[JAO]

I've asked the questions before - so sorry to go on but I'm ready to give up on it.

I took the car out for a good drive today to try and get a grip on what I thought the problem was. I've posted this up already but essentially I have what feels like a very bouncy front end. I've replaced the rear subframe and poly-bushed the lot, new Kyb standard shocks and the old springs, front has new wishbones, new Monroe shocks and Kyb springs. I've had it 4 wheel aligned. Been playing with tyres pressures but it doesn't seem to make much difference.

Fast smooth roads and its fine, as you'd expect, start going over undulations and the ride gets very unsettled, a few bumps and its bouncing around and bl00dy awful.

When I got back I decided to try just pushing each corner down to see how it felt. The front end can be moved slightly and it releases with no rebound, the back hardly moves, it feels almost solid, when I get some movement it transfers to the front. If I stand on the tread plate and jump up and down the front moves but the back doesn't, so I'm thinking that anything picked up at the rear is being transferred to the front. I've had the subframe components checked for the correct torque settings whilst having other work done at my local Indie.

I'm thinking that I've somehow put the subframe components back together incorrectly - is there a proven procedure to follow?

Any theories?

It was suggested that I get newer springs for the back but surely that will make matters worse?

 

[alfarian]

I'm no suspension expert Jao and you may get a definitive responce on the forum from someone who is, but I would suggest that the standard set up is balanced for the car, you seem to have uprated the front and kept standard on the back, maybe it's unbalanced the suspension, new kyb springs on the back aswell? as suggested.

 

[alfarian]

Just a thought Jao, are the front springs lowered at all?

 

[JAO]

Thanks for your help but I've covered that point. It's not lowered, these are replacement standard springs on the front, nothing special, its the back thats got very little movement and they are old springs. I reckon I might need to adjust something on the rear.

 

[seadart]

do you still have the original front springs??..
The only thing that I can think of is that the new KYB's up front have a higher rate than original even though they are specced as standard.. in other words the new shocks are not controlling them in rebound as they should.. even though they are also KYB .
Or the new KYB shocks are softer than original.. Have you spoken to KYB about this??
I would get onto their technical people see what they have to say..
I am currently running KYB front shocks with the original standard springs and all's fine.
Same on the rear.
My cars a coupe though.. so the chasssis will be a bit stiffer..
If you still have an original spring one way of checking the rate is to somehow put them end to end..(KYB and original) compress them a little and check that they both compress by the same amount.. easier said than done.. .

when you say 'bouncy' front end do you mean 'wallowing' up and down.. or.. just a hard, bumpy almost 'suspensionless' ride over crappy surfaces ?? because mine's pretty much like that and I think most other 916's are too.

I followed your rear suspension re-build on here.. and it's hard to believe that you made a mistake big enough to cause the front end to go looney..

Don't give up yet

 

[seadart]

Quick point.. KYB standard springs are not 'dual rate' or 'progressive' ..same as standard..
So therefore are pretty hard over uneven surfaces.. the only dual rate springs that I know of are Eibacks.. (excuse the spelling) but they also lower.. which I understand you don't want..

A 'dual rate' spring is a compromise.. it will give you an acceptable ride over potholes.. first few centimetres of travel.. and then stiffen up for the fast bends on smooth tarmac.. downside is.. initial roll will increase.. so they lower them a tad to offset the increased tendancy to roll on 'turn in'..

I'd talk to KYB see what they have to say..

 

[JAO]

Seadart - Thanks for the input

I threw the old springs away, when changing them I checked size and pattern which were identical so I know that was correct as for rates I have no way of checking.

The drive is weird, I can't describe it adequately enough, but over uneven surfaces the front just starts bumping up and down excessively as if its over-sprung with the shock absorbers not coping with it, add to that what I expect is scuttle shake and the combination is crap. All passengers comment the same way, its very distinct.

Theres nothing much that I can do with the rear aside from change the springs but at the moment there seems to be little or no movement there, can you get softer springs? The original springs are in at the moment.

The setup up front is Monroe Gas shock absorbers with KYB springs, so one is more likely to blame the other if I start asking for advice. Would you suggest KYB shocks??

I want to be sure about my next move as I'm loathed to throw any more money at it.

As I said the rear is very firm and I now think it's transferring movement up to the front. On assembly of the rear subframe is torquing up the components best done under the full sprung weight conditions or doesn't it matter? Will that make a difference?

 

[msgtv]

I have a similar issue, I'm reasonably sure that my new KYB XLG's just dont have enough rebound damping to cope with my 30mm drop front springs, I have the benefit of having done my suspension in 3 stages, rear 30mm drops fitted first, no issues, then I fitted the 30mm drop fronts but with the shocks from an ALFA I had stripped for parts, OK but clonk from nearside shock, so I got the new KYB's obviously that sorted the clonk but the front does feel bouncy on undulating surfaces, I'm reasonably sure that you have the same issue, I have decided to keep mine as is til next summer then fit koni's, I dont think mine sounds quite as bad as yours so maybe you need to act sooner.

Just because the springs you fitted look similar to the original ones does not mean they will have the correct spring rate, they could be hugely stiffer, `I still have my original springs here, you are welcome to them for free if you want to try them on your car (just the springs they are not fitted to shocks).

One other thing, you haven't just gone from 16 to 17" wheels have you?, 17's can really mess with the GTV,s handling (tramlining etc).

 

[Guest]

It sounds to me like you got a bad combination of springs and dampers. (Front end loading up the rear.)

Get your car corner weighed by someone who knows what they are doing.

brgds
peter

 

[seadart]

Ah! Monroe dampers.. they are not oil filled dampers by any chance are they??

If the KYB spring wire diameter is the same as original and they have the same number of turns and length they will be pretty much the same rate..

I think you have a bad combination of springs dampers.. I'd get onto KYB and ask advice.. maybe try to scrounge a pair of KYB shocks to try out on approval.. Don't know anything about Monroe dampers has anyone else tried them ???.. Maybe start a new thread asking ??

 

[seadart]

Just had a quick google.. they are not by any chance 'Monroe Reflex' are they ??

 

[alexGS]

It is a confusing one and I think you are right - a mismatch of damping rates front to rear will transfer movement to the front and give bounciness. Perhaps the mismatch is between the KYB shocks (which are, in my experience with other cars, really firm - being a performance shock) and the Monroe shocks (which are, again at least on other cars, usually just an OE-grade replacement intended for use with standard springs. My Uno Turbo is running on Monroe Reflexes and they are not what I'd call 'stiff', which is just as well because the springs aren't stiff either and the bodyshell has all the rigidity of a cardboard box). I suggested the spring mismatch as being the problem before but I wasn't aware you were using different brands of shock absorber too... sorry about that, perhaps I didn't pay enough attention

In general I can't think of any good FWD car that has more suspension movement (when you jump on it) at the front than the back... normally the back end needs less spring rate and less damping, since there is less mass there.

To sort it out with the least work necessary...
Perhaps get two Monroe shocks for the back (fairly cheap?) to go with the standard springs at the back. That might soften up the back end again and as I think we both agree, with a flexible chassis you don't want the suspension over-hard. I don't think a soft rear end ever causes any problems with FWD (it should just follow, not set the agenda). I like the way my old 164 drives - always feels like the front end is level-riding and in control - it's a bit soft in the back end (shocks worn) and bottoms out at the back over bumps when loaded with passengers. The Spider will never have three passengers in the back, so I can't see why it has to be stiff at the back end.

And if that doesn't resolve it satisfactorily, also get two standard springs for the front end (to fit to the Monroe shocks already there). I'm guessing that standard springs are left over from lots of upgraded GTVs and worth practically nothing, and springs don't really wear out unless they rust. The reason I suggest this is because I wonder if the Monroe shocks are able to adequately control non-standard springs that are stiffer/have a higher resonant frequency. Monroe shocks are advertised as giving a well-controlled ride, but I really believe they are designed around standard springs.

If you're trying to get a firm, racy-feeling result perhaps I'm wrong to recommend Monroe shocks all round and perhaps you need some KYB shocks for the front to match the KYB shocks at the back - but, are KYBs perhaps too firm for standard springs? Ever driven a Mk2 FIAT Punto Sporting? - the bumpiest-riding standard-production car I've ever had (used to give me a headache on some roads) and it comes with KYBs as standard, feel like they're filled with engine oil... Luckily the Punto has a rigid body to go with its stiff ride and it feels 'eager' as a result: the cornering ability is good right up until that rear torsion-beam axle gives a mighty twitch and bites back. Like I said, I prefer the back to follow the front, and not set the agenda...

Just my suggestions but it seems after what you've gone through, not much more to lose and not worth giving up. I think there should be a ready market for whatever bits you have left over... and I do think throwing away the standard springs was a mistake Though, I did just that with my Uno Turbo as well!

Cheers,
-Alex

 

[seadart]

I must be lucky then.. I fitted KYB shocks all round and re-fitted original springs.. simply because they weren't sagging..
and the ride is great..

I did check out KYB springs and they are sold as 'standard'.. and the parameters that determine spring rate such as wire diameter ..no. of coils.. etc. are the same.. there will always be a slight difference between manufacturers but the KYB springs are identical.. the only sure way to compare would be to test them..

I'd be interested if anyone has done this??

 

[alfapash]

I would re-place your rear springs, if they are the oridginal springs, they are probably tired and if you have changed everything else, they must be letting the set up down, it would be worth spending the cash. If the car is standard height, not lowered, get some new standard springs or equvilents. As I said mines been lowered all round on eibach springs, but has got new KYB shocks. If it's standard height keep it so. Don't give up yet. The only other thing is that a GTV might suit you more than a spider.

 

[seadart]

I'm getting confused here.. sorry
I understood that the rear was new KYB springs.. new KYB shocks
front was new KYB springs.. new Monroe shocks ?????????

If this is so.. IMO the joker in the pack is the Monroe shocks.. which in my experience have a reputation for being a little harder than standard in the damping department.. especially if they are oil as opposed to gas/oil..

maybe msgtv's suggestion of fitting koni fronts is the way to go.. at least then you can adjust them..

another daft question.. is the car still fitted with the 'damping mass' underside ??..

 

[alexGS]

I'm getting confused here.. sorry
I understood that the rear was KYB springs.. KYB shocks
front was KYB springs.. Monroe shocks ?????????

Yeah - my understanding is that it's standard springs at the rear and KYB shocks...
front is KYB springs and Monroe shocks...

Even though my advice (fit Munroes all round and then standard springs at front) is opposite to yours, I think we are in agreement that it's the matching that's important. It's good to hear that KYB shocks front and rear and standard springs front and rear work well, so that becomes the other option I guess.

-Alex

 

[seadart]

I'm on a mission..

I can't find a listing for a Monroe shock for the front of a 916/gtv/spider anywhere.. except for 'Monroe Reflex'.. which one site says 'will fit 916's'.. according to the Monroe site it states that they are ideal for light trucks.. 4x4's and SUV's and when you read past the marketing ******.. reduced roll.. firmer handling .. increased braking efficiency over O.E. etc. .. it seems to suggest that they are 'stiffer'..

I'm starting to wonder if you have been sold a 'nearest equivalent'..

just out of interest and not being condescending.. why did you fit Monroe shocks to KYB springs??

and another daft idea which goes a long way back..
to test the rate of a spring ..place the spring upright balance a board on the top end .. stick a hundredweight sack of spuds..bag of cement (metric equiv). on the board.. bit of a handfull.. and then measure the compression.. do some sums.. kg/cm.. coil springs are linear..

or place the spring upright on a set of bathroom scales.. compress the spring X amount.. read off the scales.. saves having to do sums.. but compressing the spring is a bit of a bugger.. bag of spuds..

 

[JAO]

Sorry for the confusion and absence after posting, I've just been out delivering a Caravan to a show, not in the Spider I may add. The sensation however was not dissimilar to that of driving the Spider up front!

Rears are KYB standard shocks with the old springs.

Fronts are Monroe Gas shocks (bought from and Alfa parts specialist) as they were the only ones in stock when I needed them. Front springs are KYB.

All of these are supposed to be direct replacements for standard parts.

I replaced the front springs as I thought they might be more worn than the rears.

I only wanted a standard setup, but was convinced on here that the standard shocks are not really up to much.

I am running on 17" wheels with 15mm spacers to correct the offset.

MSGTV - I will probably take you up on your offer - thanks:thumbs: Let me know where you are and I'll get over to you.

 

[JAO]

Have looked back and the monroe shocks came from Alternative Auto's - who told me they were a direct replacement for standard and they were identical in every way (physically anyway).

 

[msgtv]

Sorry for the confusion and absence after posting, I've just been out delivering a Caravan to a show, not in the Spider I may add. The sensation was not dissimilar to that of driving the spider up front!

Rears are KYB standard shocks with the old springs.

Fronts are Monroe Gas shocks (bought from and Alfa parts specialist) as they were the only ones in stock when I needed them. Front springs are KYB.

All of these are supposed to be direct replacements for standard parts.

I replaced the front springs as I thought they might be more worn than the rears.

I only wanted a standard setup, but was convinced on here that the standard shocks are not really up to much.

I am running on 17" wheels with 15mm spacers to correct the offset.

MSGTV - I will probably take you up on your offer - thanks:thumbs: Let me know where you are and I'll get over to you.

OK I will PM you.