E30 m3 expansion tank

[johnwoo]

Anyone used this to relocate by the passenger firewall. I’ve searched without clear answer. I have a 318is and no brackets to mount the late model expansion tank. Running e36m aluminum radiator I don’t trust the plastic on the m42 radiator. Only option is to relocate it to the firewall. Trying to figure out best way to mount the e30m3 tank to the battery tray and also where the hoses go. There are four main hoses I figured the large one (17) goes to the spider hose the front one (12) to the radiator and one is just run off but what’s the extra. Any help would be appreciated thanks.

[johnwoo]

Any ideas guys can’t figuee out the hoses

[irish44j]

odd, has one more small hose that I don't know what it is. I use an M20 tank with e36 m3 radiator with the M50. Fat hose on the bottom goes to the block exit. One skinny hose to the small nub over the radiator inlet, one skinny hose is an overflow drain. Not sure what the third skinny hose is....

[2mAn]

You can probably mount an early tank up there and not pay the ///M tax

[GeoS]

E30 m3 expansion tank

Here is my setup. This is an "in progress" picture so the runoff hose is tucked in the wrong place.

Just cap the last port you have.

Edit...

I capped the 12 hose.

The 7/8 goes to the rad (this is the oem routing on the M3). It normally attaches on the passenger side. Had to run an extra length of hose across the front since my rad had the port in the driver side.




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[johnwoo]

Thank you kind sir
How did u mount the expansion tank? I’m thinking welding some bolts and using that up there
I did contemplate using the late model but it’s not flat like the m3 one so it mounts uneven to the flat area

[CMBusch]

I used the M3 tank as well and also capped off #12. I wish I could remember how to attach images, but I drilled a hole in the bottom of the battery tray for the flat mounting tab and just used a bolt that goes into the wheel well a little bit. For the vertical mounting tab, I drilled a hole through the back of the battery tray into where the glove box is. I used a long thin bolt and two 10mm nuts on each side of the tab to lock it in place.

[johnwoo]

Thanks

[GeoS]

Here is the M3 mounting...


There is a vertical tab and the one bolt near the shock tower. Just make sure there is enough room for the hood roller guide when you weld the mounting bolts. It can get close to the 7/8 hose when all is connected.

[2mAn]

I’m not sure if this will help, but I remember my E34 M5 had a hard line that went from the driver side of the radiator and came across to the passenger side. It might help make things a little cleaner than having a soft line the whole way

[johnwoo]

Thanks for u guys help

Do u have an overhead shot of the m3 mount area?
I was thinking about routing hard lines to the driver side

[GeoS]

E30 m3 expansion tank

Sorry, no overhead shot.


I the first pic you can see the hard line from the expansion tank ending at the passenger side of the radiator. There is a short hose to the next hard line that goes over the top of the rad to the driver side.