Finally, M3 Engine Going into 525iT

[Scott H]

came out of my 92 525iT/A

What is the touring rear end ratio? I know the manual sedan is 3.23 which is identical to M3

[Jon K]

Mmmm open

[Brandon J]

Good work and do keep us updated. Isn't the M3 auto tranny the same as the 530i auto? How are you doing the vanos connector or are you using a vanos from a M50tu/S50?

Geez, I meant S52 not M52. Guess I posted that a little late for me last night. ;-) Anyway, I ran this by Brett Anderson a couple of months ago first to get his pointers. The Touring is my dog hauler and work car. I could care less about a manual trans because I'm way past the age where that's important anymore. Now it's a little power with good AC which makes me happy.

We got the engine out today between servicing our normal clientel (BMW dealership) and drop ins. Everything came out with no problems. Swapped the M3 engine onto the front suspension, added all the accessories back on the front of the engine, new belts too, attached the auto trans lines. New rubber engine mounts and all new vacuum and coolant hoses under the intake while we're there. Added the M3 injectors to the M50 intake. Will be sending out a standard throttle body to get it bored out at some point in the next couple of months when everything is running. I'll be using a set of stock 95 M3 coils for now (purchased off ebay). Everything is bolting up correctly and with no problems yet. Should have it installed tomorrow and maybe an outside shot at cranking it if it's ready. The research I've done shows the Touring rear end ratio to be almost the same as an automatic M3 so it should be transparent. Once it's driveable maybe a few updates down the road.

Paul

[gtopaul]

Good work and do keep us updated. Isn't the M3 auto tranny the same as the 530i auto? How are you doing the vanos connector or are you using a vanos from a M50tu/S50?

Different trans. I'm using the stock 4L30E GM trans with a fresh rebuild by ZF. It should be ok if I don't get too . I used a vanos wiring harness from a 94 525i sedan. I had to change the vanos solenoid on the S52 only because the E36 plug in lead was too short to plug into the E34 harness. Had to get a E34 vanos solenoid just because of the length of the wire.

Paul

PS The S52 uses a steel block so the weight difference between the alloy block V8 and the S52 is minimal.

I just found out the Touring uses the 4.10 rear end but I don't believe that will be a problem for the S52.

[ryan roopnarine]

i'm really not trying to pee into your cereal here....
but as a 4l30e owner, i just thought i'd pass this on, didn't know you'd be using the 4l30e

http://media.gm.com/division/powertr...2003_4l30e.htm

this is for a 2004 4l30e. 4l30e, as betrayed by its designation, is a gm hydramatic (so gm "makes" it). as it says, the max engine torque is 258 lb*ft. i know that some of the m3 I6s were a little short on torque, but it sounds like maybe you are about to hit the ceiling with what can be done, performance wise, with such a tranny installed. i don't even know if you can chip such an engine when its hooked up to that tranny without getting into a risky situation.

Different trans. I'm using the stock 4L30E GM trans with a fresh rebuild by ZF. It should be ok if I don't get too . I used a vanos wiring harness from a 94 525i sedan. I had to change the vanos solenoid on the S52 only because the E36 plug in lead was too short to plug into the E34 harness. Had to get a E34 vanos solenoid just because of the length of the wire.

Paul

PS The S52 uses a steel block so the weight difference between the alloy block V8 and the S52 is minimal.

I just found out the Touring uses the 4.10 rear end but I don't believe that will be a problem for the S52.

[onewhippedpuppy]

Few people seem to realize, the S52, as well as many of the other 6s, actually weigh more than the M60. 333 lbs for the S52, vs 321 for the M60.
http://www.bimmerforums.com/engine_faq/
Just thought I'd toss that out, as there has been some discussion of weight on this thread.

Sweet sounding swap, I'm sure it will feel like a different car when you're done. We will, of course, need lots of pictures.

[Elekta]

Different trans. I'm using the stock 4L30E GM trans with a fresh rebuild by ZF. ...

Is that a 5 speed? The touring really loves that 5th gear on long runs to the quail lease

[gtopaul]

Didn't take too long to get things running. Had the fuel lines swapped on the intake to begin with and then the wrong coolant sensors hooked up. Once that was figured out it cranked right up and idles very smooth. Power increase is very noticeable but it's highlighted other weak areas that need addressing. The rear end is clunking now on the first and second shift. I guess it was ok with 187k miles and the original slush box and engine. Probably will have to look for something a little newer (tighter). The trans was giving a bunch of Trans Program lights and going into limp mode at first but I think we traced that down to too much slack in the shifter cable and that seems fixed. Of more immediate concern is the leaking trans fluid which appears to be coming from the circular thing on the side of the trans. Might need a new gasket in there. I haven't dogged it yet but the car has lots more power than the origjnal six (of course), idles smoother, and doesn't seem to mind having the AC compressor on like the original did.

I took a couple of quick pics, before cleanup:

http://members.aol.com/gtopaul/private/525m3001.jpg
http://members.aol.com/gtopaul/private/525m3002.jpg

Looks like a factory installation doesn't it?

Paul

[Jon K]

Hrm..

OBDI valve cover yet you have M Power trim? So you bought the S50 engine cover? Why didn't you just use the S52 valve cover and coils?

[gtopaul]

Hrm..

OBDI valve cover yet you have M Power trim? So you bought the S50 engine cover? Why didn't you just use the S52 valve cover and coils?

When you change from OBDII to OBDI you use an earlier wiring harness that's not compatible with the S52 coils so you have to use the earlier square coils, which don't fit in the S52 valve cover, hence the change to all earlier stuff.

Paul