Exhausts Diameters?

[TheKingGrim]

now then lads im tryin to fit a turbo to my wreck of a micra and was wondering what size pipe you lot run on your exhaust for A)the mainfold and B)the actual exhaust pipe?
Now i know it dont matter how big you go really well except for weight i suppose but who ever worries bout that but how small can you go without back pressure problems ive got a load of scrap lenghts of stainless that would make some tidy pipes but i think they may be a bit puny as there only 2" inner diameter?

 

[frank]

the mani dia is,nt really important, but from the turbo back needs to be as big as possible

 

[TheKingGrim]

the mani dia is,nt really important, but from the turbo back needs to be as big as possible

yeah thought as much ive never heard anyone go bellow 4"

 

[Descent]

what the heck. 4"? thats what you do on a 6ltr V8 Turbo. But not on a little 1l or 1.4ltr micra.
2,25" is plenty!

 

[RYB]

now then lads im tryin to fit a turbo to my wreck of a micra and was wondering what size pipe you lot run on your exhaust for A)the mainfold and B)the actual exhaust pipe?
Now i know it dont matter how big you go really well except for weight i suppose but who ever worries bout that but how small can you go without back pressure problems ive got a load of scrap lenghts of stainless that would make some tidy pipes but i think they may be a bit puny as there only 2" inner diameter?

My turbo had no problem spooling half a bar instantly with a standard exhaust including the secondary cat. 2" is plenty.