CALLED TO THE BAR
I have suggested before in these pages how fortunate we Porsche owners are that so many brand-new genuine parts are still so readily available for so many of our cars. Most recently that came with the caveat – gained from experience with the plenumchamber cover for my lefthand-drive 944, which I had to modify with a pair of scissors – that they don’t necessarily fit as well as they must have done back in the days when the cars were rolling off the production line. By and large, though, we are in a pretty good place.
During the recent summer I encountered another interesting example of how Porsche has quietly but significantly changed the specification of a fairly key component – without any unduly disastrous consequences, it has to be said, but initially quite disappointing, none the less. Forewarned is forearmed, however, so I hope that what follows might help you to avoid a similarly inconvenient hold-up in any such project you might be tackling.
Rob Nugent and Robin Hayers, two of the technicians at BS Motorsport, are spending their weekends building a 944S2 trackday car, with me following the process as closely as possible. You might recall that a few months ago we ran a how-to feature on installing lightweight Dynamat sound insulation, to make it more comfortable to drive to and from the circuit. Next step was to attempt to sharpen up the ageing (OK, then, completely knackered) chassis, and to that end they are going for Powerflex polyurethane bushes all round, and hopefully a set of Bilstein dampers – all great how-to stories, and of which more in due course.
Rob also wanted to beef up the front and rear anti-roll bars, and had bought, brandnew from Porsche, essentially an M030-specification job for the sharp end. Intriguingly, but today perhaps not entirely surprisingly, the logo on the shiny black powder-coating showed that it had been manufactured by well-known German spring company, H&R. Knowing from previous experience that the centre section of an M030-spec 944S2 anti-roll bar has a diameter of precisely (and as far as I know purely coincidentally) 30mm, Rob had also ordered the appropriately sized bushes from Powerflex.
So far, so good. It soon became apparent, though, that while the new poly bushes for the drop-links between the anti-roll bar and the suspension arms were the correct size for the new bar, the single-piece items to be fitted in the mounting brackets to the body shell (below right) had by some margin too large an internal diameter. It was very easy to slide them along the bar, then, but there was no way they would then hold it securely enough for it to do any good. Back to the boxes they arrived in and, sure enough, the labels suggested that we had received the items we had requested, confirmed by measuring them with a caliper: 30mm, give or take a few thou.
But the same caliper immediately showed that the new Porsche/h&r bar has a diameter along its central section of only 28.5mm. Not much we could do about it on a Saturday afternoon, but the following Monday morning Rob was on the phone to the parts department at Reading, just in case there had been a mix-up somewhere along the line. Apparently not, though: the part number in the PET system definitely relate to that bar, and that is the only one that is now available to that specification. Presumably any reduction in stiffness through its slightly reduced diameter is either compensated for by the choice of material, or perhaps even deemed irrelevant. Who knows?
Pragmatically, Rob ordered from Reading a pair of standard M030 Porsche bushes, themselves now with an internal diameter of 28.5mm (so obviously someone, somewhere, has taken on board the fact that the bar had been modified), and unsurprisingly all is well. I think it’s worth knowing about this minor discrepancy, however, if only because you might suddenly find that any new such (Porsche) bushes you buy for your own car don’t fit the 30mm diameter anti-roll bar that came as part of any original M030 set-up.
As for the old (26mm) bar from the S2, after a thorough shot-blasting and powdercoating treatment that will eventually be going on my 944 to replace its factory-fitted 23mm job – complete with the appropriate Powerflex bushes, of course. And then, like the two Robs, I shall have to start thinking about what to do at the blunt end.
I did let Powerflex know about this situation, by the way, and while perhaps understandably they have no immediate plans to offer bushes for these later 28.5mm ‘M030’ anti-roll bars, it’s something they will if necessary consider for the future. So for them, too, forewarned is forearmed. Anyway, more on all this – and the rest of the S2’s frontend rejuvenation – within the next few months.