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<6er> RE: How to get better performance...

Well, I've been looking around on how to make my 84 633 have a bit more low
end torque - its anemic now :-<). I get low compression on all cylinders,
and believe the exhaust valves got cooked as the valve clearance was way too
low when I bought the car, and they were probably not closing completely.

So, what I'm now looking at is the Metric Mechanic catalog. Since I think I
need a head rebuild anyway, I'm seriously looking at having MM do it and
also install their new 275 cam. They have a head rebuild which is more
extensive and adds compression, but they really don't recommend it for
engines with more than 100K miles and I have 120K. They spent time on the
phone with me and explained that I'd get more torque and horsepower with
the new cam, and given I'm going to pull the head anyway it seems like a
good deal.

Based on what I've read, the best thing you could do would be find a used
3.5L engine from a 1985 or newer BMW, and install it along with a Motronic 1.1
DME. I'm told this can be done, not quite sure about all the wiring changes
(when you get the motor you would need the harness going out of the DME
as the Motronics 1.1 has more wires and a bigger connector than the 1.0 did).
Maybe someone has done this and would post what is needed (I've asked about
this in previous postings with no responses).

I don't think Jim C has a chip for the 83/84 633. I've asked him twice, no
response. I hear you get a little more top end with the K&N air filter.
If you go with a 3.5L engine as above, you can get a lot with Jim C's chip for
the 3.5L engine (using Motronics 1.1). Motronics 1.1 "adapts" to older engines
whereas the Motronics 1.0 uses fixed tables based on new motor
characteristics.

MM also has lower restriction exhaust (no resonator), ported intake and
extake manifolds, and even higher performance engine rebuilds (which cost
a lot of $$$$s). They'll send you a catalog for free (I think), and its very
imformative on how BMW has engineered the various years cars.

Your car, like mine, came with a 3.22 ratio rear. I have put in a 3.46 Limited
slip, which give you better accelleration. You could even go to a 3.64 if you
don't do much long distance highway driving (if you do, the motor will seem
to "buzz" a lot while driving as you'll be turning at 4000 RPM at 70 MPH!).
You can find a 3.64 or a 3.45 LSD for $300-$400, and it only takes a few hours
to install. This is a great way to get more performance.

Good luck!

David Hoerl
84 633CSi