Hi All,

I am figuring out the wiring on a 2001 ZX12r and was wondering if there will be any harm caused if the neutral wire to the ECU is permenantly grounded. Not sure if a lack of neutral will stop the engine starting and/or affect the engine map applied.

As the ECU has knowledge of the gear position, is there any gear dependency on engine map at all with this motor (i.e. is it better to fool it that it is in 5th gear etc).

Cheers

Paul

answer to q2 is no is does not need fooling in to thinking its in 5th but gsxrs do

Thanks for reply

Anyone know if engine will start OK in any gear if all the other interlocks are defeated (tip over, side stand etc).

- Paul

Paul,

the engine maps built into the ECU are gear dependent.

A Bonneville Box is available for the A2 (2001) model ZX12R which overcomes the 186mph restrictor built into the ECU in sixth gear. Apparently, you can also do this by wiring sixth gear into fifth but of all the bikers I know that have done this, none have proof that it works. Some say it feels faster, others say it doesn't.

In the real world, a Bonneville Box fitted to an engine in a kit car will give you maybe an extra 10mph max, when you’re flat out in sixth. Now I don’t know about you but apart from a run on a dyno at Holeshot, I have never seen 12,750rpm in sixth gear. Even if you had the box fitted, you’d probably run out of straight road before its effects were felt.

With regards to neutral, we couldn't figure out a way to overcome it and therefore our engine will only start whilst in neutral. We initially thought that this may be a problem but to date it hasn't been an issue.

Phil

Hi Phil,

Thanks for the info. I do know of some cars that start in gears other than neutral so it will be interesting to find out how they have done it.

As I am building a race car for next year I will hopefully be using full beans in 6th (it will be geared that way to maximise performance) so making sure there is no restriction in 6th could be important. I had an impression this was more of an issue of later models of this engine - I could be wrong though.

I'll have a further sniff around with some other contacts and see what they come up with. I'll report back

Cheers

Paul

Paul,

just for info, the only ZX12R engine that was derestricted as standard, is the original A1 (2000) engine. All other models are restricted. The Bonneville Box is available for 2001 to 2003 models to derestrict the limiter in sixth.

The engines were upgraded in 2004 and included revised fuel maps and secondary throttle blades. The Bonneville Box isn't available for 2004 models onwards.

There is a rumour that the first three gears on the ZX12R have a retarded timing map, which can be overcome by wiring the first three gears into fourth. If you want to give it a try, I'm sure I have the instructions somewhere.

Phil

Hello,

You can start it in all gears i've you use the clutch switch,

I wired a microswitch to my clutchpedal that way i can start it in every gear....

This is the info I have found out for the A1 ECU (it seems my 2001 engine is actually a 2000 spec one)

As long as you defeat all the other interlocks (which you can do by grounding the Green/Black wire to the ecu) you can start the engine in any gear. It is certainly possible to just ground the wire that indicates to the ECU that the bike is in 5th gear and it will start no problem, giving you the full power map.

It also looks as though it will be dead simple to make a gear indicator given that the gearbox gives you a dedicated line that it pulls to ground for each gear.

Rest seems simpler than the R1 I have wired before (famous last words).

Thanks for the inputs chaps

- Paul

Hello,

On this website http://www.pellgenesis.com/May-04b.htm

There's a gearindicator in the page, it's easy to build and cost about 10 pounds or so.
Daniel