Found an interesting potential project / build. I was thinking of adding boost to a three liter BMW motor. I was thinking taking the twin turbos from a Mitsubishi GTV3000.
Anyway what I don't know us how do the BMW motors take to boost and how much can you put to I on stock internals with a decent tune, intercooler, injectors and MS.
Conversely how much boost can you add keeping the stock ecu and just an ic and maybe a change to the FPR.
Or should I consider just getting the stock ecu re flashed.
Trying to adapt twins off a 3000gt would be a pain. Just put on one decently sized single turbo. They should take boost fine but retune the factory ecu or aftermarket would be best, youll burn it up right quick using a rrfpr because you cant adjust timing
Yeah one good sized turbo gets my vote.
The engine management issue is not a problem. I have done the MS thing several times. I have one sitting on the shelf actually. It is set up for EDIS and map. It was the semi plug and play demo unit for 944s. I have a wiring harnes compleet with all sensors and injectors hooked to it along with a stim jim kind of cool to see it all work on the bench. I have been meaning to mount it all to a board and then plumb in the injectors and a fuel pump and a for and have the injectors spray in to glass tuning of some sort that returns to the pump.
Getting off topic here but I need to find a non flammable substitute for gasoline to use for this project. Somthing that will work with the injectors and the fuel pump and not damage them but not be flamable.
clutchsmoke wrote: Yeah one good sized turbo gets my vote.
Ya. The easy way out for sure but I have always wanted to do twins on an I6 BMW motor. I think that properly executed it would look cool. REALLY COOL. Also fabrication of two three cylinder manifolds would be easier than a single one for all six cylinders. Plumbing would be a bit more complicated but nothing really all that bad. Since I do not know bmws all that well this is all me talking and speculating. I need to get eyes on the target to make the final assessment.
Kind of a dumb question but BMW motors are vertically mounted not raked over like the dam Porsche 944 motors yes?
Other than the engine managment, they do well. Some years the cam sensors are goofy, early single vanos I think.
no they are a slant, but not quite as far as a 944. this is an m52 but it's almost the same as an m54
I marvel at these contraptions... What an odd duck...
I appreciate my j-tin every time.
Looking at that it makes me think supercharger is really the easier answer.
Hummmm I have a M62 and am M90 on the shelf. . ..
I am going to have to see one in a car and see how much room there is on the exhaust side. This was the issue I ran in to with the 924s. The 951 moved the turbo over to on top of the motor on the intake side of the head for just that reason.
On a completely unrelated note I wonder if a BMW motor would fit in a 924s engine bay and how much of a sob it would be to mate it to the Porsche bell housing.
I would be impressed to see an aftermarket solution with a functioning check engine light...I've always found these cars a bit too smart for their own good.
Regarding your second question, I've used mineral spirits for injector testing. Still flammable but not explosive, and it leaves the injectors nice and clean.
Sounds like you don't have the car yet?
The 2.8l M52 is a much better choice for boost. Iron block with fully forged internals. Simpler electronics and commonly boosted with a huge knowledge base.
There are some ebay cast turbo manifolds I do believe for like $150 or so that would make life easy.. but the reason to go single is simplicity, twins as you know has two of everything and doesnt work like its all cracked up to be. Kinda like why theres lots of single turbo mkiv supras and fd rx7s. But hey its your car and I cant blame you for wanting a twin turbo bmw like the 335i and stuff so more power to you.
You also mentioned blower. Im sure this is all pipe dreams thats why im playing along but you would want the m90 or for more ultimate awesome, m90 and turbo a la compound charged
dean1484 wrote: Getting off topic here but I need to find a non flammable substitute for gasoline to use for this project. Somthing that will work with the injectors and the fuel pump and not damage them but not be flamable.
Mineral spirits?
I am not sure. I remember hearing somewhere this is some companies like Walbro used to test their production carburetors for lawnmowers and outboard motors back in the day.
I don't own the car but what I am seeing is that for the same money you can get a much nicer 530 with a manual trans versus a three series similarly optioned. I found a manual 530 with a new clutch that needs a door and has a small oil leak. They are asking 1k. It is a nice car less the door. A similar 330 would be close to 2k. So it got me thinking that why not go 5 series as a base point for a challenge build. Take a 530 add boost. Sell off as much as you can. Then add back in handling and lightness. Not sure it will better a three series but I think I would have more $$$$ to play with and that hopfully would make up for the inherently better platform the 3 series for a challenge car.
Be sure to check what the compression ratio is on any BMW engine you are thinking of getting. Many of them are relatively high which would limit boost, which means that any build for substantially increased power would involve a new set of forged pistons with lower than stock compression.
In reply to wspohn:
The 3.0 M54 runs like 10.2:1 IIRC, which is pretty high for FI but not insurmountable. Most people run superchargers with a custom tune at relatively low boost, you would definitely need a bottom end rebuild for serious boost.
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