Programmable ECU or not

[allegro]

What is the power advantage of changing my ECU suplied by Caterham for a programmable one and having it mapped. How will this effect the cars performance and MPG.

 

I have a SLR and am looking for advise on this subject from other SLR owners who have made this change.

 

Thanks

Andy Mac

 

 

[Mike Bees]

There might be some small improvements to be made, but the value is questionable. The ECU you have has already been mapped to suit the engine. There's only really any point in changing it if you're going to make changes to the engine which require remapping.

 

Mike

[Peter Carmichael]

Depends on the vintage of the SLR. If it is mapped from the induction pressure (Rover MEMS) then you can get drivability improvements from an ECU swap to one which just uses a throttle potentiometer. However you will lose the compensation for atmospheric pressure, so the car will not cope with altitude changes as well.

 

These effects will not alter the power output by much. You will only get more power if the fuelling was _wrong_ in the first place or the advance was unnecessarily conservative, which with a VHPD would appear not to be the case. Careless mapping can result in fuel being p*ssed away without good reason, but the normal procedure is to fuel at around stoichiometric (14.7:1) for the majority of throttle range and then richen up for maximum power (about 12:1) at wide open throttle. You then get economical cruising operation and full power just a toe twitch away.