Exhaust Collector Modification

[DohNut]

 

I am now the proud owner of a slightly used TechCraft Goodwood sliencer.

 

However (and I did know this when I bought it) it has a 2.25 inch inlet.

My Current collector is 2 inch, It looks a fairly easy job to modify the collector to the larger diameter by cutting off the old collector exit pipe, and a little of the collector and welding on a new bit of pipe.

 

First Question - any suggestions of who to do the work in west London. I have a fabricator in mind but he does a lot of big orders so my work either is rushed through because it is little or keeps getting put to the back of the que because its little

 

Second Question

as well as this change because the Goodwood is so much longer there is much less pipe between the collector and the start of the silencer. The current setup is Collector to 2 inch pipe for 8 inches then silencer changing to

Collector to 2.25 inch pipe for 4 inches then HUGE silencer.

Is this really going to screw up my engine ?

Or is most of the resonance happened in the primary pipes?

It is a fuel injected X-Flow with big valve head and 244 cam.

 

Thanks

Nick