on my 2001 bug eye wrx, if I were to replace the up-pipe with one without a cat

is it 1) a bugger of a job
2) gonna make passing mot's a pain emmisions wise
3) will i need to have remap done

cheers guys for any help

 

1 - Nope, can be done in an hour or 2.

2 - Yes, but some friendly MOT stations will let you off, but if your just going anywhere, you may need to swap the cat back in.

3 - It would be advised yes, as the turbo will start to overboost. There is less restriction therefore it spools up quicker, where there is not enough fuel in the map, which can cause pre detenation. So best to get a remap. It is worth doing though, ten times better with a decat and a remap and a few other supporting mods.

 

just trying to get my head round what mods to do and what order to follow. suppose its a bit of an art than a science... was thinking panel filter, up pipe decat, fuel pump (do i need injectors?) cat back exhaust, with a map in there somewhere prob at the end.

this is all in the future only just got the motor and need to do a few service bit n bobs.

thanks for help

 

common stage 1 is panel filter, decat uppipe, decat centre, sportcat or decat downpipe, walbro fuel pump and then a remap, after this look into sti topmount sti injectors and turbo and another remap, but if going for the latter I would upgrade brakes as well.

 

With what Daz said above.. filter, decat 3" system, walbro, STi TMIC, STi injectors and Turbo then a remap.

You should see 340bhp ish.

Would be a very fun road car!

 

Whats the effect of a decat up-pipe vs downpipe? I assume decat centre has less effect than either?

 

whats the price for a decat up pipe & polish and ported headders??? and would this alone make much difference?

 

yeah well looking to build it up to a real nippy street racer, i live in the highlands of scotland and the roads round my way are just superb.

 

I'm jealous!

 

If the uppipe has a cat as it does on the WRX then removing it with a properly designed uppipe to suit your turbo/spec will make the car more responsive, earlier spooling and add power.
The implications for your MOT are down to the strictness of the MOT station you use and the efficiency of your existing setup.
A purpose designed uppipe, stainless steel, slip jointed, DEI wrapped and 5 new Subaru studs is £139.
We charge the same for fitting an uppipe as we do for swapping ported headers and uppipe (£75) and the job, with all the facilities of a garage typically takes 2-3 hours. Sometimes to remove the WRX uppipe, because of the space taken up by the cat, it is necessary to slacken the engine mounts and jack the engine up to create a larger space through which to drop out the uppipe. Done on your driveway the job will take a good bit longer and you need the right tools. Start at the top by dropping off the downpipe and work on the basis that you are not going to have any spanners or sockets slipping off because once you round a nut you will need heat or cutting gear to resolve the problem.

 

up-pipe, down-pipe ?? im lost, thought they only had 2 cats ? sorry if im being naive ! any help ?

 

All New Age WRX have a cat in the uppipe.

 

 

great reply, much appreciated. so there's 2 cat's after the turbo and 1 before, to save me going outside and having a look, is the up-pipe easy to get to to change it ? cheers

and the pic is of a newage system isn't it ? (mines 04 )

 

Yes, that's a pic of the New Age WRX's system - so yours will be the same.

Not sure about up-pipe. I think it can take 2-3 hours depending on how much grief you get with sticking nuts (oo-er ), etc...

 

To change the uppipe in a workshop is 2-3 hrs as Joz says. On newer cars it is usually easier in that the nuts are not seized on but put WD40 on them the night before you do the job and again next morning. On older cars, especially those that are kept close to the sea, releasing some of the nuts can be a challenge. From time to time we have to resort to heat.
Work on the basis that once you have put a socket or a ring on a nut it is fully home and you will crack the nut without any slip.
On New Age cars particularly it is sometimes necessary to slacken the engine mountings and jack the engine up 2"-3" to get clearance for the old uppipe to come out.
Our charge for changing an uppipe is a fixed £75. There is no additional charge for swapping the headers at the same time as that is only a very small part of what is required.
Start at the top by taking the down pipe off the back of the turbo.
Joz: Very helpful diagram there.