Author Topic: CRS rebuild after a Castle Coombe incident  (Read 16070 times)

C9OBY

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CRS rebuild after a Castle Coombe incident
« on: March 18, 2010, 21:46:38 »
Hi all
   
   As some of you know, I decided to get a little closer to the grass-roots of track-days in September last year.  Or more to the point, to slide across the grass (tearing up a few roots in the process) and 'kiss the wall' rather firmly whilst strapped into my car.  The result was a slightly re-decorated Cobra.  Well, they do say that one way to improve performance is to remove weight - something that was achieved rather efficiently a few split moments after my departure from the racing line (mid-way through Tower Corner at Castle Coombe race circuit, to be precise).
   
   That was 11th September 2009, and since then I've been busy getting it all back together again.  To date, I've not put anything onto the forum as I myself found some of the challenges a little painful.  At times I did wonder if I would get it back up and running, but now that the light at the end of the tunnel is in sight, I thought it only fair to share my experience with other CRS owners.
   
   Importantly, I believe that this is the first CRS to be 'properly' damaged and subsequently repaired.  Call me the guinea-pig.  I know of one other car that was written off and another that had some minor damage remedied, but nothing like what I've been through.  Corrections welcome if I've missed anything.
   
   To sum up the experience to date, ignoring some very long hours spent in the garage / sourcing bits & pieces, I can confirm getting one of these cars repaired to 'original' standard is not that hard.  Cost does play a role, but the key highlight has been getting the carbon fibre body repaired back to original state, thus preserving it's integrity (structurally and figuratively).
   
   The body was repaired by a brilliant company called Modena Group up in High Wycombe.  Before finding them, I spoke with various other specialists who claimed to be able to fix carbon, but nobody was able to assure me that the end result would be an unblemished, structurally intact shell.  This in itself led to me considering putting a kirkham body on my AC chassis, noting however that this would have significant implications on provenance etc.  First prize was always going to be getting the car back on the road as an intact 'CRS'.
   
   Before I delve into the detail of the repairs, it's worth noting that nothing that has been achieved over the last 6 months could have been done without the help and support of a number of people, both within and outside the club.
   
   There is a very long list of contributors, but key people to mention for their continued support and involvement throughout the rebuild include Alan Faulkner-Stevens, Keith Lessiter, Alex and Alec at Thunder Road and Matthew Feltham.  Others who helped get me started with good advice and assistance include Andy Shephard, Clive Robertson, John Lewis.  Many thanks to Bertie Gilbart-Smith and Equity Redstar for sorting out my insurance payout.  And last but not least, a special mention to Ian Wyatt who kindly towed my car back to London on his trailer, leaving me to follow behind him in his absolutely beautiful MKIV Lightweight.  A very brave man indeed who hands over his keys to a recent crash victim, but Ian selflessly made the offer without the slightest hesitation or comment.  To everyone else that has sent me emails / called me wishing me well, thank you.  I am sure that you'll forgive me for not mentioning you all in person, but your support and kind words were much appreciated.

C9OBY

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CRS rebuild after a Castle Coombe incident
« Reply #1 on: March 18, 2010, 21:48:52 »
The accident
   
   So, to start.  The picture below shows C9OBY shortly before her visit to the dark side.  Happily shooting around Castle Coombe at pace, loving the laps, having a ball.
   
   
   
   
   Then, the unfortunate accident. Not a pretty sight, but not irrecoverable.  If you want to hear the details of the accident itself, I'll let you buy me a beer first!  Actual impact was rear left corner first, then a swing hard to the left into the barriers again, followed by a bounce back in the opposite direction back onto the edge of the track.  A pretty comprehensive test of rear, ride and front strength of the car...
   
   
   
   
   
   
   
   
   Next steps involved finding someone with the skills (and evidence to support) repairing carbon fibre.  Recommended through another club members insurance broker, Modena Group ultimately ticked all boxes.  After finalising the insurance details etc, the work began.
   
   Important to mention regarding insurance:  Subsequent to my accident, I've been astonished to discover how many people do not / had not taken out track insurance.  My advice - DO IT!  You never know what might happen.  I certainly didn't expect to crash, and without the insurance payout the car would most likely not have been repaired...
   
   The body
   
   Step 1: dismantle the car and assess the damage.
   
   
   Looking up at the front left suspension you can see where the bottom suspension arms were bent.  All other suspension members were fine and (jumping ahead in the repairs) these were easily replaced by two new items from Gerry Hawkridge.
   
   Inside the boot you can see how the outriggers were pushed across, holding the body off-axis, but the good news was that the main chassis proved to be 100% fine with no distortion.
   
   
   
   
   The front and rear bent outriggers were removed and magically the entire carbon body popped back into shape.  The memory of carbon is a key feature of this material, and certainly helped with the overall repair process.  This was the biggest step towards knowing whether or not we would be able to repair the body.  Take a careful look at the earlier photos - not only were the impact areas damaged, but the entire body had been distorted across the back-left to front-right axis.
   
   
   
   
   
   
   One thing to note is that there were bends and cracks in almost all parts of the body, as the shock from hitting the wall transferred through the body.  Importantly, this is probably a key reason for the chassis remaining unmolested.
   
   I can also strongly suggest that anyone with a traditional over-shoulder seat belt make the change to a full racing harness.  Wearing one certainly saved me from injury, especially as the multiple points of impact during the crash would have most likely resulted in me being thrown out of the over-shoulder seatbelt.
   
   A full-face helmet also prevented my face from being re-arranged when my head went forward and bent my lovely moto lita steering wheel.  No comments please, I happen to like my face the way it is.  The only impact to me personally was a dull ache to my neck the following day, for which I thank my lucky stars.  Considering that I hit the wall in mid-range third gear (about 60 mph from memory) I think I had a very lucky escape.
   
   

C9OBY

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CRS rebuild after a Castle Coombe incident
« Reply #2 on: March 18, 2010, 21:50:02 »
The repairs
   
   All chassis parts were removed and put in a box that arrived at my home a few days later (more on this further down).  Everything baring the gearbox, prop shaft and diff was removed.  Inside the car, only the carpets and dashboard were left in.
   
   
   
   
   
   
   
   
   The front and rear outriggers were then either re-formed or replaced, in advance of any further work on the body.  Lovely work, perfect welds and well sealed.  I couldn't tell where original undamaged metal joined with repaired sections.  Exactly as you would expect I hear you say, but nonetheless the kind of things you need to see to help raise your bruised spirits!
   
   
   
   
   As work on the body began, a number of very interesting facts became visible.  First, the CRS body had been comprehensively covered in body filler.  This is most notable on the part-uncovered front left wing in the photo below.  Not very thick, but it was applied all over.  It may help explain why on some CRS cars (that obviously benefitted from this approach) have a very smooth paint finish, whereas on other cars (where you must assume less filler was used) the carbon weave can be seen in some places.  This is in no way a criticism of the cars, just an observation.
   
   
   
   
   The entire car was stripped down to bare carbon (see below).
   
   
   
   Looking up inside the repaired body, you can see the new carbon sections that were made to repair the damaged sections.  For the most part, the repair involved making a 'negative' on one side of the body, tearing out damaged sections below, splicing in new material to the body and then re-forming the panel against the 'negative'.  This process was then repeated from the opposite side.  Afterwards, the entire car was put into an autoclave and re-baked (exactly the same as the original manufacturing process).
   
   
   
   
   
   
   The almost-finished artcle: perfect carbon repairs with just some detailing and clean-up required.
   
   
   
   Preparing for paint: to follow later on.

C9OBY

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CRS rebuild after a Castle Coombe incident
« Reply #3 on: March 18, 2010, 21:51:14 »
The suspension
   
   As mentioned earlier, the suspension and other bits were returned to me in a box.  Aside from the front left lower suspension arms, everything else was 100% fine.  However, decided that this was as good a time as any to completely overhall and refurbsh the suspension.  Considering that the the bodywork etc would take at least 2 months to complete, I had more than enough time on my hands to get stuck into the ancillaries.
   
   Hence, I started by removing all components from the main hubs (picture before strip-down below).  All nuts/bolts were catalogued before being sent off to be de-brittled and zink plated.  Jumping forward a bit, all used nylock nuts replaced, along with a number of the more worn rose joints.  New rubbers, washers, seals etc.
   
   
   
   
   
   
   
   
   
   
   Brake calipers were sent off to be refurbshed, as were the Koni dampers.  New brake pads, fresh seals and new paint resulted in 'as-new' parts being returned a few weeks later.
   
   I also sent off all the individual suspension arms etc for sandblasting and powercoating in matt black.
   
   Left and right drive shafts were also refurbished (just new seals and re-oiled).
   
   Zink plated bolts returned.
   
   
   
   Suspension reassembled.  As you can see, it looks almost better than new!
   
   
   
   
   
   
   
   

C9OBY

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CRS rebuild after a Castle Coombe incident
« Reply #4 on: March 18, 2010, 21:52:24 »
The Paint
   
   Having been through the autoclave, the car was then prepared for paint, but only after the body was prepared with minimal body filler.  Remember comments earlier on about the original having been completely covered in filler?  Some discussions later, we decided that a more hand crafted finish would be appropriate.  Whilst individual section preparation by hand took far more time, the overall result is a car that should be lighter and truer to the underlying carbon body.  Seen below, the car was about to head in for priming.
   
   
   
   
   Then came a critical decision: paint colour.  Some people argued that it would be appropriate to match the colour of the car as it left the factory.  However, as you may see from the first few photos, the car origninally was a light blue with metallic chip.  I have never really liked the metallic chip, not least because most people who saw it automatically assumed that it was a 'kit car' like so many of the 'mod-painted' replicas.  Aagain, no criticism of replicas, but I don't like having my AC confused for a non-AC car.  In the end, and after lots of research, I decided to change to a matt midnight blue, but kept the original le mans stripes with roundels.
   
   
   
   
   
   
   The end result was perfect!  Completed in late January, a final photo was taken in High Wycombe with the team that worked on the car standing around their handywork.
   
   
   
   
   The following week, I had a very special delivery!  Slowly she emerged from beneath the covers of the truck, fully repaired and ready for reassembly in my garage over the next few months.
   
   
   
   

C9OBY

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CRS rebuild after a Castle Coombe incident
« Reply #5 on: March 18, 2010, 21:56:17 »
The reassembly
   
   Having waited and prepared over the previous few months, I was extremely keen to get started on the car.  The first few days were spent ensuring that everythng that needed to go back into the car was properly prepared and ready.  In some cases, this involved finishing refurbishment to specific parts, or spending time to replace old/worn parts.  Note that as the rebuild continued over the next 2 months, time was fairly evenly split between 'assembly' and 'looking for bits & bobs'.  I have
   subsequently built up a very comprehensive list of parts and respective suppliers, from the smallest little nut to the most obscure rubber seal.
   
   First was the engine bay, seen below with just the engine in place.  Everything else sat in a number of boxes, waiting for the jigsaw puzzle reassembly to begin.  Note that only the radiator had to be replaced, as it was punctured in the accident.  I managed to source a replacement from a company here in the UK who were able to identigfy mine from photos and source a replacement from the USA.  Somthing else to remember was that whilst the engine was out the car, Modena Group very kindly fitted a new clutch for me, again sourced from the USA for a very reasonable £215 from the same UK-based company.
   
   
   
   One person not yet thanked for their help was my 'little helper', spotted here checking that I had correctly installed the battery.
   
   
   
   
   I have more photo's to upload, but a summary of other items completed to date:
   - Full engine bay completed, including replatement of all water, oil and fuel lines
   - New boot, bonnet, door and inner-arch rubber seals
   - Front half of the exhaust system reassembled and fitted
   - Interior fully refitted (more photos to come soon, including newly re-upholstered seats and door panels).
   - All electrics, lights etc re-fitted.  Note that more than half of all exterior lights were damaged, so these have all been replaced with new items.
   - Front and rear chrome nudge-bars and bumpers replaced with stainless steel quick-lift brackets.
   - Boot and bonnet brackets replaced and re-assembled.
   - Lots of other detailed bits, windscreen, tennax fasteners etc.
   
   Next steps
   
   I am currently half-way through re-assembling newly fabricated exhaust pipes to complete the system.  Welding brackets etc and setting the pipes around the reas suspension is taking time, but learnng to weld on a 'live' project has certainly been good fun and a good education.
   
   I'll be bleeding the brakes this weekend and hopefully soon thereafter fill and test the water system.  Then, once the last bit of welding has been completed on the rear exhaust system, I'll fuel the car and see if she starts!
   
   I will then need to fully re-set the suspension.  Considering that the entire system has been disassembled and re-assembled,  everything will need to be re-set.  As a result, I'll not be putting the steering wheel back on until I know that the car is 'pointing straight'.
   
   Watch this space as more photos and commentary will follow soon.  In the interim, a wing and a prayer (along with help from a magic wand) will help transfor my bashed beauty back into a proud Cobra again!
   
   

dkp_cobra

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CRS rebuild after a Castle Coombe incident
« Reply #6 on: March 19, 2010, 08:55:21 »
Wow, what a phantastic job and a true challenge (thinking of the starting point).
   
   Nice to see that your beauty is finished again.
   
   Peter

nikbj68

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CRS rebuild after a Castle Coombe incident
« Reply #7 on: March 19, 2010, 10:49:57 »
Firstly, what a shame that this report came to be written, but thank goodness you were well protected, both physically and with the track-day cover!
   It`s such a relief that you were able to retain the Carbon body, as you say, a Kirkham shell would have looked fine, BUT your car is a CRS, what would you call it if it was Ali? "Yeah, it`s an AC ARS..." No, I don`t think so.[;)]
   Anyway, what a great job Modena have done on the body, does the weave show through more now than it used to? The old colour seemed to bring out the pattern pretty well as I recall.
   Thanks for sharing your experiences with us, and highlighting 'club spirit' at it`s best, Hope you`re back on the road soon, with or without that lump of rubber!!! [:D] [8D]

C9OBY

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CRS rebuild after a Castle Coombe incident
« Reply #8 on: March 19, 2010, 11:29:40 »
The interior
   
   As mentioned earlier, everything inside the car except some of the carpets was removed.  All instruments were put in a box and wires disconnected to provide access to the body.  Thankfully the team stripping the car wrote up a quick wiring diagram, enabling me to quite easily reconnect the instruments later in the process.  However, I did need to take a 50/50 gues on one of the instruments, to be tested at the 'go-live' later on.
   
   Back to the carpets... I discovered that the foam layer laid beneath the carpet had been badly heat affected over previous years, notably from missing heat shield between the exhaust boxes and underside of the car (something that I repaired 2 years ago).  Hence replacement of this foam was required, using latest O-class heat resistant foam.  Once re-cut, it was very easy to relocate.  All carpets were thoroughtly cleaned and the returned into the car.
   
   Before work started...
   
   
   Left side done, now to do the right...
   
   
   And the finished interior.
   
   
   To the eagle eyes out there, you may have noticed that the seatbelt system has been modified from the original over-shoulder system originally fitted to the CRS (and many MKIV's).  Two years ago I had replaced the driver side belts with a Sabelt harness, using after-market brackets fitted to my roll-over bar.  Utilising the opportunity to make changes to the car whilst stripped down, the team at Modena welded in two new brackets to the existing frame, enabling me to directly mount new in-car harness connection point behind both seats.  This was relatively simple to do, and now (per the photo) both sides are fitted with a fully integrated harness.  I still need to work out how to cover the holes from the original seatbelt brackets.

C9OBY

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CRS rebuild after a Castle Coombe incident
« Reply #9 on: March 19, 2010, 12:29:51 »
quote:
Anyway, what a great job Modena have done on the body, does the weave show through more now than it used to? The old colour seemed to bring out the pattern pretty well as I recall.
   
   

   
   Hi Nik, thanks for your comments, much appreciated.
   
   The answer to your question is 'no', the weave does not show through.  My car 'as original' had only one/two spots where the weave showed through, unlike some other cars where it was quite noticeable, hence there is no real change to it's current state.
   
   However, there are two contributing factors that resulted in my 'new state' not showing any weave.  First, the process of removing the old paint and filler through blasting & sanding resulted in a smoother surface to start.  The new sections were then intentionally finished to match the rest of the body.  The second factor is determined by the rate at which the paint is allowed to dry.  Put simply, the quicker the paint dries, the more likely that weave will show through.  Hence, by allowing the car to slowly dry over a few days resulted in a lovely smooth finish.  In many situations, the commercial need to shift cars down a paint line results in cars being oven-dried (obviously, having a car sitting in a paint booth for 2 days incurs a cost to the business).  Luckily, Modena had no such need and hence the car was given plenty of time to rest, hence the glorious smooth coat that it now has.
   
   Those who have seen (and touched) the new paint are suitably impressed with both colour and finish.  It is also remarkably resilient, as demonstrated by one/two incidents when knocks to the body during reassembly did not result in any marks to the paint.  I wouldn't advise everyone uses this approach to test their paint though!
   
   Last point on paint, is that new rules/regulations ban certain chemicals from paint and hence my car is now painted in solvent-free water-based paint.  Perhaps someone else out there knows a bit more about this, but the evidence on the car is that the coat applied has great depth and strength, desite being a few microns thinner that the older paints that would have been applied.  Another factor on my car in particular is that a clear coat had been applied over the original metallic paint (sealing in the chips?).  This was not repeated on my car, hence the paint you see is the 'original' coat and has a more 'period' feel to it (whilst still retaining the required strength/resilience referred to above).
   
   Cheers
   Bruce

duggan

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CRS rebuild after a Castle Coombe incident
« Reply #10 on: March 20, 2010, 20:12:07 »
So this solves the mystery then!
   
   I was up at Modena a few weeks ago when they held a Ferrari/Lambo "coffee morning" (I've gone to the dark side and got a 360 Challenge Stradale) and I got chatting to one of the guys and after mentioning I had a 212 S/C, he mentioned they'd just repaired a CRS. I didn't want to put it out on a forum or obvious reasons, but good to hear about the results.
   
   In the morning I spent there it became very obvious from all the guys I spoke to that they really are very good at what they do and have a huge amount of enthusiasm for cars in general. Shame to hear about your accident Bruce, but great to hear it's come back even better[:D]
   
   Cheers,
   
   James

dart427

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CRS rebuild after a Castle Coombe incident
« Reply #11 on: March 21, 2010, 11:12:57 »
Very interesting to see the disassembled suspension. I think it is the same unit as used in Mk4 Cobras. Only the brakes (rotors and caliper) seem to be different. Any details available?
   Cheers,
   Horst

Mark IV

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CRS rebuild after a Castle Coombe incident
« Reply #12 on: March 21, 2010, 14:33:53 »
quote:
Originally posted by dart427
   
Very interesting to see the disassembled suspension. I think it is the same unit as used in Mk4 Cobras. Only the brakes (rotors and caliper) seem to be different. Any details available?
   Cheers,
   Horst
   

   Suspension is same as MK IV, the brakes are not. The brakes are AP Racing calipers and rotors also fitted to late Superblowres.

C9OBY

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CRS rebuild after a Castle Coombe incident
« Reply #13 on: March 21, 2010, 18:35:26 »
quote:
Originally posted by dart427
   
Very interesting to see the disassembled suspension. I think it is the same unit as used in Mk4 Cobras. Only the brakes (rotors and caliper) seem to be different. Any details available?
   Cheers,
   Horst
   

   
   Horst, what sort of details would you like?

bobbylangley

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CRS rebuild after a Castle Coombe incident
« Reply #14 on: March 22, 2010, 12:56:36 »
Bruce, well done. Your tenacity does you proud repairing the car. New colour is lovely and with all your new shiny bits you can give John Norris a run for his money at the concours!!! Looking forward to seeing it on the road very soon.