7 replies to this topic

[chizzle]

Hi,

Right im looking into stage 1 kits for my 998cc and was about to buy the minispares kit as the majority of people on here seem to recommend it until i saw maniflow have developed a new exhaust system with some kind of reverse cone megaphone? They claim it improves torque and the power curve over the original maniflow system? What is the general opinions on this new product? Is it worth getting or would it be designed for larger bore engines?

Link to system: http://www.maniflow...._stage2_lcb.htm

Thanks for the help in advance

[Bungle]

visard wrote a bit about it in his yellow bible

[chizzle]

oh right il have a look
cheers

[Paul Wiginton]

The reverse megaphone does give power, but its too big for a 998 as its 2" going into 2 1/4"

Paul

[elgarra]

I'm guessing they are supposed to be along the same lines as an expansion chamber for 2 stroke motors. Part of the pulse from the exhaust port containing unburnt mixture is "bounced" back into the cylinder(s) by the cone, resulting in more power. I didn't think such a thing would have any benefit for a 4 stroke motor.




EDIT: Actually i've just read the write up on the maniflow site. I think i understand what they mean now.

As i'm a Mini virgin, can someone explain to me why 2 cylinders share a manifold?......I'm guessing it's a space issue?

Edited by elgarra, 12 August 2009 - 11:10 AM.

[998dave]

As i'm a Mini virgin, can someone explain to me why 2 cylinders share a manifold?......I'm guessing it's a space issue?

Because it's a five port head to make both the carb and exhaust package on the rear of the engine.

Sooo. cylinders 1&2 and 3&4 share inlet ports, and 2&3 share exhaust ports.
Then 1&4's exhaust ports are joined in an lcb, or all three in other manifolds.

Dave

[elgarra]

Many thanks Dave.

[SMP]

For those of us who haven't yet bought the bible (had one once but lent it to some SOB who bought my GTM and promised to return the book - never did) - is this reverse megaphone thing any good for a road going car. How loud is it?

My 1275 SKY has a twin DTM which sounds absolutely GEORGEOUS (!!) - but it can be a bit too much on a run and it is a bit boy racerish for somebody of my tender years!!