There are many ways to go about the swap but this is how I did it and exactly what I used.
Its a 1985 325e that received a 10/1995 S50 and matching tranny.
The S50 is using its stock mounting arms but with big 6 engine mounts (E34 M5 mounts to be exact) but mounted backwards. The tranny uses all stock mounting points to the body but you can upgrade to an E30 or E36 urethane mount (or just use stock rubber). I have an E30 M3 driveshaft, unmodified. All my shifter parts are E36. I had to even change the carrier because mine was the old stamped steel model. The M3 slave cylinder needs to be changed to a regular M50 slave cylinder to match the E30 master cylinder. My old throttle cable fit.
The engine itself is basically stock, everything that is bolted directly to the engine stayed and didnt have to move. It has the silver 413 DME which had EWS but any aftermarket chip maker makes a non-EWS chip for that DME. I mounted the E36 DME exactly like the E30 DME. I just had to use slightly larger washers. I used an E36 radiator and electric fan. You can use E30 parts in both as long as the radiator is for the 325i because of the hose routing. My overflow bottle is from a late model 325i mounted on the stock place for a 325i. I changed from the Eta bottle because of location of the coolant hoses. You can use the clutch fan if you want to, I didnt.
Fitament. I shaved the studs off the blower fan cover and scraped off all the insulation. I mounted the wiring harness on the blower fan cover. The reader port is mounted where the old coolant bottle was. The engine power and ground are all still in the same spots. The engine pan is out of an M50 powered E34 and it also has the E34 pickup tube for the oilpump. There are redunant baffles, one on the engine and another on the pan. One has to be removed. THe oil dipstick and tube are from the E34 also. Its mounted to the support for the intake manifold. The canister for the fuel vapors is down by where the ABS would be if I had it. THe fuel filter was moved to the 325i location.
There are two temp sensors. One is to the DME and must be a 2 prong M50 sensor. The other is to the dash and it will be a single prong E30 sensor and will be wired to the E30 wiring harness.
My big change was braking. I used the E30 325ix booster with an E34 M5 master cylinder. Because the booster is dual chamber and the MC sticks out farther I had to use a remote brake fluid bottle. Its mounted where the relays were and used a bracket for the E36 relays.
My exhaust consists of S52 manifolds. They are just a bit lighter than the S50 manifolds. The rest of the exhaust is hand built. I dont know about how compatible other exhausts are.
Obviously a few things are not stock. The radiator is much thicker than the stock units so its a bit closer than your average swap would be. The cone is a must because I dont have a readily available way to mount the airbox nor do I care at the moment.
This car has no-AC so dont ask me about how to hook it up. This is condensed. I will add the wiring as other things as I remember them and then edit this. I just thought it would make more sense than the 40 page thread.
Its a 1985 325e that received a 10/1995 S50 and matching tranny.
The S50 is using its stock mounting arms but with big 6 engine mounts (E34 M5 mounts to be exact) but mounted backwards. The tranny uses all stock mounting points to the body but you can upgrade to an E30 or E36 urethane mount (or just use stock rubber). I have an E30 M3 driveshaft, unmodified. All my shifter parts are E36. I had to even change the carrier because mine was the old stamped steel model. The M3 slave cylinder needs to be changed to a regular M50 slave cylinder to match the E30 master cylinder. My old throttle cable fit.
The engine itself is basically stock, everything that is bolted directly to the engine stayed and didnt have to move. It has the silver 413 DME which had EWS but any aftermarket chip maker makes a non-EWS chip for that DME. I mounted the E36 DME exactly like the E30 DME. I just had to use slightly larger washers. I used an E36 radiator and electric fan. You can use E30 parts in both as long as the radiator is for the 325i because of the hose routing. My overflow bottle is from a late model 325i mounted on the stock place for a 325i. I changed from the Eta bottle because of location of the coolant hoses. You can use the clutch fan if you want to, I didnt.
Fitament. I shaved the studs off the blower fan cover and scraped off all the insulation. I mounted the wiring harness on the blower fan cover. The reader port is mounted where the old coolant bottle was. The engine power and ground are all still in the same spots. The engine pan is out of an M50 powered E34 and it also has the E34 pickup tube for the oilpump. There are redunant baffles, one on the engine and another on the pan. One has to be removed. THe oil dipstick and tube are from the E34 also. Its mounted to the support for the intake manifold. The canister for the fuel vapors is down by where the ABS would be if I had it. THe fuel filter was moved to the 325i location.
There are two temp sensors. One is to the DME and must be a 2 prong M50 sensor. The other is to the dash and it will be a single prong E30 sensor and will be wired to the E30 wiring harness.
My big change was braking. I used the E30 325ix booster with an E34 M5 master cylinder. Because the booster is dual chamber and the MC sticks out farther I had to use a remote brake fluid bottle. Its mounted where the relays were and used a bracket for the E36 relays.
My exhaust consists of S52 manifolds. They are just a bit lighter than the S50 manifolds. The rest of the exhaust is hand built. I dont know about how compatible other exhausts are.
Obviously a few things are not stock. The radiator is much thicker than the stock units so its a bit closer than your average swap would be. The cone is a must because I dont have a readily available way to mount the airbox nor do I care at the moment.
This car has no-AC so dont ask me about how to hook it up. This is condensed. I will add the wiring as other things as I remember them and then edit this. I just thought it would make more sense than the 40 page thread.
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