318 and 325 diff different?? check sensor query??

[telski789]

im putting my 325 into a 318 shell! just wondering wether the 325 diff and drive shafts are different or wether i dont need to change them over?? what about subframe and stuff at the front? the same? thanks for ya help!!

[Andy325i]

The 325i diff is wider than the 318i diff, and pretty sure the ratio's are different.

As for the front the subframe is the same

If you want any more help just ask

[telski789]

cool,anything else you can think of that is different? i know ive gotta change the drums to discs,and apparently the fuel lines need to be changed over?? what about the loom,is it attached to the interior loom or is the engine loom seperate?? thanks

Terry

[E30Adam]

The 325i diff is a direct replacement for the 318i diff. It's a little longer but all you need to do is undo the collar at the centre of the prop and slide the prop back a little to accept the larger diff. Once fitted, tighten the collar back up.

The bold holes on the diffs are exactly the same as are the driveshaft lengths.

Ratio's will be worlds apart so you'll definately need the 325 diff in there or else you'll be revving the nuts off it all the time.

[Andy325i]

cool,anything else you can think of that is different? i know ive gotta change the drums to discs,and apparently the fuel lines need to be changed over?? what about the loom,is it attached to the interior loom or is the engine loom seperate?? thanks

I did my rear disc conversion way before I dropped the 2.5 in. the driveshafts were shorter on 2.5 backend, so hence with the narrower 318i diff leaked a bit of oil and had a lot of slide on the inner joints. This was all sorted when I got round to putting the 2.5 wider diff in.

Fuel lines you will have to check, pretty sure its simular setup, one flow one return on the 2.5, think my 1.8 may have had another pipe where it goes into the tank (on the fuel pump housing?)

The engine loom is different for the six cylinder to the four. It joins on the bulkhead in a round multipin plug, and is just an engine loom (not part of the main car loom), what year is your car?

The early E30's had a 2 Row ECU, the later (plastic bumpers) had 3 row.

If you need to buy the engine loom seperatly make sure it has the injector loom on it! (this little baby costs Ԛ£130+ to buy from BMW!)

How soon are you doing the conversion?


Andy

[Brianmoooore]

Engine loom is seperate from the rest of the car, and unplugs at the C101 connector - The round one on the bulkhead just inside of the fusebox.
May be the odd wire missing from one half or the other, but all the main functions will work.
Fuel lines are different on the 325 from the 318, but I've never understood why. They both pump high pressure fuel to the injectors, and have a return line to the tank.

[telski789]

my car is a 325,ive bought a 318 complete minus the engine and box to convert my stuff over to,so ive got all the parts i need! mines a 3 row ecu (173) so will i be able to connect that c101 connector from my 325 engine loom straight to the 318 loom?? i'll do the rear discs straight away,what the easiest way to do them? have i got to weld anything inside the wing or is the flexi hose fixed to somewhere else?? thanks alot fellas!!

[telski789]

im doing the conversion from sunday onwards,just gotta figure out how im gonna get to work for a couple of weeks!! got an mtech 2 kit to fit too!!

[Andy325i]

Damn internet explorer!!!


Right, the loom will fit no probs, may have to swap a wire or two to get the heater fan to work.

as for the rear end, if you are doing subframe bushes drop the lot out, if not, just change the rear arms and diff, leaving the old sub fram in place.

as for under the bonnet welding etc, there is no stud on the nsf inner wing for the collent bottle, not too difficult to get around. and the spacing for the 2 x 10mm nuts on the air filter is slightly different, again not too dificult to sort.

[radback]

Ratio's will be worlds apart so you'll definately need the 325 diff in there or else you'll be revving the nuts off it all the time.

So what?
It's cool to have a short diff
I changed my original 3.73lsd to 4.10lsd, and I've a huge difference in acceleration!
Best mod for $$$

[Andy325i]

I had the 2.5 diff in my 318i for a while, managed just under 130 with a big tail wind lmoa! Acceleration was a little less than before

[telski789]

ok,so as you know im putting my 325 into a 318 body,which has NO CHECK LIGHTS!! so how the heck do i plumb that in? any ideas?? i need me check light!!

[Brianmoooore]

To get the check light system to work, you'll have to swap over most of the body wiring looms.
Not that difficult, if the seats, carpet and dashboard are removed.

[telski789]

so what do you reckon? i gotta take out the whole interior anyway to change it over to the other shell,will i have to cut wires here and there?? or is it literally a change over? at least if i change the complete loom over i still have my immobiliser!! what abot the roof lining,how hard is it to chnage that over? can it be done???

thanks alot

[Brianmoooore]

Only wires you may have to cut are those associated with the alarm/immobilizer if it's an aftermarket fitting. Take photos and make notes as you go though or you could get very confused.
Roof lining is OK to change, but requires front and rear screen removal to do the job properly.

[telski789]

ok,another thing,the check light,ive been told i can just unplug the 325 cheklight and plug it into the 318 loom? is this true? is it really that easy?!!