I have owned a 1991 BMW 318is for about 3 years, and have used this forum and M42club extensively for learning about the car and decided I should return the favor and post the what I have done with it and where its going.
The beginning, stock except for H&R Springs with Bilstein struts. Someone had also swapped out the headlights and swapped the clutch driven fan for a volvo electric fan wired into the AUX fan circuit.
Started autocrossing on the dry rotting old tires and very quickly decided it needed an upgrade. Couldn't find tires I wanted that fit the basket weaves so I purchased some new wheels and tires.
Then realized a lot of original rubber bushings were basically gone so replaced those with some UHMW bushing which made it much nicer when autocrossing but definitely upped the cabin noise level, but since it is mostly a project/racecar that didn't really bother me. In pursuit of a better autocrossing experience I also swapped the steering rack for one from a Z3 to get rid of the need to spin the steering wheel like a mad man to corner at low speed, in the same vein swapped the 4.10 open rear diff for a 4.25 LSD out of a Z3. Both were fairly easy swaps with help from this forum!
Drove it like that for quite some time, until the little L bracket that holds the seat back upright broke so it started flopping around when cornering. That led to an upgrade in seating
So much less sliding around in the seat!
Then Covid stopped all the racing for awhile and the desire for a bit more power than the M42 was giving me led me down the rabbit hole of engine swaps. I wanted to keep the great balance the car had so didn't want to add a bunch of weight to the front of the car so I ended up deciding to ad a turbo to the M42. It seemed like a good candidate with the forged internals. Just needed a stronger headgasket/studs and some better engine management. I spent a long time browsing through the project pages of the others that had turboed an M42. Ended up getting a good deal on a MGT2259S turbo out of a 2015 WRX.
Little twin scroll turbo that should pair well with the little 1.8l motor. Quick spooling and not too big.
Didn't take any pictures of the exhaust manifold but a guy down in south Florida fabricated an awesome manifold to take full advantage of the twin scroll turbo design.
Pulled out the Motronic and replaced it with an Haltech Elite 550. Wiring is always a pain in the butt but eventually got it all straightened out. bmwman91's The Definitive M42 Crank and Cam Angle Info Thread post was key to getting the timing figured out.
Added a few gauges in the cubby under the center console. Still need to find a AFR gauge to add in.
First idle with the turbo and standalone ECU, Haltech was very helpful in the setup and the base map they had worked great. Didn't take long to get it started and idling.
And thats about where it currently stands. Did a little road tuning although with only about 18 inches of a downpipe I welded on to get my wideband O2 sensor in for the Haltech ECU to use it is obnoxiously loud. Currently set at a max of 5 PSI boost but it already is insane how alive the car feels without a real tune on it. Still gotta get an exhaust fabbed up and get a dyno tune but very excited to see where it ends up.
The beginning, stock except for H&R Springs with Bilstein struts. Someone had also swapped out the headlights and swapped the clutch driven fan for a volvo electric fan wired into the AUX fan circuit.
Started autocrossing on the dry rotting old tires and very quickly decided it needed an upgrade. Couldn't find tires I wanted that fit the basket weaves so I purchased some new wheels and tires.
Then realized a lot of original rubber bushings were basically gone so replaced those with some UHMW bushing which made it much nicer when autocrossing but definitely upped the cabin noise level, but since it is mostly a project/racecar that didn't really bother me. In pursuit of a better autocrossing experience I also swapped the steering rack for one from a Z3 to get rid of the need to spin the steering wheel like a mad man to corner at low speed, in the same vein swapped the 4.10 open rear diff for a 4.25 LSD out of a Z3. Both were fairly easy swaps with help from this forum!
Drove it like that for quite some time, until the little L bracket that holds the seat back upright broke so it started flopping around when cornering. That led to an upgrade in seating
So much less sliding around in the seat!
Then Covid stopped all the racing for awhile and the desire for a bit more power than the M42 was giving me led me down the rabbit hole of engine swaps. I wanted to keep the great balance the car had so didn't want to add a bunch of weight to the front of the car so I ended up deciding to ad a turbo to the M42. It seemed like a good candidate with the forged internals. Just needed a stronger headgasket/studs and some better engine management. I spent a long time browsing through the project pages of the others that had turboed an M42. Ended up getting a good deal on a MGT2259S turbo out of a 2015 WRX.
Little twin scroll turbo that should pair well with the little 1.8l motor. Quick spooling and not too big.
Didn't take any pictures of the exhaust manifold but a guy down in south Florida fabricated an awesome manifold to take full advantage of the twin scroll turbo design.
Pulled out the Motronic and replaced it with an Haltech Elite 550. Wiring is always a pain in the butt but eventually got it all straightened out. bmwman91's The Definitive M42 Crank and Cam Angle Info Thread post was key to getting the timing figured out.
Added a few gauges in the cubby under the center console. Still need to find a AFR gauge to add in.
First idle with the turbo and standalone ECU, Haltech was very helpful in the setup and the base map they had worked great. Didn't take long to get it started and idling.
And thats about where it currently stands. Did a little road tuning although with only about 18 inches of a downpipe I welded on to get my wideband O2 sensor in for the Haltech ECU to use it is obnoxiously loud. Currently set at a max of 5 PSI boost but it already is insane how alive the car feels without a real tune on it. Still gotta get an exhaust fabbed up and get a dyno tune but very excited to see where it ends up.
Comment