Just a quickie is the exhaust from the cats back balanced i.e joined together. Can I replace the box that joins the two pipes after the cats??

Jonny,

 

My reply is likely to lead to opinions as strong as the 'auto Vs manual' debate BUT my opinion (based on some research) is ...

 

An X-pipe or H-pipe placed in the exhausts will need to increased torque at some point in the rev range. If you move the join then you move the point at which the improvement lies.

 

However, the increase is probably only noticeable on a rolling road. Even more importantly, the difference is likely to be VERY slight on full throttle. As it more affects partial throttle, it doesn't make you any quicker - you just put your foot down a bit more.

 

My advice is to not worry - you'll never notice the difference. Focus more on the build quality and, if you can get them, true rolling road comparisons of any exhaust.

 

Dave

 

So can I presume that the exhausts do not have to be joined together.i.e totally seperate along the centre of the car???/

The Mongoose system I have just bought has two separate sides.