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Old 09-11-2006, 04:44 PM   #91
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thanks

3rd Test Session
The track had a recent heavy rain. I vacuumed water before the start, so the track was very green.

Good news first. I had the car completely hooked up a couple of times, but only for about 6 laps in a row and then the tire pookey effect wears off. I treated front and rears. This tells me the mechanical setup is at least close to right. I had good turn in, good mid corner, I could apply decent power out of the corner, great speed on the straight good balance on the high speed sweeper. Now if they treat the track with sugar water I am sure this is the way the car will handle. I have had the touring car handle like this also but only on a well blue grooved or sugar water treated track. One of the good runs was with white label can Paragon and then Coppertone. One was with the old wintergreen heavy black label can Paragon. The heavy wintergreen Paragon is no longer available.

I had a good range of tire hardness at hand today so I did a series of test to eliminate the on power sudden oversteer 2 -3 feet out of the corner. Now as it turns out the problem gets worse as I increase the hardness of the front tire from pink to magenta to purple with white rears. This tells me what is happening is the fronts are unloading and losing their side bite. The outside rear is naturally overloaded on corner exit and is pulling harder with the outside wheel producing torque steer. The fronts need to be planted to fight this. It's like I need more front droop or softer engagement of full droop on the front. The soft treated tires front and back eliminates the problem but only for six laps.

I had some bounce on the straight where the front wheels would pull up and the car would go a good distance before they returned. I moved the black wing forward another 1/2 inch so it loads the rear but does not tend to unload the front as much.

Best tire combination I think is going to be pink rear and magenta front on this track as the white rear looses its grip too soon on a run. I got rained out before I tried it again.

I went softer on the center shock and oil. Stiffer on the side shock springs. There was no noticable change. I could not make a big change softer though.

I went from 6.92 to 6.42 overall gear. This was an improvement on corner exit (softer) and on the straight (faster speed and earlier hookup).

Last edited by John Stranahan; 09-11-2006 at 10:36 PM.
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Old 09-11-2006, 05:25 PM   #92
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Try using more traction compound. Really saturate the rear tires. The suntan lotion over the traction compound really boosts its longevity. Thats what we do to have consistant traction for 8 min on asphalt in 1/12th.
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Old 09-11-2006, 08:25 PM   #93
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This Thursday I plan to test the 1/10 Speedpec pan car from SpeedMerchant. I plan to test it with my Novak 4.5R, w/ Lipo, which is what I normally run TC with. However, maybe the gearing should be different than TC. What should I set it to? In TC I run 9.5-9.75....
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Old 09-11-2006, 10:23 PM   #94
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Adrian-Thanks.

yyhayyim- Two of us on this thread are using the 4.5 motor. I have mine geared 90/14 (6.42 overall, 29.7 mm/rev) with a 2.40 inch rear tire. This felt very good today. Azmio runs 6.3. Give us a report.

I made some mods to the car to give me more articulation of the pod. I adjusted the height of the football to make the chassis flat at my ride height. I used one nut and one .030 inch washer under the football instead of two nuts. The stock football spacing had the rear pod plate and motor higher than they needed to be. I eliminated any posibility of binding at this new location of the center pivot by beveling the chassis parts in appropriate locations. I increased center shock oil to 40 for the next test. This is all an attempt to eliminate the corner exit spins. I'll see next test session. The reason for these mods is that I think the car is lifting the front too much or too suddenly on corner exit. I can put things back where they were if there is some devious reasons for the stock location.
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Old 09-12-2006, 09:35 AM   #95
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We actually knew the amount of time (and, thus, the number of heats) that it took for our ZipGrip to soak in enough to last the 5 minutes of a race. . .something like 20 minutes. (could never remember so always asked MarkA. . . LOL)
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Old 09-12-2006, 07:16 PM   #96
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Pinion Wear

When you run a high RPM motor in these pan cars you are pretty much stuck using a small pinion. My 13 tooth pinion was short lived from wear. It is a hardcoated aluminum Robinson Racing Gear. Steel would be a better choice. Now the main problem causing this wear is evident in looking at the wear pattern on this 13 tooth gear. The spur gear is not in good alighnment. It wobbles like a swash plate. The edges of the Nylon gear ate up the pinion. There are some shims made for an Associated TC3 tranny that can be used to shim out some of the wobble without affecting diff action. They come in .003 thick x 3/8 x 1/2 inch. I used a couple in the center before I installed the spur. Play and wobble are much reduced. The link has a photo of the shim kit.

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXNZ97&P=7

Front Brace

I thought that on my bumpy track it might be helpful to have the front suspension springs actually compress a little with car weight to give me some droop. As delivered the main flex is the lower arm on the 8 x 32 chassis bolts. The .020 spring is so stiff that I think it only gives on very hard bumps. I installed some lighter springs and a cross brace that I have seen on several cars. I'll report on this later. I now have about 1 mm of droop on the front suspension with the body on. None with body off. Might have too much steering I'll see.

Smoking Motor.. - Still could not find a P-dub racing thrust bearing. Here is a link to a pdubracing site. http://www.pdubracing.com/products.htm
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-front-cross-brace-resized.jpg  

Last edited by John Stranahan; 09-12-2006 at 09:20 PM.
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Old 09-12-2006, 08:42 PM   #97
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Quote:
Originally Posted by John Stranahan
Front Brace

I thought that on my bumpy track it might be helpful to have the front suspension springs actually compress a little with car weight to give me some droop. As delivered the main flex is the lower arm on the 8 x 32 chassis bolts. The .020 spring is so stiff that I think it only gives on very hard bumps. I installed some lighter springs and a cross brace that I have seen on several cars. I'll report on this later. I now have about 1 mm of droop on the front suspension with the body on. None with body off. Might have too much steering I'll see. http://www.pdubracing.com/products.htm
With the softer front spring you may find you have bad understeer on fast corners as the spring may go solid when it loads up, I had that problem in my F1 car.
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Old 09-12-2006, 10:37 PM   #98
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I use steel pinions. I am yet to wear one out.
Indeed, the alu pinions simply wear too fast.

A 0.018" front spring is what I use most of the time. Smooths out corner entry, but increases mid-corner steering.
Go any softer and you get into troubles.
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Old 09-13-2006, 08:42 AM   #99
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John, the thrust bearing is not from Pdub, don't remember who... But if you search the 12th scale thread you'll find a link to a HPI bearing that will work fine with your stock cone, turned around... hahaha...
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Old 09-13-2006, 09:30 AM   #100
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I bought and used a thrust bearing for about 6 months and could never get it tensioned properly. It worked PERFECTLY on my 1/12th, but just wouldn't work on the 1/10th. I tried everything I could think of - ran it dry, ran it with some light lube, ran it with some good goopy grease, ran it tighter, ran it looser, cleaned it every single run, every second run, every third run, etc. I might get a single good run out of it, and then it would just be inconsistent.

It was strange - it would feel SWEET. . .it would work GREAT. . .but then it would go "funky" - it would unload or it would stick. . .it was just inconsistent and I THINK, based on 6 months of fighting it, that since it's so exposed AND since the rotating mass is so much bigger than with the 1/12th, that when stuff gets in there (as it inevitably does) it causes inconsistencies.

So - my advice - don't get your hopes up. I pulled the thrust bearing and went back to the cone washers and was IMMEDIATELY consistent again. If it works for you, cool. If it doesn't. . .don't get disappointed.
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Old 09-13-2006, 07:01 PM   #101
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Thanks for the posts guys. I read every word. I am going to blow off looking for the thrust bearing. Mine is actually working well. I do have some new blue stuff coming.

The track was clean today. I had 3 other gas guys running but they did not put many laps on so the track was still pretty green. My previous best setup was white rear, pink front, White label can Paragon and Coppertone.


Current Setup

Good News- On my last pack I was able to run 4:45 before the first spin. I had reasonably fast lap times to start with with some easing up about the 2.5 minute mark.

Here is the current setup.
Center Spring up one size to 15 lbs to keep the chassis off the ground. Front springs up one size to .022 inch diameter wire to compensate. Center shock oil up 10 to 40 weight to reduce corner exit spins. Rear droop of the pod with the car held in the air increased about 1 mm to 2 mm to reduce corner exit spins. This along with at least half the front tire sauced eliminated corner exit spins for the whole session. These spins were like an ice skater spin. The rear does not slide out. I still had the typical back end sliding out in the corner type of spins when the tire Pookey wore off.

Rear tire-white, sauce 10 minutes with wintergreen rich old paragon followed by coppertone until it turns clear. I'll need to find a more modern formula.

Front tire-Purple sauce inside 1/2 with Paragon for only 2-3 minutes then wipe off.

I did many experiments here is a list.

Front Brace- I kept it after the second test. It seems to keep the camber and toe more consistent from run to run. Did not seem to affect on track performace much, but I don't have to reset the toe as often.

White Label can Paragon
I applied let dry for 10 minutes, reapplied let dry for 10, reapplied let dry for 10 minutes. I could not go wetter than I already use so I went more often. Then coppertone for 25 minutes. I used pink rear and magenta front. This run went about 2.5 minutes before the car started sliding around at the rear. I did not try this with white rear and purple front. It may work better. I need a new session for this much treatment time.

Front Springs
I tried quite a selection of front springs to pin down their effect. It is the typical effect. The stiffer the front spring the less the steering traction. The easiest place to find this out is toward the end of a high speed sweeper turn. I started with .016 inch springs and some droop and ended up with .022 inch springs and no front droop. Corner exit was unnaffected. I had the car too loose on the sweeper with the lighter springs.

Gearing
I am geared 6.0 with a 2.4 inch tire now. This better suits both the 220 foot straight and the infield. Motor temps is 140 F. This hotter temp shows that I am starting to hook up better. Everyone remarked how fast the car was.

Diff
I had a fairly loose diff for the best run. I had the spur off for a look. The TC3 shims seem to be doing their job without any problems.

Saturday Jeff promised us a sugar water treatment to the track if the weather permits. The car should be ballistic then.

Problems that remain. I need the car to handle better when the sauce wears off, so that I don't spin out so easy. I might need to run with dry tires to do this like Pro-10-Holland does on occasion. I'll bring the Jack the Gripper the next session.

Battery Brace- Pan cars shake the battery up and down quite a bit more than touring cars. If you are running a soft sided pack it might be better to use more foam and full length braces to support the sides to prevent wear to the shrink and damage to the battery. Strapping tape for each run would work also. Note that I also reversed and lowered the center shock to improve articulation at the rear and lower the center of gravity.

It would be nice to have a car with lateral battery adjustment feature for good weight balance.
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-battery-brace-resized.jpg  

Last edited by John Stranahan; 09-13-2006 at 10:55 PM.
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Old 09-13-2006, 08:45 PM   #102
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Hey John, Have you noticed any tempature difference with the new rotor in your brushless? I'm not sure if you have had a chance to compare the two in equal chassis.

As always, great writeups!!
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Old 09-13-2006, 09:12 PM   #103
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Serpits-I have not tested the rotors back to back. I have had two of the earlier type rotors get magnetically weak from use (100 runs or so) and running on the hot side. When it gets too weak the hall effect sensors quit sensing position properly and the speed control goes spastic giving you full throttle at inapropriate times. This was corrected with a new rotor from Novak. This sintered rotor should keep its magnetism much better and it is also stronger magnetically. It has lower rotational inertia. You should see that puppy accelerate at mid straight.

Bodies
Here are a couple of Serpent Bodies that look interesting. I have a report that the Serpent Lola is a bit heavier duty than the Protoform Lola. There were two Protoform Lola bodies at the track today. Don't like the look on 1/10 scale gas cars too much as the tires are too small for the huge slab on the rear sides. Might look better with the slightly larger pan car tire. Fresh track report in my previous post.

Serpent
Lola
http://www.mytsn.com/products/desc.asp?prid=2271

GTP
http://www.mytsn.com/products/desc.asp?prid=2343

I have located a source for Trinity Tire Tweak but not SXT tire tweek

Last edited by John Stranahan; 09-13-2006 at 09:29 PM.
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Old 09-13-2006, 10:35 PM   #104
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John looks like you're getting this car down!
Have you trid different front tires and their effect on the spinouts?
When your car has a slight tendency to oversteer, your rear traction will wear off. If your car understeers, the front traction wears off first. One thing you could try is to place a few shimms at the front end to make it slightly wider. It is a subtle tweak, but it might be all you need, as you're almost there.
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Old 09-14-2006, 07:35 AM   #105
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Quote:
Originally Posted by John Stranahan
Pinion Wear

When you run a high RPM motor in these pan cars you are pretty much stuck using a small pinion. My 13 tooth pinion was short lived from wear. It is a hardcoated aluminum Robinson Racing Gear. Steel would be a better choice. Now the main problem causing this wear is evident in looking at the wear pattern on this 13 tooth gear. The spur gear is not in good alighnment. It wobbles like a swash plate. The edges of the Nylon gear ate up the pinion. There are some shims made for an Associated TC3 tranny that can be used to shim out some of the wobble without affecting diff action. They come in .003 thick x 3/8 x 1/2 inch. I used a couple in the center before I installed the spur. Play and wobble are much reduced. The link has a photo of the shim kit.

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXNZ97&P=7

Front Brace

I thought that on my bumpy track it might be helpful to have the front suspension springs actually compress a little with car weight to give me some droop. As delivered the main flex is the lower arm on the 8 x 32 chassis bolts. The .020 spring is so stiff that I think it only gives on very hard bumps. I installed some lighter springs and a cross brace that I have seen on several cars. I'll report on this later. I now have about 1 mm of droop on the front suspension with the body on. None with body off. Might have too much steering I'll see.

Smoking Motor.. - Still could not find a P-dub racing thrust bearing. Here is a link to a pdubracing site. http://www.pdubracing.com/products.htm



Sorry wrong company

http://www.slapmastertools.com/
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