Active exhaust

[l6rth]

Has anyone fitted an active exhaust valve to by-pass the centre box? If so how did you do it and how well does it work?

[shake n bake]

I know one of the guys at Amore tvr has it on his Griffith, sure they could tell you about it/do it.

[rev-erend]

Never heard of an active exhaust on a TVR but I am pretty sure some probably has used the manually switched bypass valve.

Plenty of info here..

https://www.pistonheads.com/gassing/topic.asp?t=10...

[rev-erend]

Any news.

[peaktorque]

I don't have a bypass fitted, but I have very little silencing.....

A choice of loud or louder?

[300bhp/ton]

You want an exhaust cutout. Very common in the USA. They can be manual or you get them with an electric solinoid.

All it does is dirvert the exhaust has down a different pipe. Either completely by passing the silencer or through a different one.

Something like this:
https://www.ebay.co.uk/itm/301316758029

Edited by 300bhp/ton on Sunday 11th June 22:55

[450Nick]

I've head of a lot of people trying it before but there really isn't much room to do it so I've not seen anyone succeed. You need twin pipes for the flow required, and there is not space to put two more bypass pipes (or the 4 y pieces) in between the chassis rails..

[450Nick]

swerni said:

Nick, can you expand on that?
Why would you need 4 Y pipes?

I've run cut outs on a couple of V8's but not on a TVR

Well RV8's like some back pressure so silencing or not, the pipework should run to the back of the car and I'd want to keep two tailpipes rather than 4, so you're talking about breaking the flow from both manifolds out into a silenced and non silenced path, and then back to the tail section, so four Y junctions. You could just run two and have then vent straight to air beneath the engine, but I suspect it would sound loud but a bit agricultural. Plus it would rob you of some horsepower, and have a slight worry of setting fire to any leaked oil or dry fibreglass if you were throwing flames (which you very likely would).

[300bhp/ton]

RV8's don't require back pressure anymore than any other engine. If your exhaust is restrictive, then removing the restriction will require the A/F to be optimised. This is not a need for backpressure.

On an n/a setup you also want to make use of exhaust scavenging from each bank, so will require a crossover pipe between the banks.

A cutout simply lets you by-pass the silencer. If you have a H or X pipe with dual exhaust. Then you'd need a crossover per bank. But on a Y setup youd just put the cutout after the pipe somewhere.

You can either go no silencers at all and something like a stock exhaust. So it would look standard and be standard in normal mode. But at a flick of a switch could become very loud. Or you could have the cutout directing the exhaust gasss through a different silencer. Lots and lots of options really.

I struggle to believe you couldn't do something on a TVR with a little thought.

[peaktorque]

I don't have a bypass fitted, but I have very little silencing.....

A choice of loud or louder?