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Suspension for road tracks


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Ok, got a chassis sitting on my table, about ready to body up. But, Im trying to figure out what rear suspension would really work best on this thing before it gets covered up. The car is a perimeter car, camaro stub, with a floater 9". Currently it has some sort of double pan-hard rod that runs to a movable center bracket fixed to the rear of the pumpkin. Someone told me its a "jacob's ladder" suspension. Well, I can't find a damn thing about it. The car is going to run in the American Stockcar Challenge, which is a Road course only series. So, I need your thoughts on the best rear "road-course" suspension.

 

I am also trying to find pictures of stock car suspension. There are so many diffrent pan-hard variants and wedge variants (how they are installed), I would like to see how people are using these things. Can anyone help me in that direction? I can't seem to find pictures!! :ph34r:

 

Any help would be appreciated. I was too spoiled on all the IRS roadcars, now this stockcar stuff has me second guessing setups.

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For road courses I feel the preferred method to hold the chassis directly over the rear end is what is known as the Watt's linkage.

 

I does pretty much the same thing as a Panhard bar, but it does a better job of preventing relative movement side to side. A Panhard bar is pivoted at both the axle housing and body forcing the axle to move in an arc during body roll. As we all know, this movement introduces a lateral component into the vertical movement of the axle housing. The Watt's linkage, however eliminates this lateral component.

 

The Watts linkage consists of two links mounted at each side of the chassis with Heim joints and attach to the ends of a short vertical bar whose center is mounted at the center of the third member. This center mount is free to rotate. It's really like two shorter Panhard bars, both of which rotate around a common location. But unlike a Panhard bar, the unique center mount allows each side to cancel out the negative effects, thus keeping the chassis from any lateral movement.

 

In circle track racing we are not as concerned with keeping the chassis centered. In fact, since we are only turning left, we can arrange the Panhard bar to pull the chassis in a direction we feel would benefit the handling during body roll.

 

Some time ago, I lifted this diagram from some website (can't remember which one at the moment.)

post-3-1179259861_thumb.jpg

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That is the exact linkage that is under the car now. SO, looks like I got lucky! Someone told me the wrong name for it apparently. Now, there are adjustments to move the center piece up and down on the pumpkin. Do you know which direction has what effect on the car?

 

Perhaps you guys have a suggestion on shock bound and re-bound numbers for my application? I dont have a shock prefrence (although I typically run penske), but we are restricted to under $400 a shock and no external resevoirs.

 

Thanks

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Raising the mount will induce oversteer and/or reduce understeer. Lowering the mount will induce understeer and/or reduce oversteer. Basically, you are raising the rear vertical roll center by raising the mount and lowering the rear vertical roll center by lowering the mount - very similar to a Panhard bar in that respect.

 

There are too many variables to discuss shock valving with any degree of certainty. Shocks can be used as a crutch for handling problems or they can enhance the handling of a car with no handling problems. I try to convince people to start out with 50-50 shocks until they have eliminated all the handling problems and then talk to a shock professional about how their shocks could enhance your performance.

 

Nick

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Nick

Why arent you out there with a big name team? We all love local short track racing but come on.... You could be having a lot of fun and making some $$ at the same time.

 

Because he would have to give up all of us and his immensely rewarding career as the resident dletemeister.

gotcha nick. ;)

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Nick

Why arent you out there with a big name team? We all love local short track racing but come on.... You could be having a lot of fun and making some $$ at the same time.

It's not about the $$.

 

I briefly worked as a suspension consultant with a team or two in the southeast back in the late 90's, but I quickly vowed that I would NEVER take a full time job with a Busch or Cup team. 80 hour work weeks and total dedication (forget family life, church involvement, etc) is the name of the game. Nice pay, but the sacrifice was more than I was willing to make.

 

Rather, it's about the satisfction I get working with people to get their cars handling a bit better than they did before. There's a great deal of satisfaction in seeing a few of my racing suspension seminar students run up front for the first time. It's even more fun to work one-on-one with a team that is sincerly trying to learn about racing in general and suspension in particular. Some of you have probably seen me poking tires with some lesser-known teams at various tracks. To me, that's where it's at.

 

Nick

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So how many beers would it take to get some consulting in Houston. I think I can afford a case or 2!!!

 

Arthur

 

Is this one of those 80 hours per week deals for a sx pack of Shiner Bock? LOL

 

Nick

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