Extra Power from a manifold?

[MaxedSR]

I want to get a manifold for my car but have not got a "full" exhaust system atm only the back box. Will this mean that I won't get all the power I could get from a manifold i.e. the 5bhp or whatever with a full exhaust system or is it just the power from not having a full exhaust system I won't have (i.e. the exhaust bhp)?
Cheers

Sorry that sound confusing. In simple, if I get a manifold that claims 5bhp if I only have a back box on my car will I still get the 5bhp or will i still need a full exhaust system to get the 5 bhp?

Thanks again....

[Aragorn]

well it will depend on the car

but in general a performance manifold and backbox will produce more power that the standard kit

how much more will depend on a lot of things including engine size and how limiting the center section is

[CP]

Dont bother changing your manifold. What you gain in top end hp you lose in bottom end torque according to the rally boys who have tried manifolds on the dyno. Inother words its not worth it. Stick to the std manifold and twin downpipes and then fit a performance system.

[Jim]

When I got my full exhaust system made up I asked the guy about a manifold and he said there was no need to change it. You'll get more bhp from the full system.

However, I have now got a Magnex 4-2-1 Manifold as my original was rusty and had developed a few holes. Unfortunatley these are prone to cracking around the welds :(

Spend your money on a full system rather than a manifold.

Jim

[stan*]

A 4-1 manifold DOES give better performance than a 4-2-1.
It increases torque by a noticeable ammount over low-mid rpm. It works on the "extractor" principal. With a 4-1 system there is always 1 pipe carrying gases fresh from its cylinder at any given time. This means that where the 4 pipes meet there is going to be a constant depression accross the three that, at that moment are'nt exposed to fresh gases. This depression on the other three means gases are drawn (extracted) through the manifold. This gives the engine more torque at low/mid engine speeds.
A 4-2-1 manifold does this but not to the extent as to give any performance gains.