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Old 04-11-2008, 04:50 PM   #1996
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Track Report

LRP TC edition vs Novak GTB 4 cell
I moved about 2 ounces of weight (the speed control) off the chassis and onto the rear of the pod in the last post. The immediate result was oversteer, much like a front v8 engine sedan with too much weight in the front will understeer and like a rear engined sedan like a corvair will oversteer. I moved the speed control back to its original spot but had to put it flat to clear the links. This speed control is just a bit wider than an LRP TC edition. It ended up heavy side down to keep from resoldering the lead wires. The car lost not a bit of weight going to the GTB 4 cell compared to the LRP TC edition (less fan and switch). Very similar 12 gauge wiring on both.

Some of the oversteer was the result of removing some reverse wedge. When I took the weight of the left rear of the chassis, I moved that shock collar up to level the chassis again. When I put the speed control back I had to add this reverse wedge back in.

Punch was very good = to the LRP TC spec.

The COT body by McAllister tuned up with a bit larger wing than I was running. It felt fast. I will try it in the first heat tomorrow.

John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-gtb-4-cell-installed-frame.jpg   Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-mcallister-cot-004.jpg  

Last edited by John Stranahan; 04-11-2008 at 10:19 PM.
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Old 04-11-2008, 05:43 PM   #1997
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I'm guessing that's an off-power oversteer? Is it understeering on initial entry?
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Old 04-11-2008, 06:00 PM   #1998
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Initial and mid corner over steer. I am at 90% throttle at mid corner. It was undrivable in the slightly dusty conditions. The oversteer understeer balance was partially restored when I moved the speed control back forward and then fully restored when I wound my left rear shock collar back down to level the frame. I used the well balanced Protoform dodge charger body for this test. I do note that the effect might be exagerated by moving the weight from the sprung frame to the unsprung rear pod. This is what required the big shock collar adjustment.

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Old 04-14-2008, 12:30 AM   #1999
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Race Report-The 3-link won again. This time the win had to do with whose car was the most stable to condition changes. We raced at night and some dew was settling on the track. Some cars became unstable and started to spin. The 3-link remained easy to drive and had no errors.

McAllister COT vs Protoform Charger HD
The lap time record was not printed out so my data during the race is a bit sketchy. The lap times were being called out before the race though. This allowed me to do some quick testing. I had tuned the COT body so that it was very drivable by using a large wing and small spoiler. In spite of this the car had more yaw or a higher drift angle in the corner than normal; the rear end tended to slide out a little more than normal before it took a set and a small amount of rear tire chatter resulted. Anyway I ran some very steady 4.4's with it. I put on the protoform charger body and clicked off steady 4.3's with some 4.2s. There was no rear tire chatter no large drift angle. OK I am satisfyed now that I should use a high downforce body.

Dual Dynamic Unequal Length A-arms
Time for some more tinkering. I installed one of my unequal length A-arm front suspension on the car. Now this changed a bunch of stuff, but it will be interesting to get lap times with it. The wheel base is about 1/4 inch longer by chance. The camber is set only approximately. The roll center is low. I have raised the suspension up with the normal CRC 1/4 inch blue shims to have a very low chassis for flat oval use. I use a higher ride height on the road course because there are more bumps.

This type of suspension has worked the best of those I have tried on the road course. An interesting thing happens. The tires develop a wear pattern of ripples lined up with the circumference after only a few laps. This tells me the tires are scrubbing less accross the track. As the tire goes up into bump the unequal length arms allow the contact patch to remain in approximately the same place left to right. In other words the tire is not scrubbed accross the track when a bump is encountered. The car also feels more hooked up. Lap time on the big course improve about 1.3 seconds in combination with a 3-link rear suspension. I will see if there is any advantage on our relatively smooth oval.

I gained only .8 ounces. I am at 41.3 ounces now. This would be a good weight to race. Just over the minimum.
John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-unequal-length-arm-003.jpg  

Last edited by John Stranahan; 04-14-2008 at 10:24 AM.
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Old 04-15-2008, 07:11 PM   #2000
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track report
The track was very dusty.

200 mm 3 link with Dampened Unequal length A-arm Front End.
The front end made a lot of changes to the car dimensions. Firstly it was about .4 inch longer. (Also 200mm wide in front up from 185mm).This resulted in mid corner oversteer. The wing had moved relatively forward as I kept the front tires in the same place on the body. I moved the wing back and added a little more reverse wedge by lowering my left rear shock collar (note that on a standard pan car you do this with the right rear tri shock). Mid corner and corner entry were now very good.

I had a recurrence of corner exit hooking. This is a problem for a lot of the cars and kept second place from the win last week. I added a little more left rear steer (I rotated the rear pod counter clockwise when viewed from above.) I added 1 click of right steering trim.

I drove about 5 minutes from ground level and noticed that the corner exit hooking dissapeared. My theory is that the improvement has something to do with being able to see the front wheel position. You wait just a few milliseconds more until the front wheel is straight before you apply good throttle. So it might be as another racer noted that a slow return of the servo has something to do with this problem. He had an adjustment on the radio to speed this up. Our driver stand is quite high and has no setback from the track so the front wheels are much harder to see from the drivers stand.

The front suspension is showing promise. The car is more supple and easier to toss around without error. This seems to be desirable in weaving through the wrecks and making passes.

Wide Pan Car
I drove the wide pan car on the oval with a Novak 6.5R motor (6 cell). I had done this previously with the narrow pan car. I seemed to get much better antisquat effect and better forward traction with the narrow car. I don't attribute this to the width. There are some differences in the 3 link setup in both cars. Primarily the rear shocks act on the rear of the pod on the 200 mm car and they act on the front of the pod on the 235 mm car. During acceleration the front of the pod will tend to rise as the pinion wants to climb the spur; This makes the front of the pod rise and the rear fall or torques the pod. This torque is tranlated by the 3-link to lift the rear of the chassis which loads the tires by opposite reaction. On the 200 mm car this movement is aided by the springs being on the back of the pod where on the wide car the springs hold the front of the pod down. I am going to make mods to the wide car to see if it improves. Note that these effects are much reduced, but not eliminated, with stock motor and 4 cells. My car is often better when traction is just a bit lacking.

Pics: Wide car on left, 200 mm car on right
John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-three-link-6-cell-nimh-resized.jpg   Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-3-link-oval-car-rear-end-002.jpg  

Last edited by John Stranahan; 04-15-2008 at 07:32 PM.
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Old 04-15-2008, 07:48 PM   #2001
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john did you race the wide car on the oval with the batteries like they are in the picture???
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Old 04-16-2008, 12:08 PM   #2002
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Mason. No, that was just an interesting old photo set up for road use and 6 cell NiMH. Here is a more recent shot set up for oval. There is actually room for two of these 5000 mAH LiPos in the car. I would call this a partial conversion to oval as I could add a tray on the left side to hold the electronics for a better left preload. Laps on the wide, 6.5 brusless LiPo, car were about .5-.6 seconds faster than the 200mm wide, 4 cell 13.5 brushless, car (4.3 seconds) I could lap a slower car about every 3 laps. Interestingly on the oval I could run pink fronts and profited from the extra steering. On the road course pink fronts just wear too fast because of the high speed sweeper.
John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-wide-pan-car-oval.jpg  

Last edited by John Stranahan; 04-16-2008 at 12:20 PM.
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Old 04-19-2008, 09:50 PM   #2003
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Front suspension (on the oval) Race Report
I have written about this particular front suspesion previously as I had it on a road car. Now its on the oval. It has an angled front coilover shock and twin moving A-arms. Here are the particulars. I set my personal best and track record qualifying round increasing my previous best by 2 laps. The best laps were on the order of .050 seconds each, but we run 55 laps so this adds up to about a 3 second advantage. This is not the only advantage though, for I improved two full laps, or about 8 seconds. The difference is the steering is more precise and abundant now. I could steer closer to the boards than ever before. As there are several dual arm suspensions for the front of the pan car discussed earlier in the thread that are available, I don't think I have an unfair advantage. I'll see how I do at least for a few weeks. The car is now right at 41.1 ounces so you can have your cake and eat it too. There is no weight penalty. The CRC Battle axe looks mighty inviting though. They should send me one to test.

I may be ready for a new NiMH battery already. They don't hold their capacity well at all. Although the average voltage still is good it is not like running on the high voltage of a pack early in its discharge cycle.

I helped tune Josh's L4 a bit. It was pushing. Here is what we did. We took off a little of the left down tweak, what I call taking off reverse wedge. You do this with the right rear shock collar. You basically lower the battery back down a bit. We lowered the wing angle just a bit for a little less rear downforce. Then the front suspension felt a little gritty by hand going into full bump. We removed and polished the pin. It was still straight. He took the track record briefly in the second qualifyer and had fast lap briefly. Maybe I should quit helping him. I regained fast lap in the 3 rd qualifier.

The main
I tightened my diff just a bit, I wiped off the tires which I usually just do on the track rather than in the pits. The solvents are good for the track but no so healthy on a pit towel in your bag in your room. I used a paper towel. I took my normal three lap warmup. I was determined to get a quick start. I have been losing half a lap here being catious, which comes back mighty slow. All was good. I started first. I had a half lap lead on second and came onto lapped traffic on lap 23. One good pass. And then I came upon a cluster of 5 cars. We went around the turn 3 wide just in front of me. Two more in front of them. I swear that was everbody but Mike D. who was in second. I saw a gap. I took it. I was even with their front bumpers (and a lap ahead and had anounced leader coming; who cares). They slammed me hard from both sides and shot my car up into the air and it landed upside down and broken. Such excitement. Mike D. Headed for the smoke and made a clean getaway.

john

Last edited by John Stranahan; 04-20-2008 at 10:06 PM.
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Old 04-20-2008, 01:04 AM   #2004
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Quote:
Originally Posted by John Stranahan View Post
Front suspension (on the oval) Race Report The CRC Battle axe looks mighty inviting though. They should send me one to test.john
When they do send me the instructions. I have the car and nothing else. Been asking for 3 weeks now.
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Old 04-20-2008, 02:56 PM   #2005
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There are some pictures of the CRC Pantoura earlier in the thread. This should help you out with the center pivot which may be the same on this new car. You may be able to assemble the rest of the car by looking at photographs of it ad the 1/12 car on the CRC web site. Anyway good luck. Maybe when they release a volume of cars on April 27 they will have instructions availble. When I posted my pics there were guys able to tell me when a washer was misplaced. I made corrections and reshot the pics.
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Old 04-20-2008, 04:39 PM   #2006
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Quote:
Originally Posted by John Stranahan View Post
There are some pictures of the CRC Pantoura earlier in the thread. This should help you out with the center pivot which may be the same on this new car. You may be able to assemble the rest of the car by looking at photographs of it ad the 1/12 car on the CRC web site. Anyway good luck. Maybe when they release a volume of cars on April 27 they will have instructions availble. When I posted my pics there were guys able to tell me when a washer was misplaced. I made corrections and reshot the pics.
John
Thanks ... The front end is the same as my GenX so I followed those directions and the shock setup it the same. I guess once I get it on the track it's going to be trial and error ... Oh well
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Old 04-23-2008, 12:18 PM   #2007
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Here is a link to the GenX-10 manual from CRC. There is a link on their web site now in the tech section

http://www.teamcrc.com/crc/downloads/manuals/GenX10manualcomplete.pdf

Wide Pan Car-It turns out that the wide pan car with the 6.5 was being bothered by a layer of dust in a couple of sessions. The wind has died down now and forward grip is much improved. Same as the narrow car. I will not make any modifications.
John

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Old 04-24-2008, 06:47 PM   #2008
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I aquired a couple of new (to me) products to test. Jev UK had reccomended some RW pinions. I saw them available at Lefthander-RC.com so I ordered a couple. Now they were not what I expected but look to be the lightest Aluminum hardcoated pinions available. (I thought I would receive steel tiN coated pinions) Here is a pic with a PRS gear at top left, a couple of Robinson racing Pinions at top right and the RW pinions one up one down at the bottom. The numbers are stamped large by using both sides of the small rim. I like that. The dish is as much as can be taken out to make it light. I'll test the hard coat next race. The black hardcoat on the Robinson racing or PRS spurs last only one full race, then the teeth are worn and silver colored on our outdoor track. If you are going to reduce rotating mass the motor pinion is where you do the most good. It is the sum of these tiny improvements that make your car just a touch faster than the other guys in stock and superstock.

Josh had good luck with BSR tires our last race. I bought a set in pink front and pink rear. The rear measured 2.400 and the front 2.425 inch. Thats a good diameter for our track. The larger tires get more traction when the track is a little on the rough side.

The GRP tires on the yellow wheel are becoming unavaialble. A similar tire (same foam and manufaturer) on an orange wheel is available from RC4less.com
These tires measure about 2.5 inch when new.
john
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-r-w-pinions.jpg   Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-bsr-pink-rear-resized.jpg  

Last edited by John Stranahan; 04-24-2008 at 11:23 PM.
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Old 04-25-2008, 03:58 PM   #2009
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Exciting things may be happening soon we will see.

More pics and features
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Old 04-26-2008, 04:24 PM   #2010
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is this the right truer adapter to go with the bsr/jaco tires? same adapter to cut front and rear?

http://www.integy.com/cgi-bin/webc.c...=1782&p_catid=
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