My Introduction and I have Bi-Modal Exhaust Questions

[forza]

Thanks for the replies. Here in US, for Chevy's, Mild-to-Wild makes a device that merely interrupts the electric circuit to the vacuum solenoid valve. This device connects into the fuse panel. So, basically, they are just providing a remote control switch that replaces the standard fuse. Very simple. On Euro cars, most of them do not have a dedicated fuse so one has to attack the problem differently. I make a device that connects to the vacuum solenoid itself. It works by placing a switching circuit that intercepts the electric signal from the ECU to the vacuum solenoid solenoid ... provides continuity when you want to allow the ECU to control the vacuum solenoid or opens the circuit when you want to the valves always open.

I am in the process of creating a version for the Camaro and Corvette. The reason I was asking questions here is that I was advised that you guys in Australia may have an interest in a device for the bypass valves on your cars that are so equipped.

Seems like Imoengnr has already come up with a solution. You mention that later versions are a bit more complicated ... but it seems like it should work same, but maybe what is happening is that the car's ECU is throwing a check engine light or something. That is easy to overcome.

With the electric actuated bypass valves, one would only need to understand what the characteristics are. For example, are the valves a simple open/closed type or are there intermediate states, like partially open? Are the valves open when the engine is off or are they closed. What would happen if you merely disconnected the plug from the bypass valve? Etc.

Thanks for contributing here ... I appreciate it.

Regards,

Steve

 

[PIR4TE]

Steve M2W make a unit called NPP in a box, contains all you need to connect bi-modals to Holden Zeta for $189 +p&h.

One affordable solution for 100,000 Australian V8 suffers who don't know they need it, do that. The issue is not price / value or sales mechanism but marketing. Call it something more descriptive like wireless remote muffler flap controller. To suit Holden. List mufflers it works on, including but not limited to HSV, HM, Harrop, etc.

Underline that a Forza box derestricts power and awakens the engine's personality (and the customer's and everyone within cooee) so the entire world can feel the unrestrained passion of an oversized, pulsing hot pipe, without paying needless penalty of painful drone, or guilt trips with cops, the missus or the neighbours.

Forza instantly enables the benefits of massive explosive noise with the convenient option of switching to noise-free AFM (better fuel economy, better for Eco) near stock cruising / static noise even with tuned headers, hi-flow cats and no mid muffler!

La Forza della tua pipa ... dove e quando fa comodo

The simple, stealthy bipolar passport to V8 virility and enjoyment*

*actual bi-modal mufflers not included

 

[forza]

Hi Pir4te ...

I love your marketing lines. You have a good way with words.

About the NPP in a Box ... I believe that product is for cars that did not have a bi-modal exhaust but the the owner wanted to install one. He would have to purchase and install a silencer with built-in bypass and the vacuum actuated bypass valves. For example, if he had a Chevy Corvette, he would buy the two silencers from Chevy that have the bypass valves. If he had a Holden, he would buy whatever silencer Holden has with the bypass valves. The NPP in a box then provides the controller to open and close those valves. For example, if you go to this web site ... NPP in a Box ORDER NOW ... there is the line that says, Upgrade any C6 Corvette to a bi-modal exhaust system. All you need is the mufflers. The NPP in a Box contains the vacuum solenoid valve and electrical connection. that one would then control using the remote transmitter. One then has to tap into a source for vacuum and 12VDC and you would be good to go. The idea is really very good as it provides the means to convert a standard exhaust setup to a bi-modal one for minimum cost. But, this assumes that there is a bi-modal silencer that is available to install.

For cars that do not have bi-modal replacement silencer, one would have to purchase the bypass valve(s) and customized exhaust system. One could go with a simple cut-out design. If I were doing that, I would not use vacuum actuators, but go with electric as it would be far easier than trying to tap into vehicle vacuum. And then, one could merely install a simple switch in the cockpit to open/close the valve. Much less expensive than NPP in a box. With a simple cut-out, you could have a fabricator install the cut-out immediately upstream of the silencer and route a second exhaust tip either directly down ... or if room to do so, to the rear of the car. If all you want is noise, directly down would work and you would not have to change the external appearance of the vehicle.




Regards,

Steve

 

[PIR4TE]

About the NPP in a Box ... I believe that product is for cars that did not have a bi-modal exhaust but the the owner wanted to install one.

Yes, there are more than 100,000 car owners in the total available market versus HSV owners of just a few thousand, several orders of magnitude less. Generally speaking, those posey toffs are part of of a much more conservative demographic... haha JKs, just JKs.

He would have to purchase and install a silencer with built-in bypass and the vacuum actuated bypass valves. For example, if he had a Chevy Corvette, he would buy the two silencers from Chevy that have the bypass valves. If he had a Holden, he would buy whatever silencer Holden has with the bypass valves. The NPP in a box then provides the controller to open and close those valves. For example, if you go to this web site ... NPP in a Box ORDER NOW ... there is the line that says, Upgrade any C6 Corvette to a bi-modal exhaust system. All you need is the mufflers. The NPP in a Box contains the vacuum solenoid valve and electrical connection. that one would then control using the remote transmitter. One then has to tap into a source for vacuum and 12VDC and you would be good to go. The idea is really very good as it provides the means to convert a standard exhaust setup to a bi-modal one for minimum cost.

Nothing compares, unbelievable value for money.

Thing is of course these things only come available when a fellow Zeta platform owner with HSV badges is sold on a louder 3" system. Luckily, by the time they realise what they've done the exhaust shop has already shipped the offending few thousand dollar factory option to "another great eBayer" like me, for $250 inc courier.

Yes mate Australia is a land of hidden opportunity, as another HSV fella falls off his perch and succumbs to spending more and more on his ego, these special goodies like HSV bi-modal mufflers are almost always available on eBay AU, sometimes for less than $300 for the full stainless bi-modal catback.

The OEM vacuum actuators cost more wholesale. :yarr:

 

[PIR4TE]

For cars that do not have bi-modal replacement silencer, one would have to purchase the bypass valve(s) and customized exhaust system. One could go with a simple cut-out design. If I were doing that, I would not use vacuum actuators, but go with electric as it would be far easier than trying to tap into vehicle vacuum. And then, one could merely install a simple switch in the cockpit to open/close the valve. Much less expensive than NPP in a box. With a simple cut-out, you could have a fabricator install the cut-out immediately upstream of the silencer and route a second exhaust tip either directly down ... or if room to do so, to the rear of the car. If all you want is noise, directly down would work and you would not have to change the external appearance of the vehicle.

Compliance is an issue Steve, not allowed to have cutouts or anything bi-modal not factory fitted, stated specifically.

These Special Vehicle parts on a Holden test the current letter of the law, and as I follow learned advice on the matter, am informed that change is actively petitioned against all bi-modals even factory fitted. However electric bypasses like Varex mufflers are quite common amongst lesser hoons and retrobates, and as such are bait for cops to defect and in some States impound the vehicle.

 

[lmoengnr]

Yes, there are more than 100,000 car owners in the total available market versus HSV owners of just a few thousand, several orders of magnitude less. Generally speaking, those posey toffs are part of of a much more conservative demographic... haha JKs, just JKs.

Yep, HSV owners, and 'wanna be' HSV owners.....

 

[forza]

Hi Pir4te,

Quite amazing you were able to get a full cat-back with bi-modal option for such a low price. You did indeed fall upon a great deal, IMO. The M2W sells fairly well here in US, but the NPP in a box is not a big seller.

From the info you are stating, it sounds like the legal forces in Oz are much more draconian than up here in US. We are very lax (at least in my state) on enforcement of vehicle noise emissions. Harley Davidson owners seem very prone to running their bikes with no silencers at all. Go to any car gathering and there is no end to the number of cars with no silencers ... only using the catalytic converters for any noise abatement.

Steve

 

[PIR4TE]

What makes a Special Vehicle

Yep, HSV owners, and 'wanna be' HSV owners.....

Agreed, but my thinking is with the mods I have the car is more aptly a Holden Special Vehicle than a showroom HSV. If I didn't want to make it special then I would've bought an off-the-shelf late model HSV for sure!

BTW I do cop it about the HSV livery, but practically find it serves as a first line of defence - a ruse - to deter further inspection of the Special Vehicle bits fitted. Has worked several times by the roadside (even have tickets with HSV on them) but I am under no pretension that would hold water over the pits.

 

[Loaded Dice]

Short answer is here. Costs $189, is the least expensive option. There are other offerings from $$200-$250. You can also rig up an RPM window device like MSD etc but that's starts to get really fancy and dear. I think the Mild to Wild option is good.

HSV (who pioneered the setup) have a different controller to Camaro and Corvette and the controller fuse cannot be pulled as it performs several critical functions. An in-cabin override circuit is available, and some simply reverse the return valve or install a stop tap inline under the hood.

My car (VE Series II) has a co-processor that evolved onto later US GM high performance models that can be programmed to control the exhaust solenoid so as mapped to RPM, just as it does map the fuel system flow and pressure (our e85 V8 pioneered the high performance "returnless zl1 PWM" system). Parameters set by Tech2.

However the latest model of our V8 ECU has more processing power and fuel management is entirely done via the ECU, so it no longer has the same exhaust management capability.

More info please re NPP and M2W, is the NPP just the standard vacuum controller needed to operate the bi modal valve, and the M2W basically just an electronic version that is totally controlled by the remote, kind of Varex but BYO mufflers?

Also which system can be programmed by Tech 2 to define the operating rev range.