LewisL

iTrader: (3)

Hi everybody,

Been buying some upgrades for the wagon and I got my self a slip jointed H&S up pipe a japspeed cat back 3" system and then an unkown made decat downpipe 1nd cat all in 1 which is the open mouth type and 3" all the way through but then right at the end as it would go into the cat back system it drops down to 2.5

Will this cause a restriction enouh to worry about? I plan to run somewhere around the 350hp mark I.e. Sti injectors and turbo

How much do you think it would cost to shop that end off and stick on a 3" piece?

Thanks

midnight

iTrader: (10)

It should not cause you any problems as most decat downpipes are 3' narrowing down to 2.5 ' so that they can fit onto the oe exhaust system. Rather than cut your downpipe and weld on a piece to make it 3' ,far better imho to have your japspeed section narrowed to 2.5' so it mates to the downpipe & no loss of performasnce.
You could just buy a 3' decat downpipe and mate it straight to your 3' centre,but the power gains and the expense dont way up imho. A lot of 3' catback systems are designed to fit the std downpipe have you tried it to see if it lines up ?. Normally you would use a donut gasket,but if the holes line up you may be able to join it using a flat gasket.

LewisL

iTrader: (3)

Hi mate

Yea it will all.line up.and can use a donut as you say I was just wonderig if the fact that it narrows through that lil section will cause me any issues? Or loose me a noticable amount of power I dou t it bug thought I would check

midnight

iTrader: (10)

The fact that it narrows won't cause you any probs, the blitz nur spec r is a very popular exhaust and is 3' catback. Some people mate it to a true 3' decat down pipe , most bolt it on there std cat or a 3' to 2.5' decat downpipe ,any have the car mapped this way,- minimal gains between the 2.5 & 3'.
It would be a lot more restrictive if you had a 3' decat, 3' centre section ,then the std twin pipe 'pea' shooter back box.

LewisL

iTrader: (3)

Cheers pal will leave as it is then