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Honda Civic FN2 TypeR Type R De Cat Decat Downpipe????

27K views 22 replies 13 participants last post by  SteveT 
#1 ·
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#2 ·
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
 
#6 ·
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.
 
#3 ·
Are they not also illegal to use on public roads?

Tom
 
#5 ·
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
 
#7 · (Edited)
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
 
#19 ·
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
 
#8 ·
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
 
#12 ·
what you mean heavily done?. can you explain a bit more/>? like what? any examples?
 
#21 ·
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
A decat will exacerbate exhaust noise as there is firstly far less silencing than a cat with its internal monolith and external heatshield; secondly, it may have thinner sidewalls. You should find after a few hundred miles the noise will suppress with carbon build up. You could heat wrap the pipe to try and quieten it as an option. You may also find that if you remove the centre silencer the noise will become less tinny and perhaps a little more 'boomy' :)

Sent from my D6503 using Tapatalk
 
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