Decat straight through with no remap??
 

Got a PPP'ed MY05 WRX
Now with H&S decat centre & 4.5 japstyle:luxhello:

Anyone now if i can get away with a decat downpipe without a remap? Some ive spoke to say yes others no- has anyone done, anyone see an obvious reason not too?

I understand the engine management light will come on- is this easy enough to bypass?

Cheers
Trevor

Too risky without careful monitoring IMHO, you will get overboost after replacing the downpipe which could cause problems.

CEL fix will cure the engine management light or once you get it remapped it can be taken off.

Picked my sti up yesterday with full decat and must admit it was popping and running a tad gruff on my way to meet Andy for a remap.

Best being safe mate.

I'd say yes, you will need a remap if you decat the downpipe (and up pipe) on a newage. Perhaps someone can provide the technical reasons why???

Right better start saving:thumb:

Still be nice to know the technicals if anyone knows though- cheers

Trevor

I de-catted my STI and was experiencing a dip in power at 4000 revs. Took it for a remap to TSL and they said the reason for this is that the car was overboosting and the fuel defencer was cutting in at 4000 revs so the car was running 12-15% to lean. (lambder sensor 1 what ever that means???)

Get a re-map!!!!

+ it voilds your warranty....but i think you already know that... ;)

Agree that on the STI you will get overboost problems but on a WRX it will be fine without the re-map, before Ecutek was available i ran an 01 Bugeye with a FULL de-cat for 18 months without a hint of trouble my 2 mates also ran 01 and 02 cars without any issues at all. Yes the re-map takes full advantage of the exhasut mod but dont panic that you MUST have it done.

Get a good boost gauge and keep an eye on things in that department but again stop panicking.

Sorry to barge in, does this apply for older models too? MY93?

Trevor,

You may find it hard to believe, but if you drop a reputable mapper an E-mail, you'll get the best answer and it won't be "yes you must get a remap, that'll be x hundred pounds please". If the car will run ok without it, they'll tell you.

Of course, with any modification that affects the car's breathing or fueling a remap will optimise the gains. IIRC from here, New age WRXs will run a decat without issue, although don't be surprised if the gains aren't noticeable; Andy Forrest tested a WRX (as part of Project WRX) before and after a decat and noticed only 5bhp and 3lbs ft more as the ECU was compensating for the changes. When he remapped it, the car acheived 300+ bhp and similar torque.

Ns04