8hp45

[hoveringuy]

Curious about your gearing. How was the gs6 with the 3.15? Was fist gear ‘useless’ also? I have a 3.23 LSD that I’ll be running at least in the beginning but was curious if I should just go with a 2.93.

The GS6-17 was well-matched with a 3.15. The E90's had a 3.23 so considering that my tires circumference is 9% smaller it's within a few percent of a stock E90, about 5% shorter. A 2.93 would basically be exactly the same as an E90, maybe 1 or 2% taller. The N52 easily has the torque for that.

[Striker01]

The GS6-17 was well-matched with a 3.15. The E90's had a 3.23 so considering that my tires circumference is 9% smaller it's within a few percent of a stock E90, about 5% shorter. A 2.93 would basically be exactly the same as an E90, maybe 1 or 2% taller. The N52 easily has the torque for that.

I have 3.25, it's good and 2.93 would probably be good as well. 3rd gear starts are no problem with 3.25 and car will idle along in 1st with clutch out; that's with an N54 intake.

[hoveringuy]

weekly update, lots happening!

First, I ended up throwing a second 8HP45 in my car because the first was making a noise under load that sounded like dry bearings in sand. All gears, only under load. I found a second transmission for $205 with only 27,000 miles on it and IT MADE THE EXACT SAME NOISE! Turns out, servicing the fluid level on these things is kind of finicky. Warm the car, lift it up, run it through the gears and fill while the engine is running. I ended-up tipped the car on the side and adding one more quart and then the noise went away, completely. I think it was pump cavitation. Go figure...

adam.nonis now has the original one. I drove it for a week since then and it was non-stop giggles.

Meanwhile, I've made a lot of progress on proving the electrical part.

-The paddle shifters have a straight electrical path through the SZL. No processing at all. They can feed straight into the digital input of the CANTCU and they will work, 100%

-The blinkers interface with the SZL. At rest the resistance on the discrete wire is 5100 Ohms, in the "soft" blink position it's around 2500 Ohms and in the "until cancel..." position it's like 470 Ohms. This means I can make a simple resistor network and feed the voltage into an ESP32 GPIO pin and easily make a little circuit to drive MOSFETs (or relays?) to activate the blinkers. Same with the horn and high-beams.

-The E90 SZL fits on the F30 column with a tiny bit of clearancing. That's important because I need the E90 SZL to feed my Mk60. Sorted!

-I have a cruise control stalk again. That will work, eventually.

Also, I got the 3D print metal back from China.

The cap fit perfectly. Tap to fit and the welds don't do much more than hold it in place. Bearing is snug in the bore.





I have bosses on the top to create any mounting I want. I can update to a hinge down the road to make it tilting and so on. The spline is heat-treated tool steel. 3/4-36. I doesn't quite fit my steering coupler, it needs a little filing to clean the threads.




Seems Ok...



I can't use any of the multi-function buttons so those panels will get blanked, and I need a fake airbag center. Also, power window switches integrated nicely into the center console.





Finally, I ordered the entire RFID push-to-start kit. It was $19 on Ebay, lol.