BMW E30 Cabriolet Project

  1. TwoThumbs

    TwoThumbs Member

    Messages:
    118
    Location:
    Finland
    Nice to hear about inspiration, we all need it from time to time and I'm happy if I provided some.


    No real new updates this time only few things to report.
    Car has been on the road for few days. Problems with binding front anti-roll bar seems to been resolved. Cornering has improved and is now consistent, before car was cornering one way or the other way and sometimes felt that it changed mind during the corner, it just felt wrong to me. Speaking of mounting bushes went in and ordered set of Powerflex bushings for anti-roll bars to replace tired rubber ones and will possibly report later how they feel.

    Rear end LSD seems to hook well, one tire on pavement and one on gravel it will spin both tires leaving rubber stripe on pavement, can't really hope much more than that.
    Biggest surprise for the driving season has been my ported turbocharger. It still boost same amount, no significant changes to air/fuel ratios of exhaust gasses but car feels different faster and more agressive. Only change that I found from data log compared to last summer was that maximum boost spike is now coming at least 200-300 RPM earlier than it did before exhaust porting. It feels that it made significant difference on how it delivers power and now it seems to be hitting boost like animal. Real impressed from small grinding job.

    That's all this time and hope everyone is doing well there!
     
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  2. TwoThumbs

    TwoThumbs Member

    Messages:
    118
    Location:
    Finland
    Got the Powerflex anti roll bar bushings and simple bolt on went to ape show!

    Rear bushings:
    DSC_5302.jpg

    Front bushing featuring knurled insides to hold grease better.:
    DSC_5305.jpg

    Rear ones fit acceptable, very snug to clamp the mounting brackets but got them in.
    Front ones not so lucky, don't know what boys and girls at Powerflex been thinking but it ain't gonna fit.
    Bushing is just way too tall and stiff material won't compress enough to tighten mounting brackets down.
    Powerflex vs original BMW bushing:
    DSC_5312.jpg

    Stock rubber sits well below mounting bracket:
    DSC_5321.jpg

    Unmodified Powerflex protrudes over the edges of the bracket making it impossible to install:
    DSC_5317.jpg

    Because I have bad habit of making things fit, introduced bushing to the carbide bit.
    Side picture after trimming down the bushing:
    DSC_5320.jpg

    Looks crude but will fit properly:
    DSC_5324.jpg

    Used copper anti seize to grease them, prefer it over their supplied grease.
    Front bushes installed:
    DSC_5326.jpg

    So did it make the difference? Took some measurements from heavily stressed front bar to simulate hard cornering and there was no measurable difference to the stock rubber bushings and driving experience feels same, no ill effects either.
    Maybe 21 mm and 12 mm stock anti roll bars won't stress the mounts in this application as much as a had anticipated. Still got peace of mind by replacing well used bushings with new ones tho.

    Quick report about differential again. Did early oil change couple weeks ago and checked oil for potential metal shavings. Oil was turned towards black but there was no shavings, couldn't resist taking out axle stub where I had found some shavings and now it was completely clean. Did some extensive research about diff oils with these helical gear differentials and changed oil from 75W-90 fully synthetic to conventional based 80W-90 GL5 oil to maximize locking performance. Theory is that some synthetics could be too slippery to provide needed friction for the gears to lock at their max force. Difference could be only few percentage but gotta try things and after few weeks of driving I prefer conventional over fully synthetic. Differential locking is at least as good as before but diff is now about 70% quieter when fully warm, than it was with 75W-90 oil. This diff bangs quite loud compared to standard diff due to it's internal movement of gears in their pockets.

    Well not much more to report this time. Thanks for reading!
     
  3. TwoThumbs

    TwoThumbs Member

    Messages:
    118
    Location:
    Finland
    This time venturing into upholstery and repairing typical issue with these models, back seat seam splitting. Some say it's impossible to repair and I just happen to love that word but we'll see.

    This is typical look of E30 cabrio back seat seam failure:
    DSC_5605.jpg
    Closer look reveals frayed stitching but leather is still in reasonable condition:
    DSC_5606.jpg
    Unfortunately there is no way to make lasting repair without disassembling seat cover from the foam seat body. Next pictures will show why that is the case.
    Cover is held on with metal clips or rings and there feels to be 100 or so inside and outside of the seat. They are bit tricky to get removed and put back when repair is complete:
    DSC_5615.jpg
    Here we can see second part of the this problem behind failed seam is backing fabric, that should be taking it's part of the stress but backing fabric is frayed and split as well.
    To make long term repair this will need to be either replaced or repaired with new piece of fabric:
    DSC_5636.jpg
    Seam stitching must be opened enough to get a tail of undamaged thread to each end of seam, I suggest pulling it open where backing fabric is still intact:
    DSC_5637.jpg
    Using curved upholstery needle sew single thread going from side to side of each original hole of the seam:
    DSC_5640.jpg
    Pull seam tight with new thread (I was using strong polyester thread for this), it may be easier to tighten the seam section by section. Finally tie new thread to tail of original stitching.
    Everything should line well and seam is looking presentable again:
    DSC_5647.jpg

    Will continue next post...
     
  4. TwoThumbs

    TwoThumbs Member

    Messages:
    118
    Location:
    Finland
    Back seat repair part 2.

    To add extra strength I hand stitched thread to backside going from side to side:
    DSC_5650.jpg
    Then hand stitched pieces of new non stretching black fabric to repair damaged backing fabric this will add significant support for repaired area. Obviously backing fabric should make reasonable match with leather colour so nothing odd will shine through:
    DSC_5661.jpg
    Repair is now looking like this and ready to to be assembled:
    DSC_5663.jpg
    All complete and repair feels solid:
    DSC_5670.jpg

    This repair was economical, supplies were cheap but it's time consuming and bit frustrating, all in all not too difficult job. Feels good when it's done it has been bugging me 3 years already.
     
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  5. jpmillermatic

    jpmillermatic Member

    Messages:
    778
    USA-NY
    looks great...I have kept jackets alive with similar repairs......

    JP
     
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  6. TwoThumbs

    TwoThumbs Member

    Messages:
    118
    Location:
    Finland
    Thanks again JP! Wish I would have repaired it ages ago but you know how things can take their time and must admit had to dig some info about sewing before biting that one.

    Turning wrench again with Cabrio.
    Front control arm bushes have been on the list to do and now getting them replaced and upgraded with E36 M3 3.2 bushes they have much more rubber but won't affect to road noise or vibration in a negative way.
    Old bushings were dry rotted and had some cracks I had missed before:
    DSC_5677.jpg
    Replacement set of M3 3.2 bushing these are concentric style instead of eccentric E36 M3 3.0 bushes. I have used these bushes before so went with them instead of 3.0 bushes:
    DSC_5682.jpg
    When compared to old bushings much more rubber to resist unwanted movement of the wheel under sporty driving:
    DSC_5695.jpg
    Some of you have been waiting when they will see my recently build press used with car stuff so here it was in action:
    DSC_5728.jpg
    Marks on lollipop and bush should line up like this:
    DSC_5705.jpg
    It may be challenging to install rubber bushing back to the control arm. Quick two minute tool was invented and eventually 22 mm socket was used as a spacer to drive bushing home:
    DSC_5712.jpg
    Tool will take advantage of the control arm holes, it worked good:
    DSC_5715.jpg
    Bushing in it's installation depth:
    DSC_5722.jpg
    Tightening lollipop bolts completed this job:
    DSC_5725.jpg

    Thanks for reading and cheers!
     
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  7. TwoThumbs

    TwoThumbs Member

    Messages:
    118
    Location:
    Finland
    Few pictures from latest fabrication to E30 this time making front strut brace from the cardboard up.

    Started with famous CAD sketch for base plates, shape ready to be transferred to steel plate:
    DSC_5819.jpg
    It turned out that tube bending without a special tools was challenging. After several unsuccessful methods of making two 20 degree bends on this tubing reverted back to more brute force way and made few cuts to the tubing. This tube was 25 mm diameter with 1.5 mm wall thickness:
    DSC_5880.jpg
    Cuts made bending easy and it was ready to be welded solid again:
    DSC_5884.jpg
    Test fitting tube to the 3 mm thick base plates, 3 mm steel is still flexible enough that it will deform to the uneven surface on strut towers when bolted down.:
    DSC_5900.jpg
    Had a go with my recently purchased tig welder. Lot to learn and better seams ended on the backside (of course) :
    DSC_5905.jpg
    DSC_5906.jpg
    DSC_5908.jpg
    Painted end result on the car:
    DSC_5920.jpg

    Thanks for having a look!
     
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  8. Pigeon_Droppings2 Member

    Messages:
    1,884
    Location:
    london
    Great work m8....that custom tool is right up my street. You seem to be rattling through the jobs on this car...well done.
     
  9. TwoThumbs

    TwoThumbs Member

    Messages:
    118
    Location:
    Finland
    Throwing few pictures of E30 again. Car has done good but of course had to make small repairs and development:
    Got new inner and outer ball joints for MOT:
    DSC_6581.jpg
    This will show how old inner ones were bad, they are not loose from the ball but oval shapes are worn. It's hard to notice without shaker or complete removal from the car:
    DSC_6588.jpg
    Another feature on old delphi outer one was round movement pattern, originals and Lemförder were oval like inner ones:
    DSC_6597.jpg
    Pressing them in receiver was 50 mm socket:
    DSC_6595.jpg

    Got new front strut bearings:
    DSC_6640.jpg
    New outer tie rods:
    DSC_6641.jpg
    Going in with copper grease, still need install new inner tie rods found small play on one of them:
    DSC_6644.jpg
    Found some damage from old tie, head is bent and partially stripped.
    DSC_6652.jpg
     
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  10. TwoThumbs

    TwoThumbs Member

    Messages:
    118
    Location:
    Finland
    Removing parts for cylinder head removal, mainly because of small external water leak and valve seal job and chasing small ponies from dozen or so places...:
    DSC_6663.jpg
    Head has been worked on past somewhere in 2006-2007, most likely got everything new. Valves were possibly leaking, had to do fair amount of lapping. Valves were newer been lapped and I personally suspect that it was causing them to not seat on fresh seats tolerances + tolerances + after market valves. Intake valves were magnetic but exhaust were not, stainless steel ones maybe.
    DSC_6674.jpg
    DSC_6676.jpg
    Doing exhaust and intake gasket match:
    DSC_6679.jpg
    Before exhaust manifold gasket match:
    DSC_6683.jpg
    After:
    DSC_6684.jpg
    Put some heat resistant paint on them:
    DSC_6689.jpg
     
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  11. TwoThumbs

    TwoThumbs Member

    Messages:
    118
    Location:
    Finland
    Ported intakes to semi smooth finish:
    DSC_6747.jpg
    Exhaust ported and done to smooth, intake and exhaust valve seats blended in:
    DSC_6713.jpg
    Unmodified combustion chambers:
    DSC_6670.jpg
    Combustion chambers got some light shaping around valves for hopefully improved flow, lightly smoothed around spark plug. Partially polished:
    DSC_6696.jpg

    Intake manifold on this car has been modified in the past. injector humps are smoothed I try to remember take pic on that one.
     
  12. TwoThumbs

    TwoThumbs Member

    Messages:
    118
    Location:
    Finland
    Got some progress with the head job.
    Bit of parts list that I chose for this: Head gasket Goetze, ARP head studs, valve stem seals and cam seals from BMW, intake and exhaust gaskets from Elring.
    DSC_6763.jpg

    Head assembled, valves adjusted to 0.25 mm and bolted down:
    DSC_6771.jpg
    ARP suggest tightening studs in three equal steps up to 70 ft lbs, it's about 95 Nm. However because I'm not a speedy bird, I used my own method with suggested pattern but steps of 9 Nm, 32 Nm, loosening and immediately tightening one by one back to 32 Nm, 65 Nm wait 30 minutes and finished with couple rounds of 95 Nm. Still planning to do final round of 95 Nm after 25-30 minutes of idling and cool down.
     
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