hi,can anyone tell me if a milltek mssub123 high flow sports cat downpipe will fit the existing standard oe system on a 2002 jdm sti bug?
it looks as if it is a 2.75 bore rather that a 2.5 at the end that fits to centre section.it is a 1 piece downpipe.
so will the oe 2.5 centre section taper enough to fit the doghnut gasket on the end of the downpipe?
and is the length etc correct?
milltek say it has to be fitted with the rest of the milltek system,but then they would say that......
any ideas?
thanks.

 

i dont even know if the mssub123 milltek is for a classic/newage!
ive also read a thread that a jdm bug is same fitment as a classic......really confused.

 

I have milltek on mine and its 2.75 tapered down to 2.5 at the flange

 

oh ok,so does that mean i can fit it with the rest of the oe system in place?
is yours a jdm car?thanks.

 

Not sure, but would have thought so as standard is 2.5
I have full system on mine newage blob wrx

 

when you say it tapers down,do you mean the bore of the pipe gets smaller before the flange or does the bore stay at 2.75 but the flange makes 2.5?
as the piece of pipe that the dohnut ring sits over is 2.5?
thanks for your help so far mate.

 

As far as i can remember its a 2.75 downpipe and the flange is 2.5 fittment onto the centre section think it might taper down nr the flange but dont quote me on that, my mate fitted it. I cant remember if the model number is the same but sounds familiar

 

Just done some checks but i may of been wrong. I think it 2.75 at the flanges as im sure it 2.75 all the way, and milltek say it must be fitted with milltek centre section
http://www.millteksport.com/exhaust....?variantid=105
Have a look at that.
Mine is the pic at the bottom of page the 1st one (left hand side)

 

i cant find which pic u mean?
thanks for all your help mate.
i know milltek say that but will it fit an oe centre?

 

For the downpipe I think you will need the rest of the system from Miltek mate as I have a full turbo back system from Miltek and I can't change the backbox for something louder as it wont fit

 

thats because the centre is not the same length,this does not mean the downpipe wont fit an oe system.

 

If you get a flange spacer then it could fit to make up the measurement.

 

why? are you suggesting that the milltek is longer or shorter than the oe downpipe?

 

Not sure, but im presuming that you want it to fit a oe with a 2.5 flange from a 2.75 milltek flange. Not that i would do it myselft but trying to help resolve the issue for yourself.
Try getting a flange 2.5 one and should make it fit the joint of milltek.
I would not do this myself but imo thats the only way its gonna fit.
Just find the rest of the milltek mate if i was you. Centre sections are quite cheap 60-70 poundish. Just downpipes and backboxes are a bit pricey

 

ive measured the bore of the pipe which the douhnut gasket sits over and its 2.5" on the milltek.so as long as the milltek downpipe is the same length as the oe downpipe then surely it will fit?

 

Sorted then mate
So it must taper down at the flange.
Good luck with fitment.

 

yeah its defo 2.75 all the way down,then the flange is welded on then that small bit of pipe that sticks out for dougnut ring is 2.5".
just hope the length is the same.
thanks for all your help mate.