200 cel sports cat welded into bpipe

[Russty]

Had a little search but didnt return the answer i was trying to find .

Ive been thinking about this for a while and im not sure if this would be a good idea or not . Currently got a 2.5 custom cat back on and a dcsports manifold waiting to go on. My only concern is getting my trousers pulled by vosa and the ball ache of having to change manifolds again come mot ( im sure we have all been there )


Now i know obviously a decat generates more power than a sports cat thats a no brainer , but how much more ?

I know the oem manifold is restrictive compaired to the aftermarket manifolds but never seen a race header with sports cat been tested and dyno'd nor have i seen the mugen manifold which is pretty much what im talking about all be it the sports cat further down the exhaust .


Does anyone have any info ?


Thanks

 

[Chewy]

I'm interested in this also, however to my knowledge (someone correct me if I'm wrong) with a 200 cell cat you'll still struggle to pass the MOT.

Best option I've been looking into is welding a 400 cell cat onto a B pipe, and only throwing it on come MOT time...which should be the best of both worlds, you can run a decat manifold all year and only have to change the B pipe for a day or 2 when the time comes.

 

[Russty]

I've heard that it has to be hot to pass however I'm personally not that bothered about the mot passing of it , more the vosa side . At least you will have a fighting chance if anything did happen you've got a sports cat on , apposed to not having anything at all and you get the book thrown at you haha

 

[Chewy]

My bad! Obviously not with it last night.

This whole VOSA thing is new for me, I've never really been aware of their existence in terms of actually spot checking cars and such...Must not be a big thing around my way yet...

Maybe worth dropping a line to TDI North, I'm pretty sure they were offering a B pipe with a welded in Cat to the FN2 lot...So If anyone is going to have some insightful input it's going to be the source.

I'm just not sure if it's a temporary solution to the MOT or actually meant for long term use...I'm sure I've read somewhere that the Cat needs to be as close to the manifold as possible, but if the location of it has a big impact or not to the power/flow etc, I'm not sure.

Think I'll keep a close eye on this one, I'm intrigued.

 

[Chewy]

Have a read through this as well, Page 18 from the top.

http://type-r-owners.co.uk/forums/showthread.php?79802-Staffs-Deltic-FN2-268-4bhp-182-7lb-ft/page18

 

[Teague]

Might be worth looking at this, it has a dyno graph and some details for a custom race manifold with a sports cat: http://civictype-r.co.uk/forum/viewtopic.php?f=37&t=280360

By the way the standard manifold and cat on the dc5 is not particularly restrictive, an ep3 i had made 248hp 181tq with a dc5 manifold, rm01a catback, rbc and a gruppe m

 

[Russty]

Chewy: had read threw that thread hard to gather but i think he has done what im intending to do however its still a bit unclear

Teauge : i seen that a while ago im sure it was a manifold by solid fab ?

 

[Chewy]

Chewy: had read threw that thread hard to gather but i think he has done what im intending to do however its still a bit unclear

Teauge : i seen that a while ago im sure it was a manifold by solid fab ?

Basically, It was saying having a cat welded into the B-pipe (mounted as far forward as possible) there was only a 4bhp difference between a 200cel cat and a 400cel cat, So you could assume the loss/difference would be somewhere between 8-12bhp loss running a 200/400cell cat in the B-pipe as opposed to running just a decat manifold.

You could always take a look at the 'most powerful na on here' thread and see what the difference in BHP was between the stock 220bhp with standard cat vs a map after the exhaust manifold had been changed to a decat and It'll be somewhere inbetween?

http://www.itr-dc5.com/forum/index.php?/topic/5596-most-powerfull-na-car-on-here/

There was also a group buy for the Solidfab manifolds with sports cat on TRO forum giving an example of gains;

http://type-r-owners.co.uk/forums/showthread.php?92879-SOLID-FABRICATONS-EP3-DC5-MANIFOLD-with-SPORTS-CAT-GROUP-BUY

Quote;

'There was another post shows that his manifold with sports cat, RBC catback and TEG M made 241.6 on TDi rollers and 161ft/lbs torque too,
That‘s not bad for a manifold with sports cat.
Torque curve was quite flat too.!!' - Granted this was an EP3, but it gives you an idea.

 

[Rom]

Vosa spot checks for emissions are not something I'd worry about. And you will likely get a producer type of thing rather than an on the spot fine.
I mean think how many legit cars could fail emissions, just because they passed mot say 11 months ago, the cat could be junk by now.
Cats are only tested on mot. So how is average Joe supposed to know he's breaking the law.

I know we're talking about missing cats, but the principal is the same.

 

[Russty]

I know what your meaning however even if i was to get a producer that would mean having to then put my old manifold back on , getting it tested , and then giving them the proof .

I cant really be bothered with that hassle . Im sure i read somewhere that the law states aslong as there is a cat in place to reduce emissions , regardless how much co2 it acctually reduces .

I could be wrong tho !