Overview

This blog is intended to document the build of my Gardner Douglas Mk4 Cobra; partly as IVA evidence, bit primarily to help others learn from my mistakes and/or successes.

I will endeavour to post as often as possible, with a view to entering a single post for a particular element of the build process, however inevitably some things may not be completed in one go. All posts will be tagged so it should be easy enough to find the information you seek.

Please subscribe to receive emailed updates and feel free to post any comments or questions which I will make my best efforts to respond to.

Monday, 29 February 2016

Body Collection Day

Well the day finally came to collect the first bits of my GD Mk4 Cobra and I woke up early like a kid on Christmas day. 

I had originally booked a Luton van as others had, but I decided to use my trusty ex-caravan trailer instead which allowed me to use company fuel and save a precious few pounds. A couple of pallets were screwed to the deck with some rubber matting on top to stop it sliding around which worked well. 
The rest of the stuff went in the boot protected by some old duvets and foam mattresses.
And here it is in it's home for the next couple of years. 

Thanks to Greg and his Dad for helping to load it on the trailer. 

Looking forward to getting started.... 

Wednesday, 17 February 2016

Body Skate

I should hopefully be picking up the body on 28th Feb so it's time to make sure the garage is ready to receive it.

I bought a new Halfords Industrial tool box (in orange of course) to properly organise my tools and also free to cupboard space for storing the many Cobra bits which will soon need somewhere to live.

Tonight I decided to build a skate for the body to sit on and used Dale's blog as a starting point, but just used what timber I had lying around rather than buying new.

This is what I used:
- 2 off 1370 x 610 x 18mm thick plywood
- 4 off 250mm legs cut from 5" square post
- various off cuts of 18mm OSB as side bracing
- 5 off 3" square posts
- 4 off 8" (200mm) swivel and braked castors
- Loads of screws and a few bolts

1. I placed the plywood on the floor and cut some of the OSB to form a box the same size as the plywood.
2. The 5" square posts were then placed in each corner and fixed to the OSB with drywall screws from the outside.
3. The 3" square posts were cut to length and placed around the edge in between the legs. I then screwed through the OSB sides and plywood top in to these. The 5th one was placed acros beneath the join the ply.
4. Two strips of OSB were fixed across between the feet.
5. The casters were then screwed and bolted to these cross pieces. 

This has given me a skate 1220mm(W) x 1370mm(L) x 530mm(H) which should give me a good working height. 

OSB used to create a box giving lateral stiffness 

Here you can see how the 3" square posts were used

8" casters should make it easier to roll outside if I need the garage for something else

Almost finished, just waiting for some 3mm ribbed rubber matting for the top

Monday, 15 February 2016

Out of the mould

So the body has been slightly delayed due to one reason or another, however it's now out of the mould and looking fabulous (in my opinion). Hoping to collect it in the next couple of weeks.  

This is still inside under artificial lighting so looks slightly lighter than it actually is. 
Probably a closer colour representation. I love the stripes. 


Tuesday, 2 February 2016

Gear Box Options

So the final decision of Orange with Carbon Fibre stripes has been made and the body is in the mould as I type.  I was hoping to pick it up this weekend, however one thing or another has delayed proceedings slightly, not to worry as there's still loads of prep and research to do.

Another decision I have already made is that I will be using an LS3 but as an engine and gearbox combination from new will set me back around £12k I've been exploring the possibility of a second hand unit.

LS3s are used in a myriad of American Muscle cars and a fairly readily available in the US, but after paying a minimum of $9k + shipping + import duty + VAT it's not that viable so I've ruled that out.  As far as I know the only UK sold car to come with an LS3 is the Vauxhall VXR8 which aren't exactly ten a penny, so finding a pullout is tricky, but I think I've succeeded.

There's a guy called Gary who runs a site called www.LSXV8.co.uk and is about the only UK breaker of Monaro's and VXR8s.  I got in touch and was surprised to hear that he had a low mileage (28k) 2009 LS3 with 6 speed manual available which has everything except ECU and loom, lovely.

Whilst I wait for him to put it back in a car so I can see/hear it run my thoughts turn to the gearbox and it's many guises.  He tells me it's a T56, however there seems to be about a million different variants with a million more gear ratio combinations and shifter locations, so I delve deeper....

After many hours/days of trawling Google and various forums, I 'think' it is either a TUET-2066 (T56), TEUT-2100 (T56) or TUET-10310 (TR6060) but am still waiting  back from Gary to confirm the correct part number.  In the meantime I have created a spreadsheet to compare the above three options and the T56 Magnum which GD use.

Tremec Transmission Comparison - Cruising

One of my considerations is the usability of 6th gear for cruising so you can see the relative RPMs at 80 MPH (not that I would actually drive that fast on UK roads!)  All are under 200 RPM so will offer reasonable full economy on long journeys.
Tremec Transmission Comparison - Speed
This time I've left the RPM the same so you can compare the speeds in each gear, the TUET2100 is my least favourite as I think 6th would almost become redundant so that is out.  The TUET2066 is a better set of ratios but reliability has been questions in the VXR8 community which is why Vauxhall ended up replacing a lot of them with TR6060s under warranty.

The TUET10310 is said to be much more reliable a less agricultural than the standard T56 so this would be my preference if it turns out that is what is currently attached to the engine, however both the T56 and TR6060 in a VXR8 would have a remote shifter so this would need to be repositioned.  Worst case I may end up having to get just the engine and sourcing a new T56 Magnum.

The spreadsheet automatically calculates everything by changing the ratios, RPMs or wheel and tyre sizes.  If anybody out there wants a copy let me know.

Friday, 8 January 2016

Getting closer....

Well, it's getting ever closer. I've had confirmation that they plan to laying the body up next week whuch normally takes a couple of weeks; however, as I am having the Carbon stripes it will take a little longer.

Fingers crossed it'll be ready to collect early February 😀

Saturday, 26 September 2015

GD Factory Visit

Today I visited the GD Factory to meet Andy & Meena, who greeted me with a cup of tea which is always a good way to get my business.  They are thoroughly nice people who have all the time in the world for you and Andy's passion for the cars he builds is infectious.  Being an engineer myself I was like a kid in a sweet shop walking around the factory looking at all the machinery and seeing cars in various states of build.

They had there Mk3 demonstrator as well a Mk4 on show and Andy took every one out for a spin which was fantastic.  I'd been out on the track at Castle Combe in June which was amazing, but it was great to see how the car performs on the open road as that is where is will spend most of it's time.  I was surprised to see how civil and comfortable it could be compared to the brutality on the track and that is a real selling point for me.

I presented my colour scheme which they loved and spoke about the option of replacing the grey stripes with carbon in lay and clear gel which (I think) would look incredible.  It  would difficult but achievable and Andy will knock up a sample panel to see how it turns out before I make a final decision.


So that's it, order form filled in and deposit placed which should have my body ready mid/late January, can't wait....

Chassis under construction
Two finished EURO chassis complete with LS3 engine ready for delivery
Body shell straight out of the mould
Fantastic gel coat surface finish even without any polishing
GD Mk3R demonstrator

Mk4 in background with Andy Burrows

Saturday, 19 September 2015

Colour choices

So, I have decided on the kit and have booked a visit to the GD factory next weekend to meet the team and place my order.  Due to funding, I have chosen to carry out the build body first as it's the cheapest 'big bit' to get started. The GD manufacturing process produces extremely high quality finished gel coats which can be polished up to a high shine which can save £2-3k on painting.

This does mean that I have to make a big decision prior to ordering and have to choose from any solid RAL colour.  I have trawled Google images for inspiration and found a lot of blue with white/silver stripes, grey with silver stripes, black with white stripes and red with white stripes.  These colours seem to have been done to death; and as I'm not intending to build a classic replica, I decided to keep it understated and chose ORANGE with GREY stripes!

Looking at RAL colours on line is pointless as every colour looks different depending what website and screen you are viewing it on.  I bought a RAL colour fan chart, picked my favourite colours and got B&Q to colour match some sample pots.  I then painted some scraps of plywood with the two chosen oranges (RAL2001 & RAL2010) to see what these colours would look like on a bigger scale.  It sounds daft but it does make a difference seeing it in big rather than a small swatch of colour.

RAL2010 (signal orange) appeared too light so decided on RAL2001 (red orange).  I the painted some stripes in 6 different greys on the orange for comparison and finally chose RAL7022 (umbra grey).  Below is how they look together on ply wood, only time will tell how they will look on the car.



After speaking with Andy from GD, I asked whether the stripes could be made in carbon fibre rather than grey and was delighted to hear that; although "tricky", it was not impossible. 

I have recently received a sample panel which shows the orange and carbon together (see attached photo) which I rather like, the black is there for reference.  The carbin in the sample is casually laid and will be at 45°for maximum  visual impact.