frankc5r

does anyone know if wiring for NPP option is installed on non-NPP
C7 cars. Friend wants to install NPP exhaust. ECM probably won't have
the programming but he can add a mild to wild.
Thanks for any help.

davidtcpa

I don't think so.

ErnieD

Akrapovic makes a control kit that allows use of the NPP exhaust on a C7 supplied without it: http://www.akrapovic.com/#!/car/prod...37&yearId=4241

Ernie

Boiler_81

The wiring is not there. The aftermarket systems are his only choice.

ErnieD

The Akrapovic control kit intercepts the exhaust valve control signals from the wiring harness in the rear fuse box area and provides the additional wiring to connect to the rear NPP valve actuators. Read their installation instructions for detailed info.

Ernie

grumpy63

I installed NPP on my non NPP car. The NPP valves are always open (loud position), sounds great and was very inexpensive...

TEXHAWK0

I think the actuators are electric on the C7 (unlike the C6), so it seems it might be possible to just run a manual switch to the actuators to close them when you do not want them open.

The C6 system uses an electrical solenoid to control vacuum to the actuators.

Looks like the add on controller system uses a CAN (Controller Area Network) sniffer to detect the car's signal to close the valves, which triggers a relay to provide the electrical signal..

Boiler_81

Unfortunately, the actuators are not a simple on off circuit. See this thread: https://www.corvetteforum.com/forums...-retrofit.html

Tech4882

I also am looking at this change to my non NPP stingray. It appears there are two ways to go to switch the NPP actuators on or off. One forum member has designed a solution that uses an external switch and an outfit out of Europe has a design that integrates into the CAN bus using a sniffer circuit and operates like the factory system.

You can get the switch design for around $170 usd and the CAN bus version for about $555 usd. I think plus shipping on both. PM me if you would like additional details. Most of the details are available on other posts on the forum.

The CAN bus version is only available when you purchase the exhaust system provided by the same company.

red 1

Do you know who is selling the $170.00 kit?

Tech4882

Check out these posts;

https://www.corvetteforum.com/forums...etrofit-8.html

ErnieD

The control kit is available as a separate item without purchase of a complete Akrapovic exhaust. Check with forum vendor RPI Designs for details.

Ernie

Tech4882

The HRE/Akrapovic rep told me the kits were not available for purchased separately, only as replacement items for owners with the Akrapovic systems on their vehicles.

Apparently not correct. RPI designs list these kits for sale.

C5pilot1

I reached out to Theta the creator of the module to retrofit base C7's but have not heard from him. Does anyone know if he is still selling the boards , connectors etc?

red 1

I reached out to him a few times without any response, I think I read somewhere that he was going to have to under go chemo. he may not be around anymore. I hope that's not the case.

C5pilot1

I recall something on that too. Wow I hope that is not the case also.

Trihawk

At least one forum member has done this (4th post down):

https://www.corvetteforum.com/forums...y-exhaust.html

Tech4882

That's good to know. At $555 for the kit it's good to know it works on the NPP exhaust before you invest. Here's the RPI link;

http://www.rpidesigns.com/shop/item....c-control-kit/