Originally Posted by blackbenzz

Damn, you did it CHEAP! Can you post some pics? Where did you get the TB itself so cheap??? Was the machine work done on a CNC? Nice job You cut out the price of the inlet as well by using your stock one. Some people don't want to have their car down that long though.

Originally Posted by sneakyneon

I picked up the TB used from a auto recycler(wreaking yard) considering that that the audi TB covers from 02 to 05 4.2 plus volk's with the 4.2 there are plenty around! I'm not sure how it was machined? but its came out like I expected, a about 86mm hole. I figure if you can do the work yourself and you not afraid of taking some chances you can save allot of money. I have some pics at home I can share when I get back.

Originally Posted by stevebez

What are the bolt patterns on

the MB 82mm?
the Audi 82mm (I read earlier 75mm square 106 diagonal post #60)
the MB 80mm?
- well I just measured my 80mm and It seems dayam close to 75x75 bottom<->top, top<-> top - but not sure about bottom<->bottom (could not get in there to measure with the caliper) I seem to come out at 99.5 - 100mm diagonal so looks like the bottom two bolt holes are closer to each other? Can anyone cnfm?

Is it not possible to epoxy an 82mm onto a port matched 80mm inlet housing? And use the upper two bolts as locators / support mounts?

This saves the palava of making an adaptor plate.

And anyone care to share the MB part number for the 82mm... or is this a secret?

Originally Posted by sneakyneon

I picked up the TB used from a auto recycler(wreaking yard) considering that that the audi TB covers from 02 to 05 4.2 plus volk's with the 4.2 there are plenty around! I'm not sure how it was machined? but its came out like I expected, a about 86mm hole. I figure if you can do the work yourself and you not afraid of taking some chances you can save allot of money. I have some pics at home I can share when I get back.

Originally Posted by stevebez

Please do!!!

BTW anyone have experience on part throttle drivability...?

Originally Posted by blackbenzz

Did you have to swap any wires with the Audi TB? $125 is super cheap. I haven't found the MB TB's for that price. You mind pming me the name of the auto recycler you used? I am looking for 1 TB, would prefer an MB TB though


Part throttle drivability remains the same

Originally Posted by lowprofile

I have two 82 tb. Send me a PM if you interested in the Audi version.


Steve, On the MB t/b's the bottom bolt holes are closer together as you guessed. The p/n for the Mb 82mm was posted on page 1.

Originally Posted by lowprofile

I have two 82 tb. Send me a PM if you interested in the Audi version.


Steve, On the MB t/b's the bottom bolt holes are closer together as you guessed. The p/n for the Mb 82mm was posted on page 1.

Originally Posted by lowprofile

Ok, tested the pinouts on the throttle bodies. Here's a few more photos. I labeled the 5 pins on the dual potentiometer as A-E. B and D are the pins which output values being read by the ecu.


Here is the pinout at the connector as related to the potentiometer on the MB cap. Note: It now makes perfect sense to me why people had to swap wires when using the MB 80mm throttle body. The 80mm throttle blade rotates counter clockwise (like the Audi) while the 74mm throttle blade rotates clockwise(like the MB 82mm). So, swapping 1&4 reversed the polarity to the dc motor correcting for the change in rotation direction. Swapping 5&6 corrected the inverted output values for the dual potentiometer.


Here is the pinout at the connector as related to the potentimeter on the Audi cap.



Options:
1) Pick up the MB 82mm throttle body and the electrical part of the swap is taken care of. As blackbenzz stated, "plug and play", from an electrical stand point.
2) Use an Audi t/b and swap to a MB cap. The easiest would be to souce one from a bypass valve. This will require the 1&4, 5&6, pin swap.
3) Use the Audi t/b and swap all the pins to the Audi connector plug.
4) Make a new adapter harness specifically for use with the Audi t/b.

It's been said a few times but, anyone considering this should realize that an adapter plate is needed if you want an 82mm throttle body, or a flange could be welded to the s/c inlet as blackbenzz provided a picture of. Then you will also need to modify the intake "Y" pipe outlet to match the larger throttle body. Last, you are increasing the amount of airflow so you will need to monitor your short & long term fuel trims. The computer can only compensate to a point. A custom tune may not be mandatory, but do not assume you are safe without verifying via wideband and monitoring your fuel trims.

If this all sounds like too much for you, consider the 80mm throttle upgrade. All of the components needed are factory MB parts and will bolt-on.


Thanks Shardul.