Hey Guys
E34 540i E39 540i M5 740i 750i 840i 850i M60 M62 M70 M73
As most of you who have a manual V8 BMW, or looking to convert to manual, have found is that the clutches/flywheels in these vehicles are too small, expensive and don't last the distance. So what I've done is develop a flywheel and clutch solution that will:
Be alot cheaper to replace and service hold more torque and last longer.
The factory flywheel is a dual mass item, and runs a LUK self adjusting pressure plate. These have a factory clamp load of 2800lb, which isn't too bad, but it only has a 240mm clutch disc. With a fullface clutch disc bigger is better so you will see the photo below of the standard kit and see how much more room is left on the flywheel.
Now most of the time the dual mass flywheels are stuffed and super expensive to replace, so I wanted to develop a kit that had a solid flywheel so that only the clutch kit needs to be replaced and the flywheel can be machined. If you have ever had to replace a BMW you will find they cost alot more than a normal clutch kit so I wanted to use components from another vehicle.
From what I've found there is a couple of suppliers around the world offering upgrade clutches- One of them had a 850i pressure plate and clutch disc,- that's cool if you live in Germany and they are cheap, but here in NZ you would struggle to find one in stock anywhere, and it would be $1200 + just for the clutch. Also these upgrade flywheels are more often than not made of aluminum.
The problem with aluminum is that it isn't a very good heat sink, so they get hot and stay hot and will cause the clutch to slip and get even hotter and eventually the flywheel bends causing endless clutch problems. They can also flex with high clamp pressure plates plus not to mention they are super light which can make a nice car a pain to drive.
So with a bit of kiwi "keep it simple stupid" I've designed a flywheel that uses the non vanos flexplate with trigger wheel, and a flywheel that bolts on over the top. We have to use the non vanos one becuase the vanos one seems to not have a big enough step to locate the flywheel on around the crank.
Then it accepts a Ford V8 10.5" pressure plate. Why? because these are a tried and tested unit that have been operating for around 4 decades and they are relatively cheap, especially in the US where I hope to start selling these kits to. They have around 2800lb clamp factory and have 10.5" clutch disc and alot more surface area. I've had some custom made clutch discs made with the correct BMW spline, the material is a high temp steel backed organic lining with a super strong 6 sprung hub with enclosed springs. Off the shelf HD pressure plates are 3500lb +
The factory flywheel and clutch weigh around 24kgs. With the non vanos flex plate weighing around 4kg this setup is going to be around 3kgs lighter that the factory one. We are starting here so we can see what the the characteristics are like- going too light will change the way the car drives and make it a pig and I want to be able to offer a replacement for stock vehicles.
So we are at a stage where we are going to fit it to one of Rays (Hell Bm) vehicles and we can assess what it all goes like- pedal feel (chatter if any) etc. So the hope is that we can offer an economical,reliable upgrade for V8 and V12 owners.
Will keep you posted.