decat advise
 

if i put a full decat system on my 01 wrx ,what else do i need to do ?

my friend tells me all i need is an uprated fuel pump and remap ?is this right ?

Hi there,if you put full decat exhaust(which include decat downpipe,decat centre pipe and backbox) on 01 WRX i'm afraid you will need remap.But if it possible buy decated uppipe for better results.For best results i recommend you wait and buy VF34,VF35 and STi pink injectors,3port boost solenoid and after this Fuel pump Walbro and you will see after this around 330-350BHP.
Fuel pump i'm not sure,some mappers this require or recommend ,but only this time if you are putting bigger turbo,injectors,but at this moment is pointless.
Maybe help.

I presume you have a WRX and not an STi bugeye.. Decatting will improve turbo spool and improve performance a little (but not a whole lot) as the ECU just plods along as it left the factory !

You will get CEL P0420 as the ECU also thinks your cats have gone (which they have) !

The UK 01 / 02 WRX left the factory in Japan seriously crippled in performance terms so as not to worry people who bought an STi....

The bugeye WRX comes alive with a new exhaust / panel filter and re-map :)

There are loads of tuners on here who can help but for bang per buck for such simple changes it's hard to beat someone with experience with "opensource" mapping :)

http://www.racedynamix.com/new/

Shaun

double post as someone was typing at the same time !!

just a 01 wrx mate not sti .
im pretty new to all this ,not wanting to spend too much ,just want some etxra performance and sound than the standard system .

is a remap always neccesary when decating ?

Remap is necessary,matey.
Yeah you can run without remap,but off the boost,until your car is remapped.350£ for open source mapping is much better than 600£ for EcuTek.

is this the case whether removing one or both cats ?

Decatting the Bugeye WRX will get a bit more noise and a bit better pick up but not much more as the ECU still thinks it left the factory as a WRX !

You do not need to remap the bugeye WRX as the ECU is clever enough to cope with the extra air coming through the Small TD04 turbo. Decatting the STi bug is different as the Bigger VF35 (usually) has a field day and causes boost spike problems ..

Back to your WRX....as I mentioned the WRX bug left the factory pretty crippled so as not to compete with the STi. With a simple re-map (£350 ish) you will have a completely transformed car :)

Which is how the Jap WRX left the factory in the first place..LOL

Shaun

most people leave the up-pipe cat in place along with the EGT sensor and either de-cat from the Turbo back or fit a "sports cat".

Shaun

ok mate cheers ,so to clarify what you said ,i can put a full system on without causing any harm to the engine ?but will need a remap for optimal power gains ?

my friend ****ed two engines on a 2000 classic by doing the above with no adjustments .is this not possible with mine?

bloody hell this is confusing haha:cuckoo:

You are correct in post 10 ....You can de-cat the Bugeye WRX and get a bit of extra performance, the very clever bugeye DENSO ECU will compensate for the change and the small TD04 turbo you have won't cause problems with over-boosting.

To get a real improvement in performance you need to get the ECU re-mapped :)

The earlier JECS ECU in the Classic was not so clever and could run lean and damage engines if the car was de-catted.

The DENSO ECU you have is really quite smart..I have the same ECU running a bugeye with 400 BHP on a bigger turbo with lots of mods and methanol injection :)

There were problems with the de-catted STi bugeye but that was due to the bigger turbo boosting too much.

Hope this helps

Shaun

A 3 port boost solenoid and remap to go with the decat makes it an altogether better car :thumb:

Brings the boost in much stronger, much earlier and will hold more of it to the redline.

these posts are really helpfull cheers .
thats pretty good news for me as it means i can put a system on and then get it remapped when i have the money .do i need uprated fuel pump as my friend suggested ??

what kind of bhp could i expect with the decat and remap ?

dynamix ,how much is the solenoid and is it easy to fit ?

You'll see 260-270 bhp with the following
Decat/sport cat down pipe,
Decat midpipe,
Good flowing exhaust system,
Pannel filter,
3 port boost solenoid (about 50-60 quid, and mapper can usually fit/plumb it in....but the car HAS to be remapped straight away if you fit this)
The better fuel pump will be needed if you modify the performance any more than this. :)

looking back i see CEL P0420 mentioned ,what does this mean ?
is this a warning light i will get ?can it be ignored till remap without any harm being done ?

Yes it is a check engine light code. Just says the car isn't working properly. Which it isn't cos there isn't one.

Fine to ignore but it can mask other issues so best to get it sorted sooner rather than later ImO.

cheers mate .
ive bookmarked your site ,going to have you out when i do all this .

Cool - best bet is to give me a ring a couple of weeks before you are ready to sort a date that works for us both :thumb:

i got my car remapped by andy forrest, full turbo back de-catted exhaust from meerkat exhausts(custom built), walbro fuel pump, K&N panel filter, this is a 2002 wrx bug and reach 286bhp, a completly different car, now on the greed of more power

Hi Duncan

Posted on Cumbrianscoobs technical section about my car :)

Shuan

aha - replied on there now :D

Why do people never mention the clutch when they talk about these stage 1 mods. I had a remap on my 2001 with a Miltek sports cat, k&N panel filter and uprated fuel pump, power was 281bhp but the old clutch couldn't take it in 4th, so unless you have a recent clutch then you might need to add around £450 to your budget.

would i be better to just put a cat back on ?so leaving one cat in place to avoid bringing the fault light on ?
then remap when i have the cash ,im thinking this may be a better option for me ,is there a big difference in removing both cats rather than just one ?

im new to all this haha ,just exploring all options

just bumping this one

you can just put the cat back on for now and put on the decat down pipe (and up pipe if desired) when time comes for mapping you will get a better noise but not much performance gains. if your worried about the cel the mapper can remove it or you can fit a cel delete which the are two types a resistor that replaces the sensor which tricks the ecu into think all is ok or a cel fix that removes the sensor from the direct exhaust flow so gets lower reading and ecu thinks all is ok (i have this on mine and works fine). i have full decat up pipe,down pipe and centre, a 3 port boost solenoid walbro pump and k&n typhoon kit on mine and duncan remapped it and the car pulls really well spools nice and low to cant recommend him enough car feels really different just one on the decat, it is ilegal to have a full decat and car will fail MOT so cats have to go back on once a year for that which can be a pain in the arse unless you know a friendly tester;)

De cat sensor
 

Where can you buy these sensors I just brought a Subaru impreza 52 bugeye and management light is on he told me it's because of the decat and I believe he was being honest but want to make it go away without losing performance running at 320bhp with dunno print outs

Sorry for awakening this chat

Get the code read first then I'd think about your rolling road print out should of been remapped to gain a power increase like that
Something is suspicious there ? Could be underlying problems

It's had full turbo back exhaust injectors fuel pump bigger turbo and has been remaped
I will get the code checked
The car runs 100% fine but maybe I was to trusting

Get the code read buddy, the cel for the cat effienciey should of been mapped out. Do you know who did the re map?