ZR-1 Net Registry Forums - View Single Post

Paul Workman · 04-06-2014

Not too many jumping in to comment, apparently. So, here's my 2 cents:

You may have noticed the discussions going on regarding adapting NPP valves to the ZR-1, and in particular the desire to limit their unwanted opening e.g., when driving up hills, etc.

From what little info I've seen on the VTs, it appears to be an internal mechanical/spring tensioned gate affair (operating similar to a heat riser valve) that opens when sufficient load (force) is present to overcome the spring/weight resistance holding the gate in its NORMALLY CLOSED state. So, it does appear to share the same "issue" the NPPs have if controlled by direct plenum vacuum alone.

So, after considering the VT option, I dismissed the VTs (for now), in lieu of any feedback on their use, they're inaccessible should they stick (like the heat riser valves are known to do) and that it appears (to me) they would NOT address the unintended opening, e.g., hilly/mountainous terrain, currently being researched in the NPP approach. Then there's another question regarding flow, compared to the Dynamax 17228s (recommended for use with the NPPs if B&Bs are not available for some reason), and concerns for "rattle", again like the heat riser valves were/are known to do.

I applaud Dynamax's approach to the drone issue with another approach to the gate technique. It may be just the ticket for some, and it is very simple to afford and instal. But, for me the primary issue of potential unwanted opening in accordance with normal engine loading during normal acceleration or climbing a hill; still remains. And, I'm biased too by the ability to have complete control over the valves - manually if desired - which too the VTs will not allow.

JMO...

04-06-2014	#2
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,466	Re: Dynomax VT mufflers Not too many jumping in to comment, apparently. So, here's my 2 cents: You may have noticed the discussions going on regarding adapting NPP valves to the ZR-1, and in particular the desire to limit their unwanted opening e.g., when driving up hills, etc. From what little info I've seen on the VTs, it appears to be an internal mechanical/spring tensioned gate affair (operating similar to a heat riser valve) that opens when sufficient load (force) is present to overcome the spring/weight resistance holding the gate in its NORMALLY CLOSED state. So, it does appear to share the same "issue" the NPPs have if controlled by direct plenum vacuum alone. So, after considering the VT option, I dismissed the VTs (for now), in lieu of any feedback on their use, they're inaccessible should they stick (like the heat riser valves are known to do) and that it appears (to me) they would NOT address the unintended opening, e.g., hilly/mountainous terrain, currently being researched in the NPP approach. Then there's another question regarding flow, compared to the Dynamax 17228s (recommended for use with the NPPs if B&Bs are not available for some reason), and concerns for "rattle", again like the heat riser valves were/are known to do. I applaud Dynamax's approach to the drone issue with another approach to the gate technique. It may be just the ticket for some, and it is very simple to afford and instal. But, for me the primary issue of potential unwanted opening in accordance with normal engine loading during normal acceleration or climbing a hill; still remains. And, I'm biased too by the ability to have complete control over the valves - manually if desired - which too the VTs will not allow. JMO...