VICS Sucks!!!!

[TurfBurn]

Well actually... it makes a BIG difference and a positive one at that... see the discussion below...

So here is the deal.. just dynoed today.. here is a graph of nearly back to back runs of about 8.5 9 psi... the high curve is with the VICS not being closed (the butterflies close when the actuator is activated.. if you don't activate the VICS actuator the butterflies stay open). The lower one is with VICS butterflies open until 4500 rpm's, then closed... the opposite of how stock cars work.

Now the terrible horrible ugly ass curve bounce you see is from my Boost controller freaking out. We fought with it all damn day... only got a few actual clean runs because of that... so here you go...

(the boost bounce was from 7 to 9 psi.. I have a log from the Microtech for it if you guys want to see that in excel format.)

EDIT: No timing changes made between runs... also added another graph showing AFR's.

Mazda VICS performance off the stock ECU with the butterflies held closed at low rpm's and opening at hight rpm's... but if you are driving a relay from an EMS.. you want to "de-activate" the VICS butterflies for the most power at the top end.

 

[LinuxRacr]

So if I disable the actuator, I can keep my VICS from kicking in?

 

[TurfBurn]

So if I disable the actuator, I can keep my VICS from kicking in?

Yep... but it "kicks in" below 5200 rpm's, so disabling it leaves the butterflies open the entire time. normally they are closed below 5200 rpm's.

EDIT: edited for clarity

 

[TurfBurn]

here is another set of graphs... this has the AFR's on there so you can see how consistent that was.. the only factor that changed between these two was the VICS...

 

[mp3moose]

And how does one deactivate the actuator?

 

[LinuxRacr]

here is another set of graphs... this has the AFR's on there so you can see how consistent that was.. the only factor that changed between these two was the VICS...

Yep, I noticed on the runs indicated in green that your A/F ratio dropped considerably as did the power. Am I correct in assuming that the VICS were activated on that run?

 

[LinuxRacr]

Yep...

It escapes my memory as of now, but is this a vaccum-activated actuator?

 

[TurfBurn]

And how does one deactivate the actuator?

simply remove the vac hose from it and the solenoid... you can plug the hose, or unplug the solenoid.. that should do it. (i activate it and de-activate it with the microtech... so that's how I could turn it on and off for the runs)

 

[TurfBurn]

It escapes my memory as of now, but is this a vaccum-activated actuator?

Yes... it's the higher mounted one of the two if you have VTCS i believe.

 

[TurfBurn]

Yep, I noticed on the runs indicated in green that your A/F ratio dropped considerably as did the power. Am I correct in assuming that the VICS were activated on that run?

yeah it is the green run... the AFR's were actually leaned out considerably in the maps... but the airflow was so crappy that even that wasn't enough leaning out and the AFR's still crept rich.

 

[BlkZoomZoom]

Those graphs make no sense....

VICS butterflies are normally closed when driving, they open up at 5200rpm. They do not close at 5200rpm. How do you get less airflow above 5200rpm if you get the same amount of it if you disable the system?

 

[TurfBurn]

Those graphs make no sense.

Why do you say that?

Simple as this... I did 4 or 5 runs in a row... 2 without vics butterflies being closed at all.. then 1 or 2 with vics closing the butteflies at 4500 rpm's and up and then more without. I had it set to turn on at 4500 rpm's (applies vaccum to the actuator and closes the butterflies making for shorter runners at higher rpm's). I made no changes in timing or boost levels. Only in fuel to compensate for the air flow difference with and without the vics... My intake manifold has been ported and polished so there is an off chance it made a difference... but doubtful.

 

[TurfBurn]

Those graphs make no sense....

VICS butterflies are normally closed when driving, they open up at 5200rpm. They do not close at 5200rpm. How do you get less airflow above 5200rpm if you get the same amount of it if you disable the system?

So the actuator is normally pulled on during normal driving? So every time you start the car the actuator pulls in? Because in the 'at rest' position, the butterflies sit open. So for them to "turn on" the solenoid has to be activated which then closes the butterflies... so why would Mazda set it up that the solenoid would have to be activated all the time? That's bad for the solenoid and a risk for reliability... so I may have misunderstood the VICS operation, but I don't have a stock ECU to work off of...

EDIT: I did misunderstand... BZZ corrected.

 

[BlkZoomZoom]

You got it backwards buddy, they open at 5200, not close.

 

[BlkZoomZoom]

Ever wondered why they are fed by a vacuum chamber and not directly off the manifold?

 

[TurfBurn]

You got it backwards buddy, they open at 5200, not close.

I just re-read the manual... and I see how I misunderstood when it turned on and off with the stock ECU... so then there you go... VICS system does it's job

EDIT: but you DON'T want to close them at higher rpm's. Opening them sooner than 5200 you can also see may be beneficial assuming the small increaes in power between 4200 rpm's and 5200 rpm's is due to the being open and not due to a boost difference which it may very likely have been.

 

[BlkZoomZoom]

You more than likely lost some torque down low because the way you had it set-up. lol

 

[TurfBurn]

Ever wondered why they are fed by a vacuum chamber and not directly off the manifold?

Never had thought about it.. the thing that hung me up was that the solenoid would have to active the entire time.... I assumed that activating the system meant activating the solenoid... that's what I got backwards... but the graph does show where it is good to have it open and not for peak power.

 

[TurfBurn]

You more than likely lost some torque down low because the way you had it set-up. lol

well if you check out the dyno thread you'll see I still had plenty of torque ..

it's one way to help kill some low end wheel spin then ... so there you go.. deactivate VICS for improved traction

EDIT: Statement about killing wheel spin based on general understanding in community and BZZ's quoted post that not having the VICS butterflies closed at the low end will cause a loss in torque.. no dyno graphs of mine, or any known ones on the forum show this though.

 

[TurfBurn]

BZZ... thanks for the catch and the polite correction. I appreciate it! At least the title will get people to come in and look now