Exhaust Valve Rebuild? Anyone know a company?

CatmanV2

CatmanV2

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Ebenezer said:
What might be involved in retrofitting valves to an unvalved set up... Asking for a friend..:as004:

He's also seen on line that you can get electic actuators, rather than vaccuum ones. What's the collective thought on those?

Eb
Click to expand...

The challenge with with retrofitting is that you need to have a 'less' muffled route to direct the gasses to. So either you just dump them before the rear mufflers, or you need to do something to the rear boxes. Personally I would (and did) hold out for a set of valved boxes on ebay, or get some valved Larinis or their ilk.

No real input on electric valves. Did look at them but see the paragraph above...

C
 
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Ebenezer

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Along with the electric valves, the idea seems to be you do just put valved spur in the exhaust before the rear mufflers, presumably after the x-pipe and lambda sensors, so my friends research has found.
Eb
 
CatmanV2

CatmanV2

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Ebenezer said:
Along with the electric valves, the idea seems to be you do just put valved spur in the exhaust before the rear mufflers, presumably after the x-pipe and lambda sensors, so my friends research has found.
Eb
Click to expand...

Your friend's research is backed up by the research a friend of mine did.....

C
 
Zep

Zep

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Ebenezer said:
Along with the electric valves, the idea seems to be you do just put valved spur in the exhaust before the rear mufflers, presumably after the x-pipe and lambda sensors, so my friends research has found.
Eb
Click to expand...

Well, if your friend was to do that, I imagine your friends wife would be over the moon ;). I have seen a lot of electric exhaust cut outs on those US car shows, they seem to like them.
 
azapa

azapa

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i'd mention to your friends that the spur should route through the boxes as the valved option (active) for MOT's, police officers, and the like. The straight through part would be the resting position. They may hate me for it, their neigbours too, but they'd also appreciate it was the best option, way deep down.
 
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Ebenezer

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So a hanging spur is a No No for MOT? (My friend asks). If that's so, then probably not worth the trouble..
Eb
 
azapa

azapa

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Ebenezer said:
So a hanging spur is a No No for MOT? (My friend asks). If that's so, then probably not worth the trouble..
Eb
Click to expand...
I'm sure valves are legal. Just hit the right button at the right time and you'd be fine at a MOT.
If you are thinking that the spur could dump just there, where the valve is, no. gases must vent away from the underside of the car, not sure by how much distance.
 
Zep

Zep

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Indeed. Make sure the valves are shut and there shouldn’t be an issue at MOT time.
 
ChrissGT

ChrissGT

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It all depends what your friend is looking for. On WOT there isnt much difference in sound, since the non valved boxes actually have a pressure valve inside the muffler. Which opens and creates a non muffled route.
I have the valves on a remote, but ideally it also would be coupled to rpm so at a certain rpm they always open (so engine performance is optimal). I believe there are kits available, but didnt want to bother getting into the wiring.
 
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Ebenezer

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ChrissGT said:
It all depends what your friend is looking for. On WOT there isnt much difference in sound, since the non valved boxes actually have a pressure valve inside the muffler. Which opens and creates a non muffled route.
Click to expand...
First time anyone ever has mentioned pressure valves inside the mufffler! Are you sure?
Eb
 
Gazcw

Gazcw

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Ebenezer said:
First time anyone ever has mentioned pressure valves inside the mufffler! Are you sure?
Eb
Click to expand...
Chris is correct. Well for QP anyway. There is a spring loaded flap that is pushed open with gases. It directs the flow to the larger diameter tailpipe bypassing some the sound deadening. My boxes were chopped open and flaps opened permanently.
 
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ChrissGT

ChrissGT

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Gazcw said:
Chris is correct. Well for QP anyway. There is a spring loaded flap that is pushed open with gases. It directs the flow to the larger diameter tailpipe bypassing some the sound deadening. My boxes were chopped open and flaps opened permanently.
Click to expand...

they are exactly the same muffler, GT just has shorter tips.
 
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Ebenezer

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Everyday is a school day! I can't recall anyone ever saying this before so we now know more!

So what you're saying is that each tip of thepair is different. Only one is used when the flap is not open - the smaller diameter tailpipe, and the other larger diameter taipipe is opened once the gas flow is strong enough.

Make me wonder how may are now seized one way or the other.

Eb
 
Gazcw

Gazcw

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Ebenezer said:
Everyday is a school day! I can't recall anyone ever saying this before so we now know more!

So what you're saying is that each tip of thepair is different. Only one is used when the flap is not open - the smaller diameter tailpipe, and the other larger diameter taipipe is opened once the gas flow is strong enough.

Make me wonder how may are now seized one way or the other.

Eb
Click to expand...
Gas goes into chamber where valve is, then through perforated section into wadding and out through narrow. As gas increases the valve is pushed open wider purely by volume which allows it through a u shape pipe and out the wide pipe as well.
 
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Ebenezer

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Gazcw said:
Gas goes into chamber where valve is, then through perforated section into wadding and out through narrow. As gas increases the valve is pushed open wider purely by volume which allows it through a u shape pipe and out the wide pipe as well.
Click to expand...
Going to to have to look more closely. Could figure which way was in and which way was out!
Eb
 
Gazcw

Gazcw

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I took the wadding out of mine and had the valve opened permanently so it is unsilenced but not quite straight through.
 
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