[Justin Daniels]

Not sure if this information is posted anywhere else, or if anyone even cares to know it, but I am curious about making a gearbox to adapt the valvetronic motor to be able to control a standard butterfly throttle.

To make this work, I had to figure out how many rotations of the valvetronic motor it took to rotate the eccentric shaft 180 degrees... the answer is 25 full revolutions, or 9000 degrees.

Since 9000/180 = 50
Therefore; 50 degrees of valvetronic motor rotation represents 1 degree of eccentric shaft rotation, a 50:1 reduction. This means that for every one degree of valvetronic motor rotation, the eccentric shaft rotates .02 degrees.

For my needs, I would need a gearbox where 9000 degrees of rotation equates to 90 degrees of (100:1 reduction).

Not sure if this is useful to anyone, but I searched and couldn't find it so maybe someone else will do the same!

[rjahl]

You do realize the N52 has a regular throttle body and the logic to make it work?

There is a failsafe logic that forces the VVL to full lift and then utilized the throttle body like a normal car.

[Justin Daniels]

Originally Posted by rjahl

You do realize the N52 has a regular throttle body and the logic to make it work?

There is a failsafe logic that forces the VVL to full lift and then utilized the throttle body like a normal car.

I'm aware. But I'm assuming that failsafe logic would affect other systems such as DSC, no? Or does this failsafe logic happen seamlessly to the driver other than a DTC being stored? Admittedly, I was totally going down one path and neglected to consider the failsafe use of the butterfly throttle.

Anywho. If it's useless information it's useless information. At least it's out there if someone wants it eventually!

Edit: I noticed you had mentioned in another thread that power reduction occurs along with a lowered rev limit, though other systems all function properly. I wonder if the DME, calling for reduced rev limit, would have a fit if it saw this limit exceeded?

[rjahl]

Originally Posted by Justin Daniels

I'm aware. But I'm assuming that failsafe logic would affect other systems such as DSC, no? Or does this failsafe logic happen seamlessly to the driver other than a DTC being stored? Admittedly, I was totally going down one path and neglected to consider the failsafe use of the butterfly throttle.

Anywho. If it's useless information it's useless information. At least it's out there if someone wants it eventually!

Edit: I noticed you had mentioned in another thread that power reduction occurs along with a lowered rev limit, though other systems all function properly. I wonder if the DME, calling for reduced rev limit, would have a fit if it saw this limit exceeded?

Whatever faults or fail safe this triggers, they would be far easier to fix than trying to reprogram the VVL to activate a throttle body correctly.

When I was playing with the VVL limits, I set the system into failsafe and never noticed. With the E85, I had no error in the dash and the opportunity to push it past 6500 never presented itself on that day.

The give away was a slight rush of air going into the intake during a throttle blip. Should never have that kind of intake manifold vacuum when the system is working correctly. Very little sound proofing on the E85, too heavy.

On the other side of this conversation one needs to ask, why would you lock out the VVL? It works really well. ITBs for a race car, maybe but that conversation has already happened.

[Justin Daniels]

Originally Posted by rjahl

Whatever faults or fail safe this triggers, they would be far easier to fix than trying to reprogram the VVL to activate a throttle body correctly.

When I was playing with the VVL limits, I set the system into failsafe and never noticed. With the E85, I had no error in the dash and the opportunity to push it past 6500 never presented itself on that day.

The give away was a slight rush of air going into the intake during a throttle blip. Should never have that kind of intake manifold vacuum when the system is working correctly. Very little sound proofing on the E85, too heavy.

On the other side of this conversation one needs to ask, why would you lock out the VVL? It works really well. ITBs for a race car, maybe but that conversation has already happened.

I would not be reprogramming the VVL motor, I would be using the motor with a gear reduction box to modulate a normal throttle body. This was a thought experiment relating to a drive-clean friendly engine swap. I would run whatever sensors from the N52 I could on the swapped motor, stimulate whatever sensors I couldn't, and use the N52 valvetronic system to actuate a throttle to make it a more seamless install.

Since then, our drive-clean program has been scrapped and this isn't AS big of an issue, bit I still like the idea of simulating/stimulating sensors for the DME to keep it happy when another engine is actually in the place of the N52.

Thanks for the info.

[hassmaschine]

There are many, many reasons why this would never work.

But mainly, if you're swapping in a different engine, you're not going to use the stock computer anyway. Throw it in the bin because it's never going to do what you want.

It's way easier to mock CAN messages to keep other modules happy, than it would be to totally reverse engineer the VVL algorithm. In fact there are many products that already do that using cheap commodity hardware like the Arduino.