de-cat question

[rx-paul]

iv just had a custum 3"de-cat fitted for rotastock coz i couldnt get hold of a HKS one
i find its loud but i carnt feel the increase i was expecting from it if anything it seems slower
i had to cable tie the heat sensor up and i blocked the secord pipe that entered the cat could this had anything to do with it
im running a knightsport ecu and the air pump is disconnected
can anyone help

[John Yorke]

Not quite sure what you mean by blocking off the 2nd pipe, if you have introduced a restriction then the exhaust wont flow flow well thus causing loss of power.

[Grizzly]

iv just had a custum 3"de-cat fitted for rotastock coz i couldnt get hold of a HKS one
i find its loud but i carnt feel the increase i was expecting from it if anything it seems slower

Well if you remove all the restrictions from the exhaust it will effect the low end and move the Power more up the Rev range, Its recomended thet when you fit a Decat and a Cat back on Stock twins you have a Boost gauge fitted as it is also prone to Creep and spike. This can be helped by Fitting a Profect B.

The Thing is you never know what the Knightsport Ecu is set up for ether? With such a Dramatic reduction in the Exhaust back presure you may be well to get it tuned fairly soon.

i had to cable tie the heat sensor up and i blocked the secord pipe that entered the cat

I think it fairly common to loose the Small sensor, if you do a search people tend to pull it back inside the car and roll it up under the carpet.

Out of intrest have you removed the air pump too? What other mods have you got fitted?

[Grizzly]

Not quite sure what you mean by blocking off the 2nd pipe, if you have introduced a restriction then the exhaust wont flow flow well thus causing loss of power.

I think the pipe he means is to do with the air pump (about 3/4" in dia that runs  with the Down pipe from the engine to the cat)

The Cat has only got two things connected to it, That pipe ^ and the heat sensor.

[rx-paul]

Out of intrest have you removed the air pump too? What other mods have you got fitted?[/QUOTE]

the air pump is disconnected
iv got a knightsport ecu and electronic boost controller, induction kit, de-cat and cat back exhaust, hard pipe kit thats about it i think

[Grizzly]

Disconected??

Do you mean its just had the Pipe blocked off? or Do you mean its Had the belt removed (so its not turning) and every thing is blocked off??

I don\'t know if it will make any diffrence but when i fitted My Decat i also put a set of Greddy Pulleys on and removed the Air pump completly, But i did also have it set up as it was on Run in.

[rx-paul]

the air pump is still there but all connections and pipework are dissconnected i have thourght about ditchin the air pump completly. im aslo going to get rid of the knightsport stuff coz its not programable and will hinder future mods

[Ricco_04]

Got your sig changed nice and quick there mate!  :cool

sorry back on topic