Setting up the variable length intake runners

Got a problem with your FTO? ask about it here

Moderators: IMC, Club Staff

Post Reply
User avatar
spetz
Oldtimer
Posts: 2812
Joined: Wed Mar 03, 2004 6:00 pm
Setting up the variable length intake runners

Post by spetz » Tue May 30, 2017 9:33 pm

Hi guys,

Just wondering if anyone knows the correct way to set up the variable length intake runners?

I took the motor part off and revved the engine past 4,500rpm and saw the worm drive move so I will assume that this means in resting state the runners should be set to long?

And I believe that their internal spring flicks them to the short position?

So then my assumption is that I need to install the motor at an angle (will play around to see the right angle) and then twist it to set the runners to long and screw it in?

User avatar
spetz
Oldtimer
Posts: 2812
Joined: Wed Mar 03, 2004 6:00 pm
Re: Setting up the variable length intake runners

Post by spetz » Wed Jun 28, 2017 7:48 pm

A bit of an update on this.
I ended up using a borescope camera down the brake booster connection on the plenum to check if I had set this up correctly.

The butterflies are spring loaded to be in the open position (ie, short runners).
However the little motor should normally be in the closed position (long runners) if the car was switched off and running properly.

So what you have to do is install the motor on roughly a 90 degree angle and then rotate it (along with the butterflies) and then screw it onto the plenum.

This will take a couple of goes as you want them to be in the fully closed position once you align the screw holes to the motor.

My speculation:
If this is done incorrectly I believe the ECU will understand this and will stop sending the signal to the motor to open/close and you will be able to extract error code 62 from the ECU.
I have nothing to base this on other than I believe this is what happened with my intake.

You should hear an intake noise change at 4,500rpm when the runners open up similar to but not as loud as the MIVEC switch over at 5,500rpm if this is functioning properly


Post Reply