A Mono Shock rotary damper system...

[Veefan]

I posted this on a thread that was going way off topic on Apexspeed... good idea for the rear suspension of a Vee???

https://sites.google.com/a/slu.edu/me_s ... ing/design

[brian]

Very interesting idea and very similar to the mono shock system used on the VD's a few years ago. I was told that it never worked quite well enough and they went back to the double shock set up. I think something similar could and does work for vees. The key is to find the balance between the compliance of zero roll and twitchy nature of a z bar car.

[CitationFV21]

The Gaspar had something like that. To my knowledge only 2 were built and Gene Grimes had one - and he converted the rear to a D-13 type setup. If he is lurking he can fill us in. The other car is/was owned by Wayne Boyd of RI and last I knew was still in the original form. I have not seen the car out in probably 10 years.

ChrisZ

[Matt King]

A monoshock VD was on the pole at the Runoffs this year, so maybe the concept still has potential!

[jpetillo]

The link didn't work for me. Did it work for you guys?

[cendiv37]

The above link worked for me earlier but won't now.
Try this:

https://sites.google.com/a/slu.edu/me_s ... ing/design

[jpetillo]

Bruce, thanks that helped. This is a nice setup. The D-13 setup goes a long way toward doing a similar thing - damping the roll somewhat separately from the heave damping. This is neater, and does a better job of separating damping forces. But the shifting side to side of the lower shock end may change the effective spring rate, although perhaps in a good way. John

[hardingfv32-1]

Why would you need roll dampening at the rear if the front shocks can get the job done?

Brian

[Veefan]

I don't have a clue...

But since this...

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Is in the rear of this car...

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I was looking for a simple mono shock version...

[Mystique Racing]

The small shocks on the side of the main shock controls the roll dampening. The center shock/spring controls the vertical movement and dampening. I would think something like this could be made for a Vee fairly easily.

[hardingfv32-1]

You are polluting the thread with mindless garbage. This is a plain vanilla three spring rear suspension system. Nothing to do with a mono shock. It does not even incorporate the common Sachs rotary shock. Try and find something that is remotely useful to FVs.

Brian

[Veefan]

I'm not sure who you're talking to

You are polluting the thread with mindless garbage. This is a plain vanilla three spring rear suspension system. Nothing to do with a mono shock. It does not even incorporate the common Sachs rotary shock. Try and find something that is remotely useful to FVs.

I started the thread

[hardingfv32-1]

I'm talking about the photos of the RedBull rear suspension.

Brian

[problemchild]

He's been grumpy since the Runoffs

I'll pollute the thread by suggesting adding roll resistance with a basic conventional suspension design like this.

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PS .... such a deal I'll make on a 3-pac of billet Penske shock extensions if anyone is interested.

[hardingfv32-1]

You are always ready to make a deal on useless junk!

Are we to assume this is an ordinary Z-bar rear suspension or can you demonstrate something a little more interesting?

Brian

[Veefan]

Really?

This is a plain vanilla three spring rear suspension system.

now that's funny

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[Mystique Racing]

Brian,

I think you need a vacation.

[jpetillo]

Why would you need roll dampening at the rear if the front shocks can get the job done?
Brian

Brian, that's a good question and I don't have an answer. I've never had a vee with rear roll damping so I don't know if the car would have any better feel or capability. I could believe that controlling roll damping entirely from one end of the car may not be a great idea.

Greg, what is the difference between the setup you showed and an old style z-bar twin shock setup? I wasn't around the scene in the z-bar days to remember the details. But it's not zero roll resistance, and it definitely has roll damping.

John

[problemchild]

From what the old-timers (Bill Noble being one) told me ..... a Z-bar Lynx/Caracal was faster than a zero-roll Caracal (same cars but different rear suspensions) for 3-5 laps but then faded as shocks, springs, tires, etc got heated up. This was before the Penske/Fox shocks were available. Zero-roll was trendy, easy to drive, easy to tune, with aero and maintenance benefits. Once people started using $1200 shocks, the likelihood of running two became less likely and zero-roll is still going strong.
As far as I am concerned, there are three types of rear FV suspensions. Pure zero-roll, zero-roll with secondary roll resistance (anti-roll bar), and twin-shock -third spring (Z-bar). Everything and anything else is just repackaging of these three. The only reason I do not use suspension like above is cost but mostly weight. Ultimately, the twin shock z-bar provides the best handling, although with a narrow tuning window, IMO, but 200+ lb drivers in FV have to make weight reduction their priority .... hence I run either of the first two options.

[jpetillo]

Interesting - thanks. John

[hardingfv32-1]

The suspension in the photos has been used in F1 for over seven years. That is plain vanilla in my world. It is not a mono shock system, but just a standard three spring system. The third spring is very interesting. Note the use of three springs to get a variable rate.

Brian

[hardingfv32-1]

Ok, lets approach this from a different angle. Lets assume we all want to go faster in the corners.

How does rear roll resistance help us with that goal? What handling symptom do you have that rear roll resistance will help?

Brian

[jpetillo]

Brian, an excellent question. I don't have an answer. But let me dig in a little to see if we can figure out what rear roll resistance might do.

I assume that it's the case that the zero roll resistance is chosen to slave the front end with the anti-roll chore because it has more traction available to it than the rear. Aside from economics, is there anything else the zero roll resistance does for us?

Two cornering situations are 1) initial turn in and the transition to mid corner settled suspension and 2) mid corner when the suspension is settled. For 2), since this is static, it does not apply because damping only provides a dynamic force, so mid corner is unaffected. But, for 1) it can have an affect.

For 1), during initial turn in, the faster you turn in the more force will be on the outer front tire when the suspension comes up against its maximum roll. Rear roll damping could limit the magnitude of this force by slowing the roll down using the rear tire. The question is whether during this turn in phase if the rear tires are already at their traction limit or not or if they have something to contribute. Can anyone comment on that? If this is the case, perhaps adding rear roll damping on the rear would allow a car to be turned in faster without oversteer setting in. What do you think? John

[hardingfv32-1]

While I'm sure people have had a push or the front end wash out on turn-in before, I do not think this is the norm for a properly setup car with our current tires.

1) The front camber is ideal (negative) at the start and end of a turn. As the cornering force climbs the front suspension rolls/flexes and the camber goes positive. The front end has the most to contribute to the cornering effort at the start and end zones of a turn.
2) The rear camber is very bad at the start and end of a turn, to much negative camber to generate maximum cornering force. As the cornering forces climb the rear jacks and the camber reaches its optimum setting. The rear end has the most to contribute to the cornering effort in the center section of the turn. The center section is about 50% of an average turns length.

It would seem the the rear should not be shouldering any extra duty (roll resistance) at the start and end of a turn.

Brian

[jpetillo]

Brian, Thanks. I would agree with your conclusion. John