Thread: Reverse megaphone options.

Guys, what are the pros / cons for a reverse cone / megaphone just after the collector?

Been doing some research, and there are varied results / opinions (as expected from the internet).

Where to find real world VE results; PM if the results would like to remain 'private & confidential'?

This would be for an N/A 2litre stock bottom end VE, with a worked head with N1 cams, Springs & titanium Retainers, N1 T/B, excessive intake with N1 runners off a Q45 MAF, stock primaries with modified secondaries into a 2.5" de-cat exhaust, with Nismotronic for tuning.

Any help, ideas, suggestions, opinions and real world experience greatly appreciated.

Ok I'm going to take a chance at this since no one has replied, but what the heck is a megaphone in a motor vehicle application? Besides emitting an audible siren?

A type of exhaust collector.

Well that is interesting. never heard of it..

Check out burns stainless' website. Has some good info on the matter.

From what I've read around here, the best collector would be a 2.25"

I use megaphone and reverse cone on my header and the only benefit I can think of its that you can run open header and keep power band and torque without the exhaust system you really benefit of the weight savings from removing the exhaust!!

Having the megaphone even with an exhaust will help in the midrange most. It basically ends the exhaust pulses from the header in a super efficient way so the length of your exhaust system doesn't affect the header design much if at all. With no megaphone or a bad designed choke the exhaust pipe extends the length of your header tubes and totally changes the power band of your engine and usually in a negative way. So I would put one on if you can afford it or are having your own header built.

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I too have hard they are pretty useless with full exhausts. I think they make sense with an open header.

(Also, I have this theory that they make most sense facing toward the rear of the car.)

Essentially this is what he is referring to. The other end where the Merge Collector is is where your Primaries go.