[z19930612]

Took me something like 5 hours to get them fitted (1 hour on matching the turbo out let with downpipe inlet into the clamp)

I ll make a brief instruction here with the tools you gonna need

So first thing is to take off engine cover and release two front o2 sensors(two before the cat) plugs in the engine bay which sits next to the intake manifold
The reason for doing this is because it is almost impossible to unscrew the sensor from the downpipe and it also loose the cable to prevent the cable get twisted too much and snap when you un screw it.

Unscrew the steering rack by removing two E12 screws, there is a bolt on the other end of the screw, you need to fix it by a wrench(13mm maybe?) in order to loose the screw
This step gives lots of room for you to put your tools into where they need to be

Then remove the catback holdings by E10 socket

Unbolt the four screws on the downpipes that connects to the catback, before you try to take it off, you should spray some WD40 or something else on the screw and let it sets for 10mins, as those screws are really tight and rusty, so they could break if you don't give them a little grease

Remove the O2 sensor on the passenger side downpipe by a 22mm wrench, you can take off the connector if you think you have to

And then loose the clamp that tighten the downpipe and turbo by a 13mm socket or wrench, the screw needs to be taken out completely, and you need to use a long screw driver to loose that clamp and push it away from the downpipe

Then you can try take off the passenger side downpipe, just twist around and wiggle it it will finally comeout, be careful that the o2 sensor is still on the downpipe, remove it with 22mm wrench when you drag the whole downpipe out from the car(it depends on how much did you loose the sensor cable in the first step)

Remove the 2nd downpipe with the similar way

Then you are ready to put your aftermarket downpipe into the car

First one goes into the car should be the driver side one, connect both two o2 sensors before you do anything as they cannot be reached when your downpipe is in place(the mistake that I made)

So here is the pain in the ass bit
put the clamp on the turbo, and twist the downpipe around to hope it will go into that clamp...
I don't really have any better way of doing it instead of trying it for hours... Just need to be patient and it will finally goes in, when it goes in, you should be able to squeeze the clamp together and there should be 1-2cm gap between them, anything bigger than that means you failed to clamp them together, also, be careful to avoid the waste gate actuator switch, if you block it with your clamp you will blow your turbo.

And the rest steps have nothing hard, the clamp for passenger side downpipe is much easier to fit because you can touch and adjust the clamp from the side.

Anyway, I get it done, there are some white smoke coming out from the car, I hope it came from the oil that I put on the downpipe surface with my hands.

And because my car already deleted the 2ndary cat, so now it is a pure straight pipe, and I get shocked when I start the car lol, it's just too loud, also the car now sounds similar to 1M when idle maybe because I got M3 backbox and quad exhaust.

Anyway, hope things won't go wrong on the car :/

[z19930612]

Also, I remember somebody told me that there are difference between the downpipes for LHD and RHD vehicles, my downpipe came from CP-E from US and I didn't find any difference at all, fit spot on

[z19930612]

Yo straight homie

[gaza01]

Great work!!!

[old grey steve]

Pipes look slightly thinner I'd say than the VRSF items I've got to install I've seen 3 different pipes types/brands all of which look slightly different but readying your comments re install etc. it exactly what we encounter commendable work BTW. Congrats great write up with pics to boot

[windymissile]

Originally Posted by old grey steve

Pipes look slightly thinner I'd say than the VRSF items I've got to install I've seen 3 different pipes types/brands all of which look slightly different but readying your comments re install etc. it exactly what we encounter commendable work BTW. Congrats great write up with pics to boot

The VRSF ones I have are 3" all the way to the mid section flange. These seem to be 2.5" from just behind the first bend. Probably why they fit so easy.

Either way, good going doing this on your own. It's a nasty little job.

WM

[z19930612]

Originally Posted by old grey steve

Pipes look slightly thinner I'd say than the VRSF items I've got to install I've seen 3 different pipes types/brands all of which look slightly different but readying your comments re install etc. it exactly what we encounter commendable work BTW. Congrats great write up with pics to boot

I bought all of my tuning parts from one company, so didn't really looked around :P
Anyway it is just a hollow pipe isn't it

[old grey steve]

Originally Posted by z19930612

I bought all of my tuning parts from one company, so didn't really looked around :P
Anyway it is just a hollow pipe isn't it

True and one that's a sod to fit

[zltm089]

Thanks for posting!

how's the power and noise?

[z19930612]

Originally Posted by zltm089

Thanks for posting!

how's the power and noise?

Haven't test out anything yet, car got a cracked waterpump, replacement one coming tomorrow and I ll get it fitted,(by removing the damaged water pump leaves me plenty of room to work on the down-pipes lol) should be able to drive it in this week

[jwilliams]

Do the catless downpipes make a stock system too loud or just right?

[z19930612]

Originally Posted by jordon335

Do the catless downpipes make a stock system too loud or just right?

It is a bit too loud when start actually, and then it will get quiet after the car is warmed up, I will attach a video later

[jwilliams]

Thank you. Thinking of slightly modifying my car. Maybe go for these instead of cat back.

[z19930612]

Originally Posted by jordon335

Thank you. Thinking of slightly modifying my car. Maybe go for these instead of cat back.

The catless downpipes are really release the full potential of the turbo as they sits just behind the turbo, by removing the 2ndary cat doesn't give so much contribution on power out put compare compare to the catless-downpipes
For a 335i if you want to go for 400bhp ish all you need are:
Bigger intercooler(cool down the compressed air)
Catless downpipes(gives smooth flow?)
JB4(or some other computers like Cobb) to let you adjust the boost rate and many other functions like rev limiter and turbo shut down
And you can also change the charge pipe with a blow off valve to protect your compression systems as the stock charge pipe is plastic and stock blow off valves are weak

So in total it's below around 1800 pound and you will have the full potential of your chained monster

[AWSAWS]

What does this mean with emissions?

Do you have to get a special MOT? Would a roadside test fail you or are the emissions low enough once the engine gets hot and the secondary cats get hot?

Can it destroy the secondary cats? I want down pipes and the catless are much cheaper. Plus I like the unrestricted flow helping the turbos in boost and longevity.

[AlanYoro35i]

Originally Posted by AWSAWS

What does this mean with emissions?

Do you have to get a special MOT? Would a roadside test fail you or are the emissions low enough once the engine gets hot and the secondary cats get hot?

Can it destroy the secondary cats? I want down pipes and the catless are much cheaper. Plus I like the unrestricted flow helping the turbos in boost and longevity.

Yes