So what's the deal with a 1975 car?

[carrosene]

Are these not worth getting or are they good cars and you just have to take off all the additional crap they put on for that year? I know some people on here have them and like them but I am new to all of this so I don't know much yet.

Eric

[RandyMolson]

They are fine cars. Biggest disadvantages of 1975:

• In many smog states, 1975 is often the cutoff year for requiring visuals or testing.

• 75 and 76 had the big ugly bumpers which added 100lb and 9”. You can swap with early bumpers with a little welding work.

• 75 had the thermal reactor…not an issue if you are not in a smog state

Something to look for. 75 and 76 are susceptible to rusting of the driver side firewall and floor boards. I am pretty sure it has something to do with brake fluid seepage or spillage from the brake or clutch systems. I am wrapping up a resto of those areas in my 76 and plan to routinely check for leakage.

[carrosene]

So can nothing be done about the thermal reactor? I just assumed you could swap out some 76 parts to make a 75 like a 76. Like I said before I am new to all of this so I am sorry if I am asking dumb questions.

[jerry]

there is absolutely nothing wrong with a 75 car in general, if the smog equipment has been removed.

i just recently sold my beloved 75 02 to my nephew, to thin the herd and it was a very nice car. almost zero rust and never left me stranded. the squaretails 'feel' more solid than the roundies as well.

now i need to get one of my projects running so i can once again drive an 02...

[Marty]

Yes the thermal reactor can be replaced with a standard cast iron exhaust manifold from any 02 or better yet a Tii one which will flow a little better. As stated above when checking for rust pay attention to the 4 large holes/plugs in the floor pan sometime in the 75 model BMW switched to a inferior sealant for the plugs.

[Jim_75Sahara]

The thermal reactors generated a lot of heat & could lead to a cracked head is what I have heard. So, if the head is not damaged & the thermal reactor is gone, it should be OK. One of the 1st things mine got once I bought it was a tii exhaust manifold. Adds a handful of HP and makes a beautiful sound too. Not sure if the rusty driver's side floor is just a 76 problem or if 75's are afflicted also. Too much bias vs. the 75's IMO.

[wohleb]

If you replace with a Tii manifold are there other modificationd that you 'll need to make?

[RandyMolson]

If you replace with a Tii manifold are there other modificationd that you 'll need to make?

Except for the emmissions connections, the 2 manifolds are essentially swappable. The tii manifold uses a different heat shield though, so if you still use the original aluminum o2 heat shield, you will need to get a tii shield or get a later bmw manifold gasket with integral heat shield or you can probably grind and spacer your 02 shield to fit as well.

[madjurgen]

Where is all of the extra weight in the later cars located? I know the doors are much heavier along with more sound insulation. Any other areas?

[Jim_75Sahara]

The bumpers require reinforcement, so there is added weight on both ends to hold the heavier bumpers. The US bumper standards required no damage with a very slow impact & minimal damage with a slow impact.

[Marty]

On squaries other than the bumpers the doors have a anti intrusion beam that is supposed to shift the load of a side impact to the door frames which is a good thing, and area around the rear wheel arches and trunk framing has been reinforced both of these things add a lot of stiffness to the car and not a lot of weight less than 30# i think. The bumpers add about a 100# all toll.