daniel_3855

hi guys i have a 2003 impreza wrx sti jdm its the jap import model with the twin scroll turbo, iam after a de-cat down pipe but need to know if there is any difference from the uk downpipe and the jdm downpipe, is the mouth the same that bolts on the turbo? also does it give more bhp can you feel the difference? its already fitted with the de- cat centre pipe. can anyone help guys.

TonyBurns

iTrader: (3)

These cars only have one cat to start with and thats in the down pipe, its also not the same as the uk car as the JDM cars are a twin scroll turbo setup.
If the car is fitted for instance with a miltek exhaust with the sports cat, you wont gain anything, also if you decat you WILL need to remap the car, no if's or but's, remap or pay for a new engine
Oh as i see where you are, give prosport in stockport a ring rolling road and do remaps, 0161 4329999 they can advise you about your car

Tony

daniel_3855

hi thanks for the info. it has a 4" system from the downpipe to the back no sports cat. i have the standard exhaust system and it does have a middle cat? would i gain more power if i had the de-cat downpipe fitted, also would it be ok if i had it put on rolling road and have all the mixtures done?

TonyBurns

iTrader: (3)

You would gain more power with a remap and decat, and that bit in the middle will be a resonator box and not a cat
Best to have the lot done at the same time though, change the pipe (though some mot places may fail you if you dont have a cat) and have it remapped.
Estimated power will be in the 360bhp region and similar or slightly more torque just check with your insurers first before the remap.

Tony

daniel_3855

i got a price on a remap for £650 dont really want to spend that much but phoned another tuning place think its called mtech in congleton, they said if i put the de-cat on it will be ok not to have the re-map but will need to be put on rolling road to set it up ie mixtures, air flow, and setting the boost ect and only want £100 and what they do is do the readings first then tune it all in and put it back on rolling road. what do you think mate would it be ok?