Front damper replacement

[Barrymo38]

I am having to replace my front dampers ( 1992 SE ) and have searched the various posts but cannot find the answer I seek.

I would welcome suggestions as to sourcing a pair of dampers as near to original as possible. From the various post I have searched it would appear that adjustable dampers are the only option. Am I correct? If so, what recommendations does anyone have?

Thanks

Barrymo38

[Danevansgolf]

I've just fitted a front set of avo shocks. Bought from pnm engineering.. Good price, easy to fit.. I used my old springs, just gave them a sand down and re sprayed them black with a galvanised spray.. I also changed all the bushes on the front aswell.

[Don.Hasi]

GAZ shocks from SWL

[Barrymo38]

Thanks guys - most helpful.

Barrymo38

[dapinky]

Barrymo,

I'll try and answer your actual question, and list the 'known' options...

Firstly, there is so much discussion (on this forum and elsewhere) about whether owners/drivers/enthusiasts should even think that they may know more than Lotus Engineering when it comes to suspension settings - and therefore nowt should change from what the factory setup was.

Obviously, it isn't ever that simple, and as time moves on, technology advances, materials advance and 'costs' may or may not be as important to todays' owners as it was to the company accountants back in the day.

Anyway, the 3 main options (each can be further divided or mixed/matched as you wish) are:-

1) Keep what you have
2) replace with OE stuff
3) replace with something else

Even if your car has only done a few thousand miles, it is 25 years old and the components are going to be worn to a greater or lesser extent - many cars with well in excess of 100K miles are still on the original suspension, and as degradation is an ongoing (but slow) process it is impossible to tell it is happening until there is a catestrophic failure, or you notice that fluid is leaking and the damping is no longer effective.

There were different options of damper/spring combinations originally, with seperate units for NA, SE, FED & S2 - they are probably so close to each other that any new units you may find and fit will probably show an improvement over worn originals - but don't mix them on any axle!

Then there is the rub - trying to find new OE dampers isn't that easy (and if you can, then at what price?)

So the realistic option is to change for some other make - and there are many to choose from.

The 'common' makes which are easy to get off-the-shelf are:-

GAZ - - (I've never used them and can't comment)
Protech - - (Had them before - great when they work, but I had an unacceptable failure rate - both leaking and structural failure, so I won't use them again)
AVO - - Currently fitted - not had them long enough to comment on their longevity, but have used them on other cars with no issues (and they can be sent back to the factory for re-build with a quick turnaround).
NITRON - - Probably the 'best' of the aftermarket units due to their competition herritage, design and ease/range of adjustment, but not cheap.

I'm fairly sure that if you wanted to spend the money, then Bilstein, Koni, Spax etc would make some to your exact specifications.

Realistically, the only 'choice' for most people is to get adjustable units.

But where to set the adjustment is another matter (and depends on many factors such as spring condition, bush condition, weight carried in car, hard ride/softer ride (with inversely proportional flat/leaning cornering and handling).

Ease of adjustment isn't really a huge issue (unless you use different settings regularly - track driving?) as once they are set how you want them, they are unlikely to ever be changed.

Also remember that if your shocks are worn, then the springs and bushes are also going to be worn - but maybe not enough to worry about (hopefully).

Personally, when I replaced my shocks I also fitted springs (which are easily availlable in various rates) and also new bushes everywhere. The ones which seem to make the most difference (but are the hardest to get at & replace) are the lower raft bushes - everyone who has ever changed them has commented on the improvement afterwards, but having said that, not many people have 'just' replaced those bushes, as whilst you get that far, then you may as well do the rest, and it's hard to say what bits made what changes.

[Barrymo38]

Thanks Dave,
I have looked at the various sources of the dampers mentioned - GAZ & AVO, and came across C100C123F from South West Lotus Centre. These appear to be non adjustable ( which I would prefer, not to mention cheaper than the above ) but were a Federal fitment, ex Lotus stock. From what SWLC say about them they are acceptable for UK cars if a 5 mm change in ride height is acceptable.
Incidentally, the reason for replacement is lower spring mounting flange corrosion.
Is there any experience of these within the LEC community?

[DABgp]

Thanks Dave,
I have looked at the various sources of the dampers mentioned - GAZ & AVO, and came across C100C123F from South West Lotus Centre. These appear to be non adjustable ( which I would prefer, not to mention cheaper than the above ) but were a Federal fitment, ex Lotus stock. From what SWLC say about them they are acceptable for UK cars if a 5 mm change in ride height is acceptable.
Incidentally, the reason for replacement is lower spring mounting flange corrosion.
Is there any experience of these within the LEC community?

I would be interested to hear an answer on this one. And is the ride height change up or down? I would be worried about going lower.

[mitreklov]

I saw these fed units and wondered if they would ok on a UK spec SE. The price is very good considering it includes the springs.
I think a call to SWLC is in order to find out more.

Any body here fitted them?

Tim

[Don.Hasi]

I would be interested to hear an answer on this one. And is the ride height change up or down? I would be worried about going lower.

it is said on this board, that the fed specs are higher.

[mitreklov]

Would a 5mm higher ride make that much difference? The manual indicates a ride height tolerance of +-2 mm and the diffence between new and worn tires can be 5mm or so. Maybe there are other diffences in spec like spring stiffness?

Tim

[Don.Hasi]

The fed springs are also stiffer IIRC.

I think it it a matter of personal taste. the m100 looks a bit high in stock specification. A further 5mm... I don't know. To be honest I didn't want to lower the car in the first step, but I appreciate the few mm lower of the GAZ. And the car is not on the floor...

[dapinky]

Tim,

Firstly, I haven't used the Fed springs/dampers so can't offer an 'owners' viewpoint....

.... however, they were different specs to allow for different circumstances - the Fed car is more 'nose heavy' than the UK car due to the crash structure, but not hugely different.

it may well be that the ride height is slightly higher if you use them, but not enough to make a big difference - they may be a higher rate spring, but with the weight of the car on them, it should be similar to what you have. (Not accounting for any 'sag' which you suffer from - ooh-err, missus!).

The static ride height is determined by the spring, not the shock absorber, so if you find it sits too high, it is possible to shorten the spring using an angle grinder - but I mean by a few mm at one end, not chopping a couple of coils off!!!

But because of the angles involved in the suspension design, 5mm change of spring length does not necessarily equate to 5mm change of ride height at the measuring point on the chassis.

I don't know what the difference in damping force is between the 2 units, but thay ain't gonna be huge - and a new Fed unit will probably be far better than a worn UK one anyway!

[RFlowers]

I've got a '91 Federal and having almost the same quandry as barrymo38. The front right damper is completely shot. Right rear also feels weak. I saw the front replacements at SWLC, but I can't find the rears anywhere. The low price of their front set is very appealing, but is there any worry about them sitting on the shelf for 10+ years? Also, they advised not mixing the Lotus front set with an adjustable rear set. Any thoughts on that? I had considered putting GAZ on the back and then trying to match the damping, but maybe not. I wish I could afford Nitron, but the Esprit needs some care and feeding too. I don't track it and don't need maximum performance, just a well-sorted street car. I see in the forums that people have their own likes and dislikes among the different brands, based on personal experiences, so it seems like a gamble on any brand except Nitron. The only complaint I saw on them was the price!

Regarding ride height looks, I measured the distance from the ground to the top of the wheel arch on each corner to see if any corner was sagging and it didn't appear so. The fronts were both 63.5cm and the rears were both 66.5cm. How does that compare to non-federal? Are you 5mm lower? Does anyone run original springs with GAZ dampers? Do they fit okay, or should I just go with new springs?

My last question (for now), is that I found the full GAZ set cheapest at Dampertech.co.uk. Anyone know about this company?
Thanks

PS. Shipping cost to the US really hurts!

[Barrymo38]

I bit the bullet and went SWLC route. Excellent service, excellent product.

I fitted them without changing the springs, which I may regret as the ride seems somewhat harsher although I have only driven a few tens of miles since purchase. I will fit the originals come the autumn when I plan to take the car off the road for winter.
Delighted to say that the car passed its MOT yesterday with only one advisory ( rear brake slider dust covers very close to being unacceptable - is it possible to source just the dust covers without the huge expense of buying the complete kit ? )

As to ride height on the new shocks - I can get nowhere near the ride height stated for suspension settings - much higher!

At the moment I have 66 cm at the rear and 55 at the front wheel arches.

Can anybody recommend a reliable and more importantly knowledgeable company who can carry out geometry settings?

I went Formula one and was not impressed at all.

[epipete]

Just for reference, what are the specified heights meant to be?

[RFlowers]

Lotus specifies the heights measured underneath the car to certain points (170mm front/160mm rear). I only measured to the wheel arch to see if there's a visible difference in ride heights between the US and British versions. 55cm at the front seems too low! In fact, my stock 16" wheels/tires measure 56.5cm. 7cm wheel gap in the front and 10cm gap in the rear.

[Brit-Car-Nut]

Several past LEC members went the SWL route and tried the FED damper sets but eventually, everyone removed them because the made the car ride too high in the front. I didn't bother searching for their posts, but try "fed damper" or similar to see their complaints. I believe the spring seats are in a different position on the Fed cars. They had to make the nose be higher off the ground to meet the headlamp height requirement. For some reason, I thought Sandra was one that either got her car with the Fed dampers installed or she tried them and was disappointed that they made the car look strange with the nose up so high.

BTW, the damper sets they are selling were on one of the 2007 Aftersales list for 50 quid each. They had them out for sale at STONELEIGH in 2007. That's where I got the spare set for my car.

For old posts about the differences look at viewtopic.php?f=41&t=6197&p=69981&hilit=+fed+damper+#p69940

[Barrymo38]

The first thing I did when my fed. dampers arrived was to compare spring seat position and distance from bottom spring seat to yoke hole centres. They were identical to those fitted to the car. The spring rates are clearly different although I have no knowledge of what those differences are but as referred to above the fed. spec. are stiffer hence the increase in ride height.
For the time being I am content with the increased height as my lane and local speed bumps discourage low ground clearance. ( one of the many previous owners had punctured the sump and the patch is now beginning to weep so I am very conscious of repeating the trick )

[FunElan]

Bumping this thread as I've installed the GAZ shocks with federal springs recently and had the car aligned (as detailed here: viewtopic.php?f=41&t=30280&p=382379#p382379)

Another data point, my fender heights after the alignment shop did their thing are all around 62.5cm. Since the manual uses chassis height, I measured the back of the chassis and it was 154 mm off the ground, similar to what the chassis says. I will say that the car is way too stiff and rides like s**t now though. The GAZ are tuned to 4 clicks in the front and 2 in the rear.