your uppipe comes up from your exhaust manifolds (headers) and bolts to the underside of your turbo.depending on what power your wanting will depend on whether you need to upgrade to tubular headers and up pipe.

 

Your up pipe connects from the bottom of the turbo to the passenger side manifold. I think that the sti up pipe is de catted anyway so no need to change. I'm not completely sure but someone else may be able to confirm everything.

 

When I decatted my WRX up pipe, I was advised to get an STi pipe because it was the best one (and has no cat). I don't see any reason to change yours.

 

just to jump on board with this one - are they a pig of a job to change? or easy peasy? i've got a bug wrx and the up-pipe is leaking/blowing so was gonna get a decat one and swap it.....

 

I was in at my local subaru dealer at the weekend and was asking one of the mechanics out of interest about the time it would take to change the up pipe. He said it could take up 6 hours, maybe even a day depending on the condition of the bolts. Seems a bit extreme to me though. Want mine done at some point too so I won't be going to Subaru, 55 + vat per hour. Scarey.

 

The STi up-pipe is simply a pipe........ forget about it unless you are after big power

The Newage 2.0 litre WRX up-pipes have a pre-cat and an EGT sensor ....they tend to get in the way over 280 to 300 odd BHP and can be swapped over to a de-cat

The bolts are a nightmare at times (so I have heard) so a local subaru specialist would be a good idea (not dealer) if you are as useless as me with spanners LOL

Shaun

 

Does swapping it out make a big difference in spool up time? Andy Forrest was telling me that I would gain a few BHP by removing it but the turbo response is what I'm after.

 

Meallbahn

Are you running a Bugeye WRX.....if so the big restriction is after the turbo with the crippling downpipe cat

Shaun

 

Mine came off in about six hours.... on the drive, mostly hacking through rusted bolts...

HTH

DunxC

P.S. I love bank holidays....

 

Shaun, I have a blobeye WRX. I will definately be changing the downpipe to a Ninja sport cat and also replacing the mid pipe to de cat, I would like to get rid of the up pipe too but wondering if its really worth the labour cost for the power increase I would see.

Jonny.

 

6hrs must be taking engine out too

my m8 changed both gaskets on my up pipe, 3" / 3 bolt type with 12mm bolts so very tight to get to top bolt,
All in it took 2hrs included stripping out intercooler, un-bolting downpipe, un-bolting turbo, un-bolting uppipe at top, loosen bolts on headers, removing bolts from headers to up pipe (3bolts), replacing gaskets, then put back together.

all done on my driveway using a trolley jack for access under car

only charged me 20 quid too

 

Jonny

It depends on what BHP you are chasing...On your standard turbo (TD04L) I don't think that it's worth messing with the up-pipe.

The TD04 being small has a teriffic spool up (turbo threshold) which won't be altered a lot by changing the up-pipe

Turbo cars are very sensitive to intake / charge temps quite a few BHP is lost on a warm day so with the winter coming, so it's not all down to mechanical things ........ LOL

I swapped my up-pipe when I changed the Turbo to something bigger because it needed more airflow to spin the turbo ...

HTH

Shaun

 

Thanks Shaun.

One more question for anyone who knows . . . What happens to the Lamda/oxy sensor on the mid pipe (I think) when you de cat. Is it on the mid pipe or downpipe, I can't remember. Does the wire get snipped or something?

 

The 02 sensor after the turbo is there to measure the efficiency of the Cat......if the cat is missing then the ECU throws P0420 CEL

Can be mapped out by Andy Forrest (best way) or there are a a few CEL fixes

The Bottom line is that the newage WRX's left the factory completely crippled on the performance front and can be completely transformed by re-mapping

Shaun

 

Cheers, yeah I understand that a remap would sort this problem out but I'm not sure what actually happens to the sensor itself. Does the decat section have a bung to plug the hole where the sensor would go or is there no hole to bung in the new exhaust part? Also does the sensor just get unplugged then and the other end of the wire get taped up?

 

After mapping The ECU doesn't "see" the real sensor anymore.

all the ECU sees is a happy virtual sensor created by the mapper......so the real sensor can be left in situ (usually) or removed.

Shaun

 

My centre decat had a screw thread hole where they put the sensor in and I had no CEL issues.

 

The sensor still gets fitted but the mapper alters a higher signal threshold before the CEL is triggered.

As for the STi up-pipe, don't change it for the sake of it, unless it is broken - its a pig of a job.

meallbhan - if you are changing the exhuast to that degree then half the job to remove the up-pipe is done, so I'd swap to the Sti up-pipe.
You'll need a resistor to compensate for losing the EGT sensor though.

Nick

 

So when changing the downpipe half the job is done for doing the up pipe too, so I may as well change that at the same time? Is that what you mean?

I don't understand what the EGT sensor and resistor are for though.

So for asking so many questions but I want to get it right first time I do it with no hiccups! I live way up north so long journeys are required to get things done.

 

I had the downpipe and up pipe changed at the same time by Tracktive and it took 2.5 hours, so about the same time as doing the downpipe on it's own.

The EGT is Exhaust Gas Temperature sensor which monitors for harmful temps. The resistor fools the ECU into thinking everything is OK.

If you have it all done by a specialist, you shouldn't have to worry about sensors and CELs (I didn't know all this when I had mine done, it was just given back to me with the work all done.)

 

I'm planning to take it to Perth to get the work done, I've heard there's a good Subaru specialist there, but can't remember the name of them, then head on down to Edinburgh to see Mr Forest for a remap straight after. So the people in Perth should take care of the EGT resistor/CEL's etc? If they don't I suppose it would be done with the new map.

 

AFAIK you cannot map out the missing EGT sensor for the WRX ... the WRX expects to see the EGT sensor in place and if it's not there then the ECU throws a CEL . You can fool the ECU by putting a resistor in the Plug by the drivers side suspension turret but it's not 100% .

Andy Forrest is 110% spot on if you have an apointment for mapping then just ask for advice

Shaun

 

AWD is the name of the subaru specialist in perth, they have a good reputation

AWD Motorsport Engineering for subaru, mitsubishi, nissan performance car modification, servicing, spare parts and helpful advice

AWD Motorsport Engineering,
Unit 5, Inveralmond Way,
Inveralmond Ind. Estate,
Perth, PH1 3UQ,

 

^ Thats them, have heard good reports too. Cheers. Will need to give them a buzz and get a rough idea of costs involved.