De-Cating my JDM N/A

[Cipriani]

As the title suggests imgoing to de-cat my N/A J-Spec pretty soon, does the j have 2 cats? I have a cat back stainless system on just now, so what's going to be the best option here? Looking to keep the current system but unsure of the diameter, would it likely be 2" or 3? Assuming it is still the correct size. Still not really clued up on the best places to buy supra parts so a point in the right direction would be helpfull

[JasonR24]

Not much point in decatting an NA tbh.

[Cipriani]

I'm going to be doing an NA-T in the coming months though.

[Chris Bailey]

Hope you've got some ear defenders handy

[Rich.2211]

I'm going to be doing an NA-T in the coming months though.

 

Get yourself a 3" second decat pipe. Your first cat will be replaced with whatever downpipe comes with the NA-T kit

[Herb]

I would wait until you've got all the parts for your engine swap.

 

Otherwise you could do the same is I did when building my NA:

Use a Xerd header in order to get rid of the first cat plus a Garage Whifbitz midpipe. The thing is that you won't pass smog test that way.

I welded a 200 cell high flow cat into the midpipe in oder to pass it.

With proper ECU tuning (which I did) getting rid of the stock cats does make sense on the NA.

But to do it right you will end up like me - spending twice as much as on a TT swap for a built NA. But that was my plan - I'm crazy :)

 

So stay stock for now and get you down/midpipe when doing the engine swap.

[Nic]

I would wait until you've got all the parts for your engine swap.

 

Otherwise you could do the same is I did when building my NA:

Use a Xerd header in order to get rid of the first cat plus a Garage Whifbitz midpipe. The thing is that you won't pass smog test that way.

I welded a 200 cell high flow cat into the midpipe in oder to pass it.

With proper ECU tuning (which I did) getting rid of the stock cats does make sense on the NA.

But to do it right you will end up like me - spending twice as much as on a TT swap for a built NA. But that was my plan - I'm crazy :)

 

So stay stock for now and get you down/midpipe when doing the engine swap.

 

In the UK you just need to fit the 2nd cat come MOT time, if all is in good working order it should easily pass the emission test.

[Cipriani]

Because its an N/A wont it pass as theyre not listed? Also its none of my best mates that MOT's my cars

[Cipriani]

Hope you've got some ear defenders handy

 

that bad?

[Abz]

that bad?

 

No worse than that!! After 2 months most owners report loss of hearing, experiments have deemed it is the equivalent of standing next to a Boeing 747 at take off....

 

 

[Guest Roger NE]

Removing the Cat should give you an extra 10 bhp or so, as even a new Cat is quite restrictive. (and an old one is likely to be well clogged up)

 

Personally I remove the cats but still have decent silencers, so it's no louder than a standard car (don't like to attract attention when I'm driving fast!)

Edited December 14, 2013 by Roger NE (see edit history)

[Erick]

No worse than that!! After 2 months most owners report loss of hearing, experiments have deemed it is the equivalent of standing next to a Boeing 747 at take off....

 

 

 

I agree, with decat and 3" exhaust they got very very loud!