AR7E - Alcester Racing 7's Equipe
|
|
|
| AR7E HAS MOVED!!! Please click here to view the current version of this page - the page you are viewing will not be updated - or if the link fails, try: WWW.ALCESTER-RACING-SEVENS.COM
If you've read the aeroscreen introduction page, you'll probably have realised that the installation was not terribly smooth - well, let's just say that we made mistakes so that you don't have to... This discussion is a little long - not inappropriate given how long the process took... First up - the general plan was to install the aeroscreen in such a way that the standard full-screen could be replaced at will and with minimal signs of additional holes etc. required for the aero. The JPE screen is attached to the car by five wedges and bolts (see photo below - shows the perpex screen (top half of image), a rubber sealing strip, the mounting wedge sitting on washers and the ali scuttle panel (bottom half of image)).
<Click Image for Full Size> This requires five holes to be drilled in the scuttle with bolts fitting through from the underside. In theory, the new holes can be placed underneath the areas where the standard screen seal goes - so when the full screen is back on, you can't see the holes. Now, this is all very well and good - but we've still got to think about the placement of the mirrors. Original Superlights have the side mirrors mounted directly onto the perspex screen and the center mirror bolted onto the scuttle. The trouble with this is that it is easy to crack the perspex (especially if someone bashes into the mirrors). The mirrors also vibrate more, and the centre mirror requires more holes drilled. After some experimentation, we decided to mount the mirrors directly onto the shoulders of the scuttle and to use our much-loved 3M DualLock (Mans Velcro...) to attach the centre mirror to the scuttle. So, the general plan was to:
So where does it all start to go wrong... Well, in the car in question, the previous owner had fitted the optional 'knee trim' panels that tidy up the inside shoulders of the dash. Unfortunately, these had been riveted in and it was a pain to drill the rivets out... You need to remove these panels in order to get to the inside nuts that hold the full screen on... Right, what next... Well, I suppose that the fact that the screen is not perfectly formed is unfortunate. Perspex isn't a tremendously high-tolerance material, and I think our screen was made on a Friday night by an apprentice... so basically, the holes are not going to be entirely symmetrical about the center point. This makes the drilling a bit tricky - you have to mark and drill the centre, bolt the screen into place and then mark up the next two furthest mounts before removing the screen, drilling and finally repeating the process for the outer mount points - if you don't do this, you can't work around any small variations in manufacturing tolerance in the screen. OK, none of this has been too hard yet - drill out a few rivets and take care over the screen mounts. What's the big deal...? Ah, well, you will have started to curse a bit each time you attempt to fit the bolts during the two trial-fitments needed to accurately mark out the hole positions. There just isn't enough room to comfortably drive bolts up from the underside of the scuttle. It gets even worse when you try to fit the bolts for the two outermost mounts (on the shoulders of the scuttle). They are in such awkward positions that it is hard enough to get your hand to them - let alone with a tool or bolt. The solution? Well, we found that creating some new, long, 'wing bolts' helped. Instead of the screw-headed M5x15mm bolts, we obtained some M5x25 or M5x30mm bolts and fitted wingnuts to them (basically tightened the bolt into the wingnut sufficiently hard that they became very good friends. This allowed a contorted hand to reach and tighten the bolt where conventional tools failed. Getting the bolt though the hole in the first place was pretty tricky - again, we'd suggest loosely gripping the wingbolt head with a tie-wrap and then offering this up to the hole. Once the shaft of the bolt is through the hole, you can grab it from the outside, remove the tie-wrap and then get your hand on it again from inside. You will need a lot of patience... Oookay - that sounded pretty irritating, fiddly and good for a few skinned knuckles, dropped bolts, snapped wiring (have you looked under your scuttle recently...?). Any other gotchas? Sure... Before you did all of the above, I hope you noticed in the picture of the mounting wedge (top of the page) that we'd applied some 'rubber' strip to the edge of the screen? The purpose of this was twofold - firstly, the contour of the screen does not perfectly match the contour of the scuttle - so you want to seal any gaps. Secondly, the edge of the screen could damage the scuttle skin - so you want something to cushion the two. The seal is a 'U' section strip, by the way. Trouble is, it seems ridiculously hard sourcing some UV-stable, soft rubber U-channel in an appropriate size. We ended up with something harder than desired and containing metal U reinforcements to maintain the contour. Heavy then... But nothing else seemed to be available, and after the hassle of fitting the screen in the first place, a better solution can wait... (Note - you might need some washers - see photo - to raise the mounting blocks up to match the thickness of the U-channel walls...) Alright - so a bit of foresight is handy. Surely that's the end of the problems...? Patience, grasshopper... Mirrors then. Centre first. The SPA GT center mirror is mounted on a steel, oval stem which in turn sits on a triangular steel plate. The plate has three holes drilled in it - intended for bolting the hole thing straight onto the car. These holes will be hard to cover when the full screen is on - and quite frankly, if you think we're going to put any more bolts up through the scuttle after the hassle we had with the first five, think again buddy. So 3M DualLock it is then. This stuff is strong - but it still got us... Normally, to separate two items connected by DualLock, you need to peel them apart - you can't just pull the whole lot away in one go like traditional Velcro. Now, just think about the design of the centre mirror. The mirror casing is large and directly in the airflow. It is also (as standard) 100mm high up on top of an oval column. This gives pretty good leverage... The triangular (equilateral) mounting plate can be oriented in only two ways - point forwards or point backwards. With all that leverage at speed, point forwards means that initially, only a couple of mm of DualLock at the point is preventing the whole lot from unpeeling. Bad news. Point backwards is much safer - it means that the leverage has to overcome the entire width of the triangle before the DualLock starts to unpeel. In addition, you will remember from the intro page that we replaced the 100mm post with a 40mm one to allow the mirror to allow a view underneath the FIA diagonal (pictured below to break up the monotony of the text...)
<Click Image for Full Size> Incidentally, you'll notice that the view of the rear mirror is not entirely clear even with the revised stem height... Better than before though.
Ah, so where are we now? All done and dusted? Rats. Side mirrors! OK, you'll have realised that you need taller side stems. Not really a gotcha. How about the mounting system? At the first attempt, we drilled the holes in the scuttle shoulders and tried to get nylock nuts onto the bolts that are passed through from the outside. Pretty much impossible - there is so little room to get tools into due to the close proximity of various chassis tubes (hint - before drilling, check with a magnet to see if there is a hidden tube just where you want to drill...) Now, this wouldn't be too bad - except that to adjust the mirror angle, you need to remove it from the car (the locking mechanism is on the inside of the mirror mount...) It just ain't worth the hassle. So, bring forward Rivnuts (also known as captive nuts etc.) If you've not come across these before, think of them as very large pop-rivets - but with a thread down the centre. They are applied in a similar fashion (different tool though...) from the outside of the panel in question and allow you to fit bolts into thin sheets. They are absolutely ideal for this application - just drill slightly bigger holes (about 7mm for a 5mm eventual bolt size), fit the 5mm rivnut and then just bolt the mirrors on from the outside. Takes about 1 minute to remove/replace the mirrors instead of perhaps 30 (I kid you not) if you try to fit conventional nuts from the inside. Is that it? No more gotchas? Go to the Gallery for some pictures including the mirrors in both configurations. Schools out! Yep - that's basically it. You might want to add some additional fixing points for your tonneau (without much extra help, ours is secure up to the max speed of the car) - and you definitely want to take some time thinking about eye/ear/head protection, but that's it... ...apart from the post-script. A day or so after removing the full-screen, it shattered (well, terminally cracked in a BIG way). We suspect that as the screen/frame was no longer stressed by being bolted to the car, the glass just relaxed to the point of destruction. We would therefore recommend that you physically remove the glass from the frame and store separately. YMMV though...
|
|
|
