Alright, maybe some of you can help me out here. I have a set of B&B Fusion Bi-mode mufflers on the way for my 2008 Coupe to replace the Corsa Sports I currently have. My car does not have the factory NPP option, so I will need to retrofit all the vacuum controls.

So here is my question: Do the factory NPP cars use a vacuum canister to allow the muffler valves to stay shut at low RPM/high-load? I know there is an electric vacuum solenoid that is controlled by the ECM, and it opens the valves at a certain RPM. I was told that the factory NPP control system is very expensive to piece together, but I have never seen pictures of the components.

I am looking at the different aftermarket NPP retrofit systems (NPP-in-a-box, Sunset Orange, B&B, etc.) to see what the best way to go is. The more popular systems from the forum vendors seem to just be an electric vacuum valve that is controlled by remote. They offer different options as far as how they are activated (visor, DIC, remote, etc.), but appear very similar to each other in design and function.

The other option that looks promising is the system offered by B&B. It appears to use a vacuum canister in line before the electric valve that controls the flaps. It seems that this would allow you to keep the flaps closed, even at WOT (no vacuum in manifold). At least that seems to be the theory behind what I'm seeing.

I'd like some feedback from those have retrofitted these systems or has experience with the factory control system. Below you can see the B&B system as well as one of the more popular ones sold here on the forum. You can see the vacuum canister I'm referring to.

What is the best way to do this?

Thanks,

Andy

 

I've been wondering the same things! The B & B set-up is kinda pricey!

 

Well, the quick answer is that you don't really need the vacuum accumulator unlss you want to do a bunch of high load high rpm runs and have the butterflies full closed all the way up to redline.

My kit uses a vacuum check valve which is installed at the vacuum line at the intake manifold.

The vacuum is stored in the system while you are at high rpm / high load.

For people with superchargers and turbos I offer he vacuum accululator ball to store additional vacuum so that if they are under boost for extended periods of time that they always have enough vacuum to actuate the butterflies.

For most users the vacuum check valve and vacuum stored stored in the line is plenty to allow the butterflies to stay closed under most operations.

 

Thanks, that is what I was looking for

So, answer this for me: I am cruising around with the flaps closed, and I decide to run full-throttle through first and second gears. Will the check valve be enough to keep the flaps closed (ie. 0-70mph)? What about for a full 11 second quarter mile run? Or is a vacuum accumulator a good idea?

I guess my idea of a controlled bi-mode system is full control of the flaps at all times. Obviously, keeping them open is no problem. My car has a moderate cam, headers and high-flow cats, so it is loud at full throttle. That is one of the reasons I am going with a bi-mode system. Whatever route I go, I want the flaps to stay closed if that is what is being commanded. I don't want them opening on their own during "spirited" driving


Oh, and do you have any pictures of your setup with the vacuum accumulator? Is it a neat assembly like the B&B kit?

Thanks,

Andy

 

Some people have T'ed the line into their brake booster

 

i just ran a vacuum line from the manifold to the z06 mufflers,

idle and cruzing, lots of vacuum, = flaps closed = quiet

WOT, no vacuum = flaps open = loud

of course i only hook up the line when im going on LONG trips greater than 3 hours, usually the line is just capped back at the mufflers, so its WILD all the time!!

-Carl

 

I also have the B&B Fusions and I used their kit. It isn't difficult to install and I don't have to worry about weather or not the valves will open on their own. If you are spending that much on an exhaust, why go cheap on the controller? Great choice on the exhaust. You're gonna love it.

 

I installed the mild to wild set up on my car and it works great. Easy set up and only took 20 minutes to install. It gives me the option of running with closed flaps or having them open when I choose to do so. It comes with two remotes as well as you can program them on your home link ( on older cars ). On my original exhaust the drone and waking up the wife was starting to kill me. Switching to the mild to wild was the best of both worlds. One of the best mods I have installed.
I had a friend who went to pick up his car at the museum and they recommended and sell the mild to wild set up.
Get set and easy to install !!!

 

I used the NPP in a box to retrofit NPP mufflers to my 06 LS2. It has performed flawlessly for years with no problems or issues whatsoever. The instructions were clear and precise, the install was quick and easy, and without a doubt one of the best mods I did.

In fact, a Talon90 a forum vendor is running a special on it:

http://forums.corvetteforum.com/c6-p...group-buy.html

 

We've sold the NPP in a box from Nakid Parts for years. We've sold a lot of them and they work great. Send us a PM if you'd like one. We can ship one right out for you.

Thanks!!

 

I have this on my car now and it works great now for 2 years.