Crank sensor signal mod

[Dick Protus]

	I was wondering if anyone had ever modified the output signal of a
crank sensor to make it work with an ecm that was expecting a different 
sensor/wheel combination?

	Here's a little more info if you're interested:
I have a Honda CBR600 F3 motor in an mini formula style car (FSAE car).  The
engine normally is carburated and has a distributor less ignition, right now
it has been converted to turbocharged and efi.  The problem is that I had to
replace the stock crank sensor and wheel( 12 -3 toothed) with the efi's 
(electromotive) sensor and wheel ( 60 -2 toothed).  My current setup works but
is a pain to deal with.  
	This engine has a few interesting features, 
1) 4-stroke, 4 cylinder, dohc -> so I can use a efi system made for 4 cyl. car
2) the crank shaft doesn't poke out of the block since the transmission is also
   packaged in the block-> the crank sensor wheel is mounted to end of crank,
   but under a side cover that needs to be sealed.          
3) The rotor of the alternator is mounted to other end of crank, under another
   side cover.
The biggest pain is that the efi's sensor wheel won't fit underneath the stock
engine side cover.  I have a custom fabbed one that is plain old ugly and
plagued with oil leak problems.  I also tried extending the crank shaft through
the side cover with a seal around the shaft, but I could find anything that
could hold up at 13,000 rpm.

This all boils down to: I want to use the stock crank sensor but convert its 
signal to work with my efi.  The efi's wheel has a lot more precision (60 -2)
than the stock (12 -3) wheel, but I was wondering how important that precision
was, or if they went to 60 teeth to make the math and degrees work out nice.
Also, I have the option of using the frequency of the three phase voltage from
the alternator as a speed indicator.  (wouldn't suffer from any kind of belt 
lag or slipping since its mounted to the crank) 

Am i crazy or can this be done?

Dick Protus
GT Motorsports
404-894-3222
djp at comlab.gtri.gatech.edu