de-cat question

[Eckascliovalver]

As some of you may know im having problems with my cup, now that i have the correct backbox on the car its responding well, but now i want to remove all restrictions from it and put on a de-cat,


Will it fit the standerd system ok? any recomendations? and what sort of gains will it produce? and what will it sound like, giving that its on a standerd system


Ecka

 

[Schweppy]

Dont know much about any of it LOL but i had mine decatted yesterday and i love it! Sounds awesome and is much more free revving. Has taken away the 5k kick too and it just revs continuously now. I get a few pops out of the system now as well. Not sure if thats good or bad though!

 

[Eckascliovalver]

so its loosend up the revs before 5k is it a standerd system you run, does it feel any quicker and less restrictive, what decat did you go for?

 

[Schweppy]

Its alot smoother through the whole range.

Mine isnt a standard system but i've compared it to someone with the same exhaust without a decat. Defo less restrictive. Couldnt really tell much difference speed wise but its being RR'd in a few weeks!

Decat came free with the exhaust system so dont know what make it is! lol

 

[Martin_172]

decat will fit the standard system no problem, although the standard system will be the "new" restriction!

glad to hear your getting it sorted.

 

[fil_b]

Its alot smoother through the whole range.

Mine isnt a standard system but i've compared it to someone with the same exhaust without a decat. Defo less restrictive. Couldnt really tell much difference speed wise but its being RR'd in a few weeks!

Decat came free with the exhaust system so dont know what make it is! lol

what system are you running??

could u get a pop out a stealth system?

 

[Schweppy]

I have a blueflame twin slash cut on my 182. Don know about on a 172.

 

[The Seer]

I had a YozzaSport de-cat fitted along with my BTB exhaust system to my 182 Cup last week. Also fitted an ITG Maxogen kit.

It sounds great, other than that I've not really noticed any performance increases at all from any of the above mods.

Been advised that a re-map will utilise the components properly.

 

[Eckascliovalver]

although the standard system will be the "new" restriction!

very true but surley its better than the cat restriction you would have on a standerd system

 

[Andyman]

I had a YozzaSport de-cat fitted along with my BTB exhaust system to my 182 Cup last week. Also fitted an ITG Maxogen kit.

It sounds great, other than that I've not really noticed any performance increases at all from any of the above mods.

Been advised that a re-map will utilise the components properly.

Best part of a grands worth of mods there so yeah defo get it mapped up for full effect

 

[Chavadurkin]

If you De-Cat the exhaust - your car will fail its MOT surely........?

I am currently getting a 'sports performance' Cat done in mine and it is said to allow the engine to flow more freely..... ( whatever that means ).

I am having it done by a company called zorstec if anyone wants to check them out.......


Chris L.

 

[PeteCup]

If you De-Cat the exhaust - your car will fail its MOT surely........?

I am currently getting a 'sports performance' Cat done in mine and it is said to allow the engine to flow more freely..... ( whatever that means ).

I am having it done by a company called zorstec if anyone wants to check them out.......


Chris L.

Sports CAT will have less cells per sq inch (i think thats how its measured). I have a 200cell (per sq in) in my Cupra and it made a hell of a difference to the car and is MOT freindly too. Happy days

 

[Martin_172]

bigger gains to be had on a turbo car but yeah it will make a difference on a 172.

id go for decat and swap it over at mot time but thats just me, if you would rather fit it and leave it go for a sportscat

 

[Gray]

If you De-Cat the exhaust - your car will fail its MOT surely........?

I am currently getting a 'sports performance' Cat done in mine and it is said to allow the engine to flow more freely..... ( whatever that means ).

I am having it done by a company called zorstec if anyone wants to check them out.......


Chris L.

IMO waste of money on a 182, you already have a sports cat standard fitted to that..

de-cat all the way!

 

[D1CKY]

bigger gains to be had on a turbo car but yeah it will make a difference on a 172.

id go for decat and swap it over at mot time but thats just me, if you would rather fit it and leave it go for a sportscat

Thats what i went for a decat with full stainless stealth look system and i can vouch for Schweppy in saying it "Sounds awesome and is much more free revving".

"Has taken away the 5k kick too and it just revs continuously now".

Mine has had a few pops and bangs when giving it s**t on back roads

Definately a worthwhile mod

Where was you thinking of getting it done ?


And couldn't you wait until you can stretch to a full stainless system to go with it ?

 

[mattjk]

I think a decat will be more befitcial over a full system anyday.

Stock 182 exhaust isnt to bad anyway

 

[Gray]

If anybody is interested in a 172 de-cat i am currently organising a group buy in the for-sale section...

wink wink

 

[Martin_172]

as has already been pointed out sports cats are only worth while on 172's (but even at that id get a decat )

the 182 runs a really free flowing cat anyway so not really any gain to be had by having one.

 

[Fred@BTM]

it seems you're trying to solve a problem without knowing what the problem is!

 

[franx]

as has already been pointed out sports cats are only worth while on 172's (but even at that id get a decat )

the 182 runs a really free flowing cat anyway so not really any gain to be had by having one.

I've read of 182 owners on here that decat did'nt get them ANY gains, sooner losses..!
Because the 182 exhaustmanifold is already better than the 172 manifold i think it has to do with that little bit of backpressure the engine needs.. Just like an "open" IK on the inletmanifold (sucking up loads of air) does'nt work properly either (on stock engine !).

Seems there's a pulse theory for the air in / and combustion out, BenR Angelworks (among some others) can explain this in a way so you can understand, unlike my explanation probably :S

 

[mattjk]

I disagree about the fact you lose power completely, I thought I had at first but I think this was due to the fact that is revs harder lower down so it "masks" the power increase felt at 5k.

The catalytic converter isn't there to increase backpressure its a "necessary restriction" which is needed to make the car legal.

I have heard I may be wrong though, that the flow/backpressure is mainly controlled/restricted by the manifold.

 

[lenny85]

well i'm taking note of all this got an IK fitted at mo with CAF and just bought a decat for 41 quid so will see how it feels next week!!

 

[Teleturbie]

I've had the decat removed/fitted a few times now; before grp N mapping, after grp N mapping, etc.
I'm convinced it loses quite some torque lower down the rev range and no gains top end either. It's a shame because I love the sound of a decat (with a Milltek).
No RR data to prove it though, so maybe my butt/brain is playing tricks on me.

Am I really the only one with this experience??

 

[franx]

no your not ;

JaJack, whom we have'nt seen in a while, took it off aswell. Loss of torque
This is only one name i can think of but there are others .. The 172 seems to benefit much more from the decat.

Who was explaining the "pulsing" theory ? he could shed some light on this

 

[mattjk]

Hmm it is strange how the only 2 people that think this, live in the country where ganja's legal...

Coincidence I think not :rasp:

 

[FeelX]

172 and 182 are different stories I believe!

Since the 182 already has a 200cel cat the difference is less. Also the manifold is better and might suffer from less backpressure without the cat.

The 172 cat is 400cell and much more restrictive. Changing from 400 to 200cell makes a difference and to a decat is most noticable.

 

[franx]

172 and 182 are different stories I believe!

Since the 182 already has a 200cel cat the difference is less. Also the manifold is better and might suffer from less backpressure without the cat.

The 172 cat is 400cell and much more restrictive. Changing from 400 to 200cell makes a difference and to a decat is most noticable.

Now there's someone who has'nt smoked

i'll be posting up my experience with the decat soon.. 172 experience that is

 

[franx]

Hmm it is strange how the only 2 people that think this, live in the country where ganja's legal...

Coincidence I think not :rasp:

I used to be a "legal" dealer working a very famous coffeeshop in A'dam... and i did'nt smoke jeez that was a fun job

 

[FeelX]

Didn't I smoke? I just bought from you franx j/k

Anyway enlighten us franx

 

[mattjk]

Hmm it is strange how the only 2 people that think this, live in the country where ganja's legal...

Coincidence I think not :rasp:

I used to be a "legal" dealer working a very famous coffeeshop in A'dam... and i did'nt smoke jeez that was a fun job

Awesome LOL, I think felix is meant to be bring me back some finest skunk for me at some point aint ya bud?

 

[FeelX]

sure mate! just come over to the Netherlands, I'll give you a special tour du red-light and we can visit Frank and get some skunk

Talking about de-cat and stuff

Anyway does k-tec / yozza do a backbox only for the 172?

 

[franx]

sure mate! just come over to the Netherlands, I'll give you a special tour du red-light and we can visit Frank and get some skunk

Talking about de-cat and stuff

Anyway does k-tec / yozza do a backbox only for the 172?

Thank god i wisened up and got a real job.. sorry no greens from me anymore

Yeah , Yozza has got QUALITY boxes ! My K-tec is also nice though, might look into them as well.

Yozza is famous for welding-quality. Mind you this is all from reading about on here !!my experience with K-tec untill now is good, had it for 2,5 years (stealth)

 

[FeelX]

Cool with check them out if the backbox is buggered (monday I will know for sure) I thought they only did cat-back systems

 

[Penfold84]

Sorry for the hijack but i thought i would post here instead of starting a new thread...

I have a Mk2 ph1 172, brought a 182 Manifold.... looking to buy a sport cat for it... i see on ebay there are some for around £100 these are 200 cells per square inch, would they be ok to use on this above engine and manifold?

I would rather sport cat than decat for MOT's etc.... but i dont really believe in paying tuner prices... i am happy to have a new exhaust system made for the sport cat to fit etc.

Cheers for the help

Chris
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[FeelX]

well I think that will fit, might be some minor problems with the heat shields near the cat. I'm sure it won't fit the standard system cat-->back.

However there must be some reason why they sell the special sport cat with the 182 manifold ?

 

[mattjk]

Supernotsexyxchrissmith or whatever your name is, just stick with the 182 standard cat OR decat

Not tried one but many people say a sports cat is a waste of money as the standard one isnt restrictive anyway

 

[D1CKY]

I think a decat will be more befitcial over a full system anyday.

Stock 182 exhaust isnt to bad anyway

Its a 172 cup he's asking about.

A decat will give gains and have benefits yeah.

But not so sure about it on a standard exh system on a 172 :S

Aint there to many restrictions ?

 

[mattjk]

Ah okay! Sorry

I dont think the 172 exhaust is as good as the 182 exhaust. Although they both seem suceptable to rusting