FYI - I took all the engine covers to look around and to check that my Actuator was working. It is working but I discovered that it was not fully opening. Of course, this can only be observed with the covers off.
What happened was that the cable housing was not adjusted properly and the cable had too much slack, not letting the plenum open fully. It was just about 1/8 of an inch or less but that makes a difference in the amount of air going into the engine over a period of time.

Thought you'd like to know...

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2001 Silver CL-S

 

good looking

 

Hmmm... Wonder why a lot of the "stock" cars dyno differently.

Instead of just checking the actuator, now its time to check the actual actuation event!


I really wonder how many dealers would even think to do this (while they put on the third coat of lithium grease on the door hinges).

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Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (48lbs less than stock)
• Kevlar/SS Brake lines w/Brembos?
• Comptech headers & sways
• Silver AEM CAI
• 10 coats of Zaino magic

 

The plenum valve doesn't regulate any airflow into the engine persay. It does allow for air to move back and forth between each plenum end tank to help "charge" the plenum.

Secondly, there should be about 1/8" left between the stops when the valve is opened. Otherwise it is not parallel and opens too far possibly disrupting the transitions.

 

I think it's a good idea to first just remove the plastic cover [4 bolts] to visually check for actuation - only takes a couple of minutes to do!
Since most problems are with the actuator itself however, that really isn't neccessary for a visual inspection.

BTW: Per Acura Factory Service Manual -
Cable free play should be 1/8"+/-1/16"

------------------
Red
Type S
So. Cal.
Dark Tint
18" Niche Bella 2-piece
Forged Aluminum Wheels
235/40/18 Sumo HTRZ II's
Jet Performance PCM Mod
Ram-Air CAI w/ K&N Filter
Removed Pre-muffler
Liquid Glass Finish
G-tech 0-60 in 6.1 secs
...Looks & feels faster!

[This message has been edited by Ogolden1 (edited 05-23-2001).]

 

Have been wondering. Would it make any difference in power to mechanically keep the actuator open all the time, or open up earlier in the RPM range?

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'01 3.2 CLS-Stock (So Far)

 

Question was "offered-up" by syncivic as a pre-emptive strike.

If you leave it open you loose about 10-15hp or so below 4K.

If you leave it closed, you loose about 20HP in the top end.

I left a link to syncivic info in a comment below -- he did the tests.


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Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (48lbs less than stock)
• Kevlar/SS Brake lines w/Brembos?
• Comptech headers & sways
• Silver AEM CAI
• 10 coats of Zaino magic

[This message has been edited by EricL (edited 05-23-2001).]

 

Well, at least I have a Helms now...

I don't know how much air is moving in the constant-volume-split-plenum. I actually noticed that there are now engineering courses in Automotive Engineering that talk about Helmholtz supercharging. I didn't take that course (although I did a ton of acoustic design work -- years ago), so I don't know how the pressure waves are affected by the plates not being parallel to the ground (wide open).

I would think there would be a bit of speculation going on here as too how much power was lost or gained, and it would only be wise to comment if someone ran dynos with the plate fixed at different angles.

yes -- no ???

Since I have not had my hands on the "plates" (only the actuator), I can't comment on the play required inside the plenum.

Finally, I know that the system uses pulse timing to enhance the flow, but I wonder if there are 2nd order changes that occur when the plate opens and allows the "effective" flow path (or flow volume) (for a given cylinder) to change.



------------------
Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (48lbs less than stock)
• Kevlar/SS Brake lines w/Brembos?
• Comptech headers & sways
• Silver AEM CAI
• 10 coats of Zaino magic

 

According the the Acura tech info I was given: "In Low-Mid RPM operation when the plenum valves are closed and each cylinder bank is isolated, a resonance effect unique to V6 engines is established. The resonance effect creates waves of high pressure air inside the manifold, improving cylinder filling at low engine speed. The result is increased LOW RPM TORQUE."

Look at some of the dynos - there is actually a DIP in torque right after the plenum opens for 200-300 RPM. I would say that if you were to just tie it open, that you would lose a lot of low end torque!

------------------
Red
Type S
So. Cal.
Dark Tint
18" Niche Bella 2-piece
Forged Aluminum Wheels
235/40/18 Sumo HTRZ II's
Jet Performance PCM Mod
Ram-Air CAI w/ K&N Filter
Removed Pre-muffler
Liquid Glass Finish
G-tech 0-60 in 6.1 secs
...Looks & feels faster!

 

Hmmm... I thought I said that. But you are making me think I need to go back to learn how to write better -- I though I said that... Oh, well...

There may be more to this...


Here is the link and "hard data" from syncivic's earlier post.

link:

http://www.acura-cl.com/ubb/Forum1/HTML/004601.html

excerpt/quote from syncivic:

7. Secondary air valve worth 20HP at 6100 RPM but if pinned open will loose 10-15HP below the 3700RPM transition threshold...so don't get any bright ideas.

------------------
Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (48lbs less than stock)
• Kevlar/SS Brake lines w/Brembos?
• Comptech headers & sways
• Silver AEM CAI
• 10 coats of Zaino magic

[This message has been edited by EricL (edited 05-23-2001).]

 

I am not sure about the "1/8" left between the stops when the valve is opened" part from scalbert.
According to the Service Manual, there should be between 1/8 and 1/16 of an inch of cable freeplay. That's what I have now after the adjustment and the valve now opens fully.
I doubt that an engineer would leave such critical positioning of the valve to just a cable adjustment (which stretches) instead of a stopper in fully open position which will always be consistent.



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2001 Silver CL-S

 

Well, I think your on to something here. If as long as "flex" (as in a spring, etc) is not built into the system, there should be a bulletin or service note that requires the dealers to check free-play at various service intervals, in addition to actually checking the MIRC valve actuation.

Hopefully, they will get their act together, I only know my actuator works (since I checked it myself), and for all I know my butterfly could be only partially opening too.

I loath the thought of having to "be my own best mechanic again." I am willing to pay good money for good work.

------------------
Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (48lbs less than stock)
• Kevlar/SS Brake lines w/Brembos?
• Comptech headers & sways
• Silver AEM CAI
• 10 coats of Zaino magic

 

BTW, got the M & I reversed, IMRC (Intake Manifold Runner Control).

But unfortunately I feel that this might be the case when mentioning, "being your own best mechanic". Although my dealership responds to me well now after my IMRC issue last August. I wonder how far they take the 'in the shop' inspections. Do they take the time to look at little things while under the hood or just wait until someone complains to check something.

I know dealers work according to their guidelines, but personal attention should never be dismissed. Taking the time to look at simple aspects that you know could be a potential issue is the kind of customer service that wins the buyers into being brand loyalists.

For now I do plan on inspecting everything myself, but I don't mind since it gives me something to do while cleaning under the hood. But it should never be something I should have to do. I do play under my wife's hood but I know the dealer has never over looked something (so far) so it is not a demand on my part.

 

You are lucky -- when our "belts" were tightened on our Nissans at Universal City, I immediately noticed a noise on my wife's car. I told the service manager that I could hear alternator noise mixed in with some other rumbling. They changed the idler pulleys -- they were destroyed (I had to fight them over this). A year later, the alternator noise -- that they said I was dreaming about -- turned into a broken alternator -- I had to fight them to replace it).

They also over tightened the belts on my Maxima (at a service) -- I had the service manual, and knew the free play was way out of spec. I also had new pulleys installed a few days later, after I hear loud noises coming from them. Since the car was out of warranty, I had to FIGHT to get them to replace an idler for free. I though that I had won. No way -- I, then got a call about another idler that they wouldn't cover (the 2nd one of 2). I knew that if I didn't pay-up, they would just botch the job, and they were trying to "cover" their lost shop time.

So, I've been doing mechanical stuff for 30 years (now I'm really showing my age), and I am pretty disgusted.

I've had more stuff messed up in scheduled services than fixed -- that is the sorry luck of our car history. Sometimes knowing too much is a problem -- you KNOW your getting the shaft up the rear!

BTW -- I've been mixing up my acronyms of late -- Perhaps I'm dyslexic (I'll try and fix my MIRC - IMRC valve; it was N20 - N02 the other day)

------------------
Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (48lbs less than stock)
• Kevlar/SS Brake lines w/Brembos?
• Comptech headers & sways
• Silver AEM CAI
• 10 coats of Zaino magic

[This message has been edited by EricL (edited 05-25-2001).]

 

This reminds me: I had the _Honda_ dealer do the 1st oil change on my _Honda_ Prelude a while back. The #$%^s did not even put the right amount of oil. They were one quart short


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2001 Acura 3.2 CL TypeS -- White/Ebony, No Emblems
1998 Honda Prelude -- Black/Black, MN5