R5 Turbo Replica build

[GeoffBob]

Thanks Andrew. I'd appreciate it if you could measure the length of those "extenders" for me please. I arrived at a figure of 60mm purely by measuring up my new R5T2 GRP bonnet next to a mild steel R5 bonnet. To the best of my measuring ability I would say that the R5T bonnet extends 60mm ahead of the R5 bonnet, but I could be wrong.

The attached pic (from the classic cars website) shows how on some cars the inner fenders were rebuilt to suit. You can clearly see how they have been rivoted in place. This is pretty much how mine look. I built them by hammering into shape pieces of 0.8mm mild steel sheet.



I am curious as to why Renault extended the nose of the R5T over that of the standard R5. while I am grateful of the additional space under my new bonnet, it's not as if the R5T needs the extra space, so why go to all that trouble for 60mm? Surely not for aesthetics, and since there is practically no additional weight added over the front axle its hardly an issue of improved weight distribution? Possibly aerodynamics? Maybe the whole idea for the R5T started with a larger front engined version of the R5 and progressed from there to the rear engined version once they ran out of space up front (but this sounds equally unlikely to me). Or maybe, in their wisdom, the French engineers saw me coming with my Toyota engine :?

 

[maxi.man]

in that picture it shows either kevlar/fibreglass inner wings thats why they are rivveted as per maxi these dont have extenders on them as they are already longer you just fit the shortened headlight bowls to them dont know why they are longer really often thought that. and why is the steel t2 roof rivveted at the back unlike the gordini which is spot welded ?????

 

[Michael]

This shows you the front of my T2. As it's now with someone in Spain I can't measure the extenders for you.

Why were they longer? Simples: they needed to fit the Gotti spare wheel in there and maintain room for radiator ducting and everything else! That's all.

 

[GeoffBob]

Thanks Michael, that makes a lot more sense to me now.

Those inner fenders are definitely from the standard R5. You can even see the recess in the right inner fender where the spare tyre would rest, and the hole (blanked off) where the windscreen washer bottle would usually sit.

This is a view of the front of my donor car that you probably don't want to see. The only parts that I recycled from this were the bits around and below the headlamps so I could refit the headlamps on my project car. The rest finished up in a local landfill or recycled to make roofing nails (but probably didn't make it as far away as Spain).

 

[AndyG]

Geoff,

Just measured the extenders.....you are absolutely correct in your estimate. They are exactly 6cm.

Cheers, Andy

 

[GeoffBob]

Thanks Andy, much appreciated.

'Glad I got it right as its a bit late for me to go back now

I have finished welding up my inner fenders (after moving the light sockets forward) and the wings are now bolted in place. I now have to make up the hinges to fix the bonnet in place, relocate the mounts for the intercooler and radiator, install the air intake pipe (I am locating my air filter in the cavity just below the left headlight) and then I should be able to get on with preparing the nose of the car for paint. Exciting stuff this.

 

[GeoffBob]

Well, here she is - finally beginning to look like an R5Turbo. I finished building my inner fenders and then drilled and tapped the holes in order to bolt down the wings. I am extremely pleased with how all the panels line up (in particular around the lights). I was concerned that I would have problems after looking at a number of cars on the net whose noses seem badly "out of joint". I can report, however, that it does take a fair bit of work to get everything exactly in place. I have mounted two bonnet latches at the upper corners of the bonnet to hold the bonnet down. Since this is a track car there is no internal bonnet release catch.



On the other hand, I am not at all happy with the alignment of the wings with the edge of the doors. The gap between the two is huge and very untidy. This is not due to any problem with the doors, but rather it is blatantly obvious that the GRP panels from Politecnic were not made to the correct size. In fact, its as if someone said "well lets just cut them along this line here, that should do - more-or-less". They could have at least had the decency to make them oversized, then I could have trimmed them dowm. Instead I have to make them longer.

The attention to detail on most of the GRP panels is, to say the least, absent!

But not to worry. I have, in the mean time, created the correct line with masking tape (as a guide) and will shortly build up the inside edge of the wing with GRP. Easy enough to do if you have the time and equipment. But what if you ordered a panel expecting to just paint, fit, and be done with it. Ploytecnic clearly supply the "building blocks" necessary to rebuild these cars, but they arrive in no fit state for immediate use.

This is one view that no one else in the world has through their R5Turbo bonnet. The front edge of the cam pulleys are exactly in line with the rear edge of the opening (a bit of luck that) and should give you some idea of just how far back I pushed my engine in order to improve the cars weight distribution.

 

[r5gordini]

Still looking great Geoff!

It's a shame about the GRP panels. Very disappointing.

Andrew

 

[GeoffBob]

Still looking great Geoff!

It's a shame about the GRP panels. Very disappointing.

Andrew

Thanks Andrew.

I wouldn't go so far as to say "very" disappointing. I am pleased to say that the service that I received from Monsieur et Madame Gracia at Politecnic has been very good. Their products are, however, a little rough around the edges. Speaking to others it seems that this is, however, par for the course in the GRP industry. Nothing is ever supplied exactly to size.

Or maybe I'm just a perfectionist

I only mention this because, should anyone ever have to take there R5T into the panel beaters, you can expect the bill to be composed mostly of labour due to all the extra work the shop would have to do in getting your new GRP panels to fit properly.

I wouldn't hesitate to recommend using Politecnics products (their prices were very good), just be aware that some post production work is required if you expect your car to be in concourse condition afterwards.

 

[GeoffBob]

'Have bought myself some 200gm double-twill carbon fibre cloth and epoxy resin. The fun starts this weekend.

 

[GeoffBob]

280mm diameter BMW Z1 rear discs and Alcon 2-piston calipers now on their way from the UK so that I can upgrade my rear brakes. 'Have also ordered an automatic torque biasing (AT differential from Quaife.

'Am currently feeling quite overwhelmed by this project. has been almost 3 years since I designed the car and already 2 & 1/2 years of construction over virtually every single weekend. I'm feeling tired and as if there is no end in sight. For what I have spent on this car I could have bought a neat and tidy Evo IX or similar - but then it wouldn't quite be the same as a 335hp R5 would it ? Will just have to find the energy to keep slogging on. After that I am going to hibernate for two whole years.



As with almost the entire nose of this car, the bonnet hinges are handmade.

 

[ejk]

Hey G, keep on going now, you're almost there. It'll be worth it. I guess "to hibernate" in South African translates as "driving around all day with a smile from ear to ear".

Well, enough peptalk for now :mrgreen: , what about the carbon fibre? I am really looking forward to hearing about that.

E

 

[r5gordini]

Keep going Geoff! Nearly there.

It took me 4 years to restore my Gordini Turbo. Your skill level and enthusiasm put all the rest of us to shame. It really is incredible what you are achieving.

When you've finished I would like to get the details of your car published in a UK car magazine - I know exactly the mag. They're about (hopefully) to publish another of my articles, so I'll wait for the dust to settle before writing the article about yours.

Superb project. Superb skills... astonishing. Keep going, please!

Thanks,

Andrew

 

[GeoffBob]

Thanks Guys for your generous comments - your words of encouragement are greatly appreciated.

I took a short break from the project to regain some energy/enthusiasm over the past few weekends. During this time I had a few parts arrive in the post which helped to spur me on. I now have the parts I need to upgrade my rear brakes (BMW Z1 rear discs and ALCON 2-pot calipers).

My Quaife automatic torque biasing (AT diff also arrived. This is an unusual item that works in such a way as to share torque between the drive wheels as one wheel loses traction (typically the inside wheel while cornering). It has the term automatic torque biasing applied to it since it is able to vary the percentage lock (between the drive wheels) from 20% (factory pre-load) up to 80%, depending upon just how much traction is lost at a wheel. This is unlike the more common clutch/plate type limited slip differential (LSD) which snaps the clutches together to engage a fixed percentage (typically around 25%) of lock between the wheels.

After my break, I continued work this passed weekend. The CF bonnet is now sanded an primed. I plan to paint it the same yellow, blue and white as the rest of the car. I know it is very fashionable to leave the CF visible, but it really doesn't match the rest of the car, and besides, I need the CF for its stength, not its appearance.

I have installed the air intake and filter in the front bumper. I've run a 3-1/2" thin-walled stainless tube from the air filter straight back to the 2-3/4" mouth of the turbo. Almost a direct path (slight kink required to route the tube around the radiator). I realise this must look very strange to all of you, even hilarious. Unfortunately I am seriously running out of space under the bonnet so there really was nowhere else to put the air filter. At the very least the turbo should breath very well - which is important given that this is a track car.

 

[ejk]

Hi,

Great job. I'd like to hear how you made the carbon fibre bonnet. I always thought you'd have to bake the carbon in a vacuum to make it cure properly. I am planning a small modification myself and maybe using carbon fibre is an option instead of polyester-glass fibre.

Cheers,
Erik

 

[GeoffBob]

Hi Erik,

You can work with CF in exactly the same way as GF, although a stronger (and slower curing) epoxy resin is recommended in place of the usual polyester resin. I began my job by sanding down the surface of the gel-coated bonnet with a 60-grit paper to give the epoxy resin something to bite into. This is necessary to prevent the CF delaminating from the GF. I then lay the CF over the bonnet and worked with it as if it was GF, progressively brushing the resin into the fabric. Make sure the resin penetrates the fabric and keep in mind that, unlike GF, CF has a mind of its own and will continually want to lift and reform itself into some shape other than that which you require. I therefore had to nurse my bonnet through 'till midnight as the resin slowly cured, continually pushing and smoothing down lumps and bumps as they materialised in the fabric. In short, the CF is a pain in the arse to work with compared to GF. This is why its so much better to vacuum bag CF - the vacuum literally sucks the bag down on top of the CF and keeps it in place until such time as the resin is cured. It's not necessary to bake the resin to cure it, although it does improve results. I swept a heat-gun (set to medium heat) backwards and forwards over my bonnet in order to improve the strength of the resin and shorten the curing time. You can use a cheap infra-red thermometer to sense the surface temperature of the resin - typically around 70 to 80'C is ideal. Be careful not to overheat the resin by holding the heat-gun in one spot for too long as this will result in disaster.

Once the resin is cured the hard work really begins - sanding. Starting with a 100 grit paper you want to work the resin flat without sanding through/into the CF. The idea is to produce a reasonably flat surface and then apply layer after layer of resin, progressively refining the grit of the paper, building the resin up into a smooth clear layer over the CF weave. This is the typical procedure to go through if you want to produce a bright and shiny piece of CF where the weave is fully visible. If, however, you plan to paint it, then simply sand the resin smooth with 100 grit paper and apply a coat of sanding primer. It's then a lot easier to sand down the sanding primer with a 220 and then 400 grit paper than it is to sand the rock-hard epoxy resin. And I mean rock-hard! I think the CF gets half its strength from the resin. I'm pretty sure that a good quality 200gm GF weave with epoxy resin would be way stronger than the normal GRP. Also, if the idea/expense of working with CF bothers you then consider other composite weaves like Kevlar or Twaron. Also very strong but not as stiff/stubborn as CF. CF does not like forming around complex shapes.

For more info I'd recommend "Competition Car Composites" by Simon McBeath, available here



Best of Luck,
Geoff

 

[GeoffBob]

Finished the inner fenders over the weekend. All tidied up and painted after being extended by 60mm to accommodate the longer (than expected ) wings and bonnet. Have now begun the process of refitting all the bits that had been removed to make space to do the necessary. Soon all that will be left is to finish painting the outside and put the windows in!

The air intake to the turbo goes in through the front left inside wing

'Am feeling well chuffed today! Fitted the custom PAS pump hoses last night and I now have power steering on the car. The Toyota pump works really well with the BMW E46 steering rack. Took it for a little test drive this morning (before work) and found the level of assistance to be about just right. Not too much to take away the feedback from the road, but not so little as to not be worth the effort. I was initially concerned that there would be compatability issues between the Toyota pump and BMW PAS steering rack - not so (my pure good fortune). Installing the PAS hoses and rack was also made easier by the fact that the Toyota PAS pump is on the right of the engine directly above the rack fluid connections.

'Have fitted the fluid bottle inside the front right wing (for lack of anywhere else to fit it).

 

[GeoffBob]

Spent the past weekend wrapping all the wiring in the engine bay in stretchy rubber tape stuff (that is its technical name, non?). Normal electrcians tape seems to lose its stickyness after about three to five months and then the loom comes apart, so I opted for the stretchy rubber stuff instead. Goodness but it looks sooooo much tidier under that bonnet now. I have also put in all my connections (on the end of the loom) for the headlamps, indicators, park-lamps etc.

Took a trip down to Johannesburg this Morning to "Larrys Renau t" (the "l" fell off their sign) for some new headlamps and tail-lights. Can't have a bright new shiny car with dull old lights, so I splurged on new headlamps, indicator/park-light combo, tail-lights and reverse/plate lamps. Will soon be time to refit the windscreen, and then I wont have to wear goggles with my helmet each time I wizz 'round the neighbourhood :mrgreen:

 

[maxi.man]

NICE WORK MATE how much do reckon that it has cost uyou sofar

 

[GeoffBob]

Thanks Maximan. I am embarrassed to say around k£26 thus far . This includes the cost of the donor car, materials for the frame, BMW sub-frames, Toyota 3SGTE engine, Toyota W55 gearbox, new engine internals (pistons, rods etc), engine upgrades/modifcations (including all machining), custom sump, custom inlet manifold with 70mm Throttlebody, custom exhaust manifold, Garrett GT3267 turbocharger, the Adaptronic engine management unit, the Gotti rims + road tyres, the Compomotive rims + track tyres, the intercooler, the radiator, the exhaust system, the brake upgrade components, the Quaife differential, the coil-overs, the dash instruments (including sensors), and not to mention the complete set of body panels and trim. Raw materials to build the frame and GRP to modify the panels were fairly cheap (even the aluminium floor was good value for money), but sundry costs such as gas, welding rods, grinding and cutting discs, resin, abrasives etc really added up as I used so much. The basic scrap engine and gearbox were also fairly cheap, but cost a fair bit to restore. Paintwork was good value for money as it’s fairly cheap and takes me so long to apply (a gallon of paint can easily keep me entertained for a whole month).

NOTE: Have edited the above figure after totting up my numbers last night. I have kept every receipt since I started. I think this project may constitute "a crime of passion" :roll: