Ok let's see what becomes of this. I'd appreciate it if mods could help me out. This will be kind of like a wiki. We'll try to keep the replies to 0. If someone wishes to add to this list, they can post a reply and once 2 people agree with what they say, it gets added and the thread is cleaned up. Or if there is disagreement, the suggestion is simply removed. Any questions will be removed (need the members cooperation on this one too).
Q: Does it fit?
A: yah
Q: Is it hard?
A: no, just long (and yes, pills fix that now)
Q: What does the E36 engine need to have done to it?
A: Swap the oil pan to an 1992+ E34 525i pan with the dipstick and pickup. If it's an OBDII motor (1996+), it needs an M50 wiring harness, computer, cam sensor, crank sensor, solenoid extension, intake manifold/throttle body, fuel rail/injectors, PCV valve (and a rubber hose of the right size to connect it to the OBDII valve cover) O2 sensor and either M50 exhaust manifolds or weld the oxygen holes in the OBDII manifolds and put the right size drain plug into the O2 sensor holes. The wiring harness chassis connector will need to be replaced by a chassis connector for your car. Rip one off a junked harness for the same car as yours (or your own harness), and solder the right wires together. Don't search for which ones to solder. Download the ETM for your E30 and for the right year/model your engine is from, go to the pin descriptions of each one and it will be obvious which to connect. Oh yeah, don't fuck up.
Q: Where can I get the ETM?
A: Here:
Q: What engine mounts do I use?
A: E28 535i, turned "backwards" - ie the threaded stud goes into the inside hole and the tab goes into the outside hole.
Q: Which brake booster/master do I use?
A: The most common are either 320i or iX. With the 320i you get less boost and you have to cut/rethread the rod because the pedal fork is not the same but you can reuse your stock master and reservoir. The iX double chambered brake booster is narrower but deeper. It requires a shorter master, such as that found on the M5 (25mm) and there is no room for the reservoir so get DSM (Talon/Eclipse) fittings and a 2002 remote reservoir. This setup gives better boost, a stiffer pedal and no hacking of the rod. The complete booster/master cylinder assembly you want can also be found on the E32 735i or E34 M5.
Q: How do I know which plug goes to which sensor?
A: Some are obvious. For others, download the ETM for your wiring harness, get a voltmeter, and check each plug in question (pin by pin), against possible pins on the DME connector. Or just go one by one, then get the pin number on the DME, and look what that pin does in the ETM.
Q: Anything else needs to be done to the chassis?
A: If you have an 87 or older, then you will need an 88+ radiator and upper clamp, and install the 88+ coolant tank on the driver's side. If you don't have the ground stud on the passenger side strut tower, it will need to be added somewhere in the area to provide the engine harness with a ground.
Q: What transmission?
A: Either the one that came with your engine or the one that came with your car if it's an M20 engine, your choice. The E36 transmission is easiest of all, requiring no work at all. You use the E36 drive shaft as well (as long as it has the 4 bolt rear flange, and not the 6 bolt CV joint). With the E30 Getrag it's tougher. The transmission sits at a crooked angle so the transmission brace either needs to be custom, or you need to use an E24 mount on the driver's side and any 1" mount on the passenger. You'll also need to bend your selector rod.
Q: Anything inside the car?
A: You'll need to feed the DME the road speed signal, and you'll need to pull the RPM signal and route it to your cluster. You're on your own to dig up where the cruise control speed signal wire is in the glove box, and hook up to it. If you don't have cruise, add the connector to your cluster and run the wire. To feed the speed signal to the DME, you'll need to tap the right wire at the C104 connector.
Q: Where are these wires and connectors?
A: Inside the car. The ETM will be of some help in locating them.
Q: My new engine revs to 7k and my readout is either wrong or my tach doesn't go that high or any higher, what do I do?
A: The gauge is just a voltmeter. The cluster converts ignition pulses to a voltage and feeds it to the voltmeter, which moves the dial. If you have a 6cyl car, it will be accurate but even if you have an "i" car, you will run out of numbers where the M/S5x engines run out of steam (if you wish to rev higher with a chip, you'll have to guess). The only E30 cluster with a dial that goes high enough is the E30 M3 but it's a 4 banger. If you have a 4 cyl car, then the cluster is receiving a signal that's 50% too fast (ie at 4k rpm it will treat it as a 4 banger spinning at 6k). If you simply swap the coding plug in the M3 cluster to that of a 325i, then it will still read wrong. Remember it's only a voltmeter, it doesn't know where 3500 rpm is. It just knows that for that frequency, the coding plug of the 325i will set the dial at 12 o'clock. On the M3 dial face that's 4000 rpm. So you have to retain the M3 coding plug but you need to figure out a way to change the 6 cylinder pulse to a 4 cylinder. Good luck.
Q: What do I do for the exhaust?
A: You're pretty much on your own. You can drop off the car at an exhaust shop with your favourite cat-back and wait until they call for your wallet. Installing TreeHouse Racing control arm bushings/brackets will enable you to avoid heavy modifications to the E36 downpipes should you choose to use those. You can also add a 1/4" spacer to the motor mounts for better clearance of the subframe and sway bar. If you use OBDI downpipes, the stock O2 sensor location won't work - it will hit the chassis cross brace. You either need to hack the downpipes to move the cats back or forward, or relocate the sensor.
Q: I didn't find an answer to my question above, what next?
A: Search for a few hours, being creative with your keywords and limiting the search to the 24v DOHC Swaps forum (hint: give huge preference to specific threads - only if there are none, then pay attention to results from the "comprehensive thread"). If you still fail, PM me (trust me it'll be obvious if you put in due diligence). If I don't know I'll likely recommend someone who I think would know. If not, start a new thread and ask away.
Q: Does it fit?
A: yah
Q: Is it hard?
A: no, just long (and yes, pills fix that now)
Q: What does the E36 engine need to have done to it?
A: Swap the oil pan to an 1992+ E34 525i pan with the dipstick and pickup. If it's an OBDII motor (1996+), it needs an M50 wiring harness, computer, cam sensor, crank sensor, solenoid extension, intake manifold/throttle body, fuel rail/injectors, PCV valve (and a rubber hose of the right size to connect it to the OBDII valve cover) O2 sensor and either M50 exhaust manifolds or weld the oxygen holes in the OBDII manifolds and put the right size drain plug into the O2 sensor holes. The wiring harness chassis connector will need to be replaced by a chassis connector for your car. Rip one off a junked harness for the same car as yours (or your own harness), and solder the right wires together. Don't search for which ones to solder. Download the ETM for your E30 and for the right year/model your engine is from, go to the pin descriptions of each one and it will be obvious which to connect. Oh yeah, don't fuck up.
Q: Where can I get the ETM?
A: Here:
Q: What engine mounts do I use?
A: E28 535i, turned "backwards" - ie the threaded stud goes into the inside hole and the tab goes into the outside hole.
Q: Which brake booster/master do I use?
A: The most common are either 320i or iX. With the 320i you get less boost and you have to cut/rethread the rod because the pedal fork is not the same but you can reuse your stock master and reservoir. The iX double chambered brake booster is narrower but deeper. It requires a shorter master, such as that found on the M5 (25mm) and there is no room for the reservoir so get DSM (Talon/Eclipse) fittings and a 2002 remote reservoir. This setup gives better boost, a stiffer pedal and no hacking of the rod. The complete booster/master cylinder assembly you want can also be found on the E32 735i or E34 M5.
Q: How do I know which plug goes to which sensor?
A: Some are obvious. For others, download the ETM for your wiring harness, get a voltmeter, and check each plug in question (pin by pin), against possible pins on the DME connector. Or just go one by one, then get the pin number on the DME, and look what that pin does in the ETM.
Q: Anything else needs to be done to the chassis?
A: If you have an 87 or older, then you will need an 88+ radiator and upper clamp, and install the 88+ coolant tank on the driver's side. If you don't have the ground stud on the passenger side strut tower, it will need to be added somewhere in the area to provide the engine harness with a ground.
Q: What transmission?
A: Either the one that came with your engine or the one that came with your car if it's an M20 engine, your choice. The E36 transmission is easiest of all, requiring no work at all. You use the E36 drive shaft as well (as long as it has the 4 bolt rear flange, and not the 6 bolt CV joint). With the E30 Getrag it's tougher. The transmission sits at a crooked angle so the transmission brace either needs to be custom, or you need to use an E24 mount on the driver's side and any 1" mount on the passenger. You'll also need to bend your selector rod.
Q: Anything inside the car?
A: You'll need to feed the DME the road speed signal, and you'll need to pull the RPM signal and route it to your cluster. You're on your own to dig up where the cruise control speed signal wire is in the glove box, and hook up to it. If you don't have cruise, add the connector to your cluster and run the wire. To feed the speed signal to the DME, you'll need to tap the right wire at the C104 connector.
Q: Where are these wires and connectors?
A: Inside the car. The ETM will be of some help in locating them.
Q: My new engine revs to 7k and my readout is either wrong or my tach doesn't go that high or any higher, what do I do?
A: The gauge is just a voltmeter. The cluster converts ignition pulses to a voltage and feeds it to the voltmeter, which moves the dial. If you have a 6cyl car, it will be accurate but even if you have an "i" car, you will run out of numbers where the M/S5x engines run out of steam (if you wish to rev higher with a chip, you'll have to guess). The only E30 cluster with a dial that goes high enough is the E30 M3 but it's a 4 banger. If you have a 4 cyl car, then the cluster is receiving a signal that's 50% too fast (ie at 4k rpm it will treat it as a 4 banger spinning at 6k). If you simply swap the coding plug in the M3 cluster to that of a 325i, then it will still read wrong. Remember it's only a voltmeter, it doesn't know where 3500 rpm is. It just knows that for that frequency, the coding plug of the 325i will set the dial at 12 o'clock. On the M3 dial face that's 4000 rpm. So you have to retain the M3 coding plug but you need to figure out a way to change the 6 cylinder pulse to a 4 cylinder. Good luck.
Q: What do I do for the exhaust?
A: You're pretty much on your own. You can drop off the car at an exhaust shop with your favourite cat-back and wait until they call for your wallet. Installing TreeHouse Racing control arm bushings/brackets will enable you to avoid heavy modifications to the E36 downpipes should you choose to use those. You can also add a 1/4" spacer to the motor mounts for better clearance of the subframe and sway bar. If you use OBDI downpipes, the stock O2 sensor location won't work - it will hit the chassis cross brace. You either need to hack the downpipes to move the cats back or forward, or relocate the sensor.
Q: I didn't find an answer to my question above, what next?
A: Search for a few hours, being creative with your keywords and limiting the search to the 24v DOHC Swaps forum (hint: give huge preference to specific threads - only if there are none, then pay attention to results from the "comprehensive thread"). If you still fail, PM me (trust me it'll be obvious if you put in due diligence). If I don't know I'll likely recommend someone who I think would know. If not, start a new thread and ask away.
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