Acceleration: It's all about power to weight

["Greg Stapells" <gregs@xxxxxxxxx>]

Hi everyone,

I know this seems off topic, but what I'm about to describe has got me
thinking about selling my 96 328i and purchasing
an E36 M3.

I client of mine recently spun a bearing in his 91 Cavalier (3.1L V6,
140HP,2600lbs, Manual trans). Rather than rebuild the engine he decided
to swap it out with a similar GM V6 from a 1999 Montana (3.4L, V6,
185HP, 210ft-lbs - gee, sounds like my E36 engine, just .6L bigger! :)

I offered up my garage for the swap, and two days later, the engine swap
was complete, and his car was transformed.

Power to weight ratio before:

2600lbs/140HP=18.5lbs/HP

Power to weight ratio after:

2600lbs/185HP=14.1lbs/HP

approx. Power to weight ratio of US E36 M3:

3200?/240=13.3lbs/HP

My E36 Power to weight ratio:

3231/189=17.1lbs/HP

I took his car out for an extended test/thrashing and just couldn't
believe how fast it was! Now, I've been quite happy with the power of my
E36 328i up until now, but his C$3000 engine swap has got me thinking.
Hmmm, time for an E36 M3!

To be fair, I want to be clear on something. I am only comparing the
ACCELERATION of the transformed Cavalier to my car, not
the rest of the car!  The 1991 GM does not have the balance of the BMW
(brakes, suspension, handling, refinement, etc. etc).

I'm a firm believer that it's usually more economical to sell a car and
purchase the model you're after rather than try and build
it up.  Eg. E36 325/328 owners that turn their car into an M3 with an
engine/suspension swap.

So my question is this:  If you owned a 1996 328i and wanted to end up
with, say 200HP at the wheels (car dyno'd at 174.4)
what would YOU do?

- -upgrade the power train
or
- -sell the car and buy an E36

I apologize if this message seems way off topic!

Thanks for reading...

Greg Stapells
Signa Computer Systems Inc.
Toronto, ON
www.signa.com 

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