Moton clubsport suspension

[solidONE]

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

Can you please elaborate? When you say "nose force" you are referring to the initial "damping" force at the beginning of the stroke? What are the drawbacks of lowering the gas pressure in the shock to try to gain more low load/speed compliance? I'm assuming by increasing the the size the of the orifices in the piston can help reduce this unwanted excess "nose force" along with overall damping pressures?

Seems like this is a fairly common issue with monotube motorsport type shocks being used for 'normal' driving, yes?

[MaximeT]

Originally Posted by Tor

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

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

Moton club sport is higher end. It's the same quality as JRZ RS Pro.
It's a motorsport damper setup for the street and track.

AST is still very good stuff.

[DeaconRoc]

Originally Posted by Tor

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

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

Moton were bought out by ast but the product technology is still largely separate (e.g. parts that will fit inside the Motons won't fit inside the ast's and vice versa)

The Moton clubsports use the same internals as the Moton Motorsport dampers. Moton / Ast here in the UK told me that the Motons were the more capable and durable track dampers. As MaximeT said though the Ast's are still very very good though.

[Racecomp Engineering]

Originally Posted by solidONE

Can you please elaborate? When you say "nose force" you are referring to the initial "damping" force at the beginning of the stroke? What are the drawbacks of lowering the gas pressure in the shock to try to gain more low load/speed compliance? I'm assuming by increasing the the size the of the orifices in the piston can help reduce this unwanted excess "nose force" along with overall damping pressures?

Seems like this is a fairly common issue with monotube motorsport type shocks being used for 'normal' driving, yes?

Yes for nose force I was talking about the initial and very low speed damping force. A large offset is almost like a preload. You don't see it on the plots posted in this thread previously since they are just PvP plots.

Here's an example of a CVP plot:


Too little gas pressure and you run the risk of cavitation in the shock and hysteresis.

FYI many use the term nose to refer to the knee (low speed to high speed transition). I just call that the knee but I'm not an authority.

It is something that is relatively common on monotube motorsport type shocks used in normal driving. Lots of low speed damping and lots of gas.

- Andrew

[Jonsey]

Any updates on this? Very interesting thread.

[DeaconRoc]

Originally Posted by Jonsey

Any updates on this? Very interesting thread.

Sorry I've been meaning to update this but not got around to it.

Currently they're on a 7/8 spring rate. I'm at Moton in a few weeks and were going to alter it probably to 8/10 as the 7/8 frequency is either too similar which gives a little bobbling or they're just happier with a higher spring rate.

I've driven on them quite a lot now. The low speed damping is sublime (which is what race dampers always excel on - even the ohlins TTX state they are specifically designed for low speed damping) as this is what you get at high speeds. The high speed damping (what you feel at low speeds and on sharp impacts e.g. Potholes) is a little harsh though. Again this is pretty much par for the course on these sort of dampers it seems.

Moton are going to increase the size of the piston bleed holes when I go next which should help with the high speed damping.

There is also a clunk when high speed damping is taking place. It seems after looking into every other option over the last few months that's it's either actually internal to the dampers so they're going to have a look at this next time too and see if there needs to be a slight change to the internals design for the 86 or there is something slightly moving causing the noise. One thing I've wondered about trying is a slightly longer spring but I need to speak to Moton about this.

So would I recommend them? For entirely road use no - but I think you'd have to be pretty bonkers to spend that amount just for the road. I think flex a's would still be my road recommendation even though they are a little too soft and will bottom out - something the Motons are yet to do. If you use the car on track then 100% yes - the control they provide is sublime - curbs can be used with abandon!

I'll update again after the next round of additions but any questions please ask and I'll do my best to answer them.

[Tor]

Thanks for the update. I still hope someone will try a 6/8 setup.

[DeaconRoc]

Originally Posted by Tor

Thanks for the update. I still hope someone will try a 6/8 setup.

A 6/8 and 6/6 setup is also on the list to try but so far the evidence seems to be pointing towards the Motons being happier with higher rates 👍

[DeaconRoc]

Various things got in the way of there being much happening with these but finally I think we've nailed it.

On Monday I spent the day at AST having a few more tweeks made to the Motons. While the low speed damping was excellent they just weren't as happy as I'd have liked with the high speed damping (the stuff you feel more pottering around on a daily basis).

AST had a plan as they felt it wasn't a spring issue but rather a damping one. To remedy this they produced custom pistons with 4 extra bleed holes for the rear and 2 extra for the fronts along with enlargement of some of the existing bleed holes. They went with less at the front to keep the precision and taughtness that you want on turn in. Changing the piston like this reduced both the compression and rebound damping. AST wanted to keep the compression a little lower but return the rebond to as it was so they revalved the dampers to achieve this.

So did it work?

Yes. When I first drove it, after just the rears being done, the difference was marked. The overly fidgety nature at low speeds and slight bounce this brought had gone. With the fronts done too the transformation was complete. The drive back felt more like a 'normal' car and that was with the dampers set to 2 clicks from fully soft - previously full soft was needed for road use. Finally the dampers felt like they could 'breathe' with the road

[DeaconRoc]

After the adjustments on Monday the dampers had a trial by fire at Oulton Park for a trackday on Friday and I can report that the Motons were simply awesome.

The weather was very changeable and much of the day was wet or very wet so I left them exactly as they were when I arrived (2 clicks from fully soft). They really allowed the car to breathe with the circuit while keeping excess roll well in check.

There was one section on the track where there were two quite noticeable and large bumps in the track which you were hitting at around triple figures before braking heavily - the dampers soaked these up and kept the car beautifully composed.

On the way home Waze sent me a rather strange route which involved a lot of very bumpy country roads which the dampers just soaked up beautifully. I really was impressed.

However, I'm not suggesting these have given the car a limo like ride - with the design of our dampers that's never going to be possible imho.

I'd also still recommend the Tein Flex A's for purely road use. The Motons soft are now similar to the Flex A's when they're set towards fully stiff but obviously with a world of further adjustments to stiffen them more. Since the modifications on Monday for anyone who tracks a bit and uses the car on the road I'd happily recommend the Motons whereas previously I'd really have only recommended them if the majority of your use was track.

[Icecreamtruk]

Originally Posted by DeaconRoc

After the adjustments on Monday the dampers had a trial by fire at Oulton Park for a trackday on Friday and I can report that the Motons were simply awesome.

The weather was very changeable and much of the day was wet or very wet so I left them exactly as they were when I arrived (2 clicks from fully soft). They really allowed the car to breathe with the circuit while keeping excess roll well in check.

There was one section on the track where there were two quite noticeable and large bumps in the track which you were hitting at around triple figures before braking heavily - the dampers soaked these up and kept the car beautifully composed.

On the way home Waze sent me a rather strange route which involved a lot of very bumpy country roads which the dampers just soaked up beautifully. I really was impressed.

However, I'm not suggesting these have given the car a limo like ride - with the design of our dampers that's never going to be possible imho.

I'd also still recommend the Tein Flex A's for purely road use. The Motons soft are now similar to the Flex A's when they're set towards fully stiff but obviously with a world of further adjustments to stiffen them more. Since the modifications on Monday for anyone who tracks a bit and uses the car on the road I'd happily recommend the Motons whereas previously I'd really have only recommended them if the majority of your use was track.

If I may ask, did you ever got around trying the 6/8 spring rate setup? Im probably going to try that as well (have spring rate choice) for daily and track (but only really care about track) with street 200TW tires (RS4 and the like). I hope im not too close in frequency, but im within 0,1hz between front and rear (calculated) so I might've messed up

[DeaconRoc]

Originally Posted by Icecreamtruk

If I may ask, did you ever got around trying the 6/8 spring rate setup? Im probably going to try that as well (have spring rate choice) for daily and track (but only really care about track) with street 200TW tires (RS4 and the like). I hope im not too close in frequency, but im within 0,1hz between front and rear (calculated) so I might've messed up

We didn't. AST / Moton came to the conclusion that we were going the wrong route and chasing our tails with the springs and that it was the damping that we needed to look at (@racecompengineering suggested the same) and they were right. Whereas the 7/8kg spring rate didn't work as well as hoped before the problem was clearly with the damping rather than the springs because now it's a set up that works very well - I can see why 7/7 or 7/8 is popular on the RCE Tarmac 2's now.