e-throttle as blow off / bypass

[ST205]

Hi,

We have a racing engine (700hp / 2.0L / twinscrew compressor) with a mechanically controlled by-pass valve.
We are revising the complete engine / electronics and like to use a 40mm electronic throttle instead of the mechanical by-pass valve.

So, we're planning on using the current Tps as input(Aps) for the E-throttle.
Meaning the new Tp main (e-throttle) can not be used as acceleration input.
Since this little beast is really sensitive on acceleration we're in doubt of using solely Map for acceleration.

We would like to know if there is an alternative setup in PcLink (still using new Aps as Accel input)?
And if there are other factors which we overlook?

Thanks:)

[koracing]

Is the actual engine throttle still a mechanical throttle?  If so, you're planning to try and use that throttle position as an APS input for the e-throttle to control the 40mm electronic bypass valve?  I don't know if that will work since the e-throttle requires 2 TPS inputs, and 2 APS inputs (main and sub). 

How much do you really want to vary the electronic valve open and closed?  Does it need to be progressive or more on/off given certain thresholds?  I don't know if there's a clever way to drive an H-bridge two pin push/pull setup in the Link via PWM output alone.

[ST205]

The actual engine throttle are 4 Itb's (mechanical). Yes, we're planning on using this as APS input. 2 "APS" inputs can be created by using a dual output sensor (variohm). The bypass valve should be controlled in a progressive manner.

[Adamw]

Yeah I dont think that will work well without the main TPS assigned to the sensor that is on the ITB's.  Accel enrichment, lockouts and delta's for many functions like knock control etc all require TPS.  There are plans to add a generic H-bridge control function to the ecu and I have just started on documenting it so you could consider it in-progress now and I think it shouldn't be a major job to add from what I have written so far.  I dont want to make any promises on behalf of our firmware team but my initial feeling based on similar jobs and the workload I know of at present, it might be available in a month or so.  

Otherwise you could probably find a robotics/hobby motor controller that will take a PWM aux and convert it into a CL motor position control.  

 

[ST205]

Thanks Adam! That was the answer I was looking for .
Apologies for the late reply due to illness.

I'll try and hold the situation as is for now(mechanical bypass) and will inquire again in a month or so.
I think this generic control will come in handy also for controlling true variable intake trumpets.

[ST205]

I was wondering if there are any updates regarding this subject as our client still wants to utilize the dbw Unfortunately, I didn’t see related changes in the last software update (13dec)