Ok, Matt, I see your point. Are you talking about repeatability and hysteresis that don't show up on a dyno plot?

 

I'm not talking about consistency - I'm talking about design - we all know that what shows up on an FV curve is only part of the game.


Here's just a little part of it.

Moton uses Bypass and Blow Off valves to mitigate the transition from Low to High Speed damping. They then use multiple levels of shim stacks with spacers and very low preload. They use thicker shims to get the high speed damping, instead of preloading thinner shims. The shims have a progressive spring rate, if you preload them - they lose the initial soft spring rate and go straight to the harsher rate. When you blow off at the knee of the curve, the shims snap open very quickly. By using thicker shims and low preload - the initial soft spring rate is still preserved and the transition is much smoother.

Penske on the Digressive Piston, uses simply the piston and a preloaded shim stack to get their curves. I'm not sure on the Velocity Dependent or Regressive Pistons - I'd have to check with the manual.

So you can make a Penske look exactly like a Moton - but will it work the same? Maybe - depends on how the builder put it together. I believe that if they use the same concepts - then yes it will be close.

Not only that but the Moton uses a 22mm shaft that displaces more fluid under compression and leads to a different feel.

I do know that Penske's have to be rebuilt every couple seasons - the last set of Moton's that Matt owned had near 30k miles on them and looked brand new when they opened them up.





And yes I'm saying that Clubsports are not Stock Class legal unless you run a really long bumpstop in the front. The rears are fine.

The front bodies are 14.6" long and the stock bodies are 17.25" long.

 

Derek, I think you may be confusing the diameter of the valve and the diameter of the piston.

22mm is huge for a piston. Most companies use 14mm. If you are seeing a 25mm piston then I'm going to assume that's on a strut based car and odds are that the piston is actually the body upside down.

 

Actually - you have it wrong too

22mm is tiny for a piston - Penske uses a 55mm. When Moton talks about 22mm - they mean the shaft.

 

I don't see anything in the rules that says a shock body must be of a certain length. The fully extended length of the shock has to be within 1" of the standard part but that's all I see about that. It also states that bumpstops can be cut or substituted but the initial point of contact cannnot be increased. In other words, the shocks are completely legal.

 

Oh.... When I said piston, I meant shaft. I'm definitely still learning but what's really interesting is that after being on Motons for 5 years (with a mix of Konis in there) I'm starting to see why what I've felt is true.

 

Ahh, that makes sense. Thanks for clearing that up. Yes, large shaft diameter is good, gets more fluid flowing through the compression valve in the remote reservoir. Thanks for all the info, Matt and Nick.

 

[QUOTE=glagola1,Feb 3 2010, 12:33 PM] I don't see anything in the rules that says a shock body must be of a certain length.

 

I don't think your interpretation is correct. What the rule is trying to do is prevent somebody from adding spring in the form of bumpstop.

"the compressed length of the shock at the initial point of contact with the bumpstop may not be increased..."

Take a "standard" shock with the bump stop installed. Compress it until the bump stop makes contact with the shock body. Measure the length. For example let's say the stock part is 24" tall when the bump stop makes contact. The Moton with it's shorter body will be 20" before the bump stop makes contact. 24" is more than 20" therefore 20" is not an "increase" over the standard part.

Get it?

 

Yeah I think I'm wrong