Boost referenced timing retard...Anyone ever do this?

[Lupo]

I was thinking of a system we could use that would automatically retard the timing based on boost pressure; something that is not a complete replacement for the EEC4.

As anyone who tunes know, the WOT spark curve is static, which is a PITA if you change the boost levels, or boost levels fluctuate by design, or otherwise.

A couple solutions I have been thinking about:

1. Eliminating WOT functions, especially WOT fuel and spark. Leave all timing and fuel to the tables. You would have to modify them of course, to reflect loads greater than 100% (i.e boost). But would the size of the tables give you enough "resolution" for the car to run good from 0-200%?


2. A physical solution, that simply retards timing per each pound of boost it senses, something that can be put in between the ECU, and coil. I think this would be a pretty ideal solution, as you set the spark for a normal aspiration, and any boost is taken care of automatically....


And it would be cool if you didn't have to replace the whole ECU system, like a megasquirt or something..
I am dreaming?
Has anyone ever tried this, or have any suggestions?
I am going to start looking around for possibilities, and I thought I would start here first.

 

[SHOspazz92]

I mean....Boost levels should stay stay the same at X RPM in any gear with the blower, correct? With that being said...why wouldn't you just Datalogg boost numbers and adjust the WOT Spark Table off of that?

-Sam

 

[Lupo]

They should stay the same with a S/C setup, but I am thinking more in the lines of a turbo setup. Something with a dial-a-boost.
But it would save you the trouble of trying to datalogg every time something changes in the setup, or anything that can affect boost, like altitude changes, etc...

It would be nice to set the timing once, and forget it.
But for this exercise, I was thinking of a turbo setup.

 

[yamahaSHO]

That would be nice to do, however, the ECU does not have a great deal of resolution for this. I can say that even with a good setup that does allow enough resolution, I still data log whenever I do some [new] change to the boost. You still cannot set it once and forget it unless you would like to go through all those variables in one shot.

 

[rubydist]

you can still set it so that it never goes to WOT, so it will adjust the spark advance based on the load, in which case you still have your ability to change the advance based on the amount of air flowing through the mafs which is proportional to boost and rpm.

 

[yamahaSHO]

Yes, but the resolution of load vs RPM is very limited in the stock ECU.

 

[Phoenix]

If this was possible , you could introduce anti-lag

 

[yamahaSHO]

For what, breaking more transmissions and axles? Or just spinning after shifts or off the line (launch control)?