Move crank position sensor for performance?

[RABID_MP5]

There have been attempts to fake out the ECU for performance, e.g. the intake temp sensor "chips" out there. What if you moved the crank sensor so that its apparent TDC was actually like 3 degrees BTDC? Get MP3-like performance etc.

What reasons are there why you can't do this? I realize the injectors would be a little early too, but probably be OK.

 

[Installshield 2]

Its been discussed, albeit many years ago...It wasn't by moving the sensor, but changing the teeth on the crank pulley to 'fake' the crank's position...

There isn't really a problem with it...but you won't be able to do much with it, for reasons you said...you'll quickly get injector pulses out of sync with the intake stroke (too early, and it'll get sucked right out of exhaust valves at the beginning of the intake stroke)...giving a lean mixture, which is far from what you want with advanced ignition timing...

its also a little more complicated for fuel and ignition timing...the problems i vaguely remember was that it also messed up triggering with the cam position sensor, and you'd need an adjustable cam gear to compensate for that...or something...as i said, this was like 2004...The computer in the car doesn't have a fixed amount of ignition timing, it changes between limits depending on multiple conditions...and this 'fixed' adjustment to the crank sensor wasn't completely implausible, but only allowed very marginal adjustments over stock...

I just mean you could advance timing a few degrees (not even as high as an MP3 ecu, which is more like 8 degrees in some cases iirc)...but barely more than simply using extended plugs, and with a ton of custom work...considering you can have a stock ecu flashed to mp3 settings now for $150 by a forum member, i can't really see the value in messing with the crank sensor...

 

[pw~mp5]

If the injectors are not sequential (I think they are banked), the timing is not super critical. As far as the fuel getting sucked out the exhaust, the valve timing does not change, this would be an issue with the newer direct injected engines.

The reflashed ECU is a simple and low cost solution for those with manual transmissions. Those with automatics will need a different ECU like the Haltech Platinum Interceptor or Megasquirt which allow you to advance timing.

 

[Installshield 2]

If the injectors are not sequential (I think they are banked), the timing is not super critical. As far as the fuel getting sucked out the exhaust, the valve timing does not change, this would be an issue with the newer direct injected engines.

The reflashed ECU is a simple and low cost solution for those with manual transmissions. Those with automatics will need a different ECU like the Haltech Platinum Interceptor or Megasquirt which allow you to advance timing.

Ah ok. I can't remember how the factory triggering works with which sensors...I was meaning if the injector pulses would change with the changes to the crank position sensor, you'd 'advance' fuel injection AND spark...meaning they pulse when the exhaust valves haven't yet closed at the very beginning of the intake stroke (and exhaust vacuum would pull it out)..even though valve timing hadn't been changed, the triggering could effect that...but i'm not sure...

I also can't remember if the stock proteges have sequential either...I'd guess they would, as its better for emissions and these are U-LEV cars from the factory...but not positive. By banked you mean like double pulsing? or Bank to Bank/paired injection? I've often heard that as 'batch' fire. i'm unaware of the specific duty cycles of our fuel injection. You may be right though, as often batch fire is used with wasted spark ignition systems...which we do have...so who knows...

 

[pw~mp5]

Batched is the correct term, all injectors or a group (bank) of injectors fired simultaneously versus sequential where they are fired as the intake valve opens.