Bouncing back end - first test of new coil overs

Post by **simonc** » Fri Jun 16, 2017 7:49 am

Did a quick, unscheduled run down to Singapore yesterday. It was a good chance to feel the new mount and the coil overs on a long motorway run. I’ve done my moaning about the mount on the other post, but I did encounter an issue which troubled me somewhat, and would really like your feedback.
Bottom line is this guys, on some stretches, the back end started to bounce, and by that I mean really bounce. To the point that I felt myself bouncing in and out of my seat, it really was pretty spooky. The car didn’t step out, or slew in anyway, it was just like any undulations weren’t being damped and caused the springs to freak out.
It happened more than once, so I can’t have been imagining it or just hit a freak bit of road.
The front felt planted with no bounce, just the back end. Very disconcerting to say the least.
Any thoughts?
Thanks fellas, Si.

Craig_85 · Post by **Craig_85** » Fri Jun 16, 2017 9:33 am

Are your dampers adjustable? Sounds more like insufficient damping compared to the spring rates to me.

How low is the car? We're the nuts/bolts cracked off and retorqued at its new ride height? My opinion is this helps prevent the bushes wearing prematurely but the deflection on the bush may be affecting things slightly.

One other point it's not always immediately obvious if it is the car bouncing or you in the seat that's bouncing because of a springy seat.

Post by **simonc** » Sat Jun 17, 2017 1:13 am

Hi Craig, thanks for your feedback although I'm afraid I can't answer most of your questions. however, I can tell you the dampers are adjustable and it's certainly not the seat cushion.
I had a bit of a barney with the people who made them last, most of answers flew over my head.
I'm going to post the 'conversation' later today as I'm totally lost but he's talking now about fitting longer tubes. I'll piece together the exchanges and maybe that will help.

Post by **simonc** » Sun Jun 18, 2017 3:32 am

I just thought I'd share the 'conversation' with Farouk, the MD of the company that fitted the coilovers.

These are the tubes he's talking about. But, then I guess you all know that...

As I'm seeing Jason about the mount tomorrow, I'll get his take on this inconsistency.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Sun Jun 18, 2017 4:10 pm

That's the dampers themselves, with the thread for the adjustable spring seats.

No idea what the problem is, but sounds like they're being very fair in just wanting to get on and sort the problem out at no cost to you.

Post by **simonc** » Mon Jun 19, 2017 9:55 am

You make a fair point Iain, and of course you're right. I'm sorry if I appeared a tad narky about it. It's just that I'd had a bloody rotten week and the shock absorber thing, in among all the other crap, was the icing on the cake, if you get my meaning.
With Hari Raya coming up, I've a feeling it'll be a couple of weeks till it's sorted, but I'll speak with Farouk tomorrow to see when I can get her booked in to sort it out.

Post by **simonc** » Thu Jun 22, 2017 2:18 am

I confirmed with Farouk that I'm booked in on July 3rd to sort it all out, after the Hari Raya holidays.

Post by **simonc** » Sun Jul 02, 2017 6:35 am

Tomorrow's the big day guys. I'm all set for the re-re-set of the back end.
Any advice on what I need to tell Farouk, is there an idiot list you can share, that I can physically tick off tomorrow so I know it's all right? Ta, Si.

Post by **simonc** » Tue Jul 04, 2017 3:34 am

I'm dead chuffed to report that the job was done most satisfactorily yesterday. They fitted new, longer shafts and two softer springs at the rear. They also turned the fronts a couple of clicks softer as well.
I came home on a good long stretch of motorway from their fitting centre, so it gave me a good chance to get a feel for the new back end.
It rode over undulations much better, seeming to 'soak' them up, rather than fighting back like it did before. All in all, I think we're now sorted. Happy days.

Now, what else is there for me to fret about?...

mercutio · Post by **mercutio** » Tue Jul 04, 2017 1:07 pm

sounds like the coilovers were set for a race car its an issue i had when i fitted a tanabe rear bar to the 5g there is such a thing as too much for the road