other Wondering why BMW decided to go with center exhaust?

[jimk]

There is a heat shield along the gas tank in the center (even on earlier cars).

None came on mine a 9-71 car, bought new.  But I added one because EFI recirculated gasoline warms the fuel in the tank and I didn't want any more heat sources heating the tank more.

Center exit exhaust gasses do not disperse from behind the car on center exhausts as the gasses do on side exit exhausts.  The gasses vortex and swirl up behind the trunk on center exhausts.  I ran a center exit aftermarket Prima Flow for a years and it would dirty the chrome bumper above the exit.  Side exhaust has no stains.

[otisdog]

There is a heat shield along the gas tank in the center (even on earlier cars). 

Not on any of the three 2002's that I have been associated with.

[02Les]

There was a heat shield on US '76s for sure; don't remember there being one on the early cars though.

 

[Mike Self]

I can vouch for the heat generated by the transverse exhaust pipe on the pre-'75 models.  It runs right behind the rear valence panel, and n my '69, over the years burned all the paint off the back side, allowing the panel to rust.  When I started working on my car to fix all that midwest road salt rust, I found the portion of the valence panel that had the exhaust pipe next to it was rusted through like Swiss cheese.  I had to get a replacement piece cut from a SW car and weld it in--too many holes to patch.  

 

But I doubt if that's why BMW changed the pipe's route--02 rust in other places was quite evident by 1975!

 

mike

[theNomad]

My question is why couldn't they just move it all the way to the actual center... I just have this thing about symmetry! It always looks "wrong"

[JohnH]

My question is why couldn't they just move it all the way to the actual center... I just have this thing about symmetry! It always looks "wrong"

 

Towbar

[jgerock]

Mlytle's 75 has the fuel tank heat shield and the center support bearing heat shield and some crazy wicked heat shield lining in the tranny tunnel. Those 75's cooked themselves.