ZX 16V parts

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

tecw1979
Posts: 30
Joined: 15 Jul 2003, 22:59
Location: United Kingdom
My Cars:

Post by tecw1979 »

is the exhaust bigger from the downpipe back to the volcane?
i have mi16 in mine and it feels restricted...
VisaGTi16v
Posts: 829
Joined: 27 Sep 2002, 21:39
Location:
My Cars:
Contact:

Post by VisaGTi16v »

Dont know which way round you mean but the centre box and the rear box are the same on the 2.0 8v volcane and 16v as I just got a new centre pipe (with silencer) and it was same part number as the 8v. The front bit with the cat and that goes onto the exhaust manifold may be different, not sure.
You could ring up an exhaust centre and ask for prices for a bx 16v downpipe and a zx volcane one and see if they are the same bits?
VisaGTi16v
Posts: 829
Joined: 27 Sep 2002, 21:39
Location:
My Cars:
Contact:

Post by VisaGTi16v »

Just got back from doing a Sprint at an airfield today north of London. They set up a track and its a timed event. I managed 2nd out of 9 in standard road going up to 2 litre in my zx 16v, only losing to a Civic Type R which was inevitible really. The car was going great since I put some decent rear tyres on, suffered from a bit of understeer in the hairpins but then I do have cheapo fronts. Brakes really impressed me. I changed the front pads and discs recently and overhauled all 4 calipers and they were working amazingly, pulling dead straight, no fade at all even with standard pads in this temperature. Oh and no ABS due to the common citroen ABS failing systems :)
User avatar
benj
Posts: 154
Joined: 14 Jul 2003, 19:30
Location: United Kingdom
My Cars:
Contact:

Post by benj »

well done in the racing, always nice to see a zx16v doing well
as regards to the volcane/16v comparision, the 16v bumpers also have 3 cutaway traingles in each corner of the bumpers to except the bodykit, and i think the only difference in the exhaust system is that the 1.9 volcanes originally had a round pipe and the 16v had a oval pipe. although my white 16v has and always had (previous owner replaced like for like) a round pipe, another clue hopefully to result in its french build history! others being the french stamped wheels 1991 stamped components, press plate ( i hope) iv written to dvla to determine its first owner.
a question i have is that as the 2.0 zx16v and bx 16v engines have the same head, is it possible to use the bx fabricate spaggeti exhaust manifold on my zx?
also what did citroen do to the late zx16v and the xsara vts to get 167bhp? iv heard the somewhere the speg manifold was used to gain the power? can anyone clear this up, and if it does, anyone any idea where i can get my fingers on one?
cheers.
adrianeaton
Posts: 152
Joined: 06 Mar 2001, 17:57
Location: United Kingdom
My Cars:
Contact:

Post by adrianeaton »

well I've got a spaghetti manifold sitting in the back of my garage - but that's my spare so I'm not selling [:D]
I think you'll find that the 2.0 engine only has a 4 port exhaust manifold whereas the 1.9 has 8 ports each for inlet and exhaust. That's one of the reasons for the difference in power output.
No ZX 16V's (other than those converted using BX engines) will have 167BHP - more like 140BHP - IIRC the engine is identical to that fitted to the 306 S16.
I'm not sure what they did to release the power for the Xsara and GTi-6 - suspect engine management improvements will have made most of the difference, and possibly a new inlet manifold.
The 2.0 Mi-16 has a similar variable length inlet to the ZX 16V and it's not as reliable or make as much power as the cast effort fitted on the BX.
You might be able to fit the head from a BX onto the ZX but that's an awful lot of work for not a lot of extra power!
Adrian
User avatar
benj
Posts: 154
Joined: 14 Jul 2003, 19:30
Location: United Kingdom
My Cars:
Contact:

Post by benj »

I think you'll find that the 2.0 engine only has a 4 port exhaust manifold whereas the 1.9 has 8 ports each for inlet and exhaust. That's one of the reasons for the difference in power output.
The 2.0 litre 16v engine as in my zx has only a four port manifold but each port covers two outlets, the head IS
identical to the 1.9 16v, thats why i want a spagetti manifold!!!
No ZX 16V's (other than those converted using BX engines) will have 167BHP - more like 140BHP - IIRC the engine is identical to that fitted to the 306 S16.
When citroen first introduced the 2.0 litre 16v zx the were hoping for 155bhp, unfortunatly they never managed this in the early ones gaining only 151bhp ( i dont know where u got 140 from!!!)
Also the very late zx 16v with different alloys (similar to the very latest saxo vts alloys did have the 167 bhp engine from the xsara and gti-6!
Please read cut article -
In fact the ZX 16V did not quite meet the promised 155hp because Citroen had a lot of trouble finding the extra 5hp to meet the published specification without changing the characteristics of the car and the behaviour of the engine. For that reason Citroen changed the figures in the books to 150hp in 1993.
However the PSA engineers worked hard on the engine and at the moment the Mk2 version of the ZX (new nose and bonnet/hood) was introduced this newly developed engine was made available. By applying changes to the inlet of the engine, engine management and mounting a "spaghetti-manifold the car performed very well. The power had been increased to 167hp but more importantly the torque was upped to 193Nm.
http://koti.mbnet.fi/css/zx/zx16v.html
cheers
ben
User avatar
benj
Posts: 154
Joined: 14 Jul 2003, 19:30
Location: United Kingdom
My Cars:
Contact:

Post by benj »

dont know how to attach pictures but if you want to see one of the 167bhp zx 16v please look here:
http://koti.mbnet.fi/css/zx/zx16v_2.jpg
adrianeaton
Posts: 152
Joined: 06 Mar 2001, 17:57
Location: United Kingdom
My Cars:
Contact:

Post by adrianeaton »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by benj</i>


The 2.0 litre 16v engine as in my zx has only a four port manifold but each port covers two outlets, the head IS
identical to the 1.9 16v, thats why i want a spagetti manifold!!!
<b>Fair enough [:D]</b>
When citroen first introduced the 2.0 litre 16v zx the were hoping for 155bhp, unfortunatly they never managed this in the early ones gaining only 151bhp ( i dont know where u got 140 from!!!)
<b>140 was a guess-timate based on my BX, and the fact people moan about their S16's - apologies for being 10BHP out [;)]</b>
Also the very late zx 16v with different alloys (similar to the very latest saxo vts alloys did have the 167 bhp engine from the xsara and gti-6!
<b>Also the same as Xsara VTS judging by your pic - are there any in the UK, I've only ever seen cars with the earlier alloys?</b>
However the PSA engineers worked hard on the engine and at the moment the Mk2 version of the ZX (new nose and bonnet/hood) was introduced this newly developed engine was made available. By applying changes to the inlet of the engine, engine management and mounting a "spaghetti-manifold the car performed very well. The power had been increased to 167hp but more importantly the torque was upped to 193Nm.
<b>Well I was pretty much right then! [:I]</b>
cheers
ben<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Laters
Adrian
User avatar
benj
Posts: 154
Joined: 14 Jul 2003, 19:30
Location: United Kingdom
My Cars:
Contact:

Post by benj »

im not sure if the xsara style 'alloyed' zx ever came to the uk, but my various sources of information say that all the face lifted zx 16v's (and there are a few knocking around! )have the 167bhp, so if anyone has one or access to one please have a look at your exhaust manifold and let me know!!!
another one ive heard is if you de-cat the early 16v youl get 170 bhp and if you d-cat the later one as in the xasra your knocking on 180,
anyone have any ideas/views/info on this?
iv read on some sites like Puma racing, that your can actuallly lose perforamce from de-catting a lot (but not all!) of new engines as the engine is actually designed around them, any ideas?
if its all true it seems to be the best way to raise the performance of the 16v purly from the spare parts bin of its younger siblings and a nice bit of bent pipe.
wheeler
Posts: 6847
Joined: 21 Sep 2002, 19:07
Location: United Kingdom
My Cars:
x 717

Post by wheeler »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by benj</i>


iv read on some sites like Puma racing, that your can actuallly lose perforamce from de-catting a lot (but not all!) of new engines as the engine is actually designed around them, any ideas?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote"> all new engines have to pass strict emissions regulations which are getting tighter all the time so lots of new things get added to help this,most new petrol enginges have an extra lambda sensor fitted downstream of the cat to monitor it,i would guess that removing the cat would cause the sensor to have readings that it shouldnt have, the ECU would then back off thinking there was something wrong.
User avatar
benj
Posts: 154
Joined: 14 Jul 2003, 19:30
Location: United Kingdom
My Cars:
Contact:

Post by benj »

yea i know what your getting at bt im talking about flow characteristics of the actual engine, not electronic stuff that can easily be modified!
adrianeaton
Posts: 152
Joined: 06 Mar 2001, 17:57
Location: United Kingdom
My Cars:
Contact:

Post by adrianeaton »

According to a mate of mine who does 'calibrations' for motor manufacturers early cat-equiped cars (probably including my BX and maybe early ZX's etc) just have the cat tacked on the exhaust and removal won't change the way the engine runs so long as the lambda probe is still in place.
Because of the fueling map, you won't gain much power except as a result of removing the effective bung up the exhaust. As you say, a remap should be able to sort that to allow more fuel past the lambda probe so you're then just limited by anything they've done to the internals to make the cat work. On the BX that means lower compression and different cam timing.
On later cars, issues with fuel blow-by getting into the cat were better understood and you'll find the cam timing is very much focussed towards protecting the cat - but thanks to modern ECU's it doesn't kill power as much as it used to.
Because the ECU's are smarter, removing the cat will allow the fuelling to increase but you'll still get less power than if the engine was designed without a cat in the 1st place.
Owners of GTi-6's claim some improvement from removing the cat - but that could just be down to the noisier exhaust note!!
Interestingly, my now 11 year old BX 16V's cat STILL passes the emissions test!!
Adrian
User avatar
benj
Posts: 154
Joined: 14 Jul 2003, 19:30
Location: United Kingdom
My Cars:
Contact:

Post by benj »

so you would, or wouldnt recomend me de catting mine?
adrianeaton
Posts: 152
Joined: 06 Mar 2001, 17:57
Location: United Kingdom
My Cars:
Contact:

Post by adrianeaton »

If it's post 1/1/93 I wouldn't bother as you'll have to stick it back for the MOT every year - don't know about the ZX but on my BX it means replacing the whole front section of the exhaust, and the new front section is £140!!
For existing models from 1/7/92-1/1/93 there's an opportunity to remove without any problem, but ring the MOT helpline 1st with your VIN number to confirm. That exemption applies to 'existing models' whereas new models from 1/7/92 were required to have cats.
On BX's removing the cat alone isn't supposed to do much - if you don't mind chips and some investigation of cam timing/compression ratio then it's worth it.
Adrian
User avatar
benj
Posts: 154
Joined: 14 Jul 2003, 19:30
Location: United Kingdom
My Cars:
Contact:

Post by benj »

i know about the mot regs and dates, it would be simple enuf for me to knock up a replacement downpipe and to swap it for mot time, and all the other fixes, just wanted to know if it actually gave a power gain
also my car was registered on the 1/1/93! so is it exempt or not?
i heard the rules changed that if you had a car made after 1/1/93 but its engine was designed so many years ago, cat wasnt mandatory, obviulsy i have no evidence now to back this claim, just wondering if any one else had heard it or is it a load of bollocks
Post Reply