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Discussion Starter #1 (Edited)
Since buying my 4C three years ago I’ve been critically scathing of its harsh, uncompromising ride and dangerous tram-lining. I’ve always believed that these characteristics are caused by ridiculously hard low speed damper settings (on both bump and rebound), and terrible bump steer resulting from poor suspension design. Ironically, both these characteristics aren’t as noticeable on race tracks because of the good surface (my geometry is set correctly and Alfaworks front spacers and rear arms are fitted).

After a few months of ownership (in Autumn 2016) I looked into replacement dampers but it seems that most customers want to make the car harder still for track use as reflected by frequent comments here and that’s the opposite of what I wanted. My daily driver is a Citroen which has OEM hydraulic active suspension and the ride is generally sublime when cruising, though it’s not a car to be driven enthusiastically (too soft) and becomes almost solid in some circumstances. So for 4C I wanted a Citroen or Mercedes S Class ride for cruising, the playful handling of an early Elise, and the ride of a WRC rally car over less than perfect roads. Not asking for much then.

This has been a three year journey so far which started with me luckily finding Meteor Motorsport after an Internet search (run by a guy named Simon Rogers who sprints and hillclimbs a turbocharged Hyabusa-engined 7. His YouTube videos show it to be as quick as you can imagine with around 300bhp and 500kg. Meteor re-build and custom build top level dampers, using their damper dyno to evidence their settings, and are well respected in Lotus and Caterham communities.

After indecision on my part over which manufacturer to use and whether my objectives could be achieved (Meteor recommends Nitron, Penske, Quantum, and Ohlins at a range of prices), Simon got in touch in 2018 inviting me to take a look at some new active dampers from Tractive Suspension that he’d fitted to his 7. It was strange to be able to bob the car up and down by pushing on it, or make it as hard as a board simply by the change of a dash-mounted switch setting. It seemed witchcraft so I emailed Tractive Suspension and asked them (begged - it’s a fine line) to make a set for 4C, even offering to drive to Holland if a test car were needed. They’re a busy company working with OEM and specialist manufacturers (the new Dallara Stradale is fitted with Tractive dampers) and couldn’t justify such a niche market. So I forgot about it and in April this year almost bought an Alpine A110 (which has a good ride and excellent ride/handling compromise for a sports car with passive dampers), but coincidently at the same time Simon again got in touch to say that Tractive were interested in building an active set for 4C.

At Meteor, my car was weighed and motion ratios calculated and there was much discussion of spring rates and explanations of how the new dampers worked and what they could do. By now Simon and Dan his technician had been trained at Tractive to be able to re-build these dampers, configure them, and set them up correctly. Meteor had also became sole UK distributor. Tractive has tested the OEM setup on its damper dyno and confirmed surprise of how the low-speed damping gives a very, very harsh feeling when driving the car. It evidenced my thoughts (and that shared by some others here) that 4C has very soft springs and very harsh damping.

Tractive has designed the Force/Velocity curves for 4C, which at its hardest setting is controlled conventionally using internal valving and shim stacks, but it’s possible to create an infinite range of softer curves by adjusting the setup’s CPU and accelerometer settings. Adjustments can be made (on the fly if required) via an in car touch screen, and can be stored to memory and recalled using a 5-way switch. It probably won’t help to show settings and spring rates until I know that it all works, but here’s a hand drawn plot to illustrate the range of damping available.

101307


The green line is OEM, Red shows the Force graph created by the valving and shim stack settings and will be the hardest setting available to me. Yellow shows a typical soft setting selected via the CPU. If driving along a flat road with no input from the driver (ie steering, accelerating or braking) or from the road (undulations, bumps, camber, slope, gradients) damping will be minimal because there’s minimum movement to damp, and so the ride will be comfortable. As soon as an input is introduced the accelerometer will signal the CPU to adjust the damping to whatever setting is recorded in the Force/Velocity/Position map. So the Yellow line might indicate the hardest chosen setting, though the damper rate will be infinitely variable beneath it depending on the severity of the input. Will be interesting to find how it all pans out. I’m very excited that mine will be delivered in a month and look forward to letting you know how it goes.

Meteor Motorsport -

The part of Meteor dealing specifically with dampers is named Raceshox UK

Tractive Suspension -
 

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Seems there is a problem with the picture. Mind sharing how much it cost?

Sent from my Lenovo TB-8704X using Tapatalk
 

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Discussion Starter #3 (Edited)
Cost is £4950+VAT so possibly cheaper if you’re outside Europe without having to pay the purchase tax. Fitting is easy though there’s an electrical harness to be run from CPU to each suspension leg and into the cabin to the controller and settings switch. I’ll need to decide from where to take a 15A power supply when the kit arrives.
The picture has been re-hosted and seems ok now.
 

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It was actually my effort that tractive suspension has now a product for the 4c - my set of dampers is ready to ship but I didn't have time yet to finalize everything.

As long as it's not tested it's not finished. ;)
 

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I was going to upgrade my kw to nitron until I see this thread. Thank you guys for making this happen.

Update:Spent whole morning looking online. The difference between normal ACE and the R version should be the external canister plus beefed up internal, right?

我從使用 Tapatalk 的 SM-G9650 發送
 

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Discussion Starter #9
I was going to upgrade my kw to nitron until I see this thread. Thank you guys for making this happen.

Update:Spent whole morning looking online. The difference between normal ACE and the R version should be the external canister plus beefed up internal, right?

我從使用 Tapatalk 的 SM-G9650 發送
Yes, the R-ACE is 3 way adjustable with external canister. I’m told that this is needed only for the highest level of sport - the Time Attack guys like it.

Because the damping is constantly changing settings dynamically across the whole damping range (within the chosen mapped settings) I don’t see any point on spending the extra for that.
 

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Discussion Starter #10
It was actually my effort that tractive suspension has now a product for the 4c - my set of dampers is ready to ship but I didn't had time yet to finalize everything.

As long as it's not tested it's not finished. ;)
I’m not sure how you can claim that considering I originally asked Tractive to build a set for 4C 15 months ago and received an invite a year later stating that I’ll be the first user. The pre-prod maps were still being discussed 10 days ago and production versions were only signed off on the dyno last week after a lot of discussion between Tractive, Simon and myself. But, hey, we’re all on the same side, and I’m pleased that others are buying into this. Let’s put it down to multiple independent discovery or cognitive dissonance. As they’re new (certainly to our cars) I’m hoping the results will be as good as they appear to be on others.

Are you going with the Tractive suggested spring rates, and where/how do you plan to mount the hardware? (pm me if you’d prefer). I’ll add pictures once install starts.

Good luck
 

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Well mainly because I organised a set of original suspension struts which I sent them to take measures - besides other things.

I heard that there was an other potential buyer from the uk during the development process.

As there are picture from tractive's 4c set and yours isn't build - it can't be the first ;).
 

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Discussion Starter #13
i don't know how planed to do all the electronics - but i suggest to look into DSC/TPC products - they do it for a few years already.
I plan to use Tractive electronics, though I must admit watching YouTube videos of the DSC control unit on an RS Focus helped me self-justify buying the kit. I don’t know the relationship between Tractive and DSC other than that DSC are a reseller of Tractive dampers. For info, Tractive has been selling active dampers for a number of cars for some years, it’s just that the 4C product is new. They also sell replacement control units for cars such as Porsche (using the Porsche active dampers but replacing the controller) and I’m wondering if Tractive and DSC are the same units for this.
 

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Discussion Starter #14
Well mainly because I organised a set of original suspension struts which I sent them to take measures - besides other things.

I heard that there was an other potential buyer from the uk during the development process.

As there are picture from tractive's 4c set and yours isn't build - it can't be the first ;).
Oh dear, you want to turn this into a dick measuring competition. Why not put it away and let us know how you use your car, what you find wrong with the OEM setup and what you hope the Tractive kit will achieve. I’m glad you’ve had involvement in development, and I’m looking forward to hearing your story of fitting the kit and letting us know what it’s like.
 

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i've used TPC's controller on Porsche and it indeed was much better than OEM.
later i went all in with my custom tune for it and was able to fine tune it to a great resolution.
great stuff !!!
 

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Discussion Starter #17
My Tractive Suspension dampers have arrived and look to be precision engineering at its best. Just waiting for the Hyperco and Eibach springs to be delivered and thoroughly looking forward to working with Simon @ Meteor Motorsport to get them fitted. I’ll be running custom spring rates compared with those usually supplied because of my requirement for compliance over poor road surfaces. Should work really well with the active dampers.
Lots of photos and description to follow....
 

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I am not a fan of eibach springs. I kind of feel you went top end on everything else and then went bottom end on your choice of springs.

I'd suggest you go with swift springs instead, especially because of your requirements. They have some amazing progressive springs which really aid ride quality. A bunch of prominent coil over manufacturers offer them as spring upgrades on their products.

 

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I am not a fan of eibach springs. I kind of feel you went top end on everything else and then went bottom end on your choice of springs.

I'd suggest you go with swift springs instead, especially because of your requirements. They have some amazing progressive springs which really aid ride quality. A bunch of prominent coil over manufacturers offer them as spring upgrades on their products.

RYUK....not disagreeing with you...but what have you heard about Eibach springs that you have issues with? I have used them on other vehicles, mountain bikes, etc. and never had any issues. Haven't used them on my 4C though. I did hear that the rates people have available for the 4C aren't a good match but that doesn't damn them as a product.
 
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