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Spac's adventures in BMW (was: E36 318ti rally project.

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  • SpacSpac (@Spac) Canberra-ish.
    edited February 17
    SDv2BPlh.jpg

    /\ Tyre wear is good. Less than the S40, even though the BMW feels like it is moving around more.

    \/ PS pulley eating the PS reservoir.


    2H7BEGth.jpg
    Dauntless
  • SpacSpac (@Spac) Canberra-ish.
    El Wifeo drove the rally car on the weekend, in the Rally des Femmes. Finished 5th place.
    Only mishap was getting beached in the service park when she drove over an erosion bank at the wrong angle... after doing it the correct way a dozen times before.N8r1B4yh.jpg
    egadsbgpzfm142bowiecarnut1100DauntlessTzantushkaVee_Quejamesinc
  • Heck Yeah!

    "Insert your sponsors logo here"
  • SpacSpac (@Spac) Canberra-ish.
    edited February 28
    So, progress.

    I spent a lot of money on new MCA Gold struts for the rally car, at El Wifeo’s insistence.
    TBH, I was happy with the Bilsteins, but we had to spend money on some shocks for the race car, so this sort of made sense. There’s no question that these are the duck’s nuts though!

    5TYmV9xh.jpg

    They went into the rally car yesterday.
    That was the easy part.

    The rears will be a bit more work. The skinny little Bilsteins, combined with the overly tight spherical bearing in the Chinabay tops, meant that the shafts were flexing.
    At best, this was going to wear them out super fast.
    At worst, it was going to bend a shaft and bugger the shock.
    It’s less of a problem for the race car than the rally car (less shock deflection and rides lower in the travel), but not something I was willing to ignore.

    Amongst my piles of ‘treasure’, I have an old pair of Mazda rally struts. They’re based on a pair of Commodore Bilstein rear shocks - but the bodies had been ground down and hard chromed to work as strut inserts.
    Problem is that they have worn through the the hard chrome, making them pretty much unsuitable for being used as a strut.

    But they are pretty close to the correct dimensions for the back of an E36 Compact... :) They are also much beefier than the old shocks - 50mm OD body and 14mm shaft, up from ~40mm and a 10mm shaft. As well as the obvious strength/stiffness improvement, this also means that they hold more oil - meaning that the oil lasts longer and the shocks are less likely to fade in long stages.

    Annnndd they are ‘upside down’, which reduces unsprung weight and also provides a bit more clearance around the half shafts.

    First step was to machine the top stud down to fit the Chinabay shock top.

    fdr83fQh.jpg

    I still have a few questions that I haven’t worked out the answers to, particularly regarding the lower mounting point.

    They will also need to be revalved. Hopefully Murray (the M and the C from “MCA”) will be happy to point me in the right direction.

    But my big hurdle right now is that I don’t know where the other one of these is! I had a quick look at home yesterday, assuming it was at work. But a close look at work didn’t turn it up... Hopefully it is at home...
    Vee_Que
  • SpacSpac (@Spac) Canberra-ish.
    edited February 28
    I don’t know if I mentioned it before, but the race car was “borrowing” the rally car’s Bilsteins. Seemed like a perfectly cromulent plan, but swapping them back into the rally car for last weekend... well, let’s just say that it was getting old very fast.

    So now the Bilsteins belong to the race car.

    The upper spring seat had bent, and was touching the strut top. You can see the wear marks on the spring seat in the photo below.
    It was also showing signs of metal fatigue, meaning that it was bound to let me down at some stage.

    I was also unhappy with the way the nylock top nut didn’t engage the nylon on the thread.

    Obviously time for a rethink.
    Here’s what I came up with. Left column is old setup, right is new:
    tc9GykFh.jpg

    Top is new, bottom is old.
    BuSMCFLh.jpg
    U7IehY7h.jpg

    The load from the top spring seat is now fed into an extra 2mm steel load spreading plate, then into a washer, and then into the old top spacer (which has a larger OD than the old bottom spacer.

    The top nut has been machined so it also works as a spacer. lJNZNq2h.jpg

    All of this has also raised the front of the car by a small amount - about 4mm, as best as I can measure. I think that it still should come up another 5 or 6mm, but this is a step in the right direction.
    bgpzfm142Vee_Que
  • SpacSpac (@Spac) Canberra-ish.
    Spoke to Uncle Murray this afternoon. He is sending me new valve pistons and shims.
    He wants me to fit new shock shafts with adjustment, but the price was considerably more so I'll try with the non-adjustable shafts first.
  • TzantushkaTrent (@Tzantushka) E. suburbs - Melbourne
    I spent a lot of money on new MCA Gold struts for the rally car, at El Wifeo’s insistence.

    What?!?
    I spent a lot of money on new MCA Gold struts for the rally car, at El Wifeo’s insistence.

    You are one very lucky man.
    egadsVolvirgin
  • SpacSpac (@Spac) Canberra-ish.
    You m
    I spent a lot of money on new MCA Gold struts for the rally car, at El Wifeo’s insistence.

    What?!?
    I spent a lot of money on new MCA Gold struts for the rally car, at El Wifeo’s insistence.

    You are one very lucky man.

    You misspelled “patient”?!
  • SpacSpac (@Spac) Canberra-ish.
    edited March 1
    Progress on the rally car rear shocks.

    I found the other shock last night, which was nice.

    Got the machining finished at smoko this morning. Ended up shortening the shafts by 12mm and then tapping the threads onto the end.
    I spent $20 on a M10x1.0 die nut to suit the lower shock eyes I had hanging around. They came from an ancient pair of deCarbon shocks I pulled apart in 2006...

    K2g1UJPh.jpg


    KmrjPqwh.jpg
    qyGWXeTh.jpg

    It has a shitload of wheel travel. My photos are crap, but if you look at the location of the caliper relative to the chassis rail, you might get an idea of how much travel it has.
    As a rule, ~160mm of suspension travel is the minimum for a gravel rally car, with 180mm or more being better.
    I measured 228mm at the wheel!


    Temporary bushes were some old Mazda swaybar bushes I had hanging around. Looked like they would work with a small amount of modification ... except the “old” part came into play and they crumbled.
    HckYNXnh.jpg

    I really want to fit some spherical bearings to the lower eyes. Need to work out if I should modify the deCarbon eyes or make something from scratch.
    bgpzfm142
  • SpacSpac (@Spac) Canberra-ish.
    Photo that took on the weekend but forgot to post up.
    The shocks with the green anodised tops are the skinny Bilsteins that are now in the race car. The ones between them are the shocks for the rally car.

    m2x5SQUh.jpg
    bowieVee_Que
  • SpacSpac (@Spac) Canberra-ish.
    Hopefully my lumpy welding can be forgiven, but here’s the new engine mounts.
    I will make another set for the rally car. My mate Buzz pointed me at this very useful link on the Superpro website, https://superpro.com.au/bush-sizing?fbclid=IwAR3eFRR8eWci_FnzLcEdPXBwvgNGPRGrYuurTh5MyEyHO9zjZIknV_2uolY

    The next set will be a lot tidier!


    wG72eUuh.jpg

    KeL5NgRh.jpguVWqFzoh.jpg

    The reason for the two different sized mounts is... because these are the bushes I had at home!
    Ex850Rbowiebgpzfm142Jamest5r_
  • SpacSpac (@Spac) Canberra-ish.
    And in...
    Ye0d8eCh.jpg
    S0kRBa5h.jpg

    They actually need to come back out, because the heads of the bolts that hold them to the crossmember touch the underside of the tubular part - I underestimated how much the rubber would compress with the weight of the motor.

    The gearbox mounts have been replaced with standard ones, but with straps over them to limit the tension and shear loads they will endure.
  • Noice!

    The preference for using rubber at all was just in effort to stop anything else shaking free?
  • SpacSpac (@Spac) Canberra-ish.
    Noice!

    The preference for using rubber at all was just in effort to stop anything else shaking free?

    Yes. Having put solid mounts into other things before, all sorts of weird stuff ends up with fatigue issues.
    egadsbowieVee_Que
  • SpacSpac (@Spac) Canberra-ish.
    I may have bought the green road car back...

    And by “may”, I mean that I have paid for it and it’s sitting in our driveway....
    egadsVee_Que
  • Ah don't worry, no doubt it snuck up on you. You are doing it a favour no doubt.
    Spac
  • SpacSpac (@Spac) Canberra-ish.
    edited March 17
    6th place in the race car today. Interesting sort of a day with rain and funny things happening.

    Qualifying was weird. I had NO mojo at all - did four laps on a damp track and came in to give someone else a go. My best was a 67.high. Petey's times were about the same, with one lap a fair bit better (but still not great).
    In the end, Paulie was the man for qualifying with a 65.high.

    Paulie's time qualified us in 13th place out of 17.
    He also started the race. He carved it up in the first few laps - got past three cars and was hounding 9th place. And then failed to go faster as the track dried out and faded back to a fairly distant 12th.

    El Wifeo stepped right up and massively bettered her PB with a string of 65.xx second laps, and took us back up to 10th. In our stints, Pete & I both got our shit together and started to reliably churn out 65.lows and 64.highs. Still 10th.

    Afternoon restart had us 10th, but on the same lap as the Hyundai Coupe in 9th (ie: starting right behind them). Pete got past and pulled a useful gap. We weren't going to catch 8th on speed, but needed to consolidate 9th place ahead of the Hyundai. The gap between the two cars grew and shrank depending on the driver in each car, but was growing overall.
    Then the Hyundai DNF'd and we had to drive around without doing anything stupid - we were miles behind 8th place and miles ahead of 10th, so there was no need to push.

    It started drizzling again late in the day - Pete's last stint went from dry to damp, my stint went from damp to wet, and El Wifeo's was all in the rain. Happy that I managed to overtake three or four of the fastest cars in the wet - they still finished laps ahead of us but taking a lap off is good.

    I made contact with the same Integra driver as I did in the S40 two years ago... Very similar circumstances too. Bit pissed about it, TBH - they were miles ahead of us in the race, but old mate is desperate to stop me passing and shuts the door after I'm committed. I lift and hit his car behind his door. Minor dent to the BMW's front guard.

    Here's just some of the stuff I haven't really figured out yet:
    We lost 5 laps to the fastest cars in the morning. Two laps is credible, three would be tolerable. Five feels like we must have been abducted by aliens for a bit. We only dropped two more laps in the afternoon;

    The fastest cars seemed to catch us quickly be get away very slowly;

    We were relatively slow on a damp track, but relatively fast on a wet track?!;

    LOTS of break outs from other cars, meaning lots of penalties. We ended up 6th after penalties. Not beaten by any of the Group 2 cars (who run on a 65 second break out), and were the fastest of the three RWD cars that were there.
    bowiebgpzfm142carnut1100Vee_Que
  • SpacSpac (@Spac) Canberra-ish.
    We need to make the car at least a second faster. The brakes are wooden and it understeers too much.

    The understeer isn't tragic, and it does make the car very intuitive to drive, but it is also the limiter to how fast it can be. We need to fiddle more with the camber and toe-in.
    Tyre wear says that it needs more negative camber but it already has a lot.
    I also need to extend the travel limiting straps. Since raising the front, the straps don't give enough droop travel, and allow it to lift the inside front wheel too often.

    It also needs a bit more negative camber on the LHF tyre.

    Will try some better (more expensive...) brake pads as the first step. The QFM A1RMs work great on the S40, but the BMW's hardware isn't as impressive as the Volvo's. I will ring QFM first but the fallback will be Ferodo DS3000s.

    I also want to ditch the ABS module. Given the sensitivity of the ECU about disabling the ABS, I am inclined to leave the module in place but bypass it hydraulically.
  • but is it more fun then the S40, or just a different kind of fun. The understeer comment is interesting, I thought they were snappy little things?
  • AshDVSAsh (@AshDVS) - Geelong, VIC
    We need to make the car at least a second faster. The brakes are wooden and it understeers too much.

    The understeer isn't tragic, and it does make the car very intuitive to drive, but it is also the limiter to how fast it can be. We need to fiddle more with the camber and toe-in.
    Tyre wear says that it needs more negative camber but it already has a lot.
    I also need to extend the travel limiting straps. Since raising the front, the straps don't give enough droop travel, and allow it to lift the inside front wheel too often.

    It also needs a bit more negative camber on the LHF tyre.

    Will try some better (more expensive...) brake pads as the first step. The QFM A1RMs work great on the S40, but the BMW's hardware isn't as impressive as the Volvo's. I will ring QFM first but the fallback will be Ferodo DS3000s.

    I also want to ditch the ABS module. Given the sensitivity of the ECU about disabling the ABS, I am inclined to leave the module in place but bypass it hydraulically.

    Try QFM ZX2800 or ZX3800 - they might be a good fit and should perform better than the A1RM, given your application.
    Spac
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