the cat on a vtr???

[G187]

i've been told that by taking out the cat on a vtr, it loses power(top end)? is this true?

[YM03]

are you on about fitting four branch or taking decating, as the face lift vtr has cat on manifold/downpipe, early vtr's are underneath, if done proply I don't think you lose top end, mine doesn't seem effected

[G187]

i've got the early type vtr, i've already changed the manifold to a 4-2-1, but i was told to keep the cat and not to get it decatted - is this true that it loses power?

[YM03]

it won't lose power, but I think it can drop some back pressure not sure tho.
I've got mine decated and it makes a difference seems to pull so much better, and deffo not lost anything top end.

if I was you I'd do it

[R4T]

i used to have a mark 1 vtr with a decatted exhaust and back box i notcied a suprising difference,as the man above said you do lose a little back pressure but it definately makes a difference go for it

[G187]

any1 else....

[bennivtr]

when mine was decated, de centre boxed, with a backbox i definately didnt lose top end!

[DAZ1985]

No you dont loose top end if its done right.

I've lost top end through my gearbox but it gets their quicker.

[G187]

No you dont loose top end if its done right.

I've lost top end through my gearbox but it gets their quicker.

could you tell us what you mean by done right?

cheers

[DevilDamo]

I had the cat. removed. The car felt a lot more responsive. It improved in the torque at low range too (after taking it on a rolling road). There was however a slight problem with the fuelling but that was only because I had the lambda sensor dangling in mid air and not connected to a sleeve.

[DAZ1985]

could you tell us what you mean by done right?

cheers


Yes i could its just stating the obvious though really !!!!

The right way round, make sure its in tight and sealed properly

If thier is any more someone will add

[G187]

why have gmc said this "...taking the CAT out and substituting a straight pipe will not be correct and so you will loose some power" - on their site they have explained it further more - this is the only thing from stopping me from getting decat pipe - this is the answer i thought one of you guys would point out

[ets2k9]

why have gmc said this "...taking the CAT out and substituting a straight pipe will not be correct and so you will loose some power" - on their site they have explained it further more - this is the only thing from stopping me from getting decat pipe - this is the answer i thought one of you guys would point out

Because there trying to sell you a £400 exhaust...............

Maybe we should have a thread "The Truth about decat's" as I've read all these crazy things about decats which at the end of the day is just abit of pipe.

[G187]

erm... i've spoke to other people about it is well and they've gave me the same reason why not to take it off

[ets2k9]

erm... i've spoke to other people about it is well and they've gave me the same reason why not to take it off

So your doing a survey then?

[Mattvtr]

do you not need some sort of silencer etc to keep up the pressure?

[G187]

So your doing a survey then?

no survey, just want to know more people's view's

[G187]

do you not need some sort of silencer etc to keep up the pressure?

no idea mate

[DAZ1985]

do you not need some sort of silencer etc to keep up the pressure?


Yes but surely that pressure would be retain by the middle box ???

So in theory your back pressures would alter slightly as the wave has to travel further to get to the middle box than if they went to the cat

[Mattvtr]

yeh i agree with that,i was on about if you had a straight through system,should have made that clear

[DAZ1985]

If you had a straight throught system then it would totally screw up the back pressure it would cause the car to run like a bag of shit.

This is because its the back pressure which draws more exhaust gases from the engine.

[Reef]

If you had a straight throught system then it would totally screw up the back pressure it would cause the car to run like a bag of shit.

This is because its the back pressure which draws more exhaust gases from the engine.

so ...... i'v got a straight through system on my mk2 saxo, no silencers, no thing, just manifold/cat-back all the way to back box.

Does this mean, if i get a 4-2-1 my car would run like a bag of shit ?

[DAZ1985]

Cat on the manifold im assuming ???

[Reef]

Cat on the manifold im assuming ???

yup cat on the manifold (what a stupid idea by citroen)

[Billog_VTR]

mines a late mk1 with de-cat and 4-2-1 mainfold. Back pressure sometimes bit iffy but no top end is lost if done right.