BMW 850

I think there was a discussion about it a while ago . . .but no one really wanted to tackle it.

Since the car was built with 80s era tech and electronics . . . it shouldn't be THAT hard

z31maniac wrote: Keep car as a GT, but ditch the V-12 and add LS1. Great soundtrack + dead nuts reliable. That would make about the perfect daily driver for me.

Whawhawhat?

NOTHING sounds better than an uncorked V12!

Re: engine management, a Megasquirt 3 could handle it, except for the 2 DBW throttle bodies. It does have DBW throttles, doesn't it? Or is my memory failing me? Not many ECUs out there that can handle drive-by-wire.

Cheers, Brady

In reply to bradyzq:

Yes they are drive-by wire. And as far as 80's technology - it was a new technology platrom for lots of cutting edge (read near-beta testing) technology: derive by wire, multiplexing, multi-link suspsension designs, etc. So there's limited information about what wires are controlling what as it may just be carrying information controlling multiple functions to the computers in the back of the car. And even with multiplexing it looks as if a 747 pucked its whole electrical avionics systems into the car.

The computers all talk to each other in strange unknown way such as: the speed sensors are integrated into the wiper speeds, ABS, cruise control, windows roll up automatically at 100, the traction control (which cuts the throttle), and I think, the radio volume changes with speed, etc etc.

I've seen gremlins such as the seats and mirrors start operating backwards, steering wheels that move by themselves, headlights that pop-up and retract alond with the windows going up and down, heater controls that work backwards (ask for heat and you get cold, ask for cold and you get heat).

A lot of work to have something unique vs. sell it, buy a Miata, and have fun vs swearing at electrical systems that now floor the throttle when I turn on the headlights becuase I've guddled something. Or I could buy a Totyota, I hear that they have that option from the factory.

In reply to Calypso850: Gads I can't type worth a damn on my laptop

pres589 wrote: Am I the only person that doesn't think LS1's sound that good? Not that I don't think they're a great engine, but maybe there's something else to slide into an 8 series...

I'm more of an ls3 fan than ls1 but I like pretty much all the ls motors lol

I have to agree, the LS motors aren't the best sounding V8s out there. They work really well though :)

I don't see the sense in building an 850 track car. I've got a taste of the electrical systems in my E39, and it's just looking for trouble. I'd keep it as a GT because big GTs are their own kind of fun.

Calypso850 wrote: d. And that HP is expensive is correct, I'd guess that the tab for the Schrick cams ($1500 alone), new followers. labor, Conforti Chips, and Dinan extrude honed manifolds ($2,000) was north of 5 grand for maybe 40-45 HP. Maybe he should have just bought one of those electric superchargers off e-bay insted. :-)

If its just the Dinan extrude honed manifolds you are in the the clear but keep as far away from the dinan intake manifold gasket sets. Those things leak like a sieve and can do a number on your DK motors as they try to compensate.

Dinan did do a twin turbo kit and the 850 motor gets stuck in tons of lambo replicars so there might be some decent HP out there.

I never got anything with the Dinan chip and intake though on mine HP wise.

wearymicrobe wrote:

Calypso850 wrote: d. And that HP is expensive is correct, I'd guess that the tab for the Schrick cams ($1500 alone), new followers. labor, Conforti Chips, and Dinan extrude honed manifolds ($2,000) was north of 5 grand for maybe 40-45 HP. Maybe he should have just bought one of those electric superchargers off e-bay insted. :-)

If its just the Dinan extrude honed manifolds you are in the the clear but keep as far away from the dinan intake manifold gasket sets. Those things leak like a sieve and can do a number on your DK motors as they try to compensate. Dinan did do a twin turbo kit and the 850 motor gets stuck in tons of lambo replicars so there might be some decent HP out there. I never got anything with the Dinan chip and intake though on mine HP wise.

Found one of the twin turbo Dinan 850s a few years back. Think it was 600 HP 600 lbs of tq. Price was cheep a golf pro in Fla was selling it. Researched it a bit but was gone when I tried to purchase it a few days after seeing the add.

As as avionics/electrical engineer I'll let you in on a secret; the BMW 850, from your description, sounds more complex electrically than the average business jet as far as cutting edge busing and related tech. We're coming along but it's slow change vs. car technology. Proven, reliable, safe. That's the world we work in so people arrive safely.

It kind of sounds like you might be better off leaving this alone, or if you really don't care about possibly destroying the value of the car, gut it 100% and rewire everything to take it back to basics. Megasquirt, cabled throttle plates, no radio. Ditch the body computers and the A/C, etc etc. Basically rebuild the car from the ground up and document like it's going out of style.

If you have the space, the time, the tools and the interest it could be a good project. It would seem like a great project if you could get on of these that had suffered from a small fire or other electrical "event" that would drive someone to have to rebuild the electrics anyway. But the car you're talking about sounds a bit too nice for that. My 2 cents, grain of salt, et cetera.

If I could find one with some "issues", ^ this would be the plan.

pres589 wrote: Am I the only person that doesn't think LS1's sound that good? Not that I don't think they're a great engine, but maybe there's something else to slide into an 8 series...

You won't find anything to beat the sound of a V12 with a good exhaust system. Certainly not the LS1.

These engines are smooth, but they don't put out much power (my 4 cylinder GM has about 50 BHP on them) and they are heavy as hell, plus the ECM costs more than the entire car is worth if it goes out on you. I'd just drive it and enjoy it as long as it runs

In reply to wspohn:

I have a theory that used Termi cans from Ducati's and Dr. Gas or similar X-Pipes plus resonators could make just about any V-type engine sound good without spending extreme piles of money. Even an LS1, but I don't have any way to test this, and I'm not really sure how much flow a 2.5" inlet Termignoni can offers. May not be the best flowing thing on the block...

In reply to pres589:

I think removing everything and taking it back to basics would be the way to go but: I'm not an electrical engineer and have only a basic knowledge of electrical systems, I'd still have to keep the body control module to make the power windows work and keep the drop-down/up feature that slips them in and out of their retaining groove in the window gasket seal, there'd be challenges passing emissions.

As far as value of the car - since it is semi-disassembled I got it for fairly cheap and could probably sell enough interior parts & unused components that I could probably get it down low enough to qualify it as a challenge car. Especially since the price included a LOT of extra parts from an 840 that he parted out for the interior, a lot of new parts, bins full of Griots car care stuff, some european parts, heck even several storage racks to hold all the stuff. Heck if I really worked at it and spent years peddling the slow moving parts - the stripped shell with all the running gear and minimal electronics to keep it functional could be essentially free.

I'm not sure how the car figures out when the windows are up. My first guess would be an amperage detection circuit that says "okay, when the amperage draw to push the window up goes up to X amps, turn it off". Amperage is going to go up when the motor encounters more mechanical resistance so all you need is this detection and have it turn the motor off. Easier said than done, I get that, but not impossible by any stretch. Down is probably just driving the window down for .5 seconds or so, could be done with a 555 timer. Build some little PC board for each motor control and call it a day.

What I'm saying is, don't let electricity scare you, and if you find the right people I'm sure the knowledge to get this working is out there. But it would be a serious undertaking, which you do understand, and that's a good thing.

In reply to Calypso850: Second thoughts on the challenge car:

First I'd have to figure the cost of the just the car itself (and the parts that belong to it if it was a together running car). I guess I could arrive at that price by subtracting all the extras from the total package price, if the challenge judges would allow that. Subtracting the extras would be: The fair market value of all the extra 840 parts that were not part of the car or ever intended to be. The fair market value of the new parts that were never installed ( I have the receipts) The fair market value of the European-spec parts that were never installed (I have the receipts) The fair market value of the Griots car care products (not sure I have the receipts) Whatever I can get for the several storage racks

That would have to get the net cost of the just the car itself down to the $3,000 range or less as there is a limit on the recoup costs from selling removed parts from the car. Plus I would need to buy some parts.

In reply to wearymicrobe:

Yeah the Dinan gaskets were crap - these are all EOM gaskets. The Schrick cams & Conforti chips were probably the most of the gain on this car, the Dinan manifolds probably didn't add much. I do have the dyno graphs for the car and I'd say it is making 340-350 HP as it was about that far behind a nearly new CSi, also with Dinan manifolds and chips (which did not appear to have done much of anything for the CSi.) The Conforti's were supposed to be a bit better than the Dinans.

Due to the low compression on the M70 engines they love turbos. But again you are talking two systems and good luck finding manifolds. I've been behind a Dinan Twin Turbo on full boost at it was like it was going to warp speed - the car seemed to stretch off into the distance.

In reply to Calypso850:

And if you don't think that 850's can be cheap - Here's one on e-bay with engine and other problems, but with a clear title and manual transmission, that got zero bids with a starting bid of only $2,000. http://cgi.ebay.com/ebaymotors/1991-BMW-850i-Part-Rebuild-Not-Running-/170583214782?pt=US_Cars_Trucks&hash=item27b78d4abe Some wrenching & carefull parts shopping and selling could get that down to challenge car territory.

My car would fall into the poor category on KBB as it would need substantial reassembly, Parts (such as a headliner) and maintenance work to get it driveable and back to normal operating condition. As such KKB provides no market value. 8-series with significant issues are cheap as normal sane people run screaming in terror at the mere mention of them.