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Mar 12, 2006 16:50:11 GMT
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thinking caps on! we have been "playing" at work. I am currently stuffing an e23 745i lump into an unsuspecting lhd e28 528i. now I'm stuck with the wiring. there are one thousand little boost/vacuum switches and sensors dotted around the engine wiring, some are missing, most probably don't work. also the ecu has burnt out and I haven't got another on the shelf. the engine has a two way vacuum advance/retard unit on the distributor, which (I presume) has boost retard (or at least could be configured in this way). being that this is a really dirt cheap project, the cut and thrust of it is this; can I just use the 528i ecu and wiring, fit an adjustable fuel pressure regulator (might have a rising rate one) and simply up the base line fuel pressure? this would simplify things greatly. BTW its a 3.2 litre engine, intercooled (got a pretty big AVA 'cooler in the shed, might fit), non- motronic engine. think they run about 8 psi boost stock, but this might be a reason for all the fiddly switches, ie; like a metro turbo, 7 psi in mid range then clipped to 4.5 psi at top end. 10 psi gets you about 290 bhp IIRC. sorry for the above being long winded and a bit techy, but don't let that put you off helping. what? you've gone already? you haven't even seen the pics.... ^^ unsuspecting e28 ^^^might also be the worlds cleanest vvv 745 engine the reason for needing LHD please help a child on the poverty line complete his dream of a turbo'd e28 ;D ;D
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Mar 12, 2006 17:15:35 GMT
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cool. when i play at work its generally solitaire on the pc, nothing like that. sorry, cant help.
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Mar 12, 2006 17:22:27 GMT
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would like to add that those hideous 5 spokes will be on the scrap alloy pile soon. being replaced by some nice M.I.M. looking 15s, or some e39 "steels" (they look like povo orion wheels but are actually made of alloy ). and maybe a 518 badge ;D
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turbo fuelling Q + picsBenzBoy
@benzboy
Club Retro Rides Member 7
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Mar 12, 2006 19:06:45 GMT
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Christ on a bike! That's some side project! In my opinion, the e28 ECU might not like being strapped to a 4.5.... I'm not sure if upping the fuel pressure would be enough. But then I could be entirely wrong! What injection systems do the 4.5 and 2.8 BMW's use? I always assumed the e28 was K-Jetronic but if it's got an ECU it can't be (is it Motronic?) Is there enough in the coffers for an aftermarket ECU kit?! Or sod the lot of it and lash a big Holley carb on!
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Mar 12, 2006 19:17:16 GMT
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Christ on a bike! That's some side project! In my opinion, the e28 ECU might not like being strapped to a 4.5.... I'm not sure if upping the fuel pressure would be enough. But then I could be entirely wrong! What injection systems do the 4.5 and 2.8 BMW's use? I always assumed the e28 was K-Jetronic but if it's got an ECU it can't be (is it Motronic?) Is there enough in the coffers for an aftermarket ECU kit?! Or sod the lot of it and lash a big Holley carb on! 745i's are actually 3.2 litre (bmw badging is confusing, aint it). both engines use L jetronic, with a proper distributor. here is some one doing much the same, but in a 6 series and with all correct and working fiddly bits www.islandia.is/smu/structure/645csi_project.htm
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Mar 12, 2006 19:25:28 GMT
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If its the same injection system then the ECU should be capable to get the engine to run. Someone correct me if I am wrong here but I guess the injectors will be a bigger capacity than the e28 ones so in theory if they are pulsing for the same length of time then they should give more fuel. The problem is it still might not give enough fuel. I have known people up the boost pressure before to give more fuel on some turbo conversions but personally I would be trying to get a hold of a standard ECU. Does the ECU affect the ignition timing or is this just from the vacuum and mechanical advance on the dizzy Is the ECU unit totally fubar`ed or would it be possible to replace the ECU chip. Definetely sounds like a good conversion though and one I will waiting eagerely to see.
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Mar 12, 2006 19:26:40 GMT
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Last Edit: Mar 12, 2006 19:28:56 GMT by PhoenixC
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turbo fuelling Q + picsBenzBoy
@benzboy
Club Retro Rides Member 7
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Mar 12, 2006 19:35:04 GMT
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That's superb. I didn't know BMW were fond of confusing badges - Mercedes do that too.
Having given the fueling issues a bit more thought, and with it being an L-Jet set up which is pretty straight-forward, I suppose you could just bang up the fuel pressure and see what happens. My concern would be that you'd be changing the fuel delivery by an unknown amount, and it'd be pretty hard to get right - if there's too much fuel going in, the ECU's going to try to set that right. You'd be constantly fighting the brain as it struggles to figure out what the funks going on. The ECU might even run out of data - I'm not sure how flexible these little black boxes can be! You might be able to do it a bit more strategically using calculations, figuring out how much more fuel you would be lobbing in at a given fuel psi, with the engine in a given situation. That seems like a whole lot of brain-ache to me though! I could of course be talking a load of old bobbins, in which case someone wiser can put me in my place. ;D
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Mar 12, 2006 19:35:53 GMT
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thanks, pheonix, wil have a gander at those sites. the ecu has nothing to do with the ignition other than using it for a positon reference. I think the 745 ecu is kaput, I turned it upside down the other day and water ran out
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turbo fuelling Q + picsBenzBoy
@benzboy
Club Retro Rides Member 7
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Mar 12, 2006 19:38:05 GMT
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If its the same injection system then the ECU should be capable to get the engine to run. Someone correct me if I am wrong here but I guess the injectors will be a bigger capacity than the e28 ones so in theory if they are pulsing for the same length of time then they should give more fuel. Aye that's right, I hadn't thought of that! Whether it puts in the right amount of fuel so the other sensors don't send the ECU crazy though, I don't know...
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Mar 12, 2006 19:58:04 GMT
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good stuff here, unfortunatley the ECU link is for the 3.4 motronic e32 745i(lot of numbers, eh). I too have been looking at the net, want one of these engines www.bmwmregistry.com/model_faq.php?id=4 essentially an m5 engine with a turbo ;D zoinks!
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Mar 16, 2006 18:44:57 GMT
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things are slow at work this week, so the 545i has been progressing. I now have finished the exhaust! hurray! its been a 'mare, because of the waste gate positon. you will see what I mean by the pics. this has all been conjured up out of scrap parts and what we had on the shelf. intercooler pluming tomorrow, in the mean time heres the finished front pipe can't believe this is on page 5 already! things move so fast around here, I only put this up on sunday. any more thoughts on the original Q, people?
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Mar 16, 2006 18:53:46 GMT
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I know a decent place that can test and repair ecu`s if you are interested.
If you find the minimum the other ECU needs to run. Connect that up and try it. Might be worth swapping the sensors over if possible to make sure they have the same resistance the ECU expects.
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Mar 16, 2006 19:03:05 GMT
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I know of an ecu repair man, thanks pheonix. the thing is, the e23 wiring needs to be cut and re-routed for the lhd e28 shell anyway, I just had a crazy notion that it might work on e28 stuff. the engine hasn't run in a while so we'd like to get it running before spending any more money on it. it would also simplify things, not having any of the little sensor/switches, but if we have to get the ecu repaired it isn't the end of the world. it'd just be nice to have all the pieces to hand now, 'cos projects that stall at work tend to get shoved in a corner and not seen again until we break them
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