Andy_Lucas Hi I'm going to get Tullett manifold which is 2.5" diameter. Should I get the down pipe and rest of the system in 2.25" to create back pressure or keep it all 2.5" Advice please, cheers
Matt If you go 2.5" all the way through, you'll notice quite a loss of bottom end torque. NA doesn't need 2.5", so you are probably better reducing it down to 2.25" to keep the back pressure and torque up.
Andy_Lucas OK cheers so is it worth me buying a bigger downpipe then or should I just cut out the pre cat and keep the standard one ?
Andy_Lucas Had the Tullett manifold fitted and doesn't feel any different tbh.. Seen MikeS has 2.25 downpipe pipe but seems nearly impossible to find one.. I saw Vocky recommended a 2.5" downpipe and then a smaller cat back so I might invest in the Piper downpipe ???