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Naughty but nice
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There are gains to be had from De-Cats but as we all know they'd need to dyno before and after plus if there are any other mods then this will also effect the outcome.

That one however looks rather flimsy especially at the joins so I wouldn't bother. I would stick with ones I have had recommended, probably would cost roughly the same amount - plus adding a de-cat should really be done along with a ECU to make sure you don't run the engine too lean and get the best performance
 

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Lord of JAE.....
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Are they not also illegal to use on public roads?

Tom
 

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BJJ IS NOT JUST FOR XMAS
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Lord of JAE.....
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Ahhh, I assumed they could nick you over the emissions regulations, but your right not many forces are doing the random emissions tests now...... Thank god :)

ATB,
Tom
 

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There are gains to be had from De-Cats but as we all know they'd need to dyno before and after plus if there are any other mods then this will also effect the outcome.

That one however looks rather flimsy especially at the joins so I wouldn't bother. I would stick with ones I have had recommended, probably would cost roughly the same amount - plus adding a de-cat should really be done along with a ECU to make sure you don't run the engine too lean and get the best performance
Err how would a decat cause the engine to run too lean? Unless there is something different with the K-Series engines to B-Series and H-Series and D-Series?

Your reducing the work the engine has to do to pump out the exhaust gases as removing a restriction. So there is a performance gain. If you can remap the ECU the gains are even better.

They are not illegal. It is also not an MOT failure for the car not to be using a CAT. However it is an MOT failure if the car fails the emissions (which it will without the CAT). Also if you are given a road side check and your car fails the emissions then I believe you can be prosecuted.
 

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Naughty but nice
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Going on information advised to me by Stella when I was getting mines. Here is one of the mails:

-=Stella Artois=- said:
Hi Angie,

There is quite a bit of conflicting information on the Decat. The FN2 runs lean in standard guise, this is so that the K20 engine can meet with emissions. Decatting the car will further increase the engine running lean. I had the car Decatted by ABP and I found that the exhaust note changed markedly, it became deeper but more frantic. The sound you can hear from the rolling road videos that I posted.

http://www.youtube.com/watch?v=TJUGk7HgpsQ

http://www.youtube.com/watch?v=2sXkROgus6E

The decat came into its own when I added the Hondata ECU, as prior to the Hondata the FN2 was running quite lean at 7000 -7400 rpm and there was a noticeable power plateau on the dyno runs. However the Hondata changed that and removed most of the lean issues. I say most because even with the O2 simulator fitted the K20 still suffers a slight leaning at just after the VTEC point (5400) but that's just the Hondata merging the new and old VTEC crossover points.

I was very happy with mine and the car responded very well to both the Decat and the Hondata. I know some people had issues with the Bastuk Decat pipe that ABP supply in that some found thier Decat pipes to have a narrower cross section and they found them restrictive, however mine was straight through, no decreasing in size on the lower flange and it worked a treat.

Was it worth the money. No. The increase in performance was marginal with the Decat on its own, however with the Hondata then yes.

Hope that helps,
Marc.
I would think that the other engines mentioned were not designed to cut emmissions and hence the difference in the decat running the engine leaner. If it gets too lean it can cause issues
 

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Ok. I wasn't meaning to be antagonising I was just wanting to know if it was different. I still keeping having ideas of getting rid of the CC Focus and getting an FN2
 

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Naughty but nice
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Ok. I wasn't meaning to be antagonising I was just wanting to know if it was different. I still keeping having ideas of getting rid of the CC Focus and getting an FN2
the guy I got the info from on the site no longer is on here but at the time he had a FN2 which he had spent £15k modding so was rather clued up on Type R's in general.

Your looking to maybe get one while i'm looking to maybe get rid of mines lol
 

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Err how would a decat cause the engine to run too lean? Unless there is something different with the K-Series engines to B-Series and H-Series and D-Series?

Your reducing the work the engine has to do to pump out the exhaust gases as removing a restriction. So there is a performance gain. If you can remap the ECU the gains are even better.
.
Decats will ALWAYS make a car run lean as well as removing the restriction that's why if makes the power it does.
Lean makes power BUT causes det.:idea:

A car runs in what is called "Closed loop" all the time you are part throttle. This means it is always measuring the air fuel ratio for optimum 14.7AFR for economy and self adjusting the fuelling accordingly. You will only feel the decat or lack of restriction caused by the cat at this point as the engine will be a little more responsive.

Now go full throttle. The car then comes out of closed loop are runs totally off the fuel and ignition maps and no longer auto-adjusts. Now you have removed a pretty big restriction the map that was setup for a stock intake, cat and manifold for correct "Safe" fuelling no longer has the restriction and if you have other mods also you will find it flows more air....as you rightly point out, however the cars ECU is still only delivering the correct fuel for a stock car....with restrictions....Hence it runs lean.;)

Hope this explains it a little better.

I tried a decat even with a Hondata ecu and although it made good midrange gains it actually lost me power at top end. I removed it and got the top end power back.
What was seen on several K20 decatted EP3's was you actually lost power over stock, but if you mapped to it with a mappable ECU you culd gain upto 10bhp.

Basically as has been said, it will work but only if your mapping a car. If your not it will do no good atall.
 

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The Property Man
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the above is actually a really good expanation...i have mine deatted at the minute but mines also remapped...think its a good combo...i would stay away from the decat unless ** car is heavily done...
 

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Discussion Starter #12
the above is actually a really good expanation...i have mine deatted at the minute but mines also remapped...think its a good combo...i would stay away from the decat unless ** car is heavily done...
what you mean heavily done?. can you explain a bit more/>? like what? any examples?
 

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Anybody ordered this JPerformance product?
I bought one second hand looked a good piece of kit nice welds u would need a o2 extension piece to stop the engine light coming on but it looked ok for the money although i never fitted it as bought a manifold
 

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My FN2 didnt run lean standard, in fact quite the opposite. When I did a log with hondata it was running very rich and safe I believe
Going on information advised to me by Stella when I was getting mines. Here is one of the mails:



I would think that the other engines mentioned were not designed to cut emmissions and hence the difference in the decat running the engine leaner. If it gets too lean it can cause issues
 

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Noise

Hi guys I have a fn2 type r I just put a decat on my car with standard Exaust but the noise that comes out is so tinny can anyone advice
Thank you
 
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