Amazing Write Up by an owner of a 335 Diesel
Well, this one is rather invisible but certainly not unnoticable. Turbo diesels respond fantastically to ECU tweaks, and the 335D is no exception.
With the pending re-map, I thought I'll get before and after dyno readings for comparison. This was done last Friday.
The readings were pretty consistent. Because the car is an auto, only rear wheel BHP can be measured.
I would have thought the difference between crank and rear wheel BHP is around 20%. So with those figures, we are looking at 278BHP at the crank, whcih is 8BHP down from the manufacturer's quote of 286BHP.
Torque is at 335ft/lb. Again given the 20% difference, we are looking at 420ft/lb, 19ft/lb down from the manufacturer's quote of 439ft/lb.
However, the engine has only done 2500 miles.
This is the power curve printed on the brochure.
Here is a video of the run. As you can see, the 335D is so silent that the engine and exhaust noise is completely overidden by the cooling fan noise.
So, today my D joins the rank of the 300+BHP club.
The ECU in the E92 335D is the latest Bosch DDE 7 ECU, in BMW's terminology, it's the most flexible and adaptive ECU to date. Cracking the encryption took some time, as some of you might know that over the past few months, there has been the unfortunate event of irretrievable data loss from the ECU when a re-map was attempted. However, I have to say this is no longer a problem.
Unlike other ECUs, careful research led to the approach of removing the entire ECU from the car to re-map. Using the OBD port is not deemed safe enough for us for this occasion although there are some mappers out there who are already employing the latter method . We took the failsafe route.
And here is the tiny brain that controls everything. How amazing. The ECU is made by Bosch and the latest DDE7 version. Each ECU software/micro-processor is specific to the car it comes with. My ECU is stamped with my chassis no. Cars with different specs such as i-Drive etc will have a different programme, although the majority of the processors are similar.
Crunch time. ECU guts laid bare. We had to get to the EPROM to obtain a record of the original map. Those 10 pins are the ports for information transfer.
Once the original map is obtained, it is saved for future 'reference'. The map is then emailed to Roy's source and an hour later, a custom modified map based on the original map is received. In the mean time, we shove the ECU in the freezer. No joke!
This is a vital part of the entire process. The ECU has to be within a certain temperature range for the new map to be uploaded. We had to try several times and put the ECU back in the freezer to guestimate this temperature window. Eventually, the new map was successfully transferred and a quick check to ensure no disparity in the new map and that we received on the computer.
Once the ECU is re-intalled in the car, a quick diagnostic check was performed. No fault codes! Yippeee!
We are ready to roll. Thumb the start button and the diesel block fired up straight away, settling to a steady idle. I prodded the throttle and straight away, even when the car was stationary, I could feel the difference. The throttle feels so much more alive.
On the move, MY GOD!!!! The car is totally transformed. The amount of power is mind boggling, let alone the torque! Estimated gains, 340BHP and 680Nm torque. The 335D pulls so hard in every gear that it defies believe. If I floor the throttle hard, DTC will flash even in 3rd; and today was 26 degrees and dry! Squeeze the throttle progressively and you literally blast past everything in sight. I tested with a stopwatch, 0-60 achieved in 4.8 sec, the speedometer whips from 80-120MPH in a few seconds, and it continues to pull. The re-map has also removed the top speed limiter, so the 335D should easily see 160+MPH. TBH, the in gear acceleration feels as quick as the E60 M5 I drove not long ago.
Bear in mind my 335D is a guinea pig (it's OK, no pain no gain. But I trust CA Automotive's judgement). It is a success.
Just spent several hours driving the D hard, the ECU is continually adapting to the driving style. The harder I drive the car, the more responsive the car gets. Gearbox is holding up fine. The gearbox is the major weak link as it heats up too much at too high a state of tune (automatically feed information back to the ECU to reduce engine power), despite the engine and turbos keeping up with the demand. I think we can push a little bit more once the engine is more run in.
Tonight I used 2 EvoTechnik cars for comparison, both on motorway in gear acceleration and around twisties. We chose the black ones as they are generally faster .....
In gear acceleration, the 335D is on par with the CSL until 4.5k RPM where the CSL started pulling ahead with 3k more revs to utilise. Once the 335D upshifts, it surges ahead gaining on the CSL, and then lose out again when it runs out of puff. However, overall the CSL is never more than 2 cars ahead before we had to slow down or risk an instant ban and jail. The F430 is leagues ahead, no comparison, even for the CSL.
Twisties, the gargantuant torque of the 335D enable it to tailgate the F430 in any gear. CSL was more nervous over rutty areas and the gearbox had to be worked hard; but the E92 soaked up the undulations very well. The F430 was throwing sparks from it's underbelly, still amazingly quick but didn't pull on the E92 more than a car's length.
Pretty accomplished for a diesel! Can't wait to see the 335D tackle the Ring come June.
Here are 2 quick (low quality) videos I made using my camera. The first one was immediately after the remap and the second video is after several hours of spirited driving. You can hear the engine revving a lot more aggressively in the second video.
Immediately after re-map 
ECU adjusting to aggressive driving 
So far I'm very impressed with this upgrade. The gains are more noticable than the time when I had my 330CS supercharged by Infinitas using the SK+ S/C (231 to 286 BHP).