E92 - Strip Down

By Thorney Motorsport

Its not been a bad development for the E92 M3, over the last 9 months we’ve upgraded the suspension, wheels, brakes, exhaust and power nicely so overall we’re pretty pleased with the development thus far. There have been some notable highs, such as a spirited drive from Cornwall to Milton Keynes in the early hours which demonstrated the Moton suspension and AP brakes to their finest as well as countless times where the roar of the Akrapovic exhaust simply made us smile just for being in the car. Hearing the Safety Car Drivers of the CSL Cup describe the car as the ‘best safety car they’ve ever driven’ was nice as well as well as comments from owners saying that at last they thought the car looked good also stand out. There have been some lows too, the satnav will not be missed, neither will the stupid seat belt helpers or the clutch switch which ensured you failed to start the car at least once a week can happily be consigned to the parts bin. We’ve been impressed with the quality, unimpressed by the standard cars ability on track (10 seconds slower than a Cup car is just woeful even allowing for tyres) but overall we’ve grown to love the E92 M3, warts and all, it's no CSL but its a better overall car and thats not to be sniffed at.

But the time has come for the car to continue its transformation into a full blown CSL Cup race car. People often ask what the difference between a road car and a race car so the idea now over the next few months is to explain exactly what we do when we create a race car, so this month we’re going to start with the most painful process in any race car development (other than smashing it into a wall at 60mph like its sister) – the strip.

Most race cars start life as road cars, even manufacturers start with a standard shell (albeit without all the crap that goes i it) but usually race teams start with a written off car or bare parts, not us, we take a perfectly good, 2006 M3 and gut the thing – we must be mad!

First order of business (other than cashing in the tax disk and making sure its not full of fuel)  is to de-program the cars canbus modules. The E92 is a complicated piece of kit with nearly 30 separate modules (think control ECU’s and you’d be half right) dotted around the car controlling everything from your windows to the cars fueling system. Simply hacking them out will leave you with a car that wont go (as Top Gear found out when we sorted their 24 hour race car for them) so you have to systematically deprogram each one off the system, once thats done the battery comes out so no harm can be done to the rest of the cars electrics.

 

After this the real fun begins, seats, trim, dash, carpet and all the interior tend to be first eventually leaving the car bare inside except for glue residue and the wiring harness. The harness itself is then marked up with each connector and wire and this removed usually via the dash. Then some poor sod has the really awful job of clearing out the last glue residue with brake cleaner which is time consuming (can take a whole day just to do this) but its important as the interior will be painted after the cage goes in and glue does not make for a good surface to paint on.

After this the cars bodywork is removed, front and rear bumpers are sent away for moulding to create carbon fibre race and road items the bonnet and boot are removed for single skin race versions and usually the doors are sent away for the same reason save for now as we need them to launch the car at Autosport next month so they will have to wait. Wheels, brakes, suspension are all removed for good measure.

After the front bodywork is off you can marvel at the complexity the E92 M3 is when compared to its older brother – there are 5 radiators (oil, water, power steering, gearbox and aircon)  all of which need to be removed to get access to the engine.

 

After all this we then remove the engine harness, engine and gearbox to leave the chassis with its bolt on furniture. Uts about now we can get a good look at what we need to do as regards cage and initial race set up.

Overall the E92 really is a development of the E46, the overall chassis design is remarkable similar and is a true single design with the chassis being able to run in left hand or right hand drive form. The cars braking systems are all situate in the same place as well as the dash, main shell all looking pretty familiar  - they are different for sure but you see can how its a development of the E46 not a radical change. The other thing that grabs you is just how big the car is from the inside, stripped of its trim the cabin seems huge compared to the E46.

The net result of all this work (4 full days labour for two techs) is the chassis ready for the cage to be installed and a great big pile of parts for ebay to sell. Anyone want to buy an E92 M3 interior?

Next month we’ll do the cage.