Originally Posted by JamJay
Time for pics?
Haha! alright here are a few. sorry, the install is only taking place tomorrow so I will re-post when I have those pics...
This is mainly the exhaust itself and the diffuser mod
First few pics are of the axle-back custom exhaust (2-piece). This is EXACTLY as I wanted it. What you will notice is that the pipe leading into the muffler was split into two and that the muffler has 2 inputs and 2 outputs directly opposite each other. I specifically requested this as that allows HALF the airflow to enter each side and exit each side. This is to give both the left and right sides as equal a flow as possible, so none of that massive flow one side, teeny weeny bit other side story - well, hopefully not anyway. will find out soon. This is different to most of the other designs for the 135i that I've seen which have a tiny pipe going to the right to feed both outlets there. I think the genuine Hartge is the only one that's similar to mine?
Mine is a full stainless system with the welds not ground down. It's a bit dirty as the exhaust was only just made before I took the pics. Will be cleaned and polished before mounting. Tips are 76mm I think? Decided against the 80mm blue titanium. wanted the s/s to stand out.
Onto the diffuser.
If you look at the pic of the fitting side of the diffuser you will notice the 6 white metal tabs at the top edge. These tabs need to slot into slits in your bumper. The guy manufacturing the diffuser (un)kindly placed them but in the incorrect spots, some were off by a whole CM or more. They are only held in by a powdery resin of some sort - required some chipping at with a chisel to get it off, and reposition (I had to create two extra tabs as 8 are needed in total) and then glue them on with fast-set epoxy. It helps to have a dad who used to restore cars as a hobby, helping out. Maybe get one of those, if not, and you're handy enough, just DIY, or get a body shop to do it. Though a few tips, when marking where to reposition the tabs, place the diffuser on the bumper, do not click it in fully, just drop it down a tad to check where the slits are and mark that on the diffuser with a white milky pen or masking tape. MAKE sure to remain parallel with the cars long axis (front to back) when doing this as if you move your head with the curve of the diffuser, you will inevitably incorporate error of parallax into the markings, and they can be WAY off, almost by a whole CM once again, so remember to just keep looking FORWARD when doing the marking, don't turn your head. And keep the tabs narrow, the ones on the diffuser are about twice as wide as they should be.
Once marked, you can start placing the tabs and epoxying them. Sorry I forgot to take pics after I had epoxy'd the new tabs.
Also, there is one small plastic under-tray on the car which will need to be removed, it is toward the centre, and is quite obvious which one, as the diffuser fits in its place, and the other slightly larger tray at the right side, needs to be cut to allow the pipes on the R side to exit, though your exhaust shop might naturally do this for you anyway. these pics are also included below.
lastly, one other tip - in order to support the pipes on the R side, your exhaust shop might weld a bracket onto your chassis like they did on mine (which they matched with an OEM like rubber mount). but that weld is not covered with paint, so I sprayed some Tectyl onto it (brown stuff) to prevent rust in future, just thought you should look out for that and cover that area up if yours is exposed.
That is all for now, will post up when the install is done. If you have any questions just ask away. Happy to help.