is holding up well.
I have done a few other things to make the car faster recently. My diff rings last a long time with the part number IRS 207 carbide diff Balls. $20. I have used the same set of carbide balls for the duration of the thread. I have use a set of stock ones as well. The carbide is just plain smoother. Stormer has these over priced at $40.*

IRS lightened diff rings
Because of the long wear, I ordered a set of IRS 2511 diff rings that have a lightened inner. There are two small ears that grab the D. They have been working well.

Associated Blue Aluminum lug screws
I have also started using Associated Blue Aluminum ASC 5399 4-40 x 5/16 inch screws. The longer length of the stock screw is not really neccesary nor is the weight and strength of steel here. No problems to report. I have about 5 sessions on these screws. They really are lightly loaded due to the large number of screws securing the wheel.

*Note: (No ring sanding is neccesary Just run the car at slow sped for 30 seconds holding one wheel. This puts the nice long wearing groove into the diff ring. Sanding the rings is one of those things that people do that is immediatly undone as soon as the car is run.)
John

Last edited by John Stranahan; 01-30-2007 at 10:38 PM.
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Old 01-30-2007, 10:28 PM   #908
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The porsche body you aquired is actually a porsche GT1 from Hot bodies.
Here's a pic:
http://autopixx.de/autobilder/bilder...rsche-gt1.html
Compared to the toyota GT1 from Hot bodies it has slightly less steering and less overall downforce, good for big tracks.

On the rear wheel screws: I always use 2 aluminum screws instead of 4. This has never been a problem.
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Old 01-30-2007, 10:33 PM   #909
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Nice pic. I lost the label so I had to guess. Now if I had to guess again I would still choose the 962. The body does have Porsche stencilled on the Lexan. I notice the body came with two window masks. I did choose the GT1 window mask. The 962 side window mask is smaller.

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Old 01-30-2007, 10:42 PM   #910
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I see that I am not the only one to have blowover problems. Here is a video of the full size Porsche GT1 having a blowover. Cool video.

I heard that Mercedes had three cars do this in 1999 at Lemans. Two in practice. One did a tripple flip as high as the tree line and landed on the tires during the race.
Here is the video flip video Mercedes 1999

Last edited by John Stranahan; 01-30-2007 at 11:45 PM.
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Old 01-31-2007, 01:21 AM   #911
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Quote:
Originally Posted by InspGadgt
Couple problems with that...first...there was an early gas conversion that did exactly that...used a Kyosho rear end on a pan chassis and front end. We had one at our hobby store and really had a hard time getting it to handle.
What you are talking about is a pan car conversion from a buggy rear end. I had one of those. It was an electric version made by the same people who made the Agitator (very old pan car). Also just because that Kyosho car didn't work well doesn't mean that the configuration would not work. There once was a time where the notion of running a front drive car was an absolute joke until Tamiya made the front drive sedans.

Quote:
Originally Posted by InspGadgt
Second it would be hard to find a class to run it in if you plan to race it.
Why should there be a class existing before there is a car? I thought the idea was to create a new kind of car that would spawn a new class, RWD sedan. In fact that same negative comment was used when TCs, F1s and Minis were introduced and now look what happened?
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Old 01-31-2007, 03:52 AM   #912
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And you see what happened with the popularity of FWD TCs...a few were tried then the whole thing died quickly with the exception of TCS.

As for the class all I'm saying is don't plan to race it until it becomes popular enough to generate a class. Actually there even was an attempt to popularize a RWD TC class by AE with their DS chassis which was an utter flop. They might have caught on had AE used standard sized wheels and bodies...then again they might not have.

Project cars are great and keep the hobby fun and creative...however be realistic in what you expect to be able to do with it. If it's just for fun and driving around where great! But if you want to race it, it's much easier to develop something within current rules (as John has done) then it is to get new classes/rules made up for a new car.
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Old 01-31-2007, 01:15 PM   #913
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Quote:
Originally Posted by John Stranahan
Nice pic. I lost the label so I had to guess. Now if I had to guess again I would still choose the 962. The body does have Porsche stencilled on the Lexan. I notice the body came with two window masks. I did choose the GT1 window mask. The 962 side window mask is smaller.

John
Yes only the canopy resembles the GT1 Porsche, slightly. LOL
I did one in traditional Nissan GTP colors on my first 10th pancar. It did well, only the Toyota was better.
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Old 01-31-2007, 01:56 PM   #914
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Do you have any pics of your x10?

Does it use AE parts and such?
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Old 01-31-2007, 02:11 PM   #915
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he's been posting tons of pics and descriptions of his X10. . . just start scrolling back!

and aside from a few custom parts (which they're working on making semi-production) it's all based on AE or Pantoura. . .
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