bmw 4g63?

boostn · Post by **boostn** » Sat Dec 09, 2006 1:20 pm

im new to this whole swap thing with the 4g63 but have done v8 s-10 swaps and helped on some subaru swaps. but i was thinking a bmw with a 4g63 would be a nasty sleeper. how would the wiring work? i looked at the diagrams and stuff but what about the ignition wires and stuff like that. How would i go about figuring out to make the bmw harness work with the mitsu harness? i kinda want to know what im getting into before i start buying stuff. Ps. anyone wanna buy a Evo lol

Nick

Eric · Post by **Eric** » Tue Dec 12, 2006 11:32 pm

The trick is to build a Megasquirt and wire it all up from scratch. As far as the starter, that's easy. I still haven't figured out how to connect the charging system yet.

Eric · Post by **Eric** » Sat Dec 16, 2006 12:31 pm

Well, I currently know nothing about the wires and where they go and what they do. Along with that I need to figure out how to adapt them to the BMW. I'll probably figure it out or come up with better questions when I really get into it. For now, since I'm not driving anywhere, I will use the battery charger.

Bill Hincher · Post by **Bill Hincher** » Sun Dec 17, 2006 11:42 am

Alternaters are easy to understand , Eric, once you understand what the engineers built. There are a lot of ways to wire an alternater, and thats why you have to understand what the engineers did, both to the car you are wiring and the alternater you are using.

The first thing you have to know is how the alternater is ' excited'.
The old generaters had residual magnitism, alternaters do not, an electric current has to be introduced to the brushes to create and electromagnet. When the magnetic rotor turns inside the stator windings , an alternating current is induced in the stator windings.
Now the current must be rectified from A/C and into D/C current to be useful in the automotive system.

if you look at the lower left part of the pic, you will notice the ' voltage regulater' in front of the brushes.
That voltage regulater can either provide 12v power or it can supply a ground, depending on the engineers,( in this pic the engineers supply 12v to the regulater) the amount of voltage or grounding results in how hard the alternater works.
The ingition switch curcuit is assigned to the ' starter' side of the ignition switch, that is how the fields are ' ecxited' to create the elctromagnet by introducing current to the brushes connected to the rotor.
After the engine starts and the rotor is rotating inside the brushes, the voltage regulater takes over how much current is conducted through the brushes , and power from the ignition switch stops when the key goes back to ' run ' position.
Internally the rotor turns inside the stater windings and create a/c power, the series of diodes ' rectify' the a/c power and create useable d/c power, this will be your big post on the alternater that allows 14.5v volts to flow from the alternater.
Notice, I said 14.5v flow from the alternater. Remeber ohm's law? it says that it takes one volt to push one amp ( current) across one ohm of resistance?
Well, because the battery is 12.5v in a static state, it requires 13.5v to overcome the CURRENT flow of the battery, in other words its easier for the battery to push CURRENT towards the alternater than from the alternater to the battery, so the alternater makes 14.5v to ensure the CURRENT will flow towards the battery. while we seem to focus on Voltage in the auto world, it's CURRENT or AMPERAGE that does the work.
The L side of the alternater connects to the alternater light on the dash, the indicater light has power present on both side of the bulb when the engine is running, but when the alternater is not providing power, the bulb senses ground from the alternator side and the light goes on indicating problems.
I will be glad to explain how to test how the current divides itself in different ways to supply power to the electronic loads in the vehicle and the charging system if you need it , but that should be provided for in the original wiring harnnes after you wire the alternater correctly.

Bill Hincher · Post by **Bill Hincher** » Mon Dec 18, 2006 11:17 am

Eric, the two wires you need to concern yourself with are the small guage blue wire , which is your starter input for excitation from the starter side of the ignition switch and the large guage red wire which goes directly to the battery.

the blue wire is connected to the terminal 'S' on the mits alt

the RED wire goes to termanal ' B' at the alternater ( or large post ) I like to run 2 large guage wires from the alt post to ensure amperage flow to the battery

Both BMW and Mits use 'powered regulaters' internally in the alternater.

The indicater light from BMW's scematic should not require you to use the 'L' terminal from the alt

Post by **DJpowerHaus** » Tue Dec 19, 2006 3:28 pm

The problem Matt and I ran into a few years ago was from using an LED instead of an incandescent bulb for the alternator light. I'm not sure if it was because it was a diode or because it was too low resistance. This tiny mistake cost Matt $600 in dyno days were the car would just run fine but would just fall on its face after an hour or so on the dyno. We sure did learn alot since then.

Bill Hincher · Post by **Bill Hincher** » Tue Dec 19, 2006 6:04 pm

I would have recommended a diode in the blue starter wire so voltage cant go back through the system, but from the wire harness in the BMW it shows a diode built in the system at the indicator light and I think that is where they are getting the power to keep both side of the indicator light hot.

Eric · Post by **Eric** » Tue Dec 19, 2006 9:01 pm

Thanks for finding that out, Bill. I will probably hook it up tomorrow night.

agrabau · Post by **agrabau** » Thu Apr 12, 2007 7:13 pm

I did this swap a long time ago, probably 4-5 years now. It was a really fun and fast car. Be sure you're doing it for the right reasons. If you want to do it to learn a lot, then do it. If you want a fast reliable car that's cheap, look elsewhere. I originally intended for this car to be an evolving entity, finalizing it's metamorphosis as the budget allowed, in to a race car. The transmission proved to be my undoing.

I'm sure that if I did things all over again that I would have just built a non turbo BMW motor and concentrated on what makes a race car fast, the driver.. then the chassis.. then power but instead I did everything backwards. Like I said though, I learned a lot. I used the mighty max transmission and a Clutchnet custom clutch, then when I broke the MM tranny I attempted to build a MM trans with starion internals, because "I heard" that Eric Plebani had done it, which probably was a complete fabrication because Plebani never commented on his, and refused to answer emails. I spent about a G on transmission bearings and parts for the rebuild and the damn thing made it about one block.

Fast forward a few years. I have a race car, a nice one and a nice shop, and now I'm thinking about building a Montero with a 4g63. Someone stop me, please.

The specification started as a JDM 4g63 with a 16g, then I modified an Evo 8 TDO5HR to fit the 1g block using a laser cut manifold spacer, then I installed an Ebay HKS intercooler, then an Evo 8 intercooler which fit much better. I kept hitting the exhaust on the pavement while driving it on the street. That was annoying.

screemin eagle · Post by **screemin eagle** » Thu Apr 12, 2007 11:18 pm

dent sport?

4g63mightymax · Post by **4g63mightymax** » Fri Apr 13, 2007 10:57 am

screemin eagle wrote:dent sport?

Sure is, and also very humble considering all that he has accomplished.

Alex, hopefully this summer I can get down to your shop to dyno my 4g63 D50. Maybe I can even get Anj S. to join me!
-Jeremy

peregrine · Post by **peregrine** » Fri Apr 13, 2007 2:31 pm

is the motor tilted to clear the MC?

jeffball610 · Post by **jeffball610** » Fri Apr 13, 2007 4:41 pm

I'd also like to see any more under hood shots you have. And if you took pics during the build, that would help us too.

agrabau · Post by **agrabau** » Fri Apr 13, 2007 8:03 pm

The tilt was done to make it fit height wise. Luckily it helped clear the MC also. The BMW motor, (almost all of them) are at an even more severe angle because the hoodline is low on the car and they have to tilt it to fit.

I wish I had more photos. I had like 200 of them on my old computer and i lost the hard drive. I had almost none of them online at the time because when it broke I was uploading pictures of the SR20det version and removing the pics of the 4g63 version.

Bring the D50 down anytime. We'd love to see it on the dyno.

Alex

PS-

Insofar as the wiring goes.. I don't remember the specifics of the job at the moment but I wired in the 4g63 main relay which helped a lot. That was really the only other component besides the ECU that had to be wired. The ignition signal from the key to the starter remained stock, then I spliced the wires going to the BMW ECU for power, ignition signal ground and for the fuel pump signal.

91turboGSX · Post by **91turboGSX** » Sun Apr 15, 2007 12:06 am

Nice to see the car my intake manifold I got came from.

Welcome to the site Alex, i'm sure you'll have plenty of info to share.

Definitely be down there to give your dyno a workout. Diesel torque anyone?

Sorry for the threadjacking.

4g63mightymax · Post by **4g63mightymax** » Mon Apr 16, 2007 9:18 pm

Cory,
Maybe we should both go down there to DentSport at the same time and have a D50 Dyno Challenge!

Chances are good that you will slaughter me on the dyno, but I have an extended cab, and that has to be worth a few coolness points?
-Jeremy

agrabau · Post by **agrabau** » Mon Apr 16, 2007 10:03 pm

I recovered some more pictures. Unfortunately these are all I have.

http://www.dentsport.com/gallery/v/dsg/ ... ?g2_page=2

Eric · Post by **Eric** » Sun Apr 22, 2007 6:19 pm

Hey Alex. I emailed you about 5-6 months ago asking if you still had the old pics of the bimmubishi build. I'm pretty much done with mine, but only have about 150 miles on it because I keep finding things to fix at this point.

I didn't put my engine it at such an angle and don't have room for the m/c IF it's mounted to the booster. So I'm currently running without the booster, something I definitely want to design a fix for.