Does anyone have the Simply Performance suspension kit with Gaz shocks and Eibach springs installed? Would like to get real world impressions of the setup. Looking to make my '87 V12 feel more like a sports car and less of a cruiser without being harsh.

Also interested in real world experience with non-factory suspension bushings. Some people say to change just the top front, some say just do the bottom. I'm interested in harshness and longevity.

 

I think I would rather sorce the parts
myself, you can probably beat there
price by buying from the manufacturers

 

I've done harder KYB springs and Superflex (used in the race cars) bushings. I looked into the springs but it was abit pricey ontop of my already volumous shop bills.

I believe lower front bushings need to be OEM to absorb road harshness otherwise your transfering too much damage into other components. Most people suggest retaining OEM large radius arm bushings I somewhat agree as my radius arm mounting posts began to tear without reinforcement...they failed due to excess movement in the mount and I did OEM metalastik there.

Rotating OEM radius arm bushings so the holes are side to side not front to back is a technique used to stiffen up OEM to "Sport" quality.

Overall I strongly recommend poly all around (except that front one) as it transforms the car from a luxury boat to a very sharp sporty car. Important to not forget the shock bushings (yes they have bushings to) and stiffening that up with polyurethane options does wonders aswell, aaaannnddd front and rear subframe mounts.

Lots of bushings.

 

I am waiting on my kit to arrive from them, note they are having issues at the moment getting all the parts in stock.
Whenever I get them on the car I'll come back and give an update.

 

jal1234

I have Eibach springs and Gaz shocks on the rear of my 4 litre convertible and Eibach springs with Bilstein shocks on the front. Suspension bushes are new standard all round, steering rack bushes are poly and the radius arm bushes are rotated 90degrees as per XJR-S spec.

The set up really suits me. I have:

- the compliance and ride that Jaguar designed with the standard bushes
- much better steering precision with the poly rack bushes
- flatter tighter ride with the drinks and shocks
- better axle location with the radius bushes turned round
- correct ride height through using adjustable height Gaz on the rear


It's worth spending a bit of time with the Gaz rear settings to suit your driving style. I set mine way too hard initially and the car skipped and bounced all over the road! I then changed the setting to 9 or 10 and its perfect now.

Go for it! You won't be disappointed!

Good luck

Paul

 

Thanks all for the replies. I will go with this setup.

 

Just re-reading my post i meant to say that I have a tighter ride with springs and shocks! Although I guess I might also have a tighter ride with drinks and shots!

Paul

 

Right, my kit from Simply Performance has arrived (along with polybushes for the steering rack) and I will be getting it on the car in the next 2 weeks.

I have seen lots of suggestions across this forum for rear setting (between 9-11 clicks from softest) but does anyone have experience with the fronts.
Should I use the same setting all round, or go slightly firmer at the front as more weight it there?

 

I used 15 to 17 clicks from the softest on my gaz fronts.

 

I started out on 11 clicks, and shocks are like solid rods for several kilometers. Front end bumping like if wheels were 7-sided polygons. Shocks eventually loosen up, but I want a car with suspension from start up.
I have them on 4 clicks now, which is soft, but actually still well dampened, so I need to get under the car again and try 7 or thereabout.

 

I have now had the suspension fitted to the car so can give a quick review for anyone looking to purchase the Gaz + Eibach suspension kit.
1. Do not set the shocks to hard to start with as Leo states. I had started on 10 on the fronts and 7 or 8 clicks (from softest) on the rear however the combination of crap country roads and rock solid suspension was ... interesting.
Turned the rears all the way down at the moment and the car feels a lot better (like original ride). However, there will still be some adjustment to get the correct ride height in the rear + plus i need to get a proper alignment done.

2. May just be having new suspension, but on preliminary drives the car definitely 'feels' better. I do not notice any body roll and have a lot more confidence going though corners with more speed (if that is what you desire.)
Obviously, it is still a very heavy car so I wont go saying that it is now a B road carver but I have more chance to do that without feeling I'll go off into a hedge at the next 90deg corner.

3. Cost for those interested; the kit cost me around £1200. So not cheap, but for 6 springs and shocks averages out to £100 per item. For adjustable suspension, which I hope will last for some time, I was happy with that.
Unfortunately, even though requested they forgot to assemble the rear springs before shipping them (however that was to ensure I got the parts quicker as they had troubles with stock).
Plus with nowhere to work on my car at the moment, that meant I had to pay for labour. My car with rusted spring pans and bolts which likely never had been changed was around 8-10 hours work (+polybush steering rack and other minor things);
cost that as per your areas labour rates.

All in all happy to have new suspension, even if the wallet is a little lighter .

 

Greyhound,

Good to hear that you've got everything fitted!

I'm intrigued by the fact that you've got your rears set to the softest setting (If I've understood you correctly?). I'm also assuming that you have the adjustable collar height Gaz on the rears? I had the original Gaz shocks and then changed them for the adjustable height ones as it was the only way to guarantee to get the height settings as per Jaguar spec.

I'd initially set my rear shocks at 17, as I thought that might be a nice firm setting. Wrong!! The car was almost undriveable, bouncing and skitting about everywhere. I then gradually softened them off and now run on 9 or 10 which gives a compliant but fairly tight rear end. But I find it really strange that you would back them all the way out to zero? That would seem to make the car really soft. So I wondered if you had set the ride height so the springs were tensioned up? What ride height have you got the springs set at?

Cheers

Paul

 

Paul,

Yes you are correct in thinking that at the moment the car is sitting a little high in the rear and and I have probably backed it off too soft. But I have to drive to work and didn't want a rock solid car for the short trips that I have to do.
When I get time this weekend I will be focusing on the adjustments then. Note as well that the springs will need to settle etc. as I'm sure you aware.

 

I agree with Paul, I think you have the spring pans too tightly wound up.

 

Greyhound,

When I had the fixed-height Gaz shocks with the Eibach springs, my car rode a fraction low, which is why i changed them for the adjustable height ones. As you mentioned your car is riding high, I assume you do have the adjustable height shocks and they've just been set too high.

In my experience, as soon as the car is on the ground and laden, the springs won't settle any more, so i believe your car will stay at that height now.

I would suggest you might want to adjust the collars and set the ride height correctly. Remember on your car, the ride height is measured from the base of the rear cage to level ground. I susoect that once you've set the ride height, you'll then need to turn up the shock settings. Maybe start at 8 clicks.

Good luck

Paul

 

I'm finding this to be a very useful discussion. I've been considering GAZ shocks but now I'm having second thoughts.

As I understand things the adjustment knob allows for (something like) 30 or 36 different settings...which seems useful for fine tuning.

But, I'm getting the impression that less than half that adjustment range is actually usable for street driving, yes?

Or, is the range from (let's say) 5 clicks to 10 clicks enough to satisfy most any driver?

Cheers
DD

 

Doug
I have used Gaz adjustables (not platform adjustables, just bump and rebound, which are on one knob with a set ratio between the two) for years. I started with them because with regular high fastish miles the OEM shocks went home in about 10 to 15000 miles. The Gaz shocks proved to be really good and durable. I found that the road-range of adjustment is from about click 5 to 13 on the rears, and 9 to 16 on the fronts. I wanted to duplicate the OEM ride, and as I said, just bought the Gaz for their durability. The advantage is that you really can tune the ride pretty much exactly to your taste, and (say) on the rears, a click or two really does make a difference.

 

Doug,

I echo Greg's experience about the rear shocks. There is a large range but anything above click 14 seems almost unusable. Because of the large range (24?), I set mine to 17 clicks when first fitted, and frankly the car was almost dangerous to drive on the way home, skitting the back end out on roundabouts. I then found out than even the racing XJSs never seem to go above click 13. so reset mine to position 10 which is great.

I'd really recommend them to any XJS owner. The differing quality of aftermarket springs means that it's now really difficult to get the ride height correct when you change springs on an XJS The adjustable collar height Gaz means you can set the rear ride height precisely and then tune the bump and rebound to suit your driving style.

Paul

 

Paul
About a year ago I bought the last set of rear OEM springs that Moss had,, and typically only now am I am just in the process of fitting them. They are definitely OEM ones, but they are completely different from my originals. 10 coils instead of 7; slightly wider internal diameter; different spring rate from the original spec. In fact the actual spring wire the originals were wound from is no longer made! In the early 1990s Jaguar went to a common spring set it seems, rather than, as before finely tuned springs for each model or even sub-model.
Because of the ride height unadjustability problem with any set of springs - particularly if, like me, you have a selection of genuine used factory springs and selected the best condition ones to put on the car - my ride height has never been exactly as I would like it. One side is perfect, the other about an inch higher - I measure the height to the wheelarch. So I have recently bought a couple of platform adjustables to fit on the side that i want to adjust, using the new springs both sides,
I have also established that the Berkshire Jaguar Components springs are the best quality ones around, are made in the UK, as well as being very well priced, if anyone needs new springs. But the rears, where ever you get them, will not be the same as fitted by the factory in (say) 1985.

 

Greg,

I'm sure you'll love the control you get with the adjustable platform shocks. I was just wondering why you get one side lower, if for any reason other than spring tension? I was going to suggest that if you only bought 2 adjustable height shocks, you could put one on each side to ensure you can get the ride height perfectly aligned. But thinking about it, you probably don't want 2 differently tensioned springs on each side. So that's probably not a good idea!

Let us know how you get on.

Paul