Dynomax VT mufflers

[LantanaTX]

Has anyone tried these?

[Paul Workman]

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...

[LantanaTX]

Thank you for the thought out input. The VT looked like a possible solution. Next Saturday, I will become a ZR1 owner as I am flying up to Denver to pick it up and drive it home to Dallas. It has a B&B 3" system on it and the owner said it is really loud. I guess the 12 hour drive home should give me a chance to see it the drone is unbearable.

I did see a post on "Exhaust Thoughts" where someone did the NPP/Z06 tips and flappers on the B&B Mufflers.

[msorenso]

For what its worth last Summer I became a ZR1 owner and the previous owner has magna flows 3inch not cats. I drove it from Alabama to South Dakota and it was not pleasant. To the point that I have harly drvinn the car since owning it. I am going to get something done soon to it.

[XfireZ51]

DM VTs have an internal flapper w no ability to control it. Here's an example of the problem I thought it would have. Its sort of like the flapper on a diesel truck.

http://youtu.be/nj3q7kCjZQY

[mike100]

LantanaTX- bring earplugs- it's hard to take after the first hour.

I considered those Dynomax VT's, but my exhaust guy didn't like the idea of moving parts because he didn't think it would last. Basically it could start rattling.

Speaking of that, one of my NPP valve rattle at mid travel and I think this is common because a lot of these C6 mufflers for sale are dealer warranty swaps that didn't get thrown in the dumpster. More complexity, more problems...

btw the 2008 to present Mitsubishi Lancer Evolution has an internal muffler flap as oem to help keep the resonance and dB's down on those cars. They seem to work fine.

[LantanaTX]

They have been selling these for a few years now. I will search for feedback and problems.

[zrwhat]

[I installed a set on my 415 car and it sounds like the nay sayers are the ones that have not actually tried them.

I am very pleased with mine and no, pulling a hill will no open the internal bypass unless you nail it, what will open the spring loaded flapper is volumn from exhaust flow at a rapid pace, you nail it, it opens the spring loaded valve and all hell breaks loose, normal driving is pleasant and you can hear a slight rumble but nothing like the B&B I have on my other car. AT highway speed, no drone, no resonance and you can even talk on your cell phone and actually be heard and can hear what the other party is saying.

The VT's Really woke my car up since I installed a X pipe and its 3"'s all the way back from the 2" Jeal Headers.

Would I do it again, in a NY minute! If you don't want to make noise, just keep your foot out of it, that simple.

Dave Johnson has been in my car, ask him and Mark Horner has driven my car with the VT's, Twisting up the rpms will change the tone but just pulling hills or passing without going over 4K, all is rather quiet.

I used to like my loud as hell B&Bs but not any more since I installed the VT's.

Heres what they look like with 4" corsa clone dual tips.

Gibby

[IMG][/IMG]

[IMG][/IMG]

[msorenso]

I was always interested in this combo, almost tried it but was afraid of drone.

[zrwhat]

Originally Posted by msorenso

I was always interested in this combo, almost tried it but was afraid of drone.

I have experienced none and I have 3:45's in the car, traveling 55-65 is usually the sweet spot for drone as it is with the B&B in my other ZR-1 and ZR-1 previous to that.

I did a lot of research before I jumped in the pool, Dynamax has a great lifetime warranty, if they malfunction, they will replace. They are made of Stainless.

Only heard of 1 internal failure and it was on their first batch the made, they changed something and have not heard of any since. I like the fact that in inlet and outlet are dead center so when you really get aggressive with the loud pedal, its straight through and 3" all the way through and gets rid of the spent stuff quickly.

I've got a total of about $800 tied up in the exhaust and all pipes are stainless and all are Mandrel bent and that includes the price of the tips I installed on the end of the mufflers.

Car seems to have more torque on the low end due to added back pressure while the flapper is in the closed position diverting spent gasses through the chambered sections of the muffler.

All I can say is I'm glad I went this way with this one and I have another one on the horizon when I replace my B&B on my 91.