Twincharged, Wide-arched Convertible Peugeot 405

[davetibbs]

Hi everyone!

After being a lurker on these forums for a while (and loving the project threads here!) I thought I should start my own which I can hopefully update semi-regularly.

I've owned this car for a long time as it's gone through various guises, it started off as a standard 1.6GL before I transplanted a 2.0 turbo engine from a Citroen XM into it about 10 years ago. A slight accident took it off the road a few years later and it's turned into a long-term project since then and never returned to the road. As is the case with a lot of these things the ideas get crazier and crazier, until it reaches the current state where it's essentially turned into a complete ground-up bare-shell rebuild.

The planned spec (as it stands!) is:
Exterior - convertible conversion with hydraulic roof, 2 door conversion, wide arches, vented bonnet, etc
Interior - Electric heated leather interior from Citroen XM, Peugeot 307cc dash + doorcards
Engine - 2.0 XU10J2TE from Citroen XM, fitted with 16v head, Toyota SC14 Supercharger, as-yet undecided Turbo
Drivetrain - Gearbox and 4x4 running gear from Peugeot 4007 - essentially a rebadged Mitsubishi Outlander, but the gearbox will fit the engine with very little modification (maybe a bellhousing adapter) and the wheelbase is exactly the same as the 405 (to the mm) so no prop shortening/lengthening required.
Suspension - Full air suspension front and rear

I'll let the pictures do the talking, but essentially there's very little of the car that hasn't been/won't be fettled in some way. I appreciate it's not to everyone's taste, but I love it and I've put a lot of work into it and learnt so much!

Here's a selection of progress pics:

Stripping the interior


Chassis restrengthening (more under sills, and the transmission tunnel will be replaced to allow for 4x4 running gear)


Roof removed


307 dashboard test fitment


Engine Bay Repainting




The roof I'll be using - from an E46 BMW 3 series convertible




Bonnet with vent from Toyota Rav-4 smoothed in







I'll try and get some more pics up ASAP.

[davetibbs]

Thanks for the replies everyone - I'm aware it's pretty bonkers

Progress has actually come on quite a bit further than the pics I've posted but my netbook's SSD has died and I've lost a few - I'll have to retake some when I get a chance.

As for using the 405 Mi16x4 drivetrain - the main reasons I've ruled it out are due to rarity of parts and the strength (or lack thereof). You can't really put much more than the standard power (or more accurately, torque) through the 4 wheel drive system, which wasn't particularly high to start with (155bhp). There are a few weak points, but mainly the splines on the transfer box were prone to stripping, and if you uprated them, it'd spit the diff out the back. It's a reasonable split of power front/rear, normally 53/47% but this can be changed by the viscous centre diff (which is also fairly weak).

In comparison, the 4007 drivetrain is largely the same as is fitted into the Mitsi Evo X, and therefore able to cope with far higher power outputs. It's true that the 405 Mi16x4 drivetrain could be obtained and the necessary parts upgraded, but then you're entering silly money territory, whereas the entire running gear from the 4007 can be picked up a for a few thousand.

I am however running the 405 Mi16x4 rear beam because without it the 4x4 conversion would be a nightmare with custom subframes/suspension etc. The Mi16x4 had hydraulic rear suspension like the Citroens, but I've ditched that system and am getting air shocks made to fit where the hydraulic shocks were, as well as overhauling the entire beam.

I'll try and get some more pics (probably this weekend) but in the meantime, here's some more old photos:

Painted S16 Rocker Cover


SC14 Supercharger being overhauled, though this may be scrapped as finding replacement bearings is next to impossible





S16 head rebuild





Front bumper being modified - originally a vertex-style bumper for the S14a 200SX




405 Mi16x4 Rear Beam ready for overhaul

[davetibbs]

For the rollover protection, other than extensive strengthening in the A pillars and windscreen frame (which I appreciate won't do much in the event of a rollover, but every little helps!) I'm going to use the electro-magnetic rollover hoops from the E46 convertible - main reason being that they can be tested and reset, whereas ROPS hoops from other convertibles such as the Peugeot 307cc deploy using an explosive charge, and I won't be taking the car near a road (or indeed a BIVA test) unless I'm totally happy with the system, and I can't afford to keep replacing the charges after tests! These ROPS hoops can be fitted to a frame behind the rear seats which will double up as extra bracing/strengthening.

As for their control, I will probably use the gyroscopic sensor from a car that keeps ROPS deployment separate from the CANBUS wiring to simplify the wiring! More investigation needed on this bit though.

[davetibbs]

My mate told me he thought Rollover Protection would be too much effort. I showed him this video.

http://www.youtube.com/watch?v=Cd2UOK867zE

[davetibbs]

Yes, it will need a BIVA, and I've known this from the minute I started the convertible conversion, so it's not pissing on my chips It's something I intend on working to get - it's entirely possible to get an IVA for a monocoque-converted-to-convertible, providing it's done properly. Many late nights have been spent studying the test manual, but if anyone has any advice it will be most welcome.

[davetibbs]

It does look awesome as a convertible in standard Mi16 trim (great chop by the way!), but a lot of the bodywork modifcations came before the convertible conversion, and as you said a few of them are required.

I'm trying not to make the bodywork mods *too* lairy.

[davetibbs]

You're very kind, I actually work in IT. I've just done a lot of learning over the years

[davetibbs]

Standard boring response: Why not?

Longer answer: It's been a project car (actually my first car) for as long as I can remember. Plans have expanded further and further over the years to the extent that it's reached a point where I want to see just what is possible. And at the end of the day, it was just a Peugeot 405 GL, so it's not like I'm chopping up a classic car.

I'm loving the technical challenge of it, and learning a lot in the process. Thanks for all the support

[davetibbs]

Hahaha! Well, it seemed fitting with a French car to use plenty of expanding foam, given most of the French "Work In Progress" cars featured on Barry Boys :-P

Actually, the amount of foam left on the bumper is very small (just a small lip around each hole) it's just a lot easier to get the shape you need then fibreglass over it.

[davetibbs]

Yes, a long time ago! It was about 10 years ago, yeah. How time flies

[davetibbs]

Colonial said:

I once chopped the roof off a Holden Gemini sedan (Opel Kadett kind of thing).

With an angle grinder.

I get the feeling this is going to be a lot more professional.

Love it.

Thanks for the comments

I hope it's going to be as professional as I can manage - I've got useful parts like the top of the windscreen frame for the E46 so this can be welded to both the top of the 405 frame, and the strengthening that will be added, and then blended in. This kills two birds with one stone as it firstly takes the effort away from removing any sharp edges, and also will have the catches in the right place for the BMW roof to latch onto.

Weirdly, the BMW roof appears at first glance to be (width-ways at least) a near enough perfect fit with the width of the 405 windscreen top, once the curves of the door frames have been welded onto the A pillars to finish it off and to provide more space for strengthening. Length-ways the measurements aren't so critical, as is the height, although it may require the windscreen angle to be changed, and this will have to be done before the strengthening is added.

The roof was one of the better eBay bargains I picked up, full hydraulic roof in fantastic nick, with all rams + valves attached, for £9.99 because the frame was damaged. Actually, all that had happened is that a bolt had come loose causing the frame to get caught and bend slightly, popping a rivet out. Re-straightening the frame and re-rivetting it fixed that one

[davetibbs]

gary71 said:

Whilst I admire your madness wouldn't it have been easier to start with an E46 cab bodyshell?

I appreciate that's not the point, but at least the windows and hood would all line up and it might keep some of the water out.

Good luck!

Yes, but then it'd just be an E46 cabriolet

Actually, making the windows and roof fit isn't as much of a challenge as you might think (Well, OK, it is, but...). The roof lining up with the windscreen frame is covered by having the E46 windscreen frame welded to the 405 detailed above (whilst still keeping the original 405 windscreen surround so I don't have to have a custom screen made). The rear doors have gone and will be replaced with solid panels (essentially moving the B pillar back along the car and using the original rear door skin chopped up to provide the shape), so I can use E46 rear windows so they fit the roof, then it's just a case of the front windows. I can't use 405 ones as the front doors will have been extended and the edge that seals against the rear windows is different, and I can't use E46 ones as the curve of the A pillar is probably wrong - however, it seems fairly straight forward to get custom windows (polycarbonate?) made up to a design, which could be based on the 405 with necessary changes.

[davetibbs]

NotDave said:

Makes sense to me, as the whole frame would have strength, and line up to roof. Scuttle could be adapted to suit

It's a good idea, but the whole frame wasn't available. I'll probably give it a good go with the bits I've got and the 405 windscreen frame and see if I can succeed with that. If not I'll hunt down an entire E46 windscreen frame.

[davetibbs]

True enough. However, I forsee "difficulties" with getting the bottom curve of the E46 windscreen frame joined to the 405 bulkhead - it could actually be a lot more work than the way I've planned. Since I've already got the windscreen top I'll probably stick with the "strengthened 405 frame" plan for now, and if it doesn't work I can lob it off and try and use a full E46 frame.

[davetibbs]

A lot! As I understand it, it's not uncommon for factory convertibles to have an extra 200kgs of additional weight over the saloon/coupe model. I'll probably end up with quite a bit more than that. In fairness I haven't weighed the extra metal I've added as I've prioritised chassis strength over weight saving, with the idea that if it affects performance too drastically, my engine isn't powerful enough. I might take the completed car onto a weighbridge out of interest though.

[davetibbs]

Yes, the sills already have a lot of additional strengthening (essentially box section) both inside and outside the car. The door apertures will be strengthened at the hinge end with the same strengthening for the windscreen (to provide support for longer - and therefore heavier - doors), and at the latch end to restore rigidity to the (shortened) B pillars which will also double up as support for the roof. I'll try and get some drawings up at some point to highlight where all the strengthening has gone.

[davetibbs]

Yep, the list above isn't exhaustive. There's a front strut brace (just bolt-on though), and a welded cross-brace in the rear behind the seat. Plus I'm currently beefing up the front and rear chassis legs.

I'm considering an X-brace but not sure of the best way of approaching it at the moment.

[davetibbs]

Whitean3 said:

When I first skim read the OP, I thought we were about to see a Peugeot 406 coupe to cabrio conversion (which could look pretty damn good). Then I saw it was a 4-door 405.- now that is a LOT of work! Seem to remeber one of the Max Power type mags featured a 4 to 2 door conversion on a Pug 306 saloon a few years back...

I actually had a 406 coupe which I was tempted to do the conversion on, but couldn't bring myself to chop that beautiful body so chose the 405 instead. The irony is that it's now being broken for parts in my back garden Maybe I could do it in the future

I remember the 2 door 306 saloon - it was an Ecosse job I think, I suspect they used the parts necessary (such as rear wings) from a 3 door hatch, but I have no such cheats available

[davetibbs]

Just a small update:

Making the mounting brackets for the airbags



Cleaning suspension turret mounting plates (still needs a polish)


Wishbones painted with all new bushes


Adapting Spax PSX Adjustable shocks to fit airbags:

First, cut off spring mounting cup


Then, strip paint


and weld on coilover conversion tube:



Once welds are tidied up and bottom mounts are finished, the shocks can be painted.

I also started stripping 406 Coupe Brembo calipers for seal replacement and painting:


And ordered some badge lettering on a whim

[davetibbs]

mwstewart said:

Interesting project. Did you weld those sleeves on with the damper assembly still inside?

Yes. I was in two minds whether to do so but didn't really fancy dismantling the shocks, which would have presumably required them to be regassed afterwards. As such we were very careful with the welding that it didn't get too hot, and I figure the fact that they still move afterwards means that they'll probably be fine