Suplex suspension - my experience(it's not good!).

New canister and two new front dampers arrived yesterday and I fitted them...and the new canister is equally noisy.

This one, I had to add the spacer and adjust fully just to get 350mm. More was not possible.:shrug:

Not a happy puppy!

I tried ringing Suplex twice this afternoon but got no reply.
I have emailed Jack Durham expressing my disappointment and, yes, annoyance. I await a response.

I have noticed that if I run at a lower ride height the noises are reduced but, running at 330mm can't be good for tyres.
This height problem has got to be the root cause, in my opinion.
According to Suplex, without the spacer, 18 turns from the fitting position should give you 350mm ish.
With the spacer in and 18 turns I achieved 330mm.
The spacer, by the way, is 4mm thick, and assuming a translation ratio of 3:1 ratio, this means that it is worth 12mm of ride height. So that would mean without the spacer, 18 turns would give a ride 'height' of 318mm!

What can I say other than I am glad I bought the Australian Kit.

Is this an isolated experience, or are others having similar problems? Please don't think that I am dumping on UK products, but I must say that I was getting very nervous about the Suplex Kit when there were continual delays in the delivery with ambiguous or deliberate misinformation about the delivery.....

As the list knows I have the Australian kit fitted to my F and have traveled more than 10,000km of Aussie roads without any of the dramas mentioned above.....

Murray A.

Having given this problem a lot of thought, my conclusion is that the springs inside the canisters are too soft.
This would explain the soft ride and the ride height problem. The soft spring is also allowing the spring/spring seat to contact the canister causing the noises.

I have emailed Suplex with my conclusion and this is a precis of what I sent.

In theory, when the canister is fitted and initially adjusted, the spring will compress a small amount to give a base setting (Suplex state 350mm). This is a total height from canister top to bottom of the adjuster of 206mm.
Then further turns of the threaded adjuster will move the car body up or down to give the preferred ride height. ie increase/decrease this 206mm.

What appears to be happening in reality, is that the soft spring is just compressing further with more adjustment, so that the ride height is too low and can't adjust up beyond about 330mm. So to achieve even 350mm the 4 mm spacer is required.
This means that the spring is compressed too much in normal driving and noisy over uneven ground/ speed bumps etc.

I hope this diagram explains it better. It shows how the spring is compressing rather than lifting the car body.

Here are some photos.

Wound out to Suplex recommendation before refitting wheel and lowering car to ground


After taking the car's weight


Best photo I could get showing the spring and seat disappearing up into canister

This thread on the MGF register and indeed a much earlier thread on .org (post 31 on) have been highlighted to me.
They make interesting reading when Suplex maintain to me they have had no reported problems at all with their kit.


edit
Reading these threads make me think that it is a gamble whether the units you get will have soft springs or not. ie Will or will not achieve an acceptable ride height.

After discussion with the Suplex engineer we agree that they will supply two rear units to try on the front.
I remove the soft front units and they are picked up for return to Suplex.

The two rear canisters arrive and I fit them.
I follow the Suplex fitting instructions and wind the adjuster out 18 full turns.

I test drive the car and there is no noise from the suspension. The car feels better - more sporty, if you like.

On the downside, the ride height is 380mm. the front dampers also feel a bit weak with the stiffer springs.

I wind the adjuster back to give about 360mm and test again. It seems Ok, and I let Suplex know and discuss also using the rear dampers on the front.

We continue to use this setup for a week.

Today is the Border Patrol Dales Run.
A good test, I thought.

During the run, I felt the rear suspension 'bottom out' a couple of times.
No one else has any such problem. The run represents everything from a mk1F to an LE500, so this bottoming is a concern.

Everyone comments on how soft the rear of the car seems to be.

Here is a video of me bouncing the rear of the car.

Meanwhile Suplex say they will remove the tested 'good' front canisters from their test car and replace with my returned ones.

Should the rears prove unusable, they will then send out to me the tested front canisters that were taken off the test car.

The rear dampers arrive and are fitted to the front.
This is what happened and is what I sent to Suplex.

Thanks, I have received and fitted the new dampers. The first thing I noted, after a settling in test drive, was that the front ride height had increased by 10-15mm. I found this surprising as I didn't touch the spring adjusters. I don't know why the new dampers would have this effect, I thought the ride height was down to the springs.

The ride was definitely improved and I would be content with that, however, to get the ride height down towards 353mm means 2 full turns back on the canister adjusters. This leaves the bottom of the adjuster adrift by perhaps 6-8 mm from the pin shoulder at full extension.

The possibility of dislocation was now in my mind. After returning from another gentle test drive with the fronts so adjusted, I raised the nearside and took off the front wheel I saw that although the knuckle pin was still firmly located in the adjuster, the entire knuckle had come out of the suspension arm. This has damaged the white plastic cradle, rendering the knuckle useless.

At this stage, I must admit I am pretty unhappy, and really don't know what to do from this position.

After a few prompts, I get a phone call from the Suplex engineer.

They have fitted the returned canisters to their test car and have reproduced my findings ie low ride height and clonking noises.

He promises to ring me on Monday to let me know what he finds stripping them down.

OK we are nearing the current position so bear with me.

To sum up I now have 4 rear canisters and 4 rear dampers.

Having received no phone call from Suplex, I emailed the engineer to inform them that I am going to be out of the country from the following Wednesday until July 4th, and need some usable canisters asap to leave my wife a usable MG.

I receive no reply.