philthejuggler

Hi all - just a quickie

Got an afterburner backbox on a '54 Plate WRX & looking to put a straight through tube next to it, removing the centre cat.

Will that be fine as-is, or should I really then remap for correct engine operation?

Thanks in advance

Phil

p1doc

i would remap-better safe than sorry but i am sure others may say it is ok
martin

philthejuggler

k - thanks - I suppose this would have the added advantage of a significant power increase!

fromage au pantalon

you would be wasting your money with just that one mod.

if your planning to do more to the car leave it and get it done with as many mods on it as you can before the remap.

if thats all your doing then yes ...get it done

philthejuggler

Interesting! What would you recommend & what extra bhp might they give me? (Don't want the MOT hassle of full Decat, but would consider other mods)

remfanuk

phil, my car has centre decat and uprated panel air filter and was dyno'd by previous owner as putting out 233bhp...thats on a 2000 classic uk car. i too have wondered about why a car would need a remap in some peoples minds with just a decat pipe, perhaps someone could shed some light please?

Elmer Fudpucker

I have the same Zorst mods to my 05 STi PPP,apart from slightly improved throttle response,I'd say theres no increase in overall power whatsoever.

For more BHP,how bigs your wallet?

Front mount I/C

2.5 motor

bigger Turbo

Tek 3

Theres a massive choice out there

scoobyboy1

iTrader: (16)

Ive got a 04 WRX with Graham Goode Backbox and centre Decat and have noticed a slight performance increase, the car seems to pull quicker and the noise sounds nice, dont think i need to spend any more money on performance mods, as its a WRX and i would be wasting my money trying to make it faster as the money could have been used buying a STi.

I wouldn't bother getting it mapped if your decatting the centre, but I would get it mapped if you were doing the uppipe and Downpipe.

k2iss

I thought there were no more cat on new age center section!

See scoobyworld when talking about the ninja center section:
"Please Note - the 2001-2005 model does not remove any cats by fitting this pipe, but improves gas flow over the standard centre section"

On the new age 2001>, the 2 cats are on the down pipe and on the cat pipe, before the center section. Center section has only a resonator (silencer) me think.

See:

Also are you really sure it is worth remapping when changing the cat back section (centre + back box)?
If there is no change of cat and no air induction kit added, I can't really see why the engine would need to be remapped.

Can a specialist confirm these thoughts please?

scoobyboy1

iTrader: (16)

Im pretty sure theres a Cat in the Downpipe, one in the uppipe and the last one is in the midsection. Ive removed the midsection one and left the downpipe and uppipe alone.

Read what I wrote again:

mmmiddy

I experienced problems when I fitted a decat centre section to MY01 WRX, although I did fit an STI intercooler at the same time.

If I accelerate hard and have it on boost too long, the engine cuts for a split second, feels like hitting a brick wall, then power comes back, runs ok but the Check Engine Light comes on and stays on.

Getting mine remapped at the end of the month.

mgcvk

I wouldn't bother with a remap until you get to decat the downpipe, when it becomes more essential.

scooby_matt

Saying that, is it necessary to remap with a full de-cat or can you get away without it?

jasonius

iTrader: (1)

I've had this mod on my 05 wrx (ie centre decat, resonated and ninja BB) without remap no problem at all and probably noticed than the engine reved a little easier with slightly better turbo spool up (although this could be due to getting past the first 5k miles running in..?). Since then it's been fully decatted with a few other basic mods and remapped. All I can say is I definately noticed the difference after this...!

Don't normally do this, but yesterday on m'way doing around 80 ish following a few other cars in outside lane, had a biggish bike right up my **** (although he did have a back pack on his back..!). So as soon as the cars in front moved over I shoved my toe down with the idea of pulling over to let him fly past asap, or so I thought. He bearly kept up let alone pass, and yes he was trying as he dropped down onto the tank eventually dropping back into the middle lane behind me. Only touched 120 then backed off. He then came past and gave me the finger..!!!

Now I've opened up myself up for some stick on here saying this (and the bike probably wasn't that big only a maybe 600) which I accept, but let's just say you won't regret remapping your wrx..!

PS I did'nt really notice any difference with just the above mods without remap IYSWIM.

scoobyboy1

iTrader: (16)

When I had my old classic remapped with full decat, turbo, 550 injectors, bigger intercooler,the list goes on. A 400cc motorbike pulled up next to me at the lights, which I didnt know at the time, as I dont know much about bikes, and started revving, So I thought what the hell, lights turned green and from the pull off we were the same, until I hit 3rd gear and pulled about 2 car lengths on him and after a bit I started pulling away even more, Made me happy even though it was a 400cc, but I still thought he would off beat me off the start cause he was lighter. Just shows when you have all your mods in place and things like that happen, makes you think that all that money spent was worth it.

jasonius

iTrader: (1)

That's it really, I don't bother trying anything with bikes as I know how quick they can be, and even in this instance I hadn't set out to give him a run just get out of his way asap as he was obviously in a hurry. I'm just using this 'suprise' as an indication of whats possible with desent sensible mods, even though it was probably only 125cc...! LOL

mgcvk

Yes, I'm sure most people would agree that with a full decat you would be foolish not to have a remap. The car comes conservatively mapped to cope with three catalysts in place and all those obstacles will have been removed.
The exhaust temp sensor won't know whats going on so you will probably get CEL and car may feel weird to drive if boost spikes.