Electronic Bi-Modal Valves

[stooge]

Stooge are you saying that lmoengnr is claiming to have added valves to DPE non-bimodals to make them louder? I assume that he added valves to quieten the DPE's down and that's what I'm responding to. Of course adding valves to a stock muffler won't make them louder or increase flow, it's a no brainer that I'm sure most would have the intelligence to work out for themselves. As far as making a stock muffler louder, requires you to chop it up and reconfigure the internals or fit a different less restrictive muffler.

Show me where I've recommended fitting valves to stock non-bimodals to increase flow and noise. Post that statement from me and we'll continue the discussion.

@ lmoengnr, did you fit valves to your DPE's to make them louder or to quiet them?

see you "assume" a lot lol

my first comment was not to lmoengnr but when lmoengnr posted that they had done it and to ask their neighbours i could see that he was talking about making his "quiet" and that is why i didnt continue with him again because i can gauge the context of a conversation and i was not talking about the valve not making the exhaust quieter.

also lmoengnr was not asking a question so i am not sure what straw you are going for there but it does not support your incorrect assumption.



show me where i said that adding a valve to quieten the muffler will not work?

i said that "because a non bimodal muffler has no straight through pipe adding a valve will have little effect", its a no brainer to see that i was talking about making them louder because of the missing straight through pipe.

i am sure in your 43 years of dedicated exhaust surgery that you would know what a straight through pipe does but you seem to not have the ability to workout when someone is talking about adding a valve without the straight through pipe is in reference to increasing the noise.

like i said you have the doctorate in exhaust technology so do the test and show me where adding a valve to a muffler with no straight through pipe has a substantial effect on increasing the volume.
i am honestly curious to see if you can do it because without the straight through pipe i just cannot see how blocking 1 outlet could give a volume increase.

 

[lmoengnr]

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@ lmoengnr, did you fit valves to your DPE's to make them louder or to quiet them?

Make them quieter, basically kill the resonance during a cold start in the garage.
It would make hanging pictures on my walls dance around, rattle a couple of window panes, but mostly to stop the windows buzzing in my elderly neighbors bedroom. Which is more than 10 meters away from my Maloo exhaust.
I have to wind the gain right up on my home theatre sub woofers, with test tones, to get the same effect...

I agree with your points about the VF2 factory system, it is a bit raspy. At least it sounds like a V8, compared to my Redline.
One day I'll fit up the Maloo 325kw headers, cats(euro 4) and 2.5" H pipe mid section to the Magnum.

 

[lmoengnr]

i said that "because a non bimodal muffler has no straight through pipe adding a valve will have little effect", its a no brainer to see that i was talking about making them louder because of the missing straight through pipe.

I apologise if I've upset anyone, but the above statement threw me. I can now see you meant Holden mufflers.
As the Difilippo mufflers are standard without bimodal valves I assumed you meant all mufflers.

 

[stooge]

I apologise if I've upset anyone

i dont think you have upset anyone.

 

[RevNev]

the above statement threw me. I can now see you meant Holden mufflers.
As the Difilippo mufflers are standard without bimodal valves I assumed you meant all mufflers.

That's how I read Stooge's response too, meaning that a muffler must have straight pipe inside to be bimodal capable and they don't. You nominated the DPE muffler where consequently, the Holden bimodal design isn't relevant in the event of adding valves to a DPE design.

 

[pcp20us]

Feeeecccklkkkk.

Iam never getting bimodals now. Everytime i flick the switch for , " Fully sick commodore mode", Id think of you two having an online barney... I tell you that C word has a lot to answer for. online translation, you gottas love it.

All good, I just go and drop a Shite load of cash on a SS and be done with V6's....

Holden on

 

[RevNev]

like i said you have the doctorate in exhaust technology so do the test and show me where adding a valve to a muffler with no straight through pipe has a substantial effect on increasing the volume.
i am honestly curious to see if you can do it because without the straight through pipe i just cannot see how blocking 1 outlet could give a volume increase.

Stooge I've said more than once, the blocking of a pipe refers to "quiet" mode only, not loud maximum flow and performance mode. Please, do yourself a favour and acknowledge that a bimodal has two equally important functions to change modes from quiet to loud at the flick of a switch.

If you're making a bimodal muffler first and foremost, you configure the flow rate and desired noise level with the valves open and that's your base muffler. Then you work out how to redirect exhaust flow to quieten it with the valve closed without disrupting your base muffler in loud/performance mode. You don't configure the muffler's noise level with the valve closed then work out how to increase noise and flow with the valves open.

You could use straight pipe as Holden did for loud mode but as we know, muffler deletes on VE/VF's typically sound sh*thouse with a lousy note, so I wouldn't configure loud mode that way. I'd incorporate muffling in loud mode to get a decent note. In most cases of mega loud VE/VF's with good notes, they're typically 100 cell cats or catless with no midpipe resonators and rear mufflers only, so you can get them loud enough retaining a muffled bimodal. Straight pipe or muffler bypass will never sound good in loud mode.

I'm mystified how you've perceived that anyone has claimed that adding a valve increases flow, I can't find a comment related to that perception other than you telling us what we already know. The valve opens a less restrictive and louder exhaust pathway already incorporated in the muffler design. Closing the valves redirects the exhaust into more restrictive greater dampened pathway to quieten the vehicle.

 

[stooge]

Stooge I've said more than once, the blocking of a pipe refers to "quiet" mode only, not loud maximum flow and performance mode. Please, do yourself a favour and acknowledge that a bimodal has two equally important functions to change modes from quiet to loud at the flick of a switch.

If you're making a bimodal muffler first and foremost, you configure the flow rate and desired noise level with the valves open and that's your base muffler. Then you work out how to redirect exhaust flow to quieten it with the valve closed without disrupting your base muffler in loud/performance mode. You don't configure the muffler's noise level with the valve closed then work out how to increase noise and flow with the valves open.

You could use straight pipe as Holden did for loud mode but as we know, muffler deletes on VE/VF's typically sound sh*thouse with a lousy note, so I wouldn't configure loud mode that way. I'd incorporate muffling in loud mode to get a decent note. In most cases of mega loud VE/VF's with good notes, they're typically 100 cell cats or catless with no midpipe resonators and rear mufflers only, so you can get them loud enough retaining a muffled bimodal. Straight pipe or muffler bypass will never sound good in loud mode.

nev i have said more than once that when someone is looking to increase the volume of a muffler that adding a valve to it has no effect.
the muffler will produce the volume it is going to produce without the valve and adding a valve to it will not increase it.

i interpreted the original question being asked was "could i add a valve to it" in the context of chasing a volume gain and the question about adding bimodals or adding a valve to a non bimodal muffler in the context of a volume increase has been asked many times on this forum and the answer is the same with respect to adding a valve looking for an increase.

i am fairly certain that one member just added a valve to the stock muffler, it was here or on another forum but it would not have done stuff all.

 

[RevNev]

nev i have said more than once that when someone is looking to increase the volume of a muffler that adding a valve to it has no effect.
the muffler will produce the volume it is going to produce without the valve and adding a valve to it will not increase it.

i interpreted the original question being asked was "could i add a valve to it" in the context of chasing a volume gain and the question about adding bimodals or adding a valve to a non bimodal muffler in the context of a volume increase has been asked many times on this forum and the answer is the same with respect to adding a valve looking for an increase.

i am fairly certain that one member just added a valve to the stock muffler, it was here or on another forum but it would not have done stuff all.

I've never seen a question like that but not everyone's mechanically minded and we're here to help people and discuss ideas. With the perception that someone's thinking of adding a valve to a stock muffler hoping to increase flow, we'd like to stop them wasting their time and money doing so to achieve nothing. I didn't see the questioning potential leading in that direction as you did to respond differently when ultimately, we're saying the same thing expressed a bit differently. All good mate!

Speaking of bimodal electronics, many have asked me if they can use a hard wired switch to operate the bimodal valves just opened and closed, not the remote controller most are selling. Is that possible in your electronics experience with the bimodal system?

 

[hjtrbo]

It does if you do it right. I cut my bimodals open and converted them to a centre chambered dual outlet Lukey style perforated tube fibreglass packed mufflers. The inlet is 2.25" and the outlets are twin 2" and with the valve closed exiting through one 2" pipe, it's a lot quieter and sounds almost stock inside the car. With the valves open, it's sound like a typical V8 aftermarket (sports) exhaust. It's louder than stock with the valves open and closed but I've also got the HSV 340 headers, cats and R8 2.5" midpipe. The outlet pipes must be smaller than the inlet pipe and centre chambered to make it work and a lot of aftermarket twin outlet mufflers are 2.5" inlet and twin 2.5" outlets from a Y pipe and that won't work effectively adding a bimodal valve.

We used to block one tail pipe off with Lukey HQ/HZ panel van/ute systems years ago to get work orders off them for being too loud, so I was confident this setup would work bimodal and it's pretty good!

The stock bimodals are double skinned and a mongrel to weld but nothing a good work over with a flap disc and coat of paint doesn't remedy

View attachment 226294View attachment 226295

Hey @RevNev, do you have any more photos of what you did to the internals? Currently in the middle of changing my exhaust around and looking for some out of the box ideas. Currently testing out HM headers, Manta centre section with DPE bi-modal mufflers. Previously had DPE centre section in place.