Expert: Dan Liddy - 7/13/2006

Question
Dan,

I am preparing a 1985 BMW 318i for the track.  Per the Technical
Data sheet, the car is equiped with a Bosch L-Jetronic electronic
fuel injection.  The engine the pistons are already  40 over and I
have a more aggressive cam.  In my quest for more power, I am
now turning to the ECU.  The only vendor that has a chip for this
car is Superchip, with a claimed 8bhp increase, for @$375.00.  
Considering that the car's claimed horsepower is 101bhp with
103 ft-lb of torque, an almost 10% jump isn't bad.

My Question:  Do I spring for the chip, or would it be more
beneficial to go with a fully programable ECU like an
Electromotive TEC-II or a Megasquirt?  It is my understanding
that I would have to place sensors all over the motor (crank,
intake manifold, etc) for these systems to work properly?

Your input would be greatly appreciated.

Regards,

Dave  

Answer
Hi Dave:

There are people that know more about BMWs than I do, but I can start you off I think.  

$375 for a computer chip sounds excessive, and I have heard a few horror stories about them (ECU meltdown)  Bosch FI is good stuff. All the old Datsun "Z" cars had it and they were rocketships , I had one that topped out at 160 in street trim, and beat most Camaros.

Depending on the group you're running with, I'd suggest a close survey of the preperation limits before investing in anything like an Electramotive control unit. In certain classes in SCCA it wouldn't be allowed.

As far as sensors go, there are plenty already there for the Bosch unit. Cylinder head temp, Water temp , crank angle, intake pressure , and mixture.  Most could probably be re-used and if not, the unit should have clear instructions as to what to do.  It would be a matter of plugging them to the new gizmo.

Since you're prepapring for the track, you could use the Electramotive crank-fire ignition arrangement.  I have it on one of my GT cars and it's pretty hot. I promise you will only grab a plug wire once when it's running. An illuminating experience! You will almost always find them at the front of the grid.

That's about all I can offer, I'd be interested to see suggestions you get from others though.  

Good luck!

Dan Liddy
Sarasota, Florida