BMW E30 Cabriolet Project

  1. Neilios Member

    Messages:
    133
    North East
    Good job nice looking car in the end, I have a long way to go with my e30 Touring as the welding seems endless, mine will be a track car with an M52 in it when finished.
     
  2. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    Thank you!

    Thanks! Your E30 Touring sounds like a great project. It always seems that every E30 has some rust and some rust really bad so welding becomes familiar job. M52 engine certainly will give your car a nice amount of usable power on wide range of RPM.


    And for updates:
    Slowly assembling MegaSquirt MS2 v3.0 board for adjustable and programmable engine management.
    DSC_3066.jpg
     
    Bigbungster likes this.
  3. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    Removed throttle body for cleanup and fabricated adapter plate for newer style variable resistance throttle position sensor from E36. Original sensor has only WOT / Idle switch and it won't work well with MegaSquirt.

    Original sensor is slightly bigger to every direction and E36 TPS won't fit without adapter:
    DSC_3069.jpg

    Finished adapter plate with E36 TPS. Note connector will point to the intake manifold but i don't mind.
    DSC_3071.jpg
     
  4. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    MS2 assembled, running extra firmware and doing some bench testing:
    DSC_3108.jpg
     
  5. Rig Pig

    Rig Pig Member

    Messages:
    3,492
    Location:
    Narrwich! U.K.
    how much power are you expecting the engine to produce?
     
  6. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    I would expect something like 20 horse increase from crank without additional modifications and then door is open for more. Considering that original ECU is early Bosch Motronic 1.0 and BMW upgraded ECU for 87 models which use supposedly better 1.3 system, there are room for some improvements. Also throttle response should improve as variable TPS will be added.
     
    Rig Pig likes this.
  7. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    I extracted different full throttle ignition advance curves from Motronic binaries for different BMW ECU's that were used in M20B25 engines. There were late model 173 ECU, early model ECU 081 that can be found from my car and 153 ECU file that was claimed to be stock but it's clearly ignition map from unknown aftermarket chip. I would suspect that true stock 153 would be very similar if not identical to the 081 map. I believe that 173 and 081 maps are from fully stock Motronic but can't confirm that to the 100% accuracy due to nature of these files. I wanted to share this because this information is somewhat rare and may be useful for somebody.


    Note that RPM ranges are different on 173 ignition map but 153 and 081 use the same RPM steps.

    Spark_advance_173_153_081.jpg
     
  8. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    Back again!

    Changed front turn indicator lights to clear:
    DSC_3113_blur.jpg

    New front end look:
    DSC_3116_blur.jpg

    Changed crankshaft pulley for future MegaSquirt use. Smooth pulley changed to 60-2 toothed trigger version from newer M20 engine:
    DSC_3120.jpg

    Tested and managed to read full RPM range with MegaSquirt from 60-2 trigger wheel using Hall type crankshaft position sensor from BMW M52 engine. MegaSquirt was using Vr/Universal input circuit for crank signal with 1 k Ohm pull up resistor to 5 V as explained in MS extra hardware manual.

    3-Wire M52 hall sensor pin-out is poorly documented and had to try different combinations. Colors at the M52 Hall sensor were:
    -Red to MegaSquirt 5 V ref. feed (same as TPS sensor 5V feed)
    -White to MegaSquirt black (MS ground)
    -Yellow to MS white (crank signal input).

    Change of crank pulley is kinda big job. Had to remove cooling fan, power steering belt, water pump belt and water pump pulley before getting crank pulley out. Everything didn't go smoothly as power steering belt just slips and it needs a new belt. Also coolant line from thermostat housing to throttle body started to leak and needs a new hose.
     
  9. V6BOY Member

    Messages:
    207
    Location:
    London
    Dam looks mean as fook would definealtly be moving out of its way!
     
  10. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    New power steering belt and parts for future intake system:
    DSC_3151.jpg

    Tapped M14 x 1.5 threads to the intake pipe for IAT sensor. I think that sensor will need some sealant to make secure and air tight mounting as pipe wall was so thin.
    DSC_3169.jpg
     
  11. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    Diagnosing ABS light problem. Removed ABS wheel sensors for cleanup and tested the sensors connecting them one by one and it seems that both rear sensors are dead. Also resistance from both rear sensors showed infinite instead of ~ 1 k Ohm like front ones.
    Otherwise did some fluid changes, new aux belts, plugs and distributor cleaning. Took it out from the shed for spin around the yard and she runs good after siting over the winter!

    Long pieces of mig wire was found from front ABS sensor. Guess it would make sense to protect the hubs before grinding and welding:
    DSC_3177.jpg
     
  12. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    Back with E30 updates.

    Received two new rear ABS sensors:
    DSC_3197.jpg
    Measured resistance of new sensors was approximately 1000 Ohms just like the front ones, kinda confirming that old rear sensors were shot. Unfortunately ABS system still won't operate like it should... Hopefully another 2nd hand ABS control module will solve this ABS light mystery for good.

    Added two BIP 373 ignition drivers to my MegaSquirt unit. I might be driving with wasted spark coil pack in the future:
    DSC_3194.jpg

    Few pictures of installed MegaSquirt and wiring harness. There's some tidying left to do but this was enough to get the car running and confirm that everything is functional:
    DSC_3210.jpg
    DSC_3211.jpg
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    Car starts and runs with MegaSquirt and after some quick tuning it was drivable!
    Gotta fabricate fiberglass air box or something for that cone filter. Intake temps were pushing 40-50 degrees Celsius when outdoor temp was barely above freezing, just imagine what would happen on warm day... loss of horses!
     
  13. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    Finally changed rear lights from smoked to red/clear, did quick rinse and took few photos:
    DSC_3221_blur.jpg
    DSC_3213.jpg
    DSC_3223_blur.jpg
    DSC_3227_blur.jpg

    To me rear looks now much more cheerful!

    Sharing some E30 MegaSquirt info again: Original tacho works with 0-12V output pulse signal from stepper out as explained in ms-extra manuals. Got fuel economy meter working with simply splicing white / pin 11 wire from original ECU to the one MS fuel injector output line and gauge gives "reasonable" results just like it was with factory ECU.
     
  14. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    Cheers everyone! Back on E30 once again!

    But first let's address old ABS light problem that was solved in spring:
    It turned out that replacement ABS module didn't solve my problem and i had to find second hand pair of front wheel ABS sensors. Luckily they worked fine and ABS has been working since spring! Apparently front sensors were working intermittently and dropping signal giving out warning light.

    Now to the new progress:
    After long weekend spend in the shed, doing cutting, welding and trial fitting i walk out with this creation:
    DSC_4022.jpg
    DSC_4025.jpg
    DSC_4027.jpg
    It's a turbo manifold adapter for m20 engine, all mild steel and mig welded. Bends were 90 degree pressure pipe bends and matching pipe from local plumbing supplier. Fabricating this felt challenging, available space in E30 is limited and there was many things to take into account when planing the routing of the pipes. I must say that it fits to the car but installing it was tricky.

    Some engine bay changes and mocking up turbo and 3 inch downpipe:
    DSC_4030.jpg
    DSC_4031.jpg
    DSC_4033.jpg
    Coolant tank has been relocated with newer facelift E30 parts: expansion tank, 3 piece water hose and water pump. Also car got new timing belt, tensioner and camshaft oil seals.
     
  15. Kayos

    Kayos Member

    Messages:
    4,740
    Location:
    Yorkshire
    Awesome project, my first turbo conversion was a 2.0 8v in an Astra, using a manifold from the U.S. C20GET engine and an original Megasquirt

    Much fun at the traffic lights, only hint was the 15" 5 stud Vectra steel wheels with Toyo's to hide the bigger brakes, even left the merit badges on it
     
  16. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    Thanks! Your Astra was fun for sure. Back in the day I had a hatchback with C20NE engine as well, reliable engine and reasonable quick but body started to develop serious taste for rust and had to sell it.

    Old custom exhaust system with 2x2" to 1x2.5" piping and muffler. Partially stainless:
    DSC_4045.jpg
    Going with straight flow 3" front muffler
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    Modified rear section and added 2.5" v-band.
    DSC_4056.jpg
    New front section with 3" muffler and reduction to 2.5", added v-band clamps to ease up the installation and future maintenance. Piping painted using heat resistant paint but was running out of it so need to paint rest of it later.
    DSC_4062.jpg
    Using tack by tack method, 0.8 mm wire and high heat.
    DSC_4054.jpg
    Downpipe painted with heat resistant pant and then wrapped. Ready to rock.
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    Test fitting the intercooler. IC was also painted to black.
    DSC_4071.jpg
    Front valance mounting bracket will require modding.
    DSC_4068.jpg

    Still not completely sure how much ground clearance I will have with that large 3" muffler, will it be a garage king exhaust or require another smaller muffler to make it usable, will be seen when car is taken off the jack stands. Also unsure will the heat resistant paint add to the corrosion resistance of the exhaust piping, maybe something maybe nothing.
    That's all for now.
     
    Springerdinger likes this.
  17. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    Fabricated removable support bar for intercooler and plastic radiator wind tunnel cut to fit:
    DSC_4073.jpg

    Front valance mounting points trimmed and moved apart by extra 15mm
    DSC_4076.jpg
    Oil lines done:
    DSC_4085.jpg
    Oil pan dropped, oil return drilled, fitted and pan reinstalled with new gasket.
    DSC_4089.jpg

    Turbo oil feed taken from engine oil pressure sensor location using M12x1.5 mm LMA t-piece to 1/8" NPT, 1/8" adapter to 4AN, 4AN stainless steel teflon hose with 90 degree fittings, turbo oil feed flange with 4AN fitting and 1.5mm oil restriction hole.
    Return line: Oil drain flange with 10AN fitting, 45 degree 10AN fittings and teflon AN hose. Oil pan fitting was non weld type with nut on backside.

    Cold side piping was not done but I started the engine to check for oil leaks and other problems as many things have been modified, it was nice to see that there weren't any obvious problems with the installation.

    Then the exhaust again... it can't stay like it was done there's no way around it. Ground clearance must be at least 80 mm by the Finnish law and I couldn't get block of 2x4" to pass under the center muffler so it's not even 50mm and muffler is tucked as high as it can go. Then the V-band at the end of downpipe comes too close to ground and needs to be moved higher towards engine bay. Even front section of the 3" pipe is not quite making it as it was maybe 70 mm off the ground.
    Not sure what to do to make it work, would have liked to keep the 3" piping and possibly use a lot smaller bullet/glasspack resonator for better clearance. That may open the question of moving this muffler to back and doing full 3" exhaust instead of 3" to 2.5" hybrid but i'm not sure would that provide enough added benefits.

    Cheers till next time!
     
  18. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    Charge pipes done and filter fitted:
    DSC_4111.jpg
    Fitted a Bosch 110 BOV with a small air filter. Sounds nice without being overly loud when lifting a throttle from full boost.
    DSC_4108.jpg
    Oil catch can between valve cover breather and turbo inlet.
    DSC_4109.jpg

    Intake manifold was removed and set of bigger 360cc Bosch injectors were fitted. Noticed that intake manifold runners looked unusually smooth and after some research it turns out that indeed those runners were honed, nice surprise for project like this.

    Few test runs have been made around the property road, seems to give strong push from 4000 rpm while getting minimum boost of 0.4 bars at the intake.

    Now redoing exhaust system, got small 3" Vibrant bottle resonator and aim to do full 3" exhaust all the way to the back.
     
    slim_boy_fat likes this.
  19. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    Few pictures from latest adventures with the exhaust.
    Vibrant resonator fitted and some modifications to the front piping so it would be as close to body as it reasonably can.
    DSC_4113.jpg
    V-band at middle and now full 3" piping going on.
    DSC_4115.jpg
    Rear muffler installed, now single outlet only. Fairly happy how it fits and should flow plenty:
    DSC_4118.jpg

    Some minor leaks were coming from v-bands and will try to get them properly seated, in worst case mating surfaces may need some filing if warped from welding. Otherwise I expected that this would sound noticeable louder than previous versions of the exhaust on this car but it turned out to be bout the same if not slightly quieter which was surprising.
     
    slim_boy_fat likes this.
  20. TwoThumbs

    TwoThumbs Member

    Messages:
    120
    Location:
    Finland
    Car needed radically smaller tank for windshield washer fluid so I went ahead and got universal kit with pump and all the accessories.

    Fluid level sensor taken from old reservoir, drilled a hole and fitted sensor into new tank for full OEM functionality:
    DSC_4119.jpg
    Turns out that tiny tank fits into front corner:
    DSC_4124.jpg
     
    Wallace likes this.
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