Hitchcocks Forum

How sensitive is the ECU to a silencer change? I don't mean a purposely made silencer for the ECU, but an off the shelf one, will the bike run ok or will the settings need to be changed? If changes have to be made how is it done is there a download program similar to Triumphs? or is it a visit to the dealer? I recently saw an Enfield with an AJS/Matchy type silencer and it looked really good so much better than the stock abortion thats fitted.

Hi RoSy... not sure but Hitchcocks have at least one aftermarket silencer which is designed to work well with an unchanged ECU. They alsonsay that the powercommandrr unit is needed for other silencer changes.

BTW the free-er flowing aftermarket ones cause some backfiring through the exhaust, so I suppose the ECU isnt great at correcting even minor differences

Well, Hitchcocks sell a Goldie type with a removable baffle for EFI models. That would almost no silencing at all so I would think, if the ECU will cope with that, it will cope with just about anything. As silencer choice has very little effect on carburation (or in this case, injection) I would you'll be fine.

Michael, backfiring in the exhaust on over-run is usually associated with air leaks in the exhaust system. It shouldn't happen with injected engines as the injector should shut down completely on the overrun unlike a carb that never does.

Hi RoSy, the Enfield runs a closed loop EFI system so it will automatically adjust for any new exhaust you fit.

With regards to Alaine Fontaines programme, neither his or any other system currently available is able to write to the ECU.

Personally I'd opt for a cheaper and very simple setup that adjusts the output values from the Lambda sensor so the ECU constantly trims the AFR to say 13.7:1 instead of the [anaemic] 14.7:1 it is currently set for.
This would increase Torque across the whole of the rev range (see link) instead of moving the majority of any increase further up the rev range. It would cope with the pre planned increase in Ethanol content whereas the PCV would ideally run a new map to fully compensate with this or any other change.

http://www.endtuning.com/images/airfuel.jpg

ric, You say "I'd opt for a cheaper and very simple setup that adjusts the output values from the Lambda sensor so the ECU constantly trims the AFR to say 13.7:1 instead of the [anaemic] 14.7:1 it is currently set for" how is this achieved? Thanks.

Can ric explain what on earth he's talking about!

+1 on that !