My Introduction and I have Bi-Modal Exhaust Questions

[forza]

Greetings to fellow enthusiasts,

By way of this post I wish to introduce myself as new member of the forum. I am in the US and I had a Pontiac GTO when you guys made it for us down there. Great car, but alas, Pontiac is no more.

My question is one that I cannot get an answer up here in the northern hemisphere ...

Does Holden make cars with bi-modal exhausts? Here in USA, the Chevy Camaro and Corvette can be had with bi-modal exhausts. They go by various names, but in essence, they have exhaust bypass valves which open and close. Typically, open when you start the car and they close until the vehicle achieves certain threshold of engine RPM and/or vehicle speed. When they open again, the engine noise increases and they just sound lovely.

Just wondering if you guys in Oz have these options from factory?

Thanks,

Steve

 

[someguy360]

Yes, the some of the newer HSV's have had bi modal exhausts.

The standard production line Holdens never got them but the HSV (Holden Special Vehicles) did have them with some models.

 

[PIR4TE]

Not Holden from factory, but HSV bolts onto G8. Possibly modify for GTO I have them on mine with controller. PM me if no luck.

 

[Smitty]

Yes, the some of the newer HSV's have had bi modal exhausts.

The standard production line Holdens never got them but the HSV (Holden Special Vehicles) did have them with some models.

my new GEN-F Clubsport Tourer has a bi-modal exhaust... adjustable via an 'engine mode' switch (touring, sport and performance.. and the hp and noise goes up)

 

[forza]

I would guess then that my question about bi-modal exhaust would be better posed in the HSV forum ... yes?

 

[lmoengnr]

Ask away, plenty of HSV owners here.

 

[forza]

OK ... here goes ...

How many of you HSV owners (or for that many any one) have a vehicle with vacuum actuated exhaust bypass valves? If you have a car with these valves, and they are factory installed, then typically they are controlled through the ECU and will work like the Chevy Camaro and Chevy Corvette valves do over here in USA. That is, they are open when you start the car, then immediately close as soon as the revs go above 1000 RPM and they open again when revs approach 3000 RPM or so. The actual operation might be like many Euro cars ... closed when you start the car, open when engine gets to 4000 RPM or so.

So, over here, people either pull the fuse (the Camaro has a dedicated fuse for the exhaust valves) or they merely pull the vacuum line off the valves and plug the line with a small screw or something.

By taking the vacuum away, the valve will remain open all the time. Pulling the fuse will disable the vacuum solenoid valve. Either way works, but then the noise might be annoying on, say ... a long cruise down the highway or trying to sneak home at night and not bother the neighbors.

So, what do you guys in Oz do? Is there a fuse that is dedicated to the exhaust bypass valves (actually, it would control the vacuum solenoid valve)?


Or do you pull the vacuum line off the exhaust bypass valve actuator?


Would there be any interest in an inexpensive device that you could install to manually control the bypass valves?

Thanks,

Steve

 

[PIR4TE]

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.

 

[Smitty]

.. the VF GEN-F HSV version works via the EDI in the car
and
of course also works via the switchable engine control knob on the console .
More power = more noise

 

[lmoengnr]

HSV used to use vacuum bi modal valves, latest models use electric versions.

They're controlled by a Motec module which is part of the EDI (Enhanced Driver Interface), controlled via the touch screen.

The controller has 3 selections, 'Off' (valves always closed), 'Idle' (valves only open at idle), and 'Normal' (valves open at idle, closed off idle, and open again at a specific speed/RPM setting).

The specific speed/RPM setting is designed to comply with Australian noise emissions tests (static/drive by).

The version I have was easy to override, just wire an on/off switch into the control wire to the vacuum solenoid, and hide the switch in the cabin close to the driver. When the switch is off, the valves are always open.

Later versions are a bit more difficult to override because of the electronics, so the vacuum lines are usually removed from the valves, and plugged. I do know that a few persons were working on a software override system, but haven't heard of any results so far.

The latest version with the electric bi modal valves, I have no idea about.