Thread: V8 extractors - worth it or not?

I know many have gone with a 3" exhaust but I was recommended only going to 2.5" for the reasons you stated. I have kept the first muffler but got rid of the rear muffler.

Originally Posted by HangOver

you mentioned removing the muffler boxes, I thought englines needed a certain amount of back pressure to work properly?
Doesn't a straight through actually reduce power?

Or does a larger bore pipe do the same?

urban myth.

ask yourself the last time you saw an Top Fuel car with a muffler

I cant give any figures because I have never chucked the old girl on a Dyna tune. I can say that with tuned extractors and a snorkle I have about 15% plus in torque and far more throttle response, when I need full noise (and it sounds so sweet) it's there almost instantanious, next is to fit the correct size electric fan and get rid of that power robbing fan off of the front, which according to all the literature I have read on it is between 5 and 10% .

P.S. I play in mud mostly so when I need power I need it right now not waiting for it to build up.

P.P.S. I cant comment about improved fuel consumption because firstly I dont care and secondly I love the sound of her so I drive it hard (but always within the law) I took a driver with me he was into sliding, he got out shaking said I was insane, laughted my head off poor bugger couldn't handle nearly 3 tonne in a power slide in the mud.

I spoke to Graeme Cooper about extractors for my 3.5V8 ages ago and he said 'forget it', better off putting on a decent exhaust system if more grunt is required....

Cheers, GQ

Originally Posted by Pedro_The_Swift

urban myth.

ask yourself the last time you saw an Top Fuel car with a muffler

You had better get yourself to the 4WD monthly website... I am getting a flogging over there regarding backpressure ! Bring reinforcements!!

It's not an Urban Myth.

It is most noticable on the small V8's like we have in the Landrovers and if you open things up too much you will lose power. You don't have to have a muffler, but the exhast does have to be designed so as to create the right amount of back pressure

Originally Posted by Pedro_The_Swift

urban myth.

ask yourself the last time you saw an Top Fuel car with a muffler

Crud, you lose torque, when is the last time you seen a top fueler cruise up a hill at 2oooRPM's??

Without wanting to be long winded, I think it is accurate to say exhaust back pressure MUST be matched to the engine as a whole. Changing just one part of the equation will not always give the desired results. For example, you might also have to change cam specs and timing to take advantage of the altered exhaust back pressure.