Exhausts / cat size
Discussion
OK,
I am sick of the loose baffle in my standard exhaust so want a new back box. Was going to go standard but I understand these are very expensive, and depending on what size cat I have may not be available.
I have seen the single exit s/s exhausts on MX5-parts and I'm waiting for them to come down to their offer price of £130 odd from £180, which seems to happen from time to time. A bit of extra noise might be nice!
Is this the best/cheapest option? My car is a 94 Mk.1 1.8 import, that has had the entire exhaust inc. cat replaced at some stage, so not sure exactly what's on the car at the moment. Just measured the car and as far as I could tell it was 350mm long, but MX-5parts suggests either 370 or 440.
I thought I was fairly accurate - if it's out a bit does it matter?
What options do I have?
I am sick of the loose baffle in my standard exhaust so want a new back box. Was going to go standard but I understand these are very expensive, and depending on what size cat I have may not be available.
I have seen the single exit s/s exhausts on MX5-parts and I'm waiting for them to come down to their offer price of £130 odd from £180, which seems to happen from time to time. A bit of extra noise might be nice!
Is this the best/cheapest option? My car is a 94 Mk.1 1.8 import, that has had the entire exhaust inc. cat replaced at some stage, so not sure exactly what's on the car at the moment. Just measured the car and as far as I could tell it was 350mm long, but MX-5parts suggests either 370 or 440.
I thought I was fairly accurate - if it's out a bit does it matter?What options do I have?
Decat it at the same time 
- i beleive a 94 import should be able to pass a MOT without a cat.
And i *thought* all JDM 1.8's had the 440 cat... but looking on mx5parts, they list 2 different front pipes for the 1.8 based on chassis number (before or after chassi's begging 308212)
sorry cant help about the size though.. i was looking under my car today while the geo was being done.. and its zorst system has been proper botched, it looks like its been extended which makes me think i may have the small cat... annoyingly i have a 440 decat here too
- i beleive a 94 import should be able to pass a MOT without a cat.And i *thought* all JDM 1.8's had the 440 cat... but looking on mx5parts, they list 2 different front pipes for the 1.8 based on chassis number (before or after chassi's begging 308212)
sorry cant help about the size though.. i was looking under my car today while the geo was being done.. and its zorst system has been proper botched, it looks like its been extended which makes me think i may have the small cat... annoyingly i have a 440 decat here too
Which size is the 1.6 size? I'm confused
The previous owner of my car got stiffed at an MOT and I have a receipt for a complete new exhaust system (manifold to tip including cat) for over £1200 quid! I assume it had a performance system on it before and the garage saw them coming. Or maybe it did fail the MOT? I don't want to get rid of the cat and then have it fail... So is it possible that it had a 1.6 system fitted inc cat?
Hells bells, I have no idea what to order now
The previous owner of my car got stiffed at an MOT and I have a receipt for a complete new exhaust system (manifold to tip including cat) for over £1200 quid! I assume it had a performance system on it before and the garage saw them coming. Or maybe it did fail the MOT? I don't want to get rid of the cat and then have it fail... So is it possible that it had a 1.6 system fitted inc cat?
Hells bells, I have no idea what to order now
Right.... the cats come in two lengths.
The rear end of the cat is in the same place on all cars - this is why the replacement cat back exhaust fits all Mk1's.
It is the other end which is different - the downpipe end.
Your car has the shorter Catalyst, like mine. if you buy the Cat-back exhaust, it will fit.
If you want to buy the de-cat aswell, you need to buy the shorter one. Easy
Has your car got a standard manifold on it?
It does sound like someones pinched a nice one off it perhaps!
The rear end of the cat is in the same place on all cars - this is why the replacement cat back exhaust fits all Mk1's.
It is the other end which is different - the downpipe end.
Your car has the shorter Catalyst, like mine. if you buy the Cat-back exhaust, it will fit.
If you want to buy the de-cat aswell, you need to buy the shorter one. Easy
Has your car got a standard manifold on it?
It does sound like someones pinched a nice one off it perhaps!
Interesting. I thought there was no difference for emissions tests whether it was UK/JDM. On the V5 it's a "Mazda Eunos" whatever that is 
Get the MOT done at a place my indy uses, not sure what they check it as - will it be on the certificate?
If the cat length doesn't matter why does the MX5parts page say please check?
Not sure if the manifold's standard - here's a pic of under the bonnet:
Get the MOT done at a place my indy uses, not sure what they check it as - will it be on the certificate?If the cat length doesn't matter why does the MX5parts page say please check?
Not sure if the manifold's standard - here's a pic of under the bonnet:
Looks like my only option is buying it and crossing my fingers... Is it worth me holding out for MX5P putting it on offer again?Bloody confusing, isn't it. I replaced all parts of the exhaust last year - I already had a MX5Parts dual rear in the garage from a sale price at one of the club events. I also bought their 'recommended' at the time, 440mm Decat pipe at the same time. Finally got round to fitting the new exhaust 18 months later after the manifold started to break up, so bought a new SS Manifold. Much pushing and shoving later, turns out the Decat pipe is too big, its the weekend, and the car is blocking a ramp at the garage - So I nip down to Moss in Sunbury in my other car and buy a 370mm Jackson Racing Cat, the only think in stock nearby that will fit.
Aargh! what a hassle. Anyways - Unused 440mm IL Motorsports Decat pipe back in my garage again.
Aargh! what a hassle. Anyways - Unused 440mm IL Motorsports Decat pipe back in my garage again.
jazzybee said:
I replaced all parts of the exhaust last year - MX5 Parts dual . I also bought their 'recommended' at the time, 440mm Decat pipe at the same time. And bought a new SS Manifold. Much pushing and shoving later, turns out the Decat pipe is too big.
Ah that's because the 96/7 downpipe is shorter hence the new (std 93/5) manifold was too long.OK.
So can somebody lay it on the line for me?
I have a 94 1.8 import which has had the whole system replaced with an original one (but who knows whether it's what should be on it!)
If the cat size varies, is it the back section or the manifold/downpipe section that has to be bigger/smaller to accomodate it?
So can somebody lay it on the line for me?
I have a 94 1.8 import which has had the whole system replaced with an original one (but who knows whether it's what should be on it!)
If the cat size varies, is it the back section or the manifold/downpipe section that has to be bigger/smaller to accomodate it?
NiceCupOfTea said:
OK.
So can somebody lay it on the line for me?
I have a 94 1.8 import which has had the whole system replaced with an original one (but who knows whether it's what should be on it!)
If the cat size varies, is it the back section or the manifold/downpipe section that has to be bigger/smaller to accomodate it?
Read my 2 replies above. So can somebody lay it on the line for me?
I have a 94 1.8 import which has had the whole system replaced with an original one (but who knows whether it's what should be on it!)
If the cat size varies, is it the back section or the manifold/downpipe section that has to be bigger/smaller to accomodate it?
I've just answered that.
(answer is BOTH)
NiceCupOfTea said:
Bloody hell. Why am I even more confused?
I have no idea, I've spelt it out...ALL JAP have a std (short) CAT.
As do UK cars up to 96 facelift.
The long CAT 96 on cars have a SHORTER downpipe and a SHORTER cat back.
Now do you want to start on which have EGR in place ?
Edited by OnlyMX5ives on Thursday 15th April 11:30
OnlyMX5ives said:
NeoVR said:
So how come the MX5parts stainless zorst will fit either type cat?
I suspect they sell 2 different centre pipes as otherwise it won't.From what i can "assume" from the mx5parts website.. is that as said above, the 370mm and 440mm cat must have different downpipes so cat-back is in the same position for both sizes.. its only the uk cars 96 on with the 475mm cat that are different.
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