De-Cat

[Dan Evans]

hi all, im going to be buying a Japspeed CT9 De-Cat pipe, just wondering what your thoughts are about them and will i benefit with just a De-cat or should i go for a manifold aswell????

i have seen a few manifolds, but theres one by someone on ebay who has them and selling them for 100quid, are they any good??

[Glanza_cl]

dont buy cheep! you can if you want but you will only have to buy another in a week or two.

you will see some nice benefits from just a decat- increase in torque and throttle response

[Dan Evans]

will i have to get the ecu remapped if i get a decat or can i just leave it as it is??

[DavidAshton]

Make sure you have a plan for the intake before you de cat, ive had to go back to standard intake set up and standard tmic to stop me boost creeping, even then it still creeps.

[Glanza_cl]

you cant map the standard ecu you will need a rrfpr at a minimum to get it set up on

[Dan Evans]

what do you mean with the intake set up?? I've got an apexi filter with a samco hosing pipe

[Dan Evans]

so i will have to get mapped to fit a de-cat?? its not just a bolt on and off you go then????

[dave-gtturbo]

Its a bolt on and off you go mod mate, simple and straight forward.

You'll probably find the car boosts a little harder (more pressure). On some cars, and some setups, it can boost so hard (with stock actuator, and no mods ot raise pressure) that it'll over boost (aka boost creep). If it does this badly, the boost level will creep up towards (and try to go over) fuel cut. This is usually around 12 psi...

As a result of this, the car will cut the fuel supply to keep the tuning safe. Should this happen, you'll need to introduce a restriction into your new 'free flowing' setup. Either exhaust or intake end. Cheap and cheerful way is to mask off (usually using ducktape/duct-tape) the breathable surface of the air intake (Apexi Filter in this case). Start with about 50% of the breathable surface covered, drive and see if its sorted. If not, mask more and repeat.

Only start trying to mask stuff up if it is creeping (hitting fuel cut - you'll know if you are).

The alternative to restricting the intake (Enforcing a low boost level) would be to get either and RRFPR and FCD defender setup on a rolling road. Either that, or get some sort of electronic management, setup on a rolling road. This would make the higher boost levels safe. If you do this, start thinking about an uprated clutch too though.

Also, the japspeed manifolds, and that one you posted up top are WANK, as are the Japspeed de-cats.

Speak to Dane at SPS (Starlet Part Shop) to get a decent one

Unless you like cracked manifolds, without flat flanges and decats to match

Hope this helps

Dave

[Jozinobi]

As mentioned above, Dane deals with custom fabricated mild-steel items that are much less prone to cracking than the common stainless steel manifolds and decats.

Joz

[Dan Evans]

cheers for the help