ZR-1 Net Registry Forums  

Go Back   ZR-1 Net Registry Forums > C4 ZR-1 > C4 ZR-1 Technical Postings

Reply
 
Thread Tools Display Modes
Old 04-05-2014   #31
XfireZ51
 
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,708
Default Re: NPP Exhaust Valve Controls

Quote:
Originally Posted by mike100 View Post
That studded bracket was quite useful on my installation also.
Mike,

The way I have this wired would allow me to use the wireless fob IF I can determine how to make it work. Altho don't have a ton of initiative at this point on that front.
__________________
[SIGPIC][/SIGPIC]Former Membership Chairman
Former ZR-1 Registry - BOD
1972 Corvette 4speed base Coupe SOLD long time ago
1984 Corvette Z-51/4+3 SOLD
1992 Corvette ZR-1 Aqua/Gray #474 SOLD
1992 Corvette ZR-1 Black Rose/Cognac #458
2014 Honda VFR Interceptor DX
XfireZ51 is offline   Reply With Quote
Old 04-05-2014   #32
XfireZ51
 
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,708
Default Re: NPP Exhaust Valve Controls

OK. Time to see how the check valve works.

Here's the NPP control installed in rear quarter



And then here's the NPP control working w the check valve in-line. so this will give me a ON/OFF capability depending on which way the console rocker switch is set.

__________________
[SIGPIC][/SIGPIC]Former Membership Chairman
Former ZR-1 Registry - BOD
1972 Corvette 4speed base Coupe SOLD long time ago
1984 Corvette Z-51/4+3 SOLD
1992 Corvette ZR-1 Aqua/Gray #474 SOLD
1992 Corvette ZR-1 Black Rose/Cognac #458
2014 Honda VFR Interceptor DX
XfireZ51 is offline   Reply With Quote
Old 04-05-2014   #33
mike100
 
Join Date: Feb 2011
Location: San Marcos CA
Posts: 1,802
Default Re: NPP Exhaust Valve Controls

Yeah...I gotta add an off switch to mine as well...easy enough, but where to put it?

The NPP trick is all well and good, but it is still very loud when they open up (got pulled over again). So... I need the totally turn it off when I'm in certain parts of town since the temptation to pull a gear is just too strong sometimes.
mike100 is offline   Reply With Quote
Old 04-11-2014   #34
XfireZ51
 
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,708
Default Re: NPP Exhaust Valve Controls

Bolted a pair of borrowed seats from PW and so I was able to drive the car. Took it this morning for a wheel alignment. This gave me a chance to try out the NPP control. It really sounds sweet driving w the actuators closed. You get a nice purrrrr from the back. There is some 'boom" at 12-1300rpm, but flip the switch and it really gets louder. Very noticeable. The switch works just great. An hour after shutting down, the actuators were still closed indicating that the system was holding vacuum very nicely.
__________________
[SIGPIC][/SIGPIC]Former Membership Chairman
Former ZR-1 Registry - BOD
1972 Corvette 4speed base Coupe SOLD long time ago
1984 Corvette Z-51/4+3 SOLD
1992 Corvette ZR-1 Aqua/Gray #474 SOLD
1992 Corvette ZR-1 Black Rose/Cognac #458
2014 Honda VFR Interceptor DX
XfireZ51 is offline   Reply With Quote
Old 05-09-2014   #35
Karl
 
Karl's Avatar
 
Join Date: May 2013
Location: Chicago
Posts: 980
Default Re: NPP Exhaust Valve Controls

Will something like this work instead?

http://m.ebay.com/itm/150727996468?nav=SEARCH
__________________
1993 ZR-1 #211 Yellow On Beige Beast #2
1992 ZR-1 #427 Black On Black *Sold*
1985 L98 Blue On Blue *Sold*
Karl is offline   Reply With Quote
Old 05-09-2014   #36
XfireZ51
 
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,708
Default Re: NPP Exhaust Valve Controls

Mike,

I ran a ground interrupt circuit to a simple toggle switch I installed in one of the "cup holder" recesses of the console. That, together w the vacuum check valve is working well in terms of either keeping the actuators fully open or closed shut.
I'll also reiterate that a portion of the loudness and flabby sound of the exhaust is related to a "too rich" fuel mixture. I observed that sometime ago and have confirmed it with my latest tuning sessions working w injector offset values.
__________________
[SIGPIC][/SIGPIC]Former Membership Chairman
Former ZR-1 Registry - BOD
1972 Corvette 4speed base Coupe SOLD long time ago
1984 Corvette Z-51/4+3 SOLD
1992 Corvette ZR-1 Aqua/Gray #474 SOLD
1992 Corvette ZR-1 Black Rose/Cognac #458
2014 Honda VFR Interceptor DX
XfireZ51 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:52 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright ZR-1 Net Registry 2020