Crashing over bumps

[Nigel]

The heading is a bit crude but...

my HPE is very noisy over bad roads, as if there's no shock-absorbing or at least very little.
This noise is from the front, I don't hear much from the back end. Its been like this since I
first drove it.

I fitted new rear shocks early on as one was weeping after its first 'real' trip out to Brands Hatch in
Aug 21. These were from Mark, complete sealed units.

Much later, and although the fronts weren't leaking and were functioning well, new is better, right?
I installed inserts with welded-on collars, also from Mark, in around July 23.
These also made no difference to the feel or handling, and the car was and still is very 'crashy' on
rough roads.

My recent thoughts have turned to the front top mounts and whether the rubber has hardened over
time, and no longer providing an 'insulating cushion'.
I wonder ,also, whether a strut brace would improve things, (or make it worse)

Your thoughts and experiences would be welcome.

Nigel

[squiglyzigly]

Hi Nigel,
I share your views on ride quality and I think we are spoiled by modern cars with extremely good insulation and isolation. In large part this is due to very good chassis strength.
My belief is that chassis stiffness has a very big part to play in ride quality. My view is that a stiff chassis does not necessarily give poor ride quality. Quite the opposite. A stiff chassis gives good sound deadening (a bit like a high end speaker enclosure) and allows the suspension to do its job. The suspension struts do their job controlling damping but a flexi chassis is completely uncontrolled.
Whenever I have fitted a strut brace it always feels smoother and better controlled.
Hence my HPE VX resto has become my project ‘SuperRigida’.
I doubt the top mounts hardening are causing the issue as you are stuck with the preset shocks.
Adjustable damping shocks will undoubtedly give you choice and adjustable high/low speed bump/rebound damping would be a dream. But deep pockets I do not have.

It will be next year before I can test project SuperRigida but I’m confident it will not be a harsh ride.

Ian

[peteracs]

Hi Nigel

Have you replaced the front wishbone bushes and /or anti roll bar bushes?

Just a thought

Peter

[Nigel]

Hi Nigel

Have you replaced the front wishbone bushes and /or anti roll bar bushes?

Just a thought

Peter

Hi Peter, yes, all replaced with poly stuff during the initial recommission.

Thanks for your thoughts Ian. I'll try a brace, nothing to loose!

Nigel

[SanRemo78]

What state are the engine and gearbox mounts in Nigel? Dampers too? Might it be the drivetrain bouncing around making noise?

Guy

[peteracs]

Hi Nigel

Poly bushes I would have thought will give harsher ride, but clonking as Guy says, you should check mounts and these dampers are often gone if original.

Peter

[SanRemo78]

Poly bushes will 100% give a firmer ride but also nail the suspension down and allow suspension set up to be set correctly (where adjustment is available!) and should give more steering "feel".

I've fully polybushed the car but it'll be a while before I get to drive it! The Stratos is fully polybushed and Rose jointed and it's a huge improvement over the original rubber/sleeved joints. The Alfa 159 is also fully polybushed at the front but the quality or design isn't quite right as they dry out and squeak constantly in the dry. But the plus is that the geometry is perfect and the car no longer wears out tyres for fun!

Sadly I'll be selling that car soon!

Guy

[Nigel]

Hi Gents,

All 3 engine/gearbox mounts were renewed during the recommission
around 4 years ago as were the engine/gearbox dampers, although I used
off-spec dampers. ( I recall one of them was a Mercedes item)

You've given me a lot to look at, and maybe I'll find a loose bolt or two.
A good point is that the original set up was not designed for such 'stiff'
polybush mountings. This may well be a part of the issue.

Nigel

[SanRemo78]

I don't think polybush mounts should create any additional noise Nigel (unless it's dry squeaking).

Check the subframe bolts are tight too? These noises can be a right pain to track down!

Guy

[kbetas]

Hi Nigel, can't remember if you're on std or lowered springs?.  I had exactly the same feeling you describe with our black HPE on lowered springs. The front was so stiff it just didnt move and even going over small speed bumps slowly was painful. Our rear shocks were also shot so the rear just bounced up and down on the springs. We replaced the rears with std struts from Mark as well as the fronts with new inserts / welded collars. At the same time we swapped back to the std springs and I cannot emphasise enough how much nicer the car is to drive. At standstill the front now moves when you press it down and it feels like the shocks are working properly. The rear feels softer than the front but once on the road the ride is a massive improvement and stays surprisingly flat when cornering. I've got some speed bumps on the road to my office and i can now just drive over them as if they dont exist!. My gut feeling is the front inserts were compressed too much on the lowered springs limiting movement of the suspension and unbalancing the front Vs rear.  Cheers, Kevin

[WestonE]

Hi Nigel,

When I used lowered Springs on OE platforms many years ago I halved the height of the front bump stops because they were being used too often. Other than a smoother ride I had no other issues.

Just a thought are you simply running out of front suspension travel too early?

Eric

[Nigel]

Thanks both for the input.

Kevin,
It's on standard springs and as far as I know probably original. Sounds like we have the same shock specs!
Do your rears need 'priming' after a layoff? In other words, if I bounce the rear there's no damping
until a few presses are done.

Eric, I don't know. It's going out for a drive on Friday. Before I go out I'm going to check all the
obvious bolts and also attempt to check for up/down travel.

Nigel