Moton clubsport suspension

[solidONE]

Originally Posted by DeaconRoc

The oscillation is basically a small amount of bouncing on 'normal' road surfaces. It effectively feels like the suspension is not reacting to the small road imperfections - like the suspension is following them rather than absorbing them.

Tyre pressures are currently the standard 35psi all round and haven't been altered to try to alleviate the problem.

Moton are currently designing a freer flowing pistons which should hopefully help the dampers respond better to these small imperfections and so remove the bounce.

So adjusting the damping with the knobs had no effect on the low speed/load oscillations at all?

[DeaconRoc]

Originally Posted by solidONE

So adjusting the damping with the knobs had no effect on the low speed/load oscillations at all?

The new spring set up was only fitted on Thursday so apart from the settings changes I mentioned previously I haven't had chance to try any others yet. I have a local testing route and I'm hoping to get chance to play with the settings a little on Sunday to see if I can dial it out.

The new piston design is to see if we can make the ride even softer. The aim is to try and find a set up that on full soft is very soft for relaxed commuting, medium would be suitable for fast road and stiff suitable for track.

I'll keep the thread updated with how the settings work that I try.

[DeaconRoc]

Originally Posted by Tor

Something like 6/8 would give the higher wheel frequency in the back given my crude calculations (including motion ratio and corner weights):
2.27 front and 2.44 rear approximately if my calculations are right.

7/8 might be close to harmonic with 2.45 front and 2.44 in the rear, which is to be avoided. I don't know if that could explain your bounciness.

Someone should definitely check my calculations.

My used values are:

Front (per side):
Sprung weight: 660 lbs
Unsprung weight: 80 lbs (not certain this is accurate)
Motion ratio: 0.95 (1.05 in the calculator)

Rear (per side):
Sprung weight: 495 lbs
Unsprung weight: 80 lbs (not certain this is accurate)
Motion ratio: 0.75 (1.33)

Using: http://www.racingaspirations.com/app...ncy-calculator


If I had the opportunity like you do I would try the 6/8 combo out. 5/7 might be interesting too with 2.07/2.28.

Having the rear frequency higher in the rear is referred to as "flat ride". There is an explanation about why that is beneficial for comfort (and ultimately grip) in this document:

http://www.optimumg.com/docs/Springs...Tech_Tip_1.pdf

I guess you could fine tune the handling with the Whiteline anti-swaybars, or even revert to the stock rear bar if it's too tail happy.

For reference, a stock FR-S is 1.40/1.57 given the above parameters. For flat ride you should have a 10-20 % split with a rear bias.

Thanks for the very detailed response.

We tried 7/8 this time as I know it's a rate that's been used on other well regarded set ups (like the rce tarmac 2's) and the Motons seem to respond well to a stiffer rear rate.

6/8 is also something we may try next time for the reasons you've outlined.

All the spring set ups we've tried have had a certain low speed bobble which has led us to believe that it may relate more to the piston flow or valving rather than spring rates. However I think trying a 6/8 would be a useful experiment.

[DeaconRoc]

Originally Posted by cjd

Really awesome that you're sharing your experiences - it's helped me a lot in corroborating some things I think I've observed without the confidence to believe myself.

We'll see how things go next week at nationals, but I know that 9k square is also out there for AutoX with a fast driver...

I'm on 10/12 and as far as I can tell it is simply too high a rate for the available grip I get out of the RE71's while autocrossing - unless everything is just perfect, perhaps. Certainly, as grip falls the car simply starts skating once the smallest thing unsettles it (like, say, a puddle...) I often find it challenging to get heat into the tires. Strano FSB, stock rear. Different coilovers entirely, of course. When the traction is there, it's pretty crazy - but I don't experience that enough I trust it yet.

10/12 is pretty even F/R frequencies and does indeed present some uncomfortable ride in a few places - probably similar to what 7/8 does. Changing vehicle speed helps some, but it also feels like the suspension is not following the surface and the vehicle is being pitched front/back - it's a certain stretch of road that is concrete, laid in short stretches that are all slightly higher in the middle, slightly lower each time the machine stopped. I'll not mention how the ride is on Chicago's lovely streets beyond saying that it's horrible.

Glad it's helped 👍

What coilovers are you on?

What you've described in the last two paragraphs is exactly what I was finding with the 9/11 rates. Dropping the spring rates definitely seems to have helped address those issues if not completely solve them yet for me although it sounds like your set up has a generally worse ride as even on the 9/11 rates on the terrible roads we have around here it wasn't that bad and going down to 7/8 has improved that further.

Have you tried any different spring rates?

[solidONE]

Originally Posted by DeaconRoc

The new spring set up was only fitted on Thursday so apart from the settings changes I mentioned previously I haven't had chance to try any others yet. I have a local testing route and I'm hoping to get chance to play with the settings a little on Sunday to see if I can dial it out.

The new piston design is to see if we can make the ride even softer. The aim is to try and find a set up that on full soft is very soft for relaxed commuting, medium would be suitable for fast road and stiff suitable for track.

I'll keep the thread updated with how the settings work that I try.

That would be ideal. IMO Good luck!

[Racecomp Engineering]

Sounds like you could be running a lot of gas pressure.

- Andrew

[DeaconRoc]

Originally Posted by Racecomp Engineering

Sounds like you could be running a lot of gas pressure.

- Andrew

I think it's currently set on 140 psi.

If you don't mind commenting how do the dyno graphs look to you?

[DeaconRoc]

A recent track video with the Motons on 9/11 springs

[cjd]

Originally Posted by DeaconRoc

Glad it's helped 👍

What coilovers are you on?

What you've described in the last two paragraphs is exactly what I was finding with the 9/11 rates. Dropping the spring rates definitely seems to have helped address those issues if not completely solve them yet for me although it sounds like your set up has a generally worse ride as even on the 9/11 rates on the terrible roads we have around here it wasn't that bad and going down to 7/8 has improved that further.

Have you tried any different spring rates?

Tein SRC at the moment.

Potholes can be 6 inches deep (I have to drive around those), and rough roads are often like a series of parking lot speed bumps. Even my wife's Prius is a bad ride, just not quite as jarring. Otherwise it's good, my wife knits as a passenger in my car when we road trip. I'm confident lower rates would improve the comfort still.

I have yet to try lower rates, wanted to sort the alignment first (needed less camber in the rear.) Also haven't found springs I can actually use yet... Sizes are a bit hard to find. That said, a shortened event (bad storm popped) has me feeling pretty good about the alignment... Need to experiment with settings and pressures again.

[Racecomp Engineering]

Originally Posted by DeaconRoc

The oscillation is basically a small amount of bouncing on 'normal' road surfaces. It effectively feels like the suspension is not reacting to the small road imperfections - like the suspension is following them rather than absorbing them.

I've felt that on a couple higher end "motorsports" suspension set-ups that needed some more fine tuning in order to be reasonable on the street. Generally it's a lot of nose force which can be too much low speed damping, too much gas pressure, or excessive stiction. Put longer lasting (higher friction) street type seals on a shock with lots of nose force and this happens.

140 psi isn't a ton of gas force, but in combo with other factors could be part of what you're feeling.

I certainly do not think that it has anything to do with spring rate "balance".

Originally Posted by DeaconRoc

I think it's currently set on 140 psi.

If you don't mind commenting how do the dyno graphs look to you?

They look fine, but a few more data points especially in the low speed range would be helpful. A CVP plot would tell more of the story. At full soft at least I'd expect good ride quality just based on the provided plot.

- Andrew

[MaximeT]

I do think too that's not related to spring rates but damping. I'm on JRZ 12-32 at 12k in the back.
They are slightly bumpy at low speed for street driving.

Pretty great at the track.

I'm at 16bar in the rear at the moment.

[DeaconRoc]

Originally Posted by MaximeT

I do think too that's not related to spring rates but damping. I'm on JRZ 12-32 at 12k in the back.
They are slightly bumpy at low speed for street driving.

Pretty great at the track.

I'm at 16bar in the rear at the moment.

They sound very similar to the Motons - the slight bounce is definitely speed related - above 35/40mph it pretty much disappears

[DeaconRoc]

Originally Posted by Racecomp Engineering

I've felt that on a couple higher end "motorsports" suspension set-ups that needed some more fine tuning in order to be reasonable on the street. Generally it's a lot of nose force which can be too much low speed damping, too much gas pressure, or excessive stiction. Put longer lasting (higher friction) street type seals on a shock with lots of nose force and this happens.

140 psi isn't a ton of gas force, but in combo with other factors could be part of what you're feeling.

I certainly do not think that it has anything to do with spring rate "balance".



They look fine, but a few more data points especially in the low speed range would be helpful. A CVP plot would tell more of the story. At full soft at least I'd expect good ride quality just based on the provided plot.

- Andrew

Thank you for taking the time to reply and offering some thoughts 👍

Low speed damping is definitely an area for Moton to look into further I think from your comments and a few others that have been made.

[Tor]

How do the Moton Clubsport differ from the 2 way AST 5200?

Moton is a part of AST, isn't it?