MJLJ output used for boost control?

[ribs]

I just ordered all the parts for the megasquirt and megajolt lite jr. today, and have been reading up on them and playing around with the software for both all day. I noticed that the MJLJ has 4 programmable outputs for which one can control fans, intercooler sprays, etc., based on either manifold pressure or RPMs.

I am pretty new to the MR2 thing, but have been sticking wrenches in my 944 turbo for a few years now, and the way the stock ECU controls boost with that car is with a solenoid that cycles a valve hooked up to the wastegate to bleed pressure to the port, effectively bleeding boost (I think it is pretty much the same as the VSV off of the 3S-GTE...).

So...anyone know if one of these stocker boost control systems could be adapted to run off of the MJLJ, to give a ghetto-rigged electronic programmable boost controller? Anyone ever explore this avenue before? Thanks.

[brentp]

Hi,

I tried using one of the outputs as a boost controller. the main problem is that since you need to reference the boost right at the manifold, i.e. as close to the engine as possible, you will have a big delay in response which will not allow it to correct fast enough.

As you may know , there is a bit of delay between the output of the turbo and the intake manifold, and the boost pressure at the turbo will ususally be higher, especially with an intercooled setup.

Ideally you'd want a dedicated controller to regulate it based on the boost pressure right at the turbo. Most turbos have an boost reference port that is used just for this purpose- usually it's connected straight to the wastegate actuator.

Good luck,
Brent

[KingArthur]

Have you thought about starting a boost controller. Call it MegaBoost. I bet it will go well.

[brentp]

That's something I am considering.