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      06-20-2012, 12:37 PM   #1
nailer335's Avatar

Drives: alpine '08 e92 335xi
Join Date: Feb 2010
Location: Arizona

iTrader: (0)

Transfer Case "weakness" - fact or fiction?

This will be a bit long winded, but I really want to put this to bed sooner than later...

I got my e92 335xi in early 2008 new. Thought that it was the best combination of applicable performance, style and luxury that the market had to offer anywhere near its price range and believed that it's aftermarket potential would flourish. I have been following vishnu, BMS and at the time Dinans contributions to the community since I got the car. At the time I was what you'd consider a passive enthusiast... Reading > Posting and I didn't really need online strangers recognition or attention like some seem to, I just wanted to follow the progress of the platform. The 335xi was a lease to own, as I wanted to make sure beforehand that it would be worth it personally to end up paying for the total amount the car would cost.

I was never and have never been one to pamper this car. I did not slowly break in the engine- I was hitting the kick down by 300-400 miles. By 2000 miles, I further corrupted myself with the addition of brake boosting. I havent stopped doing that since. From 2000-30000 miles, I did countless brake boost launches. At ~30000 miles, I installed the JB3 2.0 as soon as it was released, with a DCI. I did warm the car up to increased boost, much better than I warmed up my engine when it was new. Started on map 2, then 3, and after about 5000 miles map 5 was my daily driver map, on 91 octane. as many adrenaline producing activities go... Map 5 wasn't enough so I got addicted to the 100octane pump just down the street from where I lived at the time, and I constantly put the car on map 7. Many more brake boosted launches and hitting the kick down in first gear.

With 60,000 miles on the clock, about 8 months or so ago, I upgraded to JB4 15ohm, put in a Mr5 intake and a trunk tank meth kit (for various reasons). I have a CM10 going into a custom elbow and a CM3 in each intake snorkel to help the car with AZs desert conditions. Since doing this, guess what... Many more brake boosted launches. Daily driving has been done on map 3 at a 45 adder and approx 80/20 to 90/10 meth to water mix (50/50 being way too much water with pre filter intake nozzles). To satisfy my constant need for more... When I put in 100 or 109 octane I set up a custom map 6 on the JB4 playing around with different tweaks to the boost value at different RPM ranges. I usually end up somewhere around 18.5-19.5 psi between 5000-5500 rpms, dialing down to 15psi at 7000 rpm. I also shift out of gears before 6500 rpm as there is no point to redlining this car whatsoever.

For the first 50,000 miles, I serviced the car as any lease- by BMWs terms. Which many including myself find insufficient for a turbo vehicle, especially when aggressively tuned. Since then, I've been doing 5-6k motul 300v intervals, plugs every 10k miles, etc. here's the kicker (go easy on me Doyle...) I still haven't even serviced my transfer case! 71000 miles now and perhaps more brake boosted launches at higher boost than most (granted my car has only seen a commute to work and back since I got a different DD back in March)

I hypothesize that most of the transfer case hype is fiction stirred up by RWD people and spread by he said she said stories. Obviously, recalibrating a machine to operate at higher performance requirements than it was originally engineered to perform will create the uncertain "borrowed time" future for the life of the machine... But perhaps these TC stories are exacerbated a bit and really not related to people pushing higher power and torque. My story is to illustrate that I doubt many 335xi's have ever had to put up with what mine has... And according to many I should have replaced my TC and my AT by now.

I'm really interested in other peoples stories to either provide myself with clarification that my specific car was over engineered, or these TC rumors are retarding the xi community's progress way more than it should. I know that Bob Vader has been abusing his xi for a long time too and there are others who put their cars through hell too. But since the xi section is by far the quietest section on this board (although this has seen significant improvement this year I think) I really don't know if I'm anywhere close on this little hypothesis. Best case scenario, this thread gives us all a little more confidence to show people that the 335xi is not a red headed stepchild.

The more detail oriented participation in this the better.