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I am starting a new page because the last one is already too long.

I ordered the Adaptronic e420d engine management from Chris at The tuning firm's website and the customer service are very good and i have got good advice concerning the setup, sensors, tuning etc.

The Adaptronic ecu e420d finally arrived and it looks great. The two meter wire loom and its sockets are properly made. The package also includes a USB wire and a silicone hose for the internal MAP sensor which is good for 40 psi (2.8 bar) boost. This ecu should have enough functions and tuning possibilities for my needs.

The big 3.92 ASD diff arrived from Sweden. It has been in a W124 250D with 200 000 miles. The surprise was that it is an "Original Mercedes Benz Tauschaggregat" which means a factory built replacement part. So it has probably run much less than 200 000 miles.

The strategic measures of the diff: weight 62 lbs (28 kg), width 11.2" (285 mm) from flange to flange, lebgth 9.7" from flange to axle center, prop shaft bolt circle 3.5" (90 mm), axle shaft flange 4" (102 mm) and bolt circle 3.4" (86 mm), limited slip diff ASD, ratio 3.92. I must change the back plate to thr W201 back plate.

I finally found the back plate for the diff from Sweden, I couldn't find one here in Finland without buying a whole diff for a load of money. Onneksi romikset jossain päin maailmaa ymmärtävät bisneksen päälle. Next I must fix the diff, the drive shafts and the prop shaft.

These tools finally opened the drive shaft nuts.

I measured the length of the differential casings in order to get the prop shaft length right. The distance from the prop shaft flange to the back of the casing (where the back plate is attached) is about 12.2 inches (310 mm) on the big diff and about 10.8 inches on the small diff so the prop shaft must be shortened by 1.4 inches (35 mm). The drive shaft flanges on the big diff are about 3/8 inches (1 cm) nearer to the front of the car than on the small diff.

The W201 back plate fits well on the W124 diff. The gears seemed to be all right, too. The sealing between the case and the back plate is Hylomar and the screws are tightened to 50 Nm.

The diff sits well in its place with the new back plate. The prop shaft was shortened at Ko-Met Oy, and they did a good job. The prop shaft was shortened by 1.4 inches (35 mm) and the middle joint and support bearing are now beefier ones from the W124. The rear flange was changed to 3.54 inch (90mm) bolt circle. The support bearing holder is too big for the space it should be in, so this issue needs fixing.

The prop shaft and the axle shafts are fastened. I had full pressure in the ASD limited slip diff and the car was impossible to drive in tight turns. I released the pressure from the grease nipple and now the driving is better. It feels like the 3.92 final drive gives better acceleration than the old 3.23.

I installed the new pulley and moved the trigger wheel and sensor a little forward. The first test gave about 0.75 bar with the cam advanced and abput 0.9 bar with the cam retarded. The weather was a little rainy so I didn't test acceleration yet.

Today I dismantled the shifter to learn about it's anatomy. The dismantling was easy but putting it together was harder because the levers, bushings and spring washers must be well aligned. I must lengthen the shifter levers and stiffen the centering springs some time later. The spring that returns the gear lever from the 1/2 gate to the 3/4 gate is inside the shifter axle tube. It looked like it is hard to change or stiffen that spring. I also tried to chamfer the shifter lever holes to get the gear change faster but my file was not up to the job because the levers were hardened, so the result was not too good..

The old turbo intercooler and the kompressor tubing have got a new form. A special thanks to Aleksi.