Top speed runs at Nardo - MTM bimoto & RS4

**krabu** · May 27th, 2003, 21:47

Originally posted by oswald
If I had 360.000 euros to spare I'd buy bimoto at once. I've talked to polish MTM division (while chiptuning some of our company's Octavias 1.8T) and he said that bimoto is not describable with normal words. You just have to try it. It's a pity that only one exist..:devil:

For 360 000 € I think I would buy something else.

Like a stable of cars for example. (

:s4addict: )

**Kain** · June 9th, 2003, 13:06

WOW! WOW! WOW! :bigeyes:

**S1pikespeak** · June 10th, 2003, 19:00

New info about the mtm bimoto!!!

Although Audi owns Lambourghini it might be viewed as pretentious to paint your Audi TT Diablo yellow but with 652bhp on tap MTM's TT Bimoto boasts 72bhp more than the mighty Murcielago and its 215mph top speed will leave the Lambo gasping.
Unlike its Italian cousin the TT Bimotos power comes from eight cylinders rather than 12, and they are spread across two engine bays. This is the worlds first twin engineed TT and was created by Roland Mayer in the village of Wettstetten just ten miles from Audi's Inglostadt HQ.
Before he set up his own Audi tuning company in 1991 Roland worked for Treser the innovative company of former Audi Motorsports chief Walter Treser. Then he moved to Audi's development department wherehe specialised in engine manaheet systems and freelanced for Scmidt Motorsport the firm that made some of VW's rally cars. Roland found his skills were in such high demand that he left Audi in 1991 to set up MTM.
Today thanks to his close ties with his former collegues down the road MTM remains at the cutting edge of Audi tuning.
Once you are strapped into the cosy drivers' lightweight Recaro seat with its four-point race harnesses, driving the twin-engined TT is easy. Turn the ignition on and hit the chromed button that says "Eng 1". Then you hit the "Eng 2" button next door to fire up the rear engine.
Unless you are a pilot with multiengine rating, this is a weird feeling the first couple of times, and passers by do a double take when they realise there is engine noise coming from each end of the car, and then see the second motor through the rear window glass!
Driving away from you or past you at town speeds, the TT Bimoto is hardly louder than a stock TT, and so does not attract undue attention apart from its lurid paint scheme. Inside, the stripped out interior is only shielded from the rear engine bay by sheet of carbon-fibre, so the cabin sound level is much higher than normal.
The quality of that sound is very interesting for the enthusiast, and the twittering of the waste gates with every upshift overlays the harder, more concentrated sporting note of the modified turbo engines. It is a sound you cannot help indulging in, and together with the adrenalin pump effect you get when you dip into positive boost, means you can find yourself slowing down on purpose just to experience the thrill of accelerating again.
Around town, the Bimoto is as tractable and easy to drive as the standard TT, but full throttle acceler ation is stupendous. Once the boost arrives, the thrust is strong and unrelenting, and it is very hard to watch the twin rev counters, digital speedometer and the road at the same time. The car gathers speed so fast that watching where you are going is definitely the most important of these three things. Being near Ingolstadt, there was always the chance that we would run into some fast company on the autobahn and we were not disappointed. An s6 4.2 quattro driver who wanted a closer look was dispatched with little effort each time he tried to close up. When we eventually peeled off for home, its occupants would have been none the wiser were it not for the huge Bimoto script on the side of the TT
The engines are synchronised through the drive-by-wire system, a technology that has finally cured the traditional problems encountered with mechanical connection. The gearboxes are still linked mechanically, though, and the shift quality is only a little less precise than that of a standard TT. The hydraulic clutch ensures that pedal pressure is barely heavier than standard.
Each of the 1.8litre 20-valve engines has been treated to uprated lightweight pistons, polished and balanced connecting rods and high lift cams to withstand the 1.8 bar boost pressure. A bigger KKK turbo, built to MTM's spec, sits on a new exhaust manifold, and lower back pressure is further encouraged by a stainless steel free-flow exhaust system with semi-race catalytic converters. Larger fuel-injectors and a reprogrammed ECU look after the revised fuel and ignition maps and each engine now delivers a healthy 326bhp at 6,5OOrpm with 438Nm (3231b. if.) of torque at 2,3OOrpm. Each engine gets one exhaust pipe and the centre pipe is for the waste gates.
Despite its twin power units and tubular steel reinforcement, the 1,490kg TT Bimoto is no heavier than a Porsche Turbo. With 4WD, traction off the line is excellent and the car grabs the tarmac and rockets to 60mph in 3.7 seconds, even with the tall axle ratios fitted to the car when we drove it. These Golf TDI gear ratios allow a theoretical 237mph at 7,OOOrpm in sixth gear; and were installed for the car to make a top speed record attempt at the Papenburg Proving Ground in North Germany last summer. It is likely that at least 215mph is achievable.
The normal street ratios are Audi RS4 and allow ()~0mph in 3.0 sec- onds and a 200mph top speed. Stock TT ratios are much lower and only allow 180mph, but that is a moot point, as the TT's 4WD gearbox cannot be used. The Bimoto requires a 2WD gearbox with each engine rather than one 4wD unit.
Also from the Audi RS4 are mechanical locking differentials, set for 25 per cent front and 45 per cent rear to give better handling and turn in. In fact, handling balance is easily adjustable via the drive-by-wire system. Since each engine has a potentiometer on each throttle which sends a signal to the ECU, these can be used to modulate the power at each end. Each is adjustable at the turn of a knob and is used to adjust power of the front engine to between 50 and 100 per cent to fine-tune the handling bias.
Thanks to a 52/48 per cent weight distribution, cross country handling and grip are simply amazing, and in the dry you can lay down as much power as you like once the car is set up for the exit of a bend. But, if you lift off sharply while cornering on the limit, you can feel the weight in the rear trying to move the tail outwards. This was very pronounced with the stock bushes in the suspension lower arms, but since Uniball joints were substituted, the oversteering tendency has largely been eradicated.
Fat 235/35ZR19 Michelin PilotSport tyres sit on 8.Sxl9in. multi-spoke alloys from Rimstock in England. These are forged rather than cast to increase strength and save weight, and look good without hiding too much of the enormous 365mm and 335mm diameter Ferrari F50 Brembo brakes. Clamped by huge Brembo eight and four-pot callipers respectively, these generate formidable stopping power without unreasonable pedal effort.
Stability at high speed is excellent, and the car tracked perfectly at over 170mph, thanks to MTM's carbon-fibre flat bottom, rear venturi and boot-top wing. For the Nardo attempt, a front air splitter will be installed for positive down force.
Despite the side intakes that draw cooling air into the rear engine bay, and the booster fans which help to vent the rear intercooler and radiator, you do notice that the temperature gauge for the rear engine always indicates a temperature 100C higher than the front one.
Open the engine bay and you can see where the hundreds of man-hours were spent. The tubular steel cage around the hatch opening stands out, as does the 58-litre fuel tank nestled between the cabin and engine bay. Since it has two mouths to feed, it will be replaced with a 100-litre tank to give the car a more acceptable range. The luggage compartment right at the back is big enough for a couple of squashy bags for a weekend break.
With the loss of the rear floor pan, structural strength was regained with a 40mm diameter tubular steel frame that follows the inner hatchback profile. A steel perimeter frame made from 3mm square tubular steel reinforces the sills and the front and rear bulkheads, with the front bar crossing under the dashboard. The transmission tunnel area is also strengthened with two square section tubular bars joining the front and rear bulk-heads. The rear engine/gearbox and subframe are production TT with the steering system removed. The lower suspension arm bushes which create passive toe effect on a standard TT are replaced with solid ones to prevent undesirable rear steering.
The standard struts have been replaced by race-style coil-overs with adjustable height as well as bounce and rebound control, and external reservoirs. Ride height has been set up at 3Omm and 25mm lower than stock front and rear respectively. The TT Bimoto is a fully sorted road car constructed by the MTM crew in their spare time over a three- year period. One-offs are always expensive, and the car has racked up a £155,000 ($217,000) bill for parts and labour, but MTM can now build replicas relatively quickly and for a lot less per copy. If they get five firm orders, a production version will be made.
If a Pike's Peak attempt in a TT is your goal, MTM can build you a pair of 2,042cc race spec engines, each of which yields 5Olbhp and 4001b.ff. (542Nm) of torque with 120 Octane race fuel. A sequential gearbox system is on the cards as the next development for the road version as well.
This is not the end of the story for the MTM TT Bimoto. One of the complaints Audi enthusiasts frequently make is that although the 1,796cc turbo engine can be tuned to give a great deal of power, its character is rather anodyne. Word has it that Volkswagen will make a turbocharged, transversely-packaged v6 for a flagship Golf Mk 5. Once MTM has tuned them, a pair of 400hp v6 engines would give the TT Bimoto a lot more character, and even more performance.
HAVING one engine at each end of a vehicle is not new, and heavy-duty locomotives still use it to this day. But, for road legal cars and motorsport prototypes, its use has always raised eyebrows. While you can change a rear-wheel drive car to four- wheel drive with a front transfer case and extra driveshafts, the engineering required to install two engines of the original type is quite forbidding because of the complexity of the drive system.
That is not the case with front-wheel drive cars, as the engine, gearbox and driveshafts come neatly packaged, and just require duplicating at the rear. The advent of front-wheel drive in mass production cars spawned the opportunity for some creative engineering, and even the lowly Citroen 2CV received twin power plants in a limited production factory version intended for use in desert conditions.
Back in the 1960s, the late John Cooper was nearly killed when his twin-engined Mini prototype de-synchronised itself and flung the car off the road.
Throughout the 1980s, Volkswagen Motorsport flirted with twin-engined cars based on their Golf Mk 1 floor pan. Golf, Jetta and Scirocco prototypes were built to explore this concept as a possible Group B rally weapon to beat the all conquering Ur quattro. Twin-engined Golfs competed in the famous Pike's Peak hill climb in 1985/87, finishing in the top ten each year.
Seat built a twin-engined Leon prototype last year, and some after market tuners have built twin-engined cars based on Volkswagen mechanicals. A few years ago, British tuner Dubsport made a very quick twin-engined Golf Mk 3 using a pair of turbocharged vR6 units.
The physical installation of two engines has always been the easy part of the story. Synchronising the engines and gearboxes is the tough bit. It is only the advent of drive-by-wire throttle management in the last couple of years that has made throttle synchronisation easy.

and those who can love it.

Something else, when I'm angry with someone I very rarely show it, I don't like making persons felling bad.I'm also too generous with the persons I like.

**Erik** · December 22nd, 2003, 15:06

I read these test data over and over again and it just amazes me how quick the Audis are.

I get scared! Check the pics!

http://www.prototipo.org/
http://www.racingcircuits.net/Italy/Nardo.html :MTM: