IS it means that the C7 has NPP System it comes with NPP Valves in the muffler, if the C7 has no NPP System, it not comes with NPP Valves in the Muffler?

 

Correct.

 

It's more than just the valves not being there, the wiring harness is also lacking. I don't believe it is possible to retrofit NPP to a non-NPP and have it fully integrated into the system (controlled by the driver mode control and system settings).

 

And it gets trickier if deleting the NPP by adding a muffler system which has no NPP valves.

 

Yup ! Just ask one of our mods that did just atat at the bash last spring ...................

 

SO the muffler on the picture should comes from a With NPP System Corvette C7 right？

 

If I installed a Corsa Extreme Muffler on a No NPP Corvette, What might happen？

 

It might sound good. Other than that, nothing.

 

If you have a car withOUT a NPP, there is no issue. The issue is when you have NPP and install a system w/o the rear butterfly valves.

I just tied the actuators up to the frame. So far so good. Almost two years. I can't use D, however, because it causes a CEL, and use only M and the paddle shifters. Oh! woe is me, I have to shift!

 

Yes, the pictured exhaust is an NPP exhaust. The valve on the upstream (engine) side is the AFM valve. The NPP valve is on the exhaust tip and when it is open it creates a more direct/less restricted path through the muffler.

 

Sorry for my poor English, what I get from your answer is the Check Engine Light will on, nothing else? Mine is a AT VETTE BTW.Thanks.

 

Yes, I cannot drive in D for any length of time (anywhere from instantly to 600 miles, but not consistently) w/o the engine light coming on. It's not hurting anything, but with the CEL on, no other issues can be seen if it were to occur.

 

I'm confused, why you cannot drive in D for any length of time w/o CEL on? You mean if I install Corsa on NPP corvette, I can't drive in D?

 

I have B&B Bullets and was one of the first to have them on a C7, I don't know about Corsa. My actuators are zip-tied to the frame, as there is no way to eliminate them, AFAIK. The car needs to think they are still functioning.

For me, there is no hardship manually shifting, I do this on my '05 A4 as well. I like it.

 

Your car will become noticeably louder. How much so to those riding in it is the $64 k question. Steve Bell has them on his and loves the sound. I prefer the ability the NPP gives me to quiet it down for long highway trips.

 

I agree with the ability that the NPP gives me to quiet it down for long highway trips.

 

Actually, that's not entirely accurate anymore. Akropovic makes a plug and play kit that DOES tie into the driver control mode now. I believe it is getting the info for the control mode through the CAN BUS interface.

https://www.akrapovic.com/#!/car/pro...37&yearId=3895

If you already have the valves actuators, then you only need the control kit. If you do not have actuators, then you need this too:

https://www.akrapovic.com/#!/car/pro...37&yearId=3895



Ant

 

And just how expensive is their kit ? Their most basic of exhaust systems rivals the economy of some emerging third world countries.

 

cello002 : Please tell us what you are trying to do rather than asking a question. This may be easier to understand. It will be easier to give you a simple answer. Also, you will NOT get a CEL if you are using the exhaust system in your picture. The experience of owc6 is not the same as your system.


owc6 : Not to hijack this thread, but I'm 99% certain your CEL issue is from the non-OEM AFM valves in your B&B. A CEL will NOT happen if removing/disabling the NPP actuators on an OEM exhaust system (what the OP seems to be concerned with). Your CEL pretty much has to be AFM related because there are ALWAYS NPP actuator commands in all driving modes and D/M states. There is NEVER an AFM actuator command in M mode because it disables AFM. Hence why no CEL in M - no commands for it. The car "sees" the AFM actuator is attached, but since there are no actuation commands it never gets the unexpected force feedback response to throw a CEL.

Since you have an aftermarket B&B system with B&B valves, your AFM actuators are "seeing" a non-OEM spring ramp profile. This will cause a CEL because the control feedback is VERY sensitive to changes in valve actuation forces. Much of this was learned through Theta's NPP controller work in Tech. The actuators are calibrated to the OEM valves in the car. Any changes to the force profile the actuators "see" will cause a CEL since the car thinks there may be a problem. Making it trickier, it's only the AFM actuators that will always cause a CEL if disabled or modified. The NPP will throw a CEL only if it sees a modified response (like ice build-up or sticky valves some have reported); they will not throw a CEL if disabled through a fuse pull or harness disconnect.

There is an actuator re-learn procedure that a dealer can do that may cure the problem. There are MANY reports of non-OEM valves from various exhaust manufacturers causing CELs when the OEM actuators are transferred to them. This is because their valve force actuation profiles don't match OEM closely enough. I think this is why Corsa makes you cut out your OEM valves and transfer to their system... I do think this has improved over time, but there were a lot of these CEL reports in the earlier aftermarket systems. I'd honestly go back to B&B and ask them to rectify the issue if the re-learn at the dealership does not work.

 

Thanks for the info. I wasn't aware that anybody had figured this out. $555 for the control kit that uses the CAN bus.