Been noticing more recently an odd handling issue on the straight. Initially I put it down to crosswinds; felt like the car was being pushed sideway, but now it seems to be getting worse.
I have the full Performance5 Puredrive setup (shocks, pigtail springs, Mk2 tops). At first I thought maybe the worn Michelins were to blame, but these (on the rear) have been replaced with Toyo PX4s (allegedly the T1S replacement); fronts are fine, with no change. I keep the tyre pressures at 28PSI (always have done). Allowing for 100 miles break-in, there is no difference. On the commute this morning, it felt positively scarey. Had a chance to check each of the shocks carefully. No leaks; all 4 rods are dry (in fact the shocks look as they did when fitted). No play in the wheel bearings, or knuckle bushings. The only thing that was amiss was the lower locking spring perch nut on the nsf shock being a bit loose (P5 only supply 1 C-spanner and assured me that was sufficient, despite it being physically impossible to nip up the nut with only 1 spanner).
I’m stumped; short of taking it to WIM for another check (last done in May, 30k kms ago, and previously, I had never bothered in 10 years of back roads driving in Ireland. In May, the car only needed minor caster changes, so I’d be really surprised (but maybe not) if something has worked loose in 6 months, any other suggestions. My last thought is is the cold weather having an effect on the shock oil in the Protech shocks+ I’ve read that Bilsteins can be affected (get firmer). I’ve adjusted the shocks from 8F/9R to 7F/8R (what I had most of the summer), to see what difference that makes.
Just a idea and dont take this the wrong way
i have just put Puredrive shocks and complete new bushes all round on my Mk1 5 on the first test drive rear end was all over the place so back to garage check everything was tight and could not find a problem. I was stumped!!!. Then i checked the adjuster on the shocks i realized i had made a boo boo i had set the drivers side to 10 clicks to the front but i had also set the passenger side 10 clicks to the front ( yep i bet you all spotted the mistake) because the shocks are the opposite way round the passenger side should be 10 clicks to the back. So just check that you haven’t done the same, this caused the back to sway from side to side at speeds above 50 mph just an idea
Over the years this has come up a few times, and has often been caused by the tyre mix. I know you don’t see a problem with tyres of the same construction but different makes, however this has proven to be a problem for many people, me included…have a happy new year----
No, this is a problem that has come on in the last few weeks, not after I made any adjustments to the shocks, nor tyre changes. In 11 years, I have had all sorts of tyre combinations, but never what is happening right now. In fact the problem first appeared when I had 4 Exaltos on. I think I have eliminated tyres (just in case Michelins display Yokohama-like loss of cold weather grip when worn), since the issue persists.
Thanks for the advice anyhow.
The plot (or shock oil) thickens. After adjusting the shocks dow to 7F/8R, a 100 mile trip to Salisbury on saturday morning showed a distinct improvement. The return journey on a freezing sunday evening was more mixed. After 30 minutes or so, the tendancy to chuck me into the nearest ditch diminished, but was still felt. On a twistie B-road, it more or less disappeared.
Proved to be what I thought (and confirmed); in very cold weather, the shock oil will increase in viscocity.On a B-road drive, the shocks will be sufficiently worked to warm up. Apparently, to a certain extent, the change in shock performance can be detected on a stock set-up. My thoughts are, on a Mk1, with standard bumpstops and mounts, you’ll spend so much time hitting the bump stops (which the system is intended to on the rears), this variation is masked to all but the most sensitive of drivers. I have a setup that uses Mk2 topmounts and poly-bumpstops. With the extra travel, I expect to hit the bumpstops a lot less.
It seems the cure in very cold (unusual) weather is to take your settings down 1-2 clicks for road use, and accept this is less than ideal for fast cornering, but at least you won’t end up in a ditch. Even the small thaw in the last few days has seen an improvement for me.
Sometimes when driving off on a cold morning I could swear I have a flat tyre.
5 minutes down the road and it feels much better.
Then again maybe it’s just that the road where I live is particularly bumpy…