Exhaust for 1.8 16v

[Ash J]

Looking at an aftermarket exhaust system for my 2001 1.8 16v (XS).

Nothing too loud, something quite subtle (something like a Jetex).

Just wanted to double check, that my understanding is correct, in that a centre and backbox from a GTI-6 will fit on my car no problems?

From what I understand, it is the manifold and cat which are different lengths, i.e. you cannot use a 1.8 manifold and GTI cat, or vice versa? But from the cat back, centre box and backbox is interchangeable?

Only ask, as I will keep an eye out for second hand stainless systems taken off a GTI knowing it will fit mine.

Looking at the Jetex website, they state their system fits the XSI/XS/GTI-6/Rallye which would confirm my understanding?

Cheers for any help.

[welshpug]

as long as its not a twin lambda system I believe you are correct.

[Ash J]

Cheers for the reply.

As long as which one is not a twin lambda system? Are lambda's not on the cat?

[welshpug]

yep, later 1.8's have two lambda's and a longer cat.

[Ash J]

So all GTI's have one lambda?

And I'm just talking about the centre section and backbox being interchangeable, so didn't think the cat would come into it?

The 1.8 cat is longer, but fits higher up on the manifold compared to GTI, so centre section connects to the cat on both in the same place if you get me? I could be wrong, just my understanding. Slightly confused about the cat situation you mention.

Cheers

[welshpug]

read it again, later 1.8's have two lambdas rather than one, and a longer cat, so it wont fit a later car.

[PUGNUT_XS]

You would be better off fitting a complete GTI-6 set up, the 1.8 sounds fantastic with the GTI-6 exhaust manifold on it, then you could use the complete system, have a look at GTI-6 Parts on EBay, i have used them loads of time without problems.
And his prices are reasonable.

[Ash J]

Cheers for the replies guys.
I understand what you are saying now welshpug, I misread. I am pretty sure my car will have two lambdas as it is a 2001 model, will check tonight.
If it does have two lambdas, then I am not sure how I would go about fitting the whole setup pugnut, as the GTI-6 cat only has one lambda.
I believe the Xsara VTS cat has two lambdas, and will bolt up to a '6 manifold. But I am not sure if the length is the same as a '6 cat and if it would bolt onto a '6 mid section?
Hmmmm.

[welshpug]

only a phase2 xsara cat is 2 lambda, and will only fit to a phase2 xsara manifold (different join to the 306 and phase1)

also the hangers are different on the zx & Xsara, as well as the bends under the fuel tank, so they are not compatible with a 306.

you may be stuck with having to get a custom exhaust system.

[Eeyore]

okay let me say a few things. I have a 1.8 and Im about to get under it to work on the exhaust.

the gti6 has a 4 branch equal length manifold which is long then has a short cat (1 lamda) and then standard centre and backbox.
the 1.8 has a log style crap manifold with a long cat (1 lamda) and then standard centre and backbox.

GTI6 MANI-------><CAT---->< ---- CENTRE ---- > < BACK BOX >
XS MANI -><CAT----------- >< ---- CENTRE ---- > < BACK BOX >

What you need to be careful with buying after market exhausts is the joins. You will find far more aftermarket gti6 exhausts than you will 1.8.
I bought a magnex but it wont fit as its sleeved and the 1.8 cat design is flanged.
On the gti6 i believe the cat is flanged and sleeved allowing after market exhausts to fit.

As for sounds.... I run my 1.8 with a decat, decentre pipe and a standard backbox. Its really raspy, not too loud, not too quiet and with my mapping makes for epic pops and bangs.

Now that I have fitted the magnex which is a larger diameter its boomy between 1 - 2.5k and then is quiet for the rest of the range.

hope that helps!

[PUGNUT_XS]

okay let me say a few things. I have a 1.8 and Im about to get under it to work on the exhaust.

the gti6 has a 4 branch equal length manifold which is long then has a short cat (1 lamda) and then standard centre and backbox.
the 1.8 has a log style crap manifold with a long cat (1 lamda) and then standard centre and backbox.

GTI6 MANI-------><CAT---->< ---- CENTRE ---- > < BACK BOX >
XS MANI -><CAT----------- >< ---- CENTRE ---- > < BACK BOX >

What you need to be careful with buying after market exhausts is the joins. You will find far more aftermarket gti6 exhausts than you will 1.8.
I bought a magnex but it wont fit as its sleeved and the 1.8 cat design is flanged.
On the gti6 i believe the cat is flanged and sleeved allowing after market exhausts to fit.

As for sounds.... I run my 1.8 with a decat, decentre pipe and a standard backbox. Its really raspy, not too loud, not too quiet and with my mapping makes for epic pops and bangs.

Now that I have fitted the magnex which is a larger diameter its boomy between 1 - 2.5k and then is quiet for the rest of the range.

hope that helps!

That was the reason i changed all mine for a GTI-6 set up, when mine was a 1.8. Mine only had 1 lambda sensor and thats on a 1999, so the two probe set up most be 2000 onwards. I found that the car accelerated better with the GTI-6 exhaust system set up because it did not have that dog shit 1.8 exhaust manifold, i used a sportex system, it was loud but sounded great.

Talking of 1.8's i have my 1.8 engine although stripped for sale if anybody is interested, it had covered 104,000. so if anybody needs any bits no unreasonable offers are excepted.LOL Need to raise some more cash so i can get my cat made for the TCT engine.

[Eeyore]

Mine is a late 2000 and has one lambda. Im not sure I believe there are two lambdas.

[Toms306]

The 2 lambdas came in for the newer emmisions regs, around X/Y reg iirc.

[PUGNUT_XS]

Mine is a late 2000 and has one lambda. Im not sure I believe there are two lambdas.

Second that, every 306 i have worked on has had one sensor. Pictures would be good.

[laurence_13]

I've got a decat section for a 1.8 that will be for sale shortly... made out of the standard pipe with a stainless section welded in the cats place if you'd be interested?

[Ash J]

Had a look tonight guys, and I can confirm my car does indeed have two lambdas. One before the cat, and one after the cat. Mine is a 2001 'X' plate XS.

Custom system looks like the way like welshpug said.

However, I notice Supersprint do a system specific for the XS. The part number for the Supersprint centre section is different for XS (my car) and GTI-6, but the backbox is the same part number for both, which makes sense.

Laurence, I could be interested in that decat section if it was taken from a 1.8 that has two lambdas like mine?

Cheers guys

[laurence_13]

Had a look tonight guys, and I can confirm my car does indeed have two lambdas. One before the cat, and one after the cat. Mine is a 2001 'X' plate XS.

Custom system looks like the way like welshpug said.

However, I notice Supersprint do a system specific for the XS. The part number for the Supersprint centre section is different for XS (my car) and GTI-6, but the backbox is the same part number for both, which makes sense.

Laurence, I could be interested in that decat section if it was taken from a 1.8 that has two lambdas like mine?

Cheers guys

Unfortunately it doesnt, just the one I'm pretty sure, unless the other hooks up further down the exhaust..

[blaze_the_6]

You would be better off fitting a complete GTI-6 set up, the 1.8 sounds fantastic with the GTI-6 exhaust manifold on it, then you could use the complete system, have a look at GTI-6 Parts on EBay, i have used them loads of time without problems.
And his prices are reasonable.

This!! got my VTS engine from them and a cheap valeo clutch kit

[Ash J]

Unfortunately the 6 system is not an option, due to my car having two lambda sensors, and the 6 system will only have one lambda at the cat, so it would have to be a custom jobby.

Have decided I will probably go for the supersprint system I mentioned earlier.

And Laurence, unfortunately it won't fit my car. Earlier 1.8s had one lambda, seeing as mine has two I won't be able to use it. I would of have it otherwise.

Cheers

[Eeyore]

I wouldnt have thought it would be a problem putting another lamda in?

[laurence_13]

Unfortunately the 6 system is not an option, due to my car having two lambda sensors, and the 6 system will only have one lambda at the cat, so it would have to be a custom jobby.

Have decided I will probably go for the supersprint system I mentioned earlier.

And Laurence, unfortunately it won't fit my car. Earlier 1.8s had one lambda, seeing as mine has two I won't be able to use it. I would of have it otherwise.

Cheers

No worries mate, was worth a go!