Kiwi
24-02-2008, 06:37 PM
Saved this one as a web page so have pasted in the text and pics in the order from the webpage. Article from Total BMW
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe2.jpg
It's a bit of a bully, this M Coupe. It insults teachers and smokes behind the bike sheds. Older boys like Hartge and Schnitzer are hiding in a corner while the new boy thumps wimps like the M3. I mean, 400 bhp from 3.2 naturally-aspirated litres? That's sitting on the back seat of the school bus and smoking.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe3.jpg
The Digi-Tec M Coupe Race Concept has been around since 1999 but it's only this year that the project has finally come of age and given the 400 bhp to interest us. In the process it's also thrown up a couple of interesting developments. Not only does it give the extra 20 bhp to really mark it out from the others, but it's lighter too. The story began in 1998 when a new Estoril Blue car was delivered, but Digi-Tec boss Michael Pollmueller ordered the nonsunroof model -- already the idea was in his mind. "I deal with a lot of guys who race in the Porsche Cup Series and the car was developed for those who wanted something different but with similar, or even better performance," Michael says.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe4.jpg
"Initially we went for street modifications -- removing the speed limiter and giving it more power and handling improvements. These aren't bad handling cars, but they are tricky," Michael says. Peering underneath, we note the 20-year-old E30 rear axle design with its heroic semi-trailing arms. Hmm...
First job was that engine. "There was no way I was going to supercharge this engine. BMW designed the greatest straight-six engine ever and adding a blower would just ruin it," he states. We mention Dinan in the States which offers blower conversions to the M Roadster and Coupe, but then remembered that Federal versions have the limp 240 bhp version, with the basic 328i-style head and not the proper Motorsport engine. "Those cars need help," Michael adds.
The first evolution of the Digi-Tec Race Concept M Coupe featured a blueprinted bottom end, tweaked head, different exhaust manifold and special cams. This was allied to remapped Vanos and Digi-Tec Alpha N engine management, which loses the air mass meter. What's clever about the Digi-Tec version is that its ECU is filled with its own software and parts such as the throttle potentiometer and various sensors are stock BMW. Air is drawn in through a 130 mm carbon fibre plenum, made by Digi-Tec's carbon fibre maestros with a free-flow cone filter with cold air supply. A Sebring four-pipe exhaust was fitted and the catalyst replaced with a special one with just 100 big holes per inch, as opposed to 400 smaller ones. And then, with stronger valve springs to raise the rev limit, power was an impressive 380 bhp at 8000 rpm.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe5.jpg
The gearbox is a standard five-speeder, as used in the 3-litre E36 M3. "We found that with the increased torque this engine gives, there was no point in having six gears," Michael explains. We mention the rumour that the six-speed box was a weaker unit, but Michael would do no more than nod in agreement.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe6.jpg
Feeding this power through a standard clutch wouldn't necessarily kill it, but it wouldn't last that long. No, the reason Michael went for twin 6 inch race clutches is because he used a Group A M3 flywheel, which weighs 8.35 kg when combined with the clutch -- half the standard weight and one of the reasons this engine revs like a dentist's drill.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe7.jpg
As BMW made them, the M Coupe rear axle assembly was the ultimate factory interpretation of the E30 idea, born over 20 years ago. Since then, the E30 M3 has come and gone, but the Motorsport Three's rear axle was the starting place with its stronger construction, plus M3 owners will notice the reinforcing beams across each trailing arm's axis. Even so, Michael found room to improve. "The final drive was getting very hot around the Nurburgring. I've done around 1500 laps getting it just right and the oil was overheating. So we came up with the oil pump and cooler which is operated from the old air conditioning switch inside."
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe8.jpg
As for suspension, Digi-Tec worked with Bilstein to create the height adjustable dampers to go with this car and the Eibach springs it rates so highly. While retaining some rubber, such as the rear axle-to-body mounts, Digi-Tec replaced everything else with steel, and items like the top strut's mounts are on steel Rose-joint mounts. "This makes so much difference to the handling and it's so precise. One of our biggest concerns was the strength of the differential-to-chassis mounting and we re-engineered it. It hasn't broken yet!" he laughs. Brakes? Brembo if you must ask, with 322 mm vented discs on the front, 304s on the rear and alloy four-pot calipers front and back. Four pots on the back axle think about that. It still runs ABS, but now with a manual override switch and Pagid Blue fluid with alloy ceramic Pagid RS14 pads.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe10.jpg
OK, so that's the mechanical stuff. Now for the body, and you'd be surprised to learn that most of the exterior panelwork is carbon fibre. Bonnet, doors, that rear spoiler whose downforce allows an extra 25 mph around one sweeping section of the Ring, plus the deeper side sills, the front splitter and those panels that fit between the sills and bonnet. These have brake cooling ducts built in and apart from adding these Slimfast panels, Digi-Tec also removed the ballast that BMW fitted inside the original bumpers to aid weight distribution. Weight loss? How about 12 kg for each door and 28 kg for the bonnet. The original car weight was over 1500 kg, now it's just 1180 kg. Inside, everything that suggested Western decadence has gone -- carpets, air con system, electric windows and all sound deadening. Instead, we've got two Recaro race buckets with Sabelt harnesses, that airbag wheel gave way to an OMP threespoke like your dad's 1971 Escort Mexico had, plus a big Wiechers roll cage. Smaller details catch your eye though. E30 window winder mechanisms replace the lechy motors and a Digi-Tec 300 kph speedo face means business. In the back, carbon fibre replaces the carpeted floor, while carbon fibre door trims and OMP pedals add to the race car feel. Rear seats? It never had any.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe11.jpg
Since then, the 2002 evolution has arrived -- just what we've been waiting for. Power is now 400 bhp at 8500 rpm, but it wasn't easy. "It's known that at over 8000 rpm the connecting rods in these engines can fail," says Michael, and he's right. A number of derestricted E46 M3s have gone this way and the trouble comes on the over-run where the engine braking has to slow the speeding car from 8000 rpm. The conrods stretch and... bang!
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe12.jpg
Michael knew he needed an extra 300 rpm to get that last spoonful of power, so a set of titanium rods were made and mated to Group A racing pistons. With this on board, plus refitting the standard exhaust manifold, power touched just over 400 brake, or 125 bhp per litre. "With the manifold, we found the standard item lost very little power but gave us more useable torque. Also, we got rid of the standard viscous cooling fan, as that costs real power when it's working. Instead, we used the redundant air con fan and it works fine, Michael explains. Switching to a special Digi-Tec exhaust also helped the cause.
But what's it like to drive? Well, after the shoot was over, Michael gave us the key and told us to give it a run. Initial trepidation led to one stalling moment but on the second attempt we got cleanly away, showering our Audi hire car with stones and mud. Ha! Now, standard M Coupes are quite brisk but this is incredible -- 0-60 on well-worn street tyres takes a smoking, writhing 4.5 seconds (less on slicks) and traction is the big problem. You can hear the poor LSD rattling away back there. By 150 mph a standard M Coupe is starting to slow down, but along a quiet, straight country road alongside an old air base we wound this one up to 160 mph and were still accelerating before the road ran out.
The brakes are strong enough to give you a nosebleed and wiped off 50 mph. Through a long, sweeping right-hander it just gripped, and it went at over a ton without any feeling of an "oh my God' moment. This was a car we could have driven all day, but it was getting dark and we had 200 miles of autobahn ahead. Starting with a new base car, Digi-Tec can build something similar for about 60 grand including the car -- less if you keep the interior standard. Pricey, but faster than anything else for the money. Shocking, absolutely shocking.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe9.jpg
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe2.jpg
It's a bit of a bully, this M Coupe. It insults teachers and smokes behind the bike sheds. Older boys like Hartge and Schnitzer are hiding in a corner while the new boy thumps wimps like the M3. I mean, 400 bhp from 3.2 naturally-aspirated litres? That's sitting on the back seat of the school bus and smoking.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe3.jpg
The Digi-Tec M Coupe Race Concept has been around since 1999 but it's only this year that the project has finally come of age and given the 400 bhp to interest us. In the process it's also thrown up a couple of interesting developments. Not only does it give the extra 20 bhp to really mark it out from the others, but it's lighter too. The story began in 1998 when a new Estoril Blue car was delivered, but Digi-Tec boss Michael Pollmueller ordered the nonsunroof model -- already the idea was in his mind. "I deal with a lot of guys who race in the Porsche Cup Series and the car was developed for those who wanted something different but with similar, or even better performance," Michael says.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe4.jpg
"Initially we went for street modifications -- removing the speed limiter and giving it more power and handling improvements. These aren't bad handling cars, but they are tricky," Michael says. Peering underneath, we note the 20-year-old E30 rear axle design with its heroic semi-trailing arms. Hmm...
First job was that engine. "There was no way I was going to supercharge this engine. BMW designed the greatest straight-six engine ever and adding a blower would just ruin it," he states. We mention Dinan in the States which offers blower conversions to the M Roadster and Coupe, but then remembered that Federal versions have the limp 240 bhp version, with the basic 328i-style head and not the proper Motorsport engine. "Those cars need help," Michael adds.
The first evolution of the Digi-Tec Race Concept M Coupe featured a blueprinted bottom end, tweaked head, different exhaust manifold and special cams. This was allied to remapped Vanos and Digi-Tec Alpha N engine management, which loses the air mass meter. What's clever about the Digi-Tec version is that its ECU is filled with its own software and parts such as the throttle potentiometer and various sensors are stock BMW. Air is drawn in through a 130 mm carbon fibre plenum, made by Digi-Tec's carbon fibre maestros with a free-flow cone filter with cold air supply. A Sebring four-pipe exhaust was fitted and the catalyst replaced with a special one with just 100 big holes per inch, as opposed to 400 smaller ones. And then, with stronger valve springs to raise the rev limit, power was an impressive 380 bhp at 8000 rpm.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe5.jpg
The gearbox is a standard five-speeder, as used in the 3-litre E36 M3. "We found that with the increased torque this engine gives, there was no point in having six gears," Michael explains. We mention the rumour that the six-speed box was a weaker unit, but Michael would do no more than nod in agreement.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe6.jpg
Feeding this power through a standard clutch wouldn't necessarily kill it, but it wouldn't last that long. No, the reason Michael went for twin 6 inch race clutches is because he used a Group A M3 flywheel, which weighs 8.35 kg when combined with the clutch -- half the standard weight and one of the reasons this engine revs like a dentist's drill.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe7.jpg
As BMW made them, the M Coupe rear axle assembly was the ultimate factory interpretation of the E30 idea, born over 20 years ago. Since then, the E30 M3 has come and gone, but the Motorsport Three's rear axle was the starting place with its stronger construction, plus M3 owners will notice the reinforcing beams across each trailing arm's axis. Even so, Michael found room to improve. "The final drive was getting very hot around the Nurburgring. I've done around 1500 laps getting it just right and the oil was overheating. So we came up with the oil pump and cooler which is operated from the old air conditioning switch inside."
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe8.jpg
As for suspension, Digi-Tec worked with Bilstein to create the height adjustable dampers to go with this car and the Eibach springs it rates so highly. While retaining some rubber, such as the rear axle-to-body mounts, Digi-Tec replaced everything else with steel, and items like the top strut's mounts are on steel Rose-joint mounts. "This makes so much difference to the handling and it's so precise. One of our biggest concerns was the strength of the differential-to-chassis mounting and we re-engineered it. It hasn't broken yet!" he laughs. Brakes? Brembo if you must ask, with 322 mm vented discs on the front, 304s on the rear and alloy four-pot calipers front and back. Four pots on the back axle think about that. It still runs ABS, but now with a manual override switch and Pagid Blue fluid with alloy ceramic Pagid RS14 pads.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe10.jpg
OK, so that's the mechanical stuff. Now for the body, and you'd be surprised to learn that most of the exterior panelwork is carbon fibre. Bonnet, doors, that rear spoiler whose downforce allows an extra 25 mph around one sweeping section of the Ring, plus the deeper side sills, the front splitter and those panels that fit between the sills and bonnet. These have brake cooling ducts built in and apart from adding these Slimfast panels, Digi-Tec also removed the ballast that BMW fitted inside the original bumpers to aid weight distribution. Weight loss? How about 12 kg for each door and 28 kg for the bonnet. The original car weight was over 1500 kg, now it's just 1180 kg. Inside, everything that suggested Western decadence has gone -- carpets, air con system, electric windows and all sound deadening. Instead, we've got two Recaro race buckets with Sabelt harnesses, that airbag wheel gave way to an OMP threespoke like your dad's 1971 Escort Mexico had, plus a big Wiechers roll cage. Smaller details catch your eye though. E30 window winder mechanisms replace the lechy motors and a Digi-Tec 300 kph speedo face means business. In the back, carbon fibre replaces the carpeted floor, while carbon fibre door trims and OMP pedals add to the race car feel. Rear seats? It never had any.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe11.jpg
Since then, the 2002 evolution has arrived -- just what we've been waiting for. Power is now 400 bhp at 8500 rpm, but it wasn't easy. "It's known that at over 8000 rpm the connecting rods in these engines can fail," says Michael, and he's right. A number of derestricted E46 M3s have gone this way and the trouble comes on the over-run where the engine braking has to slow the speeding car from 8000 rpm. The conrods stretch and... bang!
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe12.jpg
Michael knew he needed an extra 300 rpm to get that last spoonful of power, so a set of titanium rods were made and mated to Group A racing pistons. With this on board, plus refitting the standard exhaust manifold, power touched just over 400 brake, or 125 bhp per litre. "With the manifold, we found the standard item lost very little power but gave us more useable torque. Also, we got rid of the standard viscous cooling fan, as that costs real power when it's working. Instead, we used the redundant air con fan and it works fine, Michael explains. Switching to a special Digi-Tec exhaust also helped the cause.
But what's it like to drive? Well, after the shoot was over, Michael gave us the key and told us to give it a run. Initial trepidation led to one stalling moment but on the second attempt we got cleanly away, showering our Audi hire car with stones and mud. Ha! Now, standard M Coupes are quite brisk but this is incredible -- 0-60 on well-worn street tyres takes a smoking, writhing 4.5 seconds (less on slicks) and traction is the big problem. You can hear the poor LSD rattling away back there. By 150 mph a standard M Coupe is starting to slow down, but along a quiet, straight country road alongside an old air base we wound this one up to 160 mph and were still accelerating before the road ran out.
The brakes are strong enough to give you a nosebleed and wiped off 50 mph. Through a long, sweeping right-hander it just gripped, and it went at over a ton without any feeling of an "oh my God' moment. This was a car we could have driven all day, but it was getting dark and we had 200 miles of autobahn ahead. Starting with a new base car, Digi-Tec can build something similar for about 60 grand including the car -- less if you keep the interior standard. Pricey, but faster than anything else for the money. Shocking, absolutely shocking.
http://i256.photobucket.com/albums/hh183/azumaj/performancebmw103mcoupe9.jpg