Power Steering

Eventually got round to making more progress on the power steering installation. After a couple of trial fits in the car and lots of measurements I am now very happy with the position of the column. The top left picture shows the replacement cross member – this replaces the GD cross member due to structural and geometry requirements. as well as substantially beefing up the mounting bar and the side fixing plates it has to lie in a slightly different position to accommodate the power steering. I chose to mount the power steering to a top hung bracket so the columns collapse mechanism can operate as intended in the Oem installations (hope i never get to test that out though)!

Once installed everything fits very well and the wheel position falls in the correct place.dsc_0065

only just fits in – but im happy with “Only Just”. Notice the little bracket on the square section bar with two holes – these will take further reinforcement straps fixed down the side of the body tunnel adding even more rigidity to counteract the torque of the motorised column.

New wiper motor mount cradle required. and new demister vent fabrication to allow for glovebox.

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The column on the engine bay side. A new bracket will be fabricated to fasten directly to the body at this corner location Rather than fasten it to the GD chasis. This should work  well since it means the uppermost column is attached entirely to the body, with the lower part of the of the column attached to the chassis. The next section of column incorporates a splined slip joint, so small movements between body and chassis will be taken up in this joint.dsc_0042

Final Check that wheel sits nice and square to the car and approx 120mm back from the A post shutline.

Wiring

I now have the wiring well underway. I purchased the GD body loom and dash loom but made the mistake of getting the ls3 engine loom direct from Canems. Not that there is anything wrong with the Canems ls3, on the contrary, it is clearly a quality loom but it is missing the wiring parts that connect directly to the GD body loom via the two Round pin Lucas connectors (9 pin and 5 pin). Since I cant go back in time (which would have been my preferred choice) the only solution was to obtain the Lucas plugs (these need to be purchased as pairs even though I only needed one side). Fortunately Dave at Canems was very helpful in enabling me to figure out his loom and  Luckily I have a pal with a genuine genius in electronics and what may have proved a wee problem for me, was resolved in a couple of hours between Dave and Chris. The new loom additions are now made up and terminated /labelled as well as identifying where and what everything does from the gearbox outputs, fuel pump sensors etc.

s-l1600Lucas Rists 9 Way E Series Circular Sealed Electrical Wiring Connector

Reverse Lockout Solenoid

One problem I can see is that there is no real provision for the reverse lockout wiring.

Here’s the problem00jeep0001_3Downshifting from 6th to 5th presents a distinct possibility of pushing into reverse rather than 5th. OK I appreciate that it would be very hard to push it into gear, more likely there would just be a very unpleasant grinding of gears but that still means something between a very unhealthy situation and a very nast one.

Tremec deliberately make the Reverse position very difficult to push across to to avoid any accidental sloppy driving that may event in such an outcome. and to overcome this they expect the vehicle manufacturer to adopt a control system that energises a solenoid that in effect removes the pressure required to shift across to reverse. Obviously this solenoid should only be activated when it is safe to engage reverse, so the logical control is to use the ecu and a speed sensor that energises the solenoid at speeds at or below circa 3mph.

This is not a problem for the volume car manufacturers indeed its a designed in system for safety.  However this presents a problem for the retrofit market or low volume manufacturers such as ourselves because the system is not technically complete without the control from the ecu to trigger the solenoid at low speed only. It appears there are several workarounds to this problem:-

  1. I guess the most widely adopted is to ignore it.  do nothing,  just use brute force to pull the shift lever across to reverse effectively fighting against the solenoid spring.
  2. Wire it up to the brake switch (and/or the clutch switch).
  3. install momentary switch or switch on timer at the gear knob or appropriately positioned switch to engage the solenoid for a short period whilst the driver wishes to engage reverse.

There are some other variants and combinations of these solutions but in truth they all seem a compromise over how it should work. Additionally, option 1 also apparently leads to excessive wear on the shifter parts that are being forced, probably not a big issue on such low use vehicles. Option 2 is not a real safe solution since you could still be going at high speed when touching the brake and downshifting. Option 3 is just messy.

Further research suggests two better alternatives both of which allow the reverse select mechanism to work as intended.

  1. Aftermarket speed sensor/ reverse lockout control module such as00jeep0001_15 A couple of these units exist unfortunately they are all from the USA and run about $100.
  2. Utilise the ECU. Trigger this from the aftermarket ECU if available. all the above device does is recognise the speed the vehicle, then allows a 12v trigger if that speed is below a set level (say 3mph). I’m not sure if this can be done from the Canems unit but I will be try to find out. It seems such a solution is possible from other ecu units such as Megasuirt, which can capture speed data and output a switch at a determined speed. such an ecu trigger output control that switches on a nitrous pump at a set speed could be hijacked and used. I’ll take this up with Dave At Canems This would be the tidiest and lowest cost solution effectively working like any mass produced car using the tremec’s. If not I’ll probably opt for the aftermarket control unit http://reverselockout.com/

 

 

 

 

Pedal box and master cylinders

Final set up of pedal set and master cylinders. Used aluminium spacers between the master cylinders and the bulkhead to achieve the correct free play in the clutch and brake pedal. The modification to the fulcrum point on the pedal set has worked well since I have not had to cut the push rods on the two brake cylinders (to the left) and end up with about 5mm of spacers to get the correct clearance. I ended up cutting about 12mm off the clutch cylinder pushrod otherwise i would have had more like 18mm of spacer. Used some laser cut aluminium spacers in 2mm and 0.8mm. the first 2mm spacer goes across all three cylinders then individual spacers to get the correct setting. Then finally connected the high pressure and low pressure lines. I’ll get a bracket made for the master cylinders, some jubilee clips and should get this plumbing finished next week.

In the first picture I have done a little bit tidying of the footwell pocket formed to the right of the accelerator pedal. It has ended up a reasonable silk finish gelcoat which I may just leave unfinished when i carpet or may end up putting some thin carpet in this pocket. Tried the pedal action with a mock seat setup and find the pocket really helps with the space – I remember feeling a little cramped when I tried this in the GD demonstrator but I’m pleased to say it now feels very “ordinary”….

Heater Box

Got round to installing the heater box into the battery compartment- its all a bit tight but I do like the way all the space is utilised – makes for a really tidy installation. Disassemble the heater box and added a few M6 rivnuts for easy assembly  I fixed a bit of neoprene foam to the face of the heater panel before bolting up. Installation is no easy project.

I have also found that the outlet pipes do not line up with the holes I predrilled in the inner wing using the marks left by GD… Benefit of hindsight here, I wish I had not drilled these particular holes until I had trial fit the box, small matter I guess the pipes are going to come through a slot rather than a hole. With trial and error I found it necessary to fit the little elbow rubber pipe to the heater box “before installation”(after slightly shortening one leg) since it proved impossible to get at the bottom jubilee clip if you put the box in first. I cut both flanges off the face of the box since they also hinder installation and are unnecessary once you fit the rivnuts in the face. Some people recommend taking the motor off before assembly this may have helped but I found it would just go in without it off – once its tightly in place there is only approx. 20mm of space between the motor and the forward bulkhead.

The picture on the left is taken with a torch looking up to show how tight the fit is, since when trying to install the box whilst fully assembled, the two air outlets protrude about 40mm on the opposite face so it is necessary to get these into alignment (ie in their respective holes) as you roll the heater box assembly in place – otherwise the suggestion of removing the motor first may be a better option.

Side Vents

I have looked at a lot of Cobra Replicas and one of the features that always left me a little underwhelmed was the side vents. At the Stoneleigh show earlier this year I was interested to look around at all the variations of the side vents utilised by the different manufacturers. Some looked better than others but I felt they all looked a little thin and false. Others I am sure will love the look of the folded laser cut but to me it was just a little too obvious. One car that I thought stood out in the side vent department here was the demonstrator from XCS.xcs_427_side_vent_img_9593_optimized

I wasn’t convinced about the width of the louvers they seem a little large using only three blades instead of the more conventional 4 or 5? but I did like the craftsmanship and they looked as though they had been designed and installed for a high end sports car …. yes I was inspired ( Ok my wife thinks I’m sad ). Onwards with that inspiration I’m going to stick with a similar design but leave it at 5 blades as well as incorporating a slight curve on the blades…. After quite a few hours playing with paper cut-outs I’m finally in aluminium

fabrication and almost there. My final vents are going to be Red……    or maybe Black. Still undecided on final livery and theme but I’m happy with the shape, they will bolt through as the final version will have studs welded  in place of the 4 small holes on the rear corners. Red or Black??

 

 

 

Pedal Box

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Ive decided to make a new pedal box that carries the standard GM throttle pedal in normal location ie.  alongside the brake. The picture above shows the Standard GM fly by wire throttle (to the right) with its mounting bracket (middle) removed. The new throttle pedal frame (to the left) will accommodate the ls3 or any standard GM throttle pedal.

Getting everything dialled in geometrically was the main challenge here. Andy was kind enough to loan me one of the castings he presently uses as a starting point. Ive made quite a few changes including moving the pedal pivot point further towards the driver to minimise the thickness of the spacers needed on the rear of the bulkhead.C:UsersmkbulDesktopMarks COBRApedal boxPedal Box profiles

I also plan to cut in a footwell extension box on the accelerator side of the inner wing – similar to the engine side footwell extension molding provided by GD, but for the opposite side. I cut an area out with a hole saw just to the right of where the throttle pedal will be, then removed the foam inner wing filling and realised there is an extra 40mm of width to be gained here! more if I do the extension box in Aluminium and leave it without carpet. Ill get this new footwell extension fabricated over the next week or so and get some pictures taken. That will give me a generous 360mm across the footwell in the pedal area, which is pretty good and

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First prototype, I’ve incorporated some adjustment at the pedals for angle height and offset, and there is adjustment on the GM pedal. Think I’ll make some stainless steel pedals next week, more pics to follow. I want to get the pedal box installed soon so I can get the body back on and make progress with the power steering.

After a couple of modifications… Final Model

 

A few changes but Im finally happy with the whole box. I have made the actual pedal faces removable so I can modify this part easily once installed, which will allow a bit of fine tuning of the pedal geometry without the need to remove the majority of the pedal box from the car.Before I fit the pedal box I have to decide what to do with the cut out in the right side of the footwell.

This sequence of photos shows the cut out in right hand of footwell and the 40mm extra width that can be achieved by this butchery! The final photo shows the cut out glassed back in – I used some West System Epoxy resin and glass sheet to overlap the edges then coated with a black pigment resin gelcoat (or flowcoat). This way the structural integrity of this side panel is probably improved rather than weakened. I did consider making a fabricated panel to fit into the cutout but in the end i think the glass-up is the better solution. once it dries tomorrow ill fit the pedals for the final time.