just wondering whether the cheaper exhausts i.e Japseed K2 or toyosports would make the  
same performance gains as say a nismo, tanabe , buddy club etc  
  
they are a fraction of the price , i know they probably wont last as long and may need adjustment , but once fitted do you think the gains will be negligable ? 
  
I can get a cheaper exhaust and y pipe for say £450 / £500 and have money left over for maybe a 
spacer and remap. Where as a nismo , tanabe etc are £££ 
  
i would be interested to see if a cheapo exhaust would cause restriction or poor flow 
  
any comments?