Section XVIII Interior & Instruments

Warning:- Before carrying out any modifications to the standard design seek written approval from the Kit Designer. Use only high quality materials and fasteners and lock all threads. This applies particularly to Safety Critical items such as Brakes, Steering & Suspension Components.

SVA Note:- My car failed the SVA because the Dash was NOT sufficiently padded above the passenger footwell. A well padded Dash lower edge would seem to be mandatory. Before you go any further see last paragraph below:- New Instrument Panel and Dash

Now that all the interior components aft of the cockpit are completed, Fuel Tank, Pipes, Sender, Brakes and Boot. We can turn our attention to the Propshaft Tunnel Cover and the Dashboard. There is little point in having the tunnel cover removable as there is nothing under it anyway, apart from two chassis tubes very close together. Before fitting, take time to consider what pattern of gear lever rubber boot or cover you intend to fit. Altering the hole before fitting is easy, afterwards almost impossible. Position this with the large hole central to the Gear lever making sure that the lever has full movement in all 5 gears, and pop rivet in place as before. Peen over the edges to give a smooth round line, which in due course will be covered by carpet etc. The font end curves sharply upwards to meet the dash proper and will need trimming and peening to blend in. If the dash is to be removable, fix the panel to the base of the dash with a couple of c'sk screws only. This is well covered in the video. A leather gaiter will need to be sewn up to cover the panel gear lever interface or you could modify the Sierra gaiter.

The Sierra Instrument Cluster needs to be modified to fit the stainless steel dash panel and again this is well covered in the video. The problem with the video method is that there is a very good chance of getting plastic swarf into the works, scratching the dials etc. After removing the 6 self tappers holding the clear plastic front, carefully remove the 5 holding the back in place. Hey presto ! the front falls off. Take care with the foam gasket. The front panel can now be cut down as required, away from the actual instruments, before refitting. (turn the foam gasket over to give a fresh face) Any scratches can be touched up with matt black aerosol to give a perfect job. After trimming there are still 3 holes and 2 brackets left in the original panel which can be used to fix the instrument panel to the dash.

While you have the instruments stripped down remove and check the bulbs and give them a polish. Remove the Speedo by very carefully pulling of the pointer and undoing the two screws and alloy clips at the rear. The mileometer drum is retained by a small plastic clip and once the drum is removed you can clean up the numerals, it is surprising how dirty they get, and then wind it forwards to 00000. Refit all the parts in reverse. This is known as "clocking" in the trade and is illegal. But as we are effectively building a new car (the instrument panel could have come from anywhere, so the mileage on the clock is irrelevant as far as the cars history is concerned) I am sure this is perfectly legal. I set mine to 99900 so it will turn over to 00000 during running in, ie. after about 100 miles.

These instructions apply only to the Sierra Instruments fitted with a Speedo and a Rev Counter plus Fuel and Oil. Others can and do vary. (who wants a sports car without a Rev Counter) There is not a lot of room between the chassis tubes for the Sierra instrument cluster, and this more or less determines the final position of the stainless steel dash panel. The best approach is to position the dash centrally and sitting as low as possible, you may need to trim a little off the panel to clear the steering column behind the binnacle. Once you are happy with the location, loose clamp and mark off the position of the two vertical chassis tubes at the rear of the dash. Ignoring the old cut outs, mark off a new rectangular aperture, that will sit centrally between the tubes and low enough to use the two top plastic clips on the cluster. This will be approx. 314mm x 105mm with 12mm rounded corners. This size cut out should remove the old RHSC's laser cut holes, which are the wrong size anyway ! Drill 6 holes in the clear plastic supplied. This is very brittle. Round off the 4 corners, and fit next to the panel, use the turned over vinyl as a gasket. With the instruments mounted in the new aperture, the dash can be loose fitted with a couple of self tappers, marked up and final trimmed to size.

There is quite a lot of excess material to remove from the top face of the dash, which should be marked off in conjunction with the final position of the scuttle. (this is due to the fact that RHSC's do not intend that the scuttle fits hard down on the top tube. See section on Bonnet. ) This will eventually be covered by the scuttle overlap. Cut a little loose to allow for some anti rattle-trim on the top edge and the turn over of the vinyl. Any excess can now be cut off the tunnel cover where it folds up to meet the lower edge of the dash. I covered my dash with a layer of foam rubber and fitted some clip on edge trim to the lower edges, wrapping the foam over this. The whole lot was covered in black vinyl. The Sierra instrument cluster fitted last. The screws show but this is unavoidable, without going to a lot of trouble. Bear in mind the requirements of the SVA, as they are very particular in this area. Radius of screw heads, knobs, switches etc. Fit the standard Sierra instrument layout until after the SVA when you can do as you wish. Another point for the dash is the lower edge. This will need a radius to comply with the SVA. You can either fit a foam trim or peen the lower edge inwards with trim on the sharp inner edge. Your vinyl will wrap over this anyway ! Use the radius edge (bull nose) off a scrap kitchen worktop as a former, this works quite well. See photo'. My Dash failed the SVA, see Section XXV The SVA Test.

Note:- The Tunnel Top is a bit of a problem as when it is folded down over the top tubes the pop rivets for the sides get in the way. I got around this by removing about 4mm from each side of the RHSC's blank. When folded round it just misses the pop rivet heads. Fit this panel before the Dash as it slips under the lower edge of the dash but the compound fold needs to mate up exactly to the lower edge of the Dash. see photo. This compound bend is a real b----- to do properly. Do not worry too much as the whole lot is covered in carpet or vinyl anyway !

The carpet supplied by RHSC's is a bit on the heavy side, but there is enough supplied to do the your Lounge as well. !! I bought some very good quality soft black car carpet at a kit show and used this to carpet the Seat Back Panel and the Tunnel Top. With care you can carpet the Tunnel Top with one large piece that runs from the Seat Back Panel right through to the footwells. Just a couple of small triangular gussets are required near the seat fronts. Use the unwanted RHSC's carpet as a pattern and fix using the spray on adhesive, more or less spraying as you go. You will need a couple more cans but these are quite cheap from most DIY's.

The Harness & Seat fitting are covered in the Handbrake section.

The Interior sides were trimmed using 3mm hardboard panels, cut to match the interior sides. Allow clearance for the cross tube on the floor and the seat belt mounting bolts. Paint the hardboard panels with marine varnish all over, including the insides, paying particular attention to the lower edges, as these are bound to get wet sooner or later. (you could of course use marine ply) Fit the carpet with a combination of Evo-Stik and spray on adhesive, then trim off any excess carpet. Once the carpet is fitted give the exposed inner faces another coat of varnish, and as it goes tacky cover with thin polythene sheet to keep any moisture out. Secure to the side tubes with self tappers and cup washers. Note that the area adjacent to the Throttle is VERY cramped. Finish the panel on this side at the vertical chassis tube and stick a layer of carpet directly to the side panel from the tube to the footwell end. This gives the side of your shoe something to "bite" on rather than a sheet of St Steel. Floor carpets can use the heavy RH supplied  material fitted to some 12mm ply, this raises your  feet a tad, as the pedals are a bit on the high side. This is all best left as a final job once the car is more or less complete. Trimming the interior of cars is a specialist job and is covered in many good books.

The open area underneath the dash scuttle area (over your legs) must be filled in with suitable material, leathercloth covered hardboard or corrugated plastic have been suggested as suitable. Do not overfix as it may need to come off from time to time. I used the heavy RH carpet, quite loose fitted, and this passed with no comments.

New Instrument Panel and Dash

After having gone to all the trouble detailed above, I finished up with a Dash panel looking like a cross between a feather mattress and a black leather Li-Lo. All to fulfill the requirements of the SVA, needless to say it came off as fast as possible. The replacement was a bit of a lash up as I was keen to get out on the road, and after 2 years hard, work getting a set of non Sierra gauges to work was one job too many. With the car off the road for the winter, this was one of the first jobs on my lay-up list. I picked up some Smiths Classic gauges at Stoneleigh and the new dash incorporates these plus one or two left over from a previous build. (a full set of new Smith's Classic gauges and senders will set you back £600.00 !!) The old slider controls are out, as a heater is more or less a waste of time, if it's that cold stay at home. It is now set to 'demist only' and controlled by the illuminated fan switch. No fan no heat.

The dash is cut from a sheet of 3 mm hardboard, covered in black leather cloth with no padding. Give the dash a good coat of varnish on both sides before fitting the leather cloth as bare hardboard absorbs water like a sponge. The bottom edges of the dash are slightly flared, and mdf does not bend like hardboard. It is possible to convert a Smith's Classic Positive Earth Tacho to Negative Earth. The old St Steel panel was used as a template and all the gauge holes were cut just a tad oversize so the gauges were a tight fit with the leather cloth trapped down the sides of the hole and folded back on the inside. Problems were experienced with the original steel dash getting the leather cloth to adhere. With a hardboard dash the glue grips much better. If you are really clever you can secure the dash from the rear with no screws showing to the front at all. All gauges require an earth. See Wiring Appendix XI "Smith's Classic" Instrument Connections

I have retained the old Sierra Instrument socket and made up a dummy plug from an old PCB edge connector with 0.200" pitch fingers, then soldered some new wires (of my own colour's) to this. These wires go to the new Gauges and Warning Lights. Using this method it is possible to revert to the old Sierra dash unit should the need ever arise. The Premier Wiring Systems Loom includes wires for individual gauges, such as the oil pressure sender.

One problem with older gauges is voltage stabilization. A nominally 12 volt battery can go as high as 13 or 14 volts and well below 12 volts after a cold start. This causes the gauge readings to vary in line with the battery voltage, so a voltage regulator is required. (most older gauges are designed to work on 10 volts anyway, so beware, as the full line voltage can cause serious damage the gauges, and give false readings to boot. ) The voltage regulator Europa Part No.BR1307 (a similar unit is built into the Sierra Instrument Panel) gives out a more or less stable 10 volts with any input of between 10 & 35 volts. If you do buy a Speedo make sure it is the correct type ie. revs per mile etc. This is covered elsewhere in some detail, and also ensure that the cable end fitting is the same as the Sierra. Much better to go the whole hog and get a modern electronic unit. Fully adjustable and no speedo cable to worry about. Just expensive.

A 'mechanical' oil pressure gauge has been fitted to the Pinto block via a special manifold. This allows the existing oil pressure warning light to be retained (1/4" BSP Thread). Parts were obtained from Europa Specialist Spares. Capillary tube - LMA004, Manifold (Tee Piece) - TPV, Adaptor Bush - LMA009. Smear all threads with Red Hermetite jointing compound.

The finished Dash.

The end result is a very professional looking dash, fully in keeping with the original Lotus 7 and the rest of the build.

See also Section XXI Heater/ Demisters and Wipers.

 Go to Section XIX

Copyright Text © Colin Usher 2011 Illustrations © Colin Usher 2011

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical or photocopying, recording or otherwise without the prior permission of the copyright holder. Except for private & non-profit use.