7 replies to this topic

[minimaded]

Okay, its about time I started my own install thread.

 

I don't have a huge amount of time to do a comprehensive write up with each step but I will try to make up for it with pictures.

 

The install in my mini started a few years ago after I got my first taste of bass and it has slowly evolved but I have finally settled for what I want.

 

So starting at the beginning it is time for the Audi A4 120a alternator to go and I am going to squeeze this Mercedes S320 200a alternator in. I got the alternator with seized bearings so I have already replaced them and the slip rings. A quick test shown it is now working fine but only outputting 14.2v compared to the 14.7v from the Audi unit, so I might upgrade the regulator to an adjustable one in the future.

 

 

I have all ready swapped out the crank and water pump pulleys for mpi poly fee belt pulleys so it should be a fairly simple swap.

 

Thanks

Ed

 

[Ro8bieg]

Did you get any further on this?

[minimaded]

No, not yet, with L2B coming been concentrating on mechanical issues.

[TehMarchant]

I am really interested in how the alternator preforms, I need some more amperage for my midge.

[lonoma01]

Where did you get your pulleys to swap over to the serpentine belt. I am in dyer need of those. I am about to start building a chain and sprocket setup for mine if I can't locate any. I have a 160amp alt and I also have a 370amp running off a jack shaft

[minimaded]

Hi, they are the standard pulleys off a mpi mini, I got them on eBay.

[minimaded]

Update coming soon, the 200A alternator is in.

[minimaded]

So its time for a much over due update, been busy with my new job and going back to college, so I have been short of time to write up my progress.

 

After much head scratching I designed a mount for the new alternator, retaining as many of the old mounting positions as possible allowing me to revert back to the old alternator without too much effort.

It was a squeeze and was a lot of trial and error until I got something that worked.

 

 

I fabricated a mount for the top of the alternator, it uses the original mounting holes and I used a few washers either side to allow adjustment to align the pulleys.

 

 

I used my new toy to check the alignment of the pulleys.

 

 

Once happy I fabricated the bottom mount and used on of the timing chain cover bolts to secure it to.

 

 

The bottom mount also supports a modified vauxhall corsa drive belt tensioner. As well as allowing the belt to be tensioned easily it also increases the wrap round on the alternator and crank pulleys to help reduce belt slip.

 

 

Here are a couple more pictures of the mounts.

 

 

 

To help the alternator deliver the extra power I fitted a new 0 gauge earth cable from the alternator body to the bulk head.

 

 

 

I fitted the new 0 gauge battery cable too, with 250a fuses at each end.

 

 

Also I gave the engine bay a bit of a spruce up, will take some more pictures. Including rewiring most of the front end electrics.

 

 

The alternator performed well but I was a bit disappointed with its voltage being only 14.1v, so I ordered a new regulator and set about modifying it to increase the voltage.

 

As standard the regulator is set at 14.1v but I wanted closer to 15v to get more power from my amps. So I opened up the new regulator and reversed engineered it with the help of some schematics of simular regulators.

 

 

 

 

 

With some trial and error i designed a circuit that would allow me to increase the voltage with a switch from inside the car. It allows the voltage to be increased to between 14.8v and 15.2v.

 

 

I built the circuit with some components I had kicking about and fitted it into the regulator. I disconnected the unused DFM wire and reused the terminal for voltage increase switch.

 

 

I made a hole for the pot screw and glued it in place.

 

 

I then filled the case with Raytech magic gel to keep the water out and stuck the cover on.

 

 

I fitted the new regulator and gave it a test, I gave 14.2v standard and when I flicked the switch the voltage increased to 15.1v so I reduced it down to 15.0v.