Adjusting 1.6L intake

Brian5475E · Post by **Brian5475E** » Mon May 23, 2005 7:10 pm

I was wondering if there is a way to adjust the rpm that the intake manifold opens up the other chamber. I was wanting to fool with it on a dyno to see if I can pull some more power down low. Is it controlled electronicly

Audacity Racing · Post by **Audacity Racing** » Mon May 23, 2005 10:38 pm

i thought the etec swith was a vacuum operated thing...

BosnianLanos · Post by **BosnianLanos** » Mon May 23, 2005 10:50 pm

VGIS (Variable Geometric Intake System) I believe is vaccuum operated, as there is no kind of solenoid attached to the butterflys to get them to move.

The entire VGIS system is optimized from the factory so messing with it would be tempting fate. People have tried zip-tieing the butterflys in certain positions and they claimed "50% performance increase" but actual dyno testing has proven that only a drop in HP is noticeable.

Daewoos are some of the only "cheap" cars that come with VGIS and they are, again, optimized by Daewoo for the most low end torque and HP, I say don't mess with it, it can only bring trouble.

MMamdouh · Post by **MMamdouh** » Wed May 25, 2005 7:14 pm

the issue was raised before on other forums and the answer is always the same: NOT A GOOD IDEA.

MMamdouh

evilaveo · Post by **evilaveo** » Mon Jul 18, 2005 10:53 pm

Yeah I already messed with this. The vaccum reg is on the left of the intake amn, looks liek a fuel pressure reg, but it has a rod connected to it. Just look at the right side of the intake at the brass this and rev the motor from the throttle body to 4500 rpm and youll see it move. If you tie this rod up you'll gain bout 2-3 hp low end , then lose dramatically at top end- 10-20 hp. If you disconnect the hose, you lose 2-3 hp low end and gain max 4hp at top, once it hits 4500 it feels like a turbo/boost/ but it is actually the cam profile. Not worth a damn.

tango · Post by **tango** » Tue Jul 19, 2005 5:57 am

evilaveo wrote:Yeah I already messed with this. The vaccum reg is on the left of the intake amn, looks liek a fuel pressure reg, but it has a rod connected to it. Just look at the right side of the intake at the brass this and rev the motor from the throttle body to 4500 rpm and youll see it move. If you tie this rod up you'll gain bout 2-3 hp low end , then lose dramatically at top end- 10-20 hp. If you disconnect the hose, you lose 2-3 hp low end and gain max 4hp at top, once it hits 4500 it feels like a turbo/boost/ but it is actually the cam profile. Not worth a damn.

Toyota tried and ditched a similar system on its 4AGE years ago. It's good in theory but those buterflies only pose an overall restriction I say. When it comes to cars, there's no such thing as "no compromises". There has to be a tradeoff of some sort.