M35 Dump Pipe Diy Install

[datmoo]

I know there are a lot of different dump pipes running around out there but thought I would do a write up on my install of Scotty's dump and front pipe with lots of pics for those who have not done this before. Thanks go to Scotty for all his tips and tricks.

First put your car up on stands (or a hoist if you are lucky). Make sure your exhaust is cold and spray the crap out of your dump pipe nuts, o2 bung, front pipe bolts, gearbox mount bolts, dump support bracket bolts and attessa line mounts with you favourite brand of penetrating lubricant . Go to bed.

Wake up bright and early and go and spray all of the above again. Go and have a coffee, breakfast, read the paper and have a dump (pun intended).

Next lift your bonnet and remove the plastic engine cover (if you haven't already). Disconnect the o2 plug and feed it down to the dump (green plug on the right).

Get back under the car and remove the front pipe (I had to cut mine even after soaking overnight). Support the front of the mid pipe with some wire or rope around the tail shaft. Undo the first three attessa line mounts so it doesn't get bent when you drop the gearbox (you could probably get away with just the first one). No need to disconnect the tail shaft or shifter linkage. Leave the dump support bracket attached for now.

Then you want to drop the gearbox so take the weight on a transmission stand and undo the four gearbox mount bolts and let the gearbox down (it will only go so far as it will rest on the steering rack). If you do not have a transmission stand then rig up something dodgy to rest it on and raise your hoist. I take no responsibility for people using milk crates as transmission stands .

Next, chose your weapons! I used a cut down 22mm spanner for the o2 sensor, a 500mm 1/2" drive extension, 1/2" to 3/8" adaptor, 3/8" universal joint (a ball style universal will not give enough angle) and a 3/8" 14mm socket (a cut down 6 point deep socket is recommended but I got away with a standard multi point one). I then used the 22m spanner and breaker bar with a bit of steel tube on the end to leaver against the dump support bracket to remove the o2 sensor. Now you can remove the dump support bracket.

Now comes the dump nuts. Surprisingly mine were not too tight and I actually used a 1/2" drive universal and socket on all the nuts apart from the top left one closest to the firewall which needs the 3/8" universal and socket. Inspect the turbo and gasket (i reused mine). Stock turbo still looking good, spinning freely with little play.

A bit of a comparison and pics of new vs old showing the very restrictive factory dump. Old front pipe about 6kg, new 4.5kg. Old dump 4.5kg, new 1.75kg. So with my Nismo exhaust that is a total weight saving of about 14-15kg over stock.

Next you will need to cut down the bottom two turbo studs by about 15mm, enough so the new dump sits flush (remember you can always cut off more). Shove a rag or something in the turbo to keep the crap out. I also ended up cutting about 10mm off the top three studs so I could get the dump on with the o2 sensor in as with Scotty's dump the o2 sensor is offset and you can do up all the bolts with it in place (put some anti seize on for easier removal next time). Clean up the threads with a 10mm x 1.25mm die.

To attach the new dump you can use the factory nuts for the top three studs but will need lower profile nuts for the bottom two. Put a bit of anti seize on the studs. A bit tricky to get the bottom two on especially with exhaust wrap so you sort of have to get the dump away from the turbo face, put the nuts in place and then you can get a few threads on and pull the dump against the turbo. Dump in!

After that comes the dump support bracket, worth the effort to take some strain off the turbo. I drilled out the spot welds and ground down the factory dump heat shield to remove and get better access to the bracket.

Then I cut through the dump flange to remove the spot welds holding the bracket, cut off the rusted studs and nuts and cleaned it up. I also had to elongate the holes on my gasket to fit the factory bracket.

Now you can attach the factory bracket, raise and bolt up your transmission (or lower your hoist trying not to crush your milk crate ), bolt your front pipe back on and do up the attessa brackets. Push the o2 plug and lead back up so you can plug it in from the top and then give her a test run checking for leaks when the exhaust is both cold and hot. Step back and admire your work.

To cat, or not to cat, that is the question.

[Jetwreck]

nice write up.

you forgot to tell everyone how much you swore during this though.....and how many new cut you have.

[datmoo]

Big bump on my head and most swearing from walking into the hoist arm!

My shed is not high enough to lift to maximum height and I'm 6"2" but better than not having a hoist.

[datmoo]

So i've been driving around for about 2 weeks now with my new dump and front pipe and could not be happier with the result.

The extra response and power is awesome and now really compliments the brake cut mod and Transgo shift kit.

Extra growl from the Nismo is nice too.

I drove around for the first few days without doing an ecu reset (13.5L/100km) and then did the ecu reset, pedal and idle relearn and am getting 12L/100km around town.

Now I'm no tree hugging hippy but I decided to do the right thing and put a Magnaflow 200 cell cat in (no noticeable difference).

Felt a bit bad cutting up Scotty's beautiful work.

Thought about driving around like this.

Getting it lined up. Milk crates, is there anything they can't do?

Tacked and then welded in. Not pretty but still learning to use my lift TIG.

Also got myself a 12" thermo fan in preparation for HDI front mount and then I'll be looking at an Innovate Motorsports SCG-1 wideband and boost controller.

[Brick]

Should have just bought Scottys front pipe that has the 100cl cat in the first place . Good work though. Car is coming along mate.

[datmoo]

Should have just bought Scottys front pipe that has the 100cl cat in the first place . Good work though. Car is coming along mate.

Dump pipe was brand new but the decat front pipe came off Alek's (Fishingfreak) car which had a wideband bung already welded in which was a bit of a bonus.

Was good to do the experiment of no cat vs cat though.