Performance Tweaking

[nick_vts]

Hi, I have just read the FAQ on modifiying engines. Im slightly confused about some of the steps and to what i would have to actually go through to achieve this. Please be patient with me, im still learning! smileys/happy.gif

so..

Performance air filter
Uprated exhaust system (cat-back)
De-cat pipe (removes catalytic converter)
4-branch exhaust manifold

Performance air filter

I have a viper induction kit air filter thing


De-cat pipe (removes catalytic converter)

I already have the cat removed!

So far im fine, but the other 2 points im not too clear on, could someone go in to a little more detail as to what it actually involves?

Also could having the cat out cause problems in an MOT?

thanks!

Nick

[SaxoAL]

yeh , just get another cat and put it back in for the MOT. 15 min job

[Smithy]

Uprated exhaust is basically replacing the standard exhaust system with a performance set-up. Loads to choose from but the best is probably the BTB system. Bout £400ish but very good. It also de-cats at the same time. By law you need to have a cat on all cars made after a certain date 1992 i think. If you still have the cat then you can just replace it at mot time. Cat back systems are uprated exhaust systems that join onto the existing catalytic converter. You will see gains but not as much as if you de-cat the system.

4 branch manifold is a replacement for the existing exhaust manifold.

Scott or simo will be able to explain it better than me, i'm just rambling. smileys/smiley4.gif

[nick_vts]

I have the old cat so ill get it put in for the MOT cheers, hope the garage that i ask to do the MOT wont find it cheaky if i ask them to put the cat back in before the MOT then take it back out again smileys/smiley17.gif.

Thanks for the reply smithy, im still not fully understanding it tho! smileys/happy.gif

[SaxoAL]

do the cat yourself the day before !! literally took me 15 mins to get mine off! Then found out my new decat pipe was an inch too short. So got custom one made up !

[Scott]

4 branch manifold: Aftermarket manifold using much larger bore than the standard cast iron shitter, also a lot lighter than the iron one so less weight. Big gains when coupled with the full system and enclosed filter

Cat back system: Basically an after market exhaust system that goes from the cat backwards i.e. the centre section and the back box.