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Old 11-24-2010, 01:16 PM   #1711
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A single side shock is my preferred setup. I put an RC 18T rear shock on the left side. Works great outdoors.
John
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Old 11-28-2010, 01:17 PM   #1712
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Carlos-Congrats your new Scimitar Pro 10 is on the way to the Dominican Republic. Hope to see some pics or reports after you are up and running.
John

Here is a link to the new Scimitar.
http://www.rctech.net/forum/7867739-post1655.html
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Old 11-28-2010, 05:11 PM   #1713
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John, I have a question regarding your pan car designs: Every pan car I have ever seen has a center oil-filled shock that connects to the rear pod; yours does not. Instead you use what looks like a turnbuckle shaft with ball cup ends.

This would appear to eliminate forward/backward flex of the motor pod and main chassis plate that all other pan cars share in common.

I would like to know the purpose and reasoning behind this. Personally I have always felt that having a center shock was unnecessary, but I would like to know why you eliminated it and replaced it with the turnbuckle shaft.

I apologize if this question has already been asked before.
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Old 11-29-2010, 08:52 AM   #1714
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Hi John, I am happy to see that my friend Carlos Di Vanna bought one

Scimitar.

I will help him to set the car right for our track and to keep you posted. José Álvarez.
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Old 11-29-2010, 09:45 AM   #1715
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Quote:
Originally Posted by Enforcerman View Post
John, I have a question regarding your pan car designs: Every pan car I have ever seen has a center oil-filled shock that connects to the rear pod; yours does not. Instead you use what looks like a turnbuckle shaft with ball cup ends.

This would appear to eliminate forward/backward flex of the motor pod and main chassis plate that all other pan cars share in common.

I would like to know the purpose and reasoning behind this. Personally I have always felt that having a center shock was unnecessary, but I would like to know why you eliminated it and replaced it with the turnbuckle shaft.

I apologize if this question has already been asked before.
Goto msg 999 in this forum. Its pretty much where john started posting about his rear suspension. His forum makes for a good read if you have the time. Lots of good info.

Shawn
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Old 11-29-2010, 10:31 AM   #1716
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Quote:
Originally Posted by Enforcerman View Post
John, I have a question regarding your pan car designs: Every pan car I have ever seen has a center oil-filled shock that connects to the rear pod; yours does not. Instead you use what looks like a turnbuckle shaft with ball cup ends.

This would appear to eliminate forward/backward flex of the motor pod and main chassis plate that all other pan cars share in common.

I would like to know the purpose and reasoning behind this. Personally I have always felt that having a center shock was unnecessary, but I would like to know why you eliminated it and replaced it with the turnbuckle shaft.

I apologize if this question has already been asked before.
As Shawn said, this thread is all about John's rear suspension. . . but to sum it up, it's a four-link suspension using two vertical shocks near the rear axle.

There are three trailing arms and a lateral (pitman) arm that provide close to optimal suspension movement (you want up/down action, not pivot, preferably) along with excellent damping characteristics due to the two shocks. . .
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Old 11-29-2010, 02:32 PM   #1717
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Jose-Look forward to a report. E-mail me if you have setup questions. [email protected]

Boomer, Shawn68z. Thanks for the helpful posts.

Enforcerman-I thought I would add to Boomer's post.
When I started running pan cars on a big bumpy track, It was plagued with severe problems. At about 52 mph the cars would fly on a bumpy straight. Note Mercedes Benz and a few other marques had a similar problem with their full size GTP cars a decade or two back in time. The Problems was so severe it caused cancellation of the pan car nationals one year and then the class was not revived as a national race. The problem was the undampened front suspension was inadequate. The car also lacked traction on the straight. You could hear that 3.5 brushless motor screaming down the straight but a lot of wheel spin was created over bumps. The rear suspension was inadequate.
So what I have done is adapt the latest solid axle race car suspension to the rear. In the states it is commonly called a 3-link, the suspension does have a fourth lateral link that prevents side to side motion. It is often called a Panhard bar. Examples can be seen on the latest Ford Mustang Also on full size trans Am race cars when they last raced. Instead of a hinge in the middle of the car (the center bends down when you hit a bump) You now have a floating pod that moves up and down on the links. Wasted rotating motion of the motor can and pod are eliminated, the suspension is more supple. It has more forward traction due to generous antisquat. It is more supple so it has more cornering traction as well. These last two items are very important and make the car more drivable when it is slick out. The body no longer rattles when you go around the track giving a better driving experience. The car is a remarkable 4 mph faster on that bumpy straight. 1.4 seconds faster on lap time.

At the front I have simply rearranged CRC parts to give a Dual A-arm Dampened suspension. Some of the 1/12 pan car companies are following suit as we speak. This suspension is much preferred on a race car instead of a McPherson Strut. The latter is raced when the rules demand it. What we have on pan cars is an inverted McPherson strut. My experience tells me it scrubs the tires badly going up into bump. This causes a loss of traction and feel compared to the dual A-arm. The dampening solved the flight issue. A front diffuser helps even further.
Attached Thumbnails
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-2-js-pro-10-dual-arm-suspension.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-4-js-pro-10-rear-panhard-bar-view.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-porsche-962-body-001-resized.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-front-diffuser-001.jpg  
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Last edited by John Stranahan; 11-29-2010 at 02:45 PM.
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Old 11-29-2010, 04:21 PM   #1718
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Thank you for explaining it to me; I kind of figured that was the reason, but wanted to confirm.

My next question is, since I race a 1/10 pan car on a carpet track that has no bumps and is very smooth; what would happen if I replaced my center shock with a turnbuckle/strut like the one on your car John, since it seems to me that on a smooth carpet surface you don't even need the fore/aft pivot movement of the rear pod? In theory, the side to side movement properly dampened is more important on a carpet track.

What are your thoughts?
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Old 11-29-2010, 04:56 PM   #1719
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Quote:
Originally Posted by Enforcerman View Post
Thank you for explaining it to me; I kind of figured that was the reason, but wanted to confirm.

My next question is, since I race a 1/10 pan car on a carpet track that has no bumps and is very smooth; what would happen if I replaced my center shock with a turnbuckle/strut like the one on your car John, since it seems to me that on a smooth carpet surface you don't even need the fore/aft pivot movement of the rear pod? In theory, the side to side movement properly dampened is more important on a carpet track.

What are your thoughts?
It's more than just a pivot point - he redesigned the whole thing.

If you go with a solid link, you will lose any give at the rear (except side to side) and that will likely cause traction problems since you will lose any front-to-rear weight transfer during braking or acceleration. . .
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Old 11-29-2010, 06:36 PM   #1720
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Enforcer-ONe of the key differences between a standard pan and my 3-link is that I do not use a center pivot or T-plate. That allows the pod to move up and down. If you use a solid top link and have a center pivot then you are binding the whole thing up. You will lose traction.
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Old 11-29-2010, 08:36 PM   #1721
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Understood. Thanks.

I do like the design of the rear suspension on your pan car; it's the solid rear axle design that actually makes sense to me given the fact that ROAR and other sanctioning bodies mandate that pan cars have to have solid rear axles.

Wish they would change that rule.
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Old 12-01-2010, 06:39 AM   #1722
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John, I have built a temporary proof of concept car using my L2O and made a 3-link just like yours, My question is about rear springs and static weight. How much left side weight % did you have in your oval car and what were the rear springs? I know you made some special springs for your other on road cars but did you use one of them on the oval car? If so can you buy just the springs on your website?

Thanks in advance
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Old 12-01-2010, 02:29 PM   #1723
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slsspark-congratulations. Send us a pic. I believe that I ran 2 lb springs at the rear but we were using NiMH which are heavy. I was able to achieve a full 12 oz preload on the left rear by having the right rear spring almost unloaded at normal ride height. I don't think you can achieve that with LiPo. I ran a few tests with LiPo and the new car. I was quite satisfied, but never put the rear on two scales. I might try the Gold Associated RC18T springs due to the lighter load. They are about 1 lb/in. I do also sell a custom made 2lb/in spring from the Web site.
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Last edited by John Stranahan; 12-02-2010 at 01:05 PM.
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Old 12-01-2010, 08:01 PM   #1724
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Hi John, Carlos Di Vanna is going to send you an email asking for help to track his car. There is no info in USPS tracking system and he had problems before with Pay Pal in the sense that they include the name Dominican Republic together with the Miami shipping adress and it is confusing.José Álvarez.
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Old 12-02-2010, 01:59 AM   #1725
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slsspark

If you go back a few pages and take a look at SWT posts. He is using my Stranahan car at the TQ carpet track here in SoCal. It has been very interesting trying to get the car to work on carpet.

I will try to have SWT post here with the adjustments he made at the last race. It has been an interesting time.

Steve
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