Originally built with a 2.1 VW flat 4 aircooled motor using running gear from a VW Beetle Baja racer, then converted to a Renault transmission and RX-8 rotary engine for a few years, now coming to the end of a conversion to a supercharged S2000 engine, along with many, many upgrades to suspension, brakes, etc, along the way.
Basic Performance Stats: 0-60mph - 4.6s (on gravel/dirt + M/T tyres) 0-100mph - 9.0s (gravel/dirt) Top Speed - 137mph (runs out of gears) Horsepower - 360-500+ (dependent on boost) 360bhp is the basic setup currently. Torque - 250lb ft Weight - ~800kg (including fuel, etc) Power/Weight Ratio - 450+bhp/tonne
A 30 year old UN5 transaxle sourced from a Renault Master van. Only the finest components used here! It has a strong gearset and a large final drive (5.85:1) allowing the use of the tall off-road tyres. Unfortunately, for some reason, Renault chose ratios that aren’t very good for racing with a 9000rpm capable engine, strange choice on their part. Basically that means 1st gear is redundant - it’s quite short and will only take the car to 30mph. So unless you really want to kill a set of rear tyres, it’s only use is for shunting around the pits and driving onto the trailer.
Actually 2nd gear is only much use in the deepest of power-sapping clay and peat terrain too - it will spin the wheels in 3rd up to 90mph or so if you wish…
In a similar fashion, a 5th gear that is great for fuel economy on a low-revving diesel van at 70mph on the motorway, is rather long when combined with 9000rpms, somewhere in the region of 165-170 is possible. But not when your aerodynamics are worse than a house-brick and it’s pushing 4 parachutes disguised as mudguards either corner, so 5th actually resides on a shelf, weight saving and all that….
Okay, onto the boring bits for the gearheads, greasemonkeys, and those of you who’ve just had way too much caffeine today:
The clutch is a hybrid, using the S2000’s flywheel, but machined and faced on the lathe in order to take the pressure plate (uprated with a stronger diagphram spring for more clamping load) and friction disc from a 200SX - this gives a 230mm instead of a 215mm disc for a little more torque capacity, and the friction plate is a 3-puck cerametallic paddle type for minimum MOI. The main reason for the swap is that switches the assembly to a push instead of pull clutch to work with the Renault gearbox and release bearing - that does mean of course that you need to put the Renault input shaft into the 200SX’s friction plate - so the centre spline has been replaced on the plate to suit.
The input shaft is also machined to suit the end support bearing in the engine - and then shortened too because we’ve cut and rewelded the gearbox back together in order to shorten it and push the engine forwards for better weight distribution.
The differential is a standard open one, mainly because nobody seems to make performance plate diffs for Renault commercial vans - gap in the market there - and it feeds into a set of GKN Porsche 930 CV joints which have been uprated with chromoly internals and remachined cages so that they are much stronger and will do more angle than a standard joint. These are fitted to spring steel driveshafts which are specifically designed to twist like a torsion bar to take out shock loadings from the drivetrain and prevent gearbox damage, and at 31 inches long they didn’t come particularly cheap, but they’re a vital part of keeping the car reliable.
They feed into our own billet aluminium uprights at the rear, which are made to have a pair of wheel bearings so big that the CV joint feeds clean through the middle of them and virtually bolts to the wheel itself - that’s to allow those shock-absorbing shafts to be as long as possible, and reduce the angle seen by the CV joints to reduce wear and allow lots of suspension travel at the rear.
The wheels are Mitsubishi Shogun/Pinini as they have loads of offset and are fairly light, but they used to be steel wheels we made ourselves - which is what is on it in the action shots, 16x7J at the rear and 16x6J fronts, shod in 235/70 and 195/70 Fedima EvoExtreme (competition soft compound) tyres.
All the calipers are fitted with low-retraction seals and anti-knockback springs behind the pistons to keep the pads snug up against the disc - even with all the vibration and shock encountered - to keep the brake travel consistant. As for the discs, there are a few reason the discs are scalloped as they are
And the most important reason is of course that they look funky ;) They’re all homemade - discs, bells, hubs, etc, etc, so is the anti-knockback kit in the calipers.
In terms of other bits, we also run a valve in the rear line that can reduce hydraulic pressure - which means that the brake bias is altered depending on how much grip the car has at that moment in time - and the independent rear cylinders means the car can be slewed around the rear wheel in tight forest tracks or used as a pseudo-LSD by manually braking the inside wheel out of tight corners.
Tubular steel spaceframe to MSA/FIA regulations, made from T45 seamless tube which is similar to American chromoly DOM, but a bit stronger and better from a welding perspective.
Dash instrument gauges consist of:
A bespoke fan control unit allows soft starting and speed control of the twin 16” engine cooling fans to reduce the strain on the electrical system when they first start up (80+ amps startup current).
There’s probably more I’ve forgotten that should be in that section so any specific questions please ask so I can answer them here
To Follow Shortly, when I have less RSI
No longer have to sit in the seat making vroom noises: Told you it was about time @the_oily_one pic.twitter.com/aXDpP96Qzh
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