Butterfly Valves Open or No? Dyno Proven

[Paul]

Ok, so some of you may remember my thread about keeping the butterfly valves open or not.
Well I was going to have the car dyno'd and figured I would try it each way.
I don't have the chart with me, cuz i'm at school right now but here are some numbers.

My only mods on the car were basically a Corksport exhaust and a Front Motor mount

With the butterfly valves held open
145whp
With the butterfly vavles working normally
159.99whp and i believe 157tq

So my mistake for thinking the car would have more balls w/ them open.
What do you guys think of these numbers for an exhaust only?
I'm extremely happy with these results.

 

[Super Matty P]

sounds good to me...I'd like to see the graphs though...peak numers mean very little if they are spikes. It's the curve and the area under the curve we wanna see improve.

 

[Paul]

ok, i'll take some pics of the graph when i get off of work

 

[BlkZoomZoom]

Makes no sense at all. The butterflies are open above 5200 rpm anyways. I don't see how your peak numbers changed. Unless you are talking about VTCS and not VICS.

 

[MetalSpeed]

???subscribing?????

 

[JCell]

^^ same here, interested

 

[Paul]

Makes no sense at all. The butterflies are open above 5200 rpm anyways. I don't see how your peak numbers changed. Unless you are talking about VTCS and not VICS.

well i'm not very familar w/ this motor so i don't know which ones they are exactly.
it's what the solenoid on the passenger side of the intake manifold holds open.
is that the vtcs or the vics? what is the diff of each?

 

[BlkZoomZoom]

They are both actuated by solenoids on the passenger side of the motor. They are right next to each other. The VICS and VTCS are both located on the upper half of the intake manifold and are actuated by vacuum supplied through said solenoid valves. The VTCS is a tumbler valve at the end of the intake manifold right next to the head. The VICS is right in the middle between the upper and lower intake manifold halves. The VTCS basically blocks airflow to the motor to decrease cold start emissions. The VICS changes the plenum area for the motor.

My bet is you left the VTCS closed for the one run.

 

[Dr.Sound]

^ resulting in better air flow.

 

[Paul]

yep it was the one on the intake manifold.
there was a big debate about this on the sentra board when i had my spec v.
people w/ the turbos took them out so i thought it might help on the mazda.


but anyway how does 159.99 sound w/ a exhaust only? is that low?normal? or high?

 

[Paul]

this is the best copy i could get, my scanner sucks
http://www.msprotege.com/members/Paul/dyno0012.JPG

 

[Dr.Sound]

normal

 

[Paul]

so where should i be when i get my fmic/intake?

 

[BlkZoomZoom]

^ resulting in better air flow.

No resulting in lower airflow, thus the lower numbers. You should have left the VICS open on one run instead of the VTCS.

 

[Paul]

No resulting in lower airflow, thus the lower numbers. You should have left the VICS open on one run instead of the VTCS.

that's the one i did. the seloniod in the middle of the upper and lower intake manifold.

 

[Dr.Sound]

No resulting in lower airflow, thus the lower numbers. You should have left the VICS open on one run instead of the VTCS.

wait, i thought he left the vics open....
but u're right Blk, i just confused.

 

[CommieSpeed]

If there was a smiley that indicated "info going over my head" I would use that now. Hold on, maybe I can express myself with these: (confused) (scratch) (stoned)

 

[BlkZoomZoom]

wait, i thought he left the vics open....
but u're right Blk, i just confused.

At first I did too. however the numbers only make sense if he left the VTCS closed for one run.

 

[MetalSpeed]

those look like pretty good numbers dosent seem to being running too rich or too lean. And your car is all stock?

 

[MetalSpeed]

I wonder how other mods will alter the dyno? for you.