Project ’Weight Loss’ M3 Part 2

Hey Toby, dont bother welding the sunroof back in unless you dont care about making waves in the roof.   did you remove the entire sunroof carrier? it looks like that is not all?  my carrier was a lot longer than yours...

Here is what I did:

-- removed the entire sunroof subframe/carrier and the sunroof. installed a CF sunroof panel. when it gets repainted it will look like there was never a sunroof on the car. painted from the top and bottom side.  this mod saves about 18-20 kg of weight at the highest point of the car. quite worthwhile and almost makes up for half the cage. my weld in gr. A heigo cell weighs 36 kg.

-- the interior is completely stripped (you saw that last year already)

-- the hood/fenders/front and rear bumpers/rear wing etc. are all CF. that is a lot of weight right there. particulary the bumpers. removing these really lowers the polar moment of the car.

-- the weld in cell picks up the front and rear strut towers, the diff, the axle pickups, the roof and so on.  I did not like the OMP stuff which is pre-assembled and often does not fit correctly without additional work. therefore I got a Heigo, nothing is pre-assembled, but all fits very well. you can tell the difference right away.  I also have the car on a JIG to prevent any possible deformation during welding. Since the car has a few ring miles on it, I also want to make sure that nothing has shifted as the metal works around a bit on the track.

-- I used H&R 22 / 18 mm anti roll bars last year on toyo R888  R-tires and this combo turned out very well. Im going to stick with it, even for the new suspension.  I think it goes in the right direction. On the DTM cars, they ran 27 / 22 mm solid bars (before the hollow bar era) on slicks. That looks like a LOT of front end stiffness, but it makes sense after a while. Of course tire is important. This would not make sense on a street tire.

-- I run a 75% motorsport differential. That made a big difference. It has a very positive feel and makes you more aggressive on the track. 

-- At easter I should have my new DTM 6 speed installed. The gearing ratios are awesome. I cant wait to run this. For starters I will stick with 3.73 rear end as it is the recommended ratio using a 1.92 circumference tire on the Ring, and Im using a 1.90 circumference tire.  needless to say 1st gear will do 100 kmh, so that means in klostertal I can downshift into 1st if I like :) or at Wehrseifen...

-- for aerodynamics, im not done yet, but I went ahead and got the flossman splitter/undertray. it seals off the entire bottom side of the engine. I may find out that I need much more rear end down force. we are working on a rear difusor for my car without relocating the exhaust system. relocating exhaust would be ideal, but Im willing to do a compromise here at this point.  there are also winglets for the flossman setup, so I may add those, but that is secondary.

my only concern right now is that Im going to be finished by easter.

this will really suck if I cant make it to easter, that would be the first time in many years.

If I cant make it with my car, Id come up to give FREE driver instruction, assuming anyone wanted me to sit in and give driver tips. But if I cant drive myself, or give any laps, then standing around in the parking lot would get a bit boring for me. Lets hope it doesnt come to this, I have 8 weeks left. 

cheers

John

Hi Toby, sounds good, you are already tracking the car again?

We are buried in snow here in Munich, I can almost not get my DD car out of the garage today. got 50 cm of snow in the last day.

My car is still in pieces, its on a Jig right now to finalize all the welds now.  this is a crmo cage and all the welds are being done twice, first weld, then again at lower heat to stress relieve.   End of next week it goes for painting (inside and out).  Then it gets put back together. All the carbon stuff is here now too.  My engine is out and I saw the large oil pan was starting to develop a leak, so I will put it on the stand and reseal it. Then the new gearbox has to go in.  I dont think I can get the new suspension in and tune it as well in time for easter, so I think Im going to have to leave that off.   As it is Im going to have to take first few laps easy just to make sure we got all the bolts tight :)  not that I loose a rear axle or anything :)

John

Toby,

Sucks fakes, now I know why your car is so light. Your car looks worse that the 2002 I`m currently stripping, and I thought that it was bad.

Look on the bright side, at least you have found while you can still save it. Could have been worse if left longer. Have you thought of speaking to Jake about his shell he has on offer, as may be a better way to go.

Anyway, keep up the progress and hope to see on track soon,

Regards,

Dave