3.0CS Turbo Project

[sreams]

Hello all,

I have a 1972 3.0CS Automatic. I recently picked up an '84 745i (originally thought it was an '83... but turns out it's an '84, which means it has the larger 3.5 turbo motor). My plan is to transplant the motor into my 3.0cs. I've gotten started pulling apart the 745i. It looks like I'll need to use a custom intercooler and piping, as the 745i intercooler won't fit in the 3.0cs. It also appears that the 3.5 turbo engine's intake manifold is going to interfere with the brake booster in the CS. I could either go with a different manifold, like the one that is stock in a 3.0csi (anyone know where to get these?)... or, I was considering transplanting the entire ABS braking system from the 745i into the CS. It looks to be intact and in good shape. Does anyone know if this is a possibility? I also plan to eventually get a hold of a Getrag 265 5-speed. I'll be posting here as I make progress. BTW... I'm near Sacramento, CA if anyone feels like helping me out!

-Scott

 

[Malc]

Scott, sounds like a fun project
some questions and suggestions:

• 
  1.. Is the 745i an automatic or manual?
  2.. The early type intake manifold can be obtained from 1970s - 1980s BMWs with a "big" six engine, for example early 5 series, early 6 series
  3.. Forget transplanting ABS. I looked into it but it's a shed load of work both engineering and electronics wise.
  4... You can use the hydraulic servo instead of a vacuum servo. I am going to do this and gazzol on the board here has done it.
  5... Take the 745 master cylinder too
  6... You need to take the 745 ECU, sensors, FI wiring loom etc (I assume it's motronic of some kind)
  7... You will need the 745 fuel pump and in tank "pre pump" if fitted. You will have to fit a fuel return line or fuel swirl pot
  8... Not sure if an E9 Autobox is up to the output of the 745 engine, but is the 745 Autobox ok? - possible swap
  9... If your thinking of going to a manual gearbox you will need a pedal box from an E3, E9 and maybe an E12. (somebody here will know)
  10.. Also need clutch master and slave cylinders associated plumbing , plus a manual flywheel (Motronic compatable) / clutch assembly.
  11.. If your transplanting the engine you might as well go manual now, save pulling the engine again.

Enough list stuff :roll:

What else, Well to get around the Intercooler (air/air) issue consider using a charge cooler (air/water) as they are more compact. They are standard on the Lotus Turbo Esprit and Abbot racing (UK) makes one for the classic 900 turbo where the intercooler is pretty useless. The Lotus one is often adapted for the Lancia Delta Integrale. A seperate cooling radiator and pump can be used in a charge cooler system
Finally An uprated radiator is a definite and an oil cooler amost a must!
I'll shut up now
Where's my Anorak? :wink:
Malc

 

[sreams]

Thanks for all the good info. I looked at the hydraulic brake servo in the 745i... Since my CS has manual steering, I assume I need to switch to power steering... or at least install a power steering pump and cap the lines that would go to the steering gear, correct?

-S

 

[Malc]

Hi Scot
Yes you will need the PS pump and the pressure "bomb" to work the hydraulic servo. As you plan to take the whole 745 engine then keep the PS pump.
I am not that familiar with the 7 series car you have and thus I don't know if it has rack and pinion steering or the older style power steering box.
If you decide to go with PS you will need a PS box and associated plumbing. I believe an E28 (older 5 series) box will fit, but you need to check, that or a 2nd hand E9 PS box will work.
You also need to check your front subframe for the correct mountings of the PS box and of course the mounting of the 745 engine.
Otherwise to retain manual steering you can modify the the PS plumbing to just work the pressure bomb and servo.
Malc

 

[pj]

Hey good luck with the Project, I was going to put a 3.2 turbo m30 in my coupe , now its going into my e30 track car. I am looking forward to seeing the beast when you get her going. I am just down the road in Santa Cruz.

PJ
73 csi
87 325is

 

[dang]

PJ, I had considered the E30 turbo swap myself but thought the weight difference might be a little difficult to deal with. Are you planning on mounting the drivetrain farther back to help?

I didn't want to hijack this thread (change the subject), but I didn't see your email address. When you have something to share with us about your E30 start another thread here.

Dan

 

[nealkeith]

Turbo

The Lotus charge cooler is in my opinion not a good way to go. It is only good for short spurts. When the water gets hot you lose the effectivness. There are many air to air intercoolers that will fit and work better. Just my 2 cents. Sounds like a great project, need pics!

 

[shanon]

Sounds like a rowdy project :twisted:

drop me a line if your seeking a good local E9 power steering set-up, I will be converting to manual sometime (my manual box is on the shelf), maybe your project will expedite my conversion.

I'm in the SF/East bay area. Good luck and keep us posted.

-shanon

 

[velocewest]

I'm heading somewhere similar. I've got an M106 block, it will be mated with the crank and pistons from an M90, with an M30B35 head. Should net about 8:1 compression with a shorter stroke than the M30. I want the M106 block because it has the oil return for the turbo and the oil squirters for the pistons. I'm using the M106 exhaust valves, they're a high-strength alloy that was chosen by BMW for its stability in high heat. Don't let anyone tell you BMW used sodium filled exhaust valves, that's bunk.

I'm using the K27 turbo and the original BMW exhaust manifold, for now. Down the road I'll likely swap to the TCD manifold and a Garrett turbo, but for round one the K27 will be fine. I'll use the original 745 wastegate too, with a manual bleed valve for boost control (Alpina style) and vacuum activated bypass valve.

I'm going to use Megasquirt to control the injection. If you want to use Motronic, I'd skip the 745 version and just get an 059 box and harness from a mid '80's 5 series, or better yet a 179 box and harness from a 90's 5 series or 7 series. The later version uses a 60-2 wheel on the front damper and a single sensor instead of the two sensors running off the flywheel, which saves you the trouble of finding a Motronic bell housing and flywheel.

I'm using the hydro booster, but not for clearance -- but because you need a hydro booster if you want power brakes. Vacuum boosted brakes don't tend to work well with positive manifold pressure.

For intake I'm using and L-jet log with e21 runners, an L-jet fuel rail and low-impedance Motronic style injectors. It will look like a D-jet setup to the untrained eye. I want the average person to look under the hood and not even notice the turbo.

I'm planning for a front mounted intercooler, with the inlet and outlet both on the passenger side. There will be no A/C, so I'll have plenty of room.
I've played with the idea of putting the A/C in the trunk, with a compressor running off a belt drive from the drive shaft, like they did the alternator in some of the race cars.

 

[velocewest]

A couple other thoughts regards Malc's comments -- the 745 uses a 4hp22E autobox. The e9 will have either a BW box or a ZF 3hp22. I'd say the 3hp22 would be OK with a turbo, at least something putting out the 250hp or so of a stock 745. The 4hp22 from the 745 has two problems -- one, it's electronically controlled, and tied into the Motronic brain (piggyback ECU) on later cars like a 1984. Second, it's physically a bit fat for the e9 tunnel. If you don't mind getting out the hammer, you can get non-electronic 4hp22's -- my Range Rover has one -- but in the end, the 5 speed swap is the best answer.

Continuing on the piggyback ECU -- it doesn't like to be run without the 4hp22E, so that's another strike against using the 745i brain. There's bodge you can do to fool it into thinking the transmission is still in situ, but from what I've read it's not very reliable.

 

[Cvitan]

745 engine in 3.0 CSI

I put on a brake booster from a earlier 5-serie when I mounted 745 Engine in my -74 CSI

 

[robinasu]

How is this going?

Sounds like a cool/fun project. Please update!

 

[de coupe]

There is a turbo e9 on the e28 board

Just wanted to let you know there was good about of information, on the e28 board www.mye28.com. Look under force induction section.I did get a chance to ride in that e9 and it is the FASTEST e9 I have ever been in. Good luck with your build I would recommend putting a later model hydro booster on your car with a big brake kit.

I would like to hear what you are contemplating as far as reinforcing the body of your car.

 

[gazzol]

In response to the power steering and power brake issues. The 745 uses a steering box but I don't know if it will fit the E9 subframe like wise with the E28 one, if you can't get and E9 power steering box an E12 one will bolt straight up. You will however have an issue with the lenght of the steering column shaft, it will be too long and will need to be cut down, I'm not sure by how much but others on the board will know as they have gone the opposite way and fitted non assisted steering boxes to assisted cars (for purity of feel) and had to lengthen their steering columns.
Fitting the power brakes system will be considerably easier on a left hand drive car than it was for me (right hand drive) but it won't be a walk in the park. The reason for this is that there isn't enough room on the bulkhead (firewall) for the hydraulic booster to bolt right up if you have a manual car, if you stay auto you may be ok but it might still be a problem due to the shape of the firewall where the brake master cylinder bolts up as it isn't flat and the "footprint" of the hydraulic booster is considerably bigger than the original master cylinder. You may be able to over come this by making a new firewall section where everything bolts up as that part it self bolts to the main firewall any way. Another way to do it would be to make a steel plate that the hydraulic booster will bolt up to out of 10 mm ( 3/8 ) thick steel, this will need a hole in the middle which is slightly larger than the diameter of the existing master cylinder. Next take the original master cylinder off the car and after a lot of measuring and careful working out you need to take out the pistons and cut through it with a hacksaw. If when you've done all your working out and cutting you find that you're left with one of the pipe union lugs just grind it back till it's flush with the rest of the cylinder. Next take the cylinder and insert it through the hole in the plate you made earlier and weld the two together. Et voila! You now have something that you can bolt the hydraulic booster too that in turn bolts up to the firewall. All you need to do now is make up a link rod from the pedal to pass through the old master cylinder to the booster. One other thing I would do and did do when I converted mine is once its all in place is make a strong bracket to tie it all to the inner wing (fender) I bolted through where the master cylinder bolts to the booster and you'll have to get a longer bolt.
Take a look at the picture below you'll see what I mean bolted to where the master cylinder and the booster join is a bracket which was bolted to the inner wing just to give it all a bit more rigidity.

 

[de coupe]

This car was just done great head work by Paul Burke

http://www.mye28.com/viewtopic.php?t=64568

 

[Clubsport_CSi]

The german way...

...of a M106 conversion. I know the owner and he drove about 11.5 on the 1/4 mile. Guess he aims for more :mrgreen:

Best,
Daniel