We have noticed that there are multiple customers who spend a lot of their driving time on roads that are causing issues with the currently available suspension options.
Id like to introduce you to the latest and greatest Apex coilover kit, the Limo:
We do already offer a coilover kit that is extremely supple when judged against offering from the rest of the coilover suppliers, the Apex Comfys with 5/4kg.mm spring rates. It is also compared favourably with after market spring and KYB combinations where customer have reported the swap from KYB and spring to Apex Comfys to actually improve ride quality as well as offering a much greater adjustability and massive improvement in handling.
However there are still customers out there who require a more supple set up that even our Comfys offer. This is where the Limo kit comes in. There are customers whos driving experience incorporates either extremely poor quality road surfaces or lumpy bumpy, twisty country roads. Such roads require another step forward in terms of damping and spring rate.
Roads like this. This was on the way to a rally day in darkest Wales. I was in a Jag which did suprisingly well as the supple ride wasnt phased by the undulating road surface. Which is what the Limo kit is designed to replicate, but not to the same extent as the Jag.
What did we do to spec the Limo kit? How does it differ from other coilovers?
There are two basic factors to designing a coilover kit. The first is the damping rate and the second is spring rate.
Damping rate
The damping rate is determined by two things, the curve and the overall rate. The damping rate and chacteristics have a huge impact on the ride quality of the kit, its not all down to spring rate.
The reason lots of coilovers feature hard damping rates is because the harder the rate the slower the body roll so the smaller the geometry changes cause by roll and so the better the car ultimately handles and the higher the grip level with less static camber being necessary. However this is applicable for smooth surfaces only. The rougher the surface the slower the car will became because the wheels start losing their contact with the tarmac reducing control and grip thus forcing the driver to back off to avoid being punted unto a hedge.
A softer car is also more forgiving at the limit than a stiffly set up car making the car easier to drive.
For the Limo kit we wanted dampers that werent going to transmit road surface changes, pothole impacts and undulations straight through to the cabin so it needed to be specced with a mild damping rate to allow piston travel as opposed to a harder damping rate that restricts piston travel and so forces impacts and road surface impections directly through to the shell and so its occupants.
The softer damping rate allows greater total piston travel than with a more highly damped unit so the total piston travel needs to be increased to prevent the strut constantly hitting the bump stop. The bump stop should not be relied on to control travel, hitting the bump stop whilst turning into a corner prematurely stops body roll and unsettles the car.
This means that to go along with the softer damping rate we also had to increase total damper travel within the Limo kit.
Spring rate
Spring rate determines the cars ultimate angle of lean mid corner, the higher the spring rate the less the body will roll. The less the body rolls the less the alignment changes and the better the handling and grip levels.
However the higher the spring rate the more road impefections and distortions are transmitted into the shell so reducing ride quality.
The Limo kit was therefore specced with 4kg.mm front and 3kg.mm rear spring rates. this compares to our prevously softer kit, the Apex Comfys, spring rate of 5/4kg.mm and our fast road track kits rates of 6/5kg.mm. We do of course supply hgiher rates kits, right upto 18/16kg.mm and higher. All of our kits feature damping rates and damper travel matched to the spring rate. We dont just swap springs on a damper and kick the kit out of the door.
One issue that arises with softer springs is that the car will natuarlly sit lower as the spring compresses more than a higher rated one. This leads to more static sag which does two things that need dealing with when the kit is designed:
1) It uses up damper travel which mean you need more travel in the first instance to avoid hitting the bump stops. This is extra travel in addition to the travel dialed in to accomodate the softer damping as explained above.
2) The greater static sag means the car sits lower so if a 6/5kg.mm kit will run upto standard ride height a 4/3kg.mm kit is going to sit 35mm lower even at maximum height, all other things being equal. To ensure the correct range of ride height adustment we have to make the threaded damper bodies longer.
You can clearly see the above info in action with the pictures below. They show an Apex 6/5kg.mm front and rear damper against the new Limo kits front and rear dampers. Note both the longer threaded damper body and also the longer damper rod.
Although the Limo kit isnt designed specifically for track work it is designed to be competant on the occasional track day and trip to the Ring, its not like you wont be wizzing round other cars on track with them fitted
The Limo kit features all the same great functionaility and durability as found in all the Apex coilover kits including:
- New damper units with a wider range of adjustment
- Integrated bearing in front spring top platform to prevent spring binding and smooth out steering
- Lightweight bottom mounts to reduce unsprung weight
- 30 way click damping adjustable
- Modular design allows easy and cost effective servicing
- Various springs rates available, easy to change
- Spring platform adjustable for corner weight adjustment
- Ride height adjustable through bottom mount to retain full damper travel
- Ultra reliable brand, very low damper failure rates with full warrenty and after sales back up
- Pillowball front top mounts
- Camber adjustable front top mounts
- Rubber centred rear top mount for ultimate refinement
The kit retails at just £649!
We are just finalising testing on them on the Apex S14a test mule but so far so good
Some feedback
Originally Posted by Jonny Wilkinson
Well, I said I'd provide feedback and I can confirm I have absolutely no affiliation to Bren or Apex.
Bren very quickly provided me with a set of the new 4/3 coilovers (call them Limos or whatever) but I was away on business. Once I got back, it took me 2 weekends to get them fitted and recommission the car, get it insured and taxed so I could get them set up and do an extended road test but now (5 weeks later), its all sorted and I can provide said feedback.
All I can say is....
Shit the bed, Bren. Why haven't you been making these for years ?
They are quite simply brilliant. A-roads, B-road and nasty rutted tracks.
I'm not an easy person to please and, tbh, my high standards meant I was mildly disappointed in the Gen 1 comfys.
However, these offer astonishing bump absorption without compromising bodyroll. They give good feedback so you can feel when the tyres are starting to let go and yet the car feels very neutral in terms of under/oversteer (almost go-kart like).
Don't get the idea that these are "soft" coilovers though. The springs are still twice the strength of standard springs...and that is all they need to be.
I've driven numerous sports cars including Porsches, BMWs, Subarus and even an Aston Martin and the handling of my car is now up there with the best I've driven and so is the ride and compliance.
There are one or two minor improvements I am going to suggest to Bren by PM but these are more to do with the flexibility for setting them up and not with the way they work.
Now, if you want a pure track car, I'm sure there are better coilovers available with harder springs.
Similarly, if you have a standard S13 with OEM ARBs and no chassis strengthening (strut braces et al), then you might be happier with Comfys to try to compensate for the body roll and chassis flex.
If, like me, you have ARBs and front and rear strut braces, get these limo coilovers, set the damping to 10 from Soft or thereabouts, find a road and simply enjoy
If anyone wants to experience them from the passenger seat, I will be at the Kent meet on Thursday and the HWH meet 2 weeks after so just ask. I think you'll be impressed.
I'm most of the way through writing a detailed fitment guide for the S13 too as I don't think anyone has done one for the 13, so watch out for that in Tech S13 soon.A bit more feedback for you too. Its great on A-roads too. Not just B-roads.
I went along to the Kent meet last night and its lovely and smooth on M-ways. I came back along the A130 - a dual-carriageway notorious for its uneven surfaces and long yumps (dips in the road about a car length long).
With the comfys I'd be bounced out of my seat in 3 or 4 places with my head hitting the rooflining over the worst one. It even upsets the Impreza which is a bit softly sprung tbh.
Now, in the S13, all I get is a nudge in the pants in a few places and a nod of the head over the worst one.
The ride is spot on IMO. Firm enough to give great feedback without being uncomfortable. You can feel the suspension working.
I really am soooo pleased with them.
Thanks.
Jonny.I got a spin in Jonny's 13 tonight and I have to say, those coilovers are pretty damn good in terms of ride quality.
In terms of my butt suspension dyno, I'd say they feel very similar to my stock DC2 ride quality wise, firm but not jarring or harsh in any way. They seem to manage this without feeling soggy too, still providing good body control and little roll (admittedly due to the weather it was a low speed jaunt tonight but still enough to tell how they cope with bends and bumps).
Definitely worth a look if you're wanting to replace your suspension but don't want spinal surgery further down the line in my opinion
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