Hi all I’ve just bought myself my first mk1 mx5, been into classic minis previously, I’m looking to fit a new nicer sounding exhaust, ive had a quick look into this and it looks like fitting a catback is not simple as you would need to replace cat also for a smaller one , (i think this is what I read) Is this true ? If so is it easier to fit a decat pipe and what is required to fit a de cat pipe looking at japspeed (opinions ?) by doing this what Would be required? And recommendation and advice people can give I will be very grateful for :)
Exhaust options depend on the year and whether your car is UK spec or not. The problematic cars are UK late 1995 onwards, with a 470mm cat. These cars have a different catback, different cat and a different manifold downpipe. If you have one of these, either a custom bespoke catback, or just change the whole lot, from engine back.
For all other cars, the catback is the same. 1.8 imports had a 370mm cat, whereas the UK 94-95 cars had a 440mm cat, same as the US. What this means, if you have a 1.8 Japanese import, a UK or US sourced stainless steel manifold without also changing the cat. Conversely, Japanese sourced manifolds won’t be a straight fit on a UK car (also imports won’t have EGR).
I would do the exhaust before thinking about the decat pipe. A decat won’t give you any extra power, and in combination with an aftermarket exhaust, can sound awful, plus you have a sooty bumper.
My car is a 1996 uk spec, what would you recommend doing ?
The first thing you need to do is check the current system. There is a good chance that you have the 435mm or thereabouts cat, in which case most aftermarket catbacks will fit straight on.
If you have the longer 475mm cat you take the advice from the previous poster. Bespoke system made for the longer cat or PM me for prices on replacement front pipe and 435mm cat which will then facilitate you fitting the usual aftermarket catbacks.
My bet is your car has the 435mm cat. Leave that in place as required for the MOT - the right catback will no doubt give you what you are after.
Cheers thank you will Check it out appreciate the advise and help :)
http://www.japspeed.co.uk/mazda-mx-5-na-nb-1-6-89-01-exhaust-manifold-single-downpipe
http://www.japspeed.co.uk/mazda-mx-5-na-1-6-89-97-decat-exhaust-system
was looking to fit this system and remove the cat, can I just Bolt on and go or will this cause and engine light to come on from the lambda sensor ?
Confused. The description for the manifold says this is for a 1.6, and will fit any model with a 440mm cat. Except 440mm cats were never fitted to 1.6 MK1s. I can see a fitting for a lambda sensor, but a second fitting for a EGR pipe. The NA has a male thread, the NB has a female thread. This appears to have a female thread. The cat flange fitting looks more similar to a NB cat fitting. The manifold itself seems to be a rather pointless copy of the stock manifold, a 4-1 design, not 4-2-1.
The exhaust will bolt up, but you will fail the MOT. Fitting this system means everytime you need to go through a MOT, you need to fit a cat. If you have the 90hp 1.6, then that has the long cat? What have these muppets sized the cat pipe to? For a 370mm cat? Then you will also need to buy a 370mm cat for the MOT, so another £80-100. On the other hand, maybe its a random size.
If a 1.6, the MX5parts 4-2-1 manifold is a better bet for a cheapie manifold, then just add a 370mm cat and cat back…
stupid question maybe, what would the diference in standard & the above manifold be APART from cost?
sorry for my cynacism but it sure looks like a copy of a standard manifold
from the advert / webpage
the standard manifold is tubular
Rich.
I’m considering buying a 97 model mk1 so I suspect I will have the longer cat. I would also like to change the exhaust for perhaps a Cobalt.
Is it not possible to shorten and weld the first section of the Cobalt system rather then replace the standard cat and downpipe?
Yes, but now you have no warranty on your band new exhaust. And I’ve never seen a cut exhaust fit quite right,
Anything is Possible Graham but this is not recommended.
The front pipe and cat are cheap enough to buy if this is the way you want to go. Quite a number of owners going this route at the moment.
You will be able to sell the original cat for reasonable money - probably pay half the cost of the new parts.
Thanks for the quick reply, where would I buy a front pipe and cat?
Thanks for the quick reply, where would I buy a front pipe and cat?
Meeeeeeeeeee…
I will PM you.
440mm cat:
Front pipe:
Probably the cheapest approach is to find a local Powerflow exhaust specialist, and they fit a bespoke catback system, which will be far better quality than the budget Cobalt system, plus have a lifettime warranty.
Some cheap cats don’t last that long, and its probably not a good start to MX5 ownership to fit scrapyard parts.
Powerflow can either do a full catback exhaust for you, or cut the existing system, if that’s sound, and fit a rear box. None of the cheapie exhausts like the Cobalt, will give any extra power,
A full Powerflow system will be about £350. Backbox only will be a lot less.
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Have you read the reviews on MX5Parts cats? Aside from not being that cheap they have a miserable reputation. This has been the case for years so a mystery as to why a generally, quality supplier like MX5Parts stick with this particular manufacturer.
This option is available but not everyone wants to spend £160 + delivery on a front pipe where much cheaper alternatives are available.
I assumed that the original poster just wants to facilitate fitting of his catback of choice in an affordable and effective way so…
http://www.mx5bitz.co.uk/mx5/view_product.php?product=102
http://www.mx5bitz.co.uk/mx5/view_product.php?product=20
I worked with the UK manufacturer to develop the front pipe when one of my customers had a problem fitting our existing part for the longer 475mm cat to his 435mm cat. It was only around two, maybe three years ago we found out that the front pipe for the longer 475mm cat is not suitable for the 435mm cat. They needed an original part which they keep. A bespoke Jig is made for the part and caliberation is checked with the original part between batch manufactures.
The Powerflow backbox that came with my 1996 Roadster sounded quite good when I first got that car. Probably most cost effective solution, when 99% of people just want an exhaust for sound/aesthetics, which frankly, that’s all the Cobalt exhaust does.
I cited the links as examples, not endorsement. There are many alternatives. The long cat was fitted to UK cars for a reason, and that was to improve our environment. So there is a moral question as to why you want to make your car dirtier.
I’d like to see what a 575mm cat looks like. I know 370mm (375), 440 (435), 475mm, but not 575.
I hadn’t posted to get into a debate about your business, and whether your cats are better than MX5parts. I have no opinion on your cats. I have no opinion of MX5parts either. Would be easier if your Username matched your business name, so that we remember you are MX5Bitz.
That is reasonable but as I had posted my intent before on the thread, reasonable to counter I think particularly where there is a problem with the MX5Parts cat. You just need to read the reviews really. If your genuine overriding concern is the environment why drive an inefficient petrol burner in the first place? Your theory on the longer cat may be correct but given the age of the cars, servicing and maintenance is more likely to reduce emissions output than the size of the cat. Lots of these cars fail miserably on emissions at MOT time. We have been lucky with our 1991 Eunos and 1997 MK1. The Eunos with original short cat produces less emissions than the more recent MK1 with longer cat.
It is 475mm, I misquoted the measurement…but you already knew that. Will edit post above to avoid confusion and reprogram brain. I actually spent time looking for a picture of an original one to post before the penny dropped.
Who’s debating my business. I made it clear to the original poster I was going to PM him about the front pipe and cat - you took time to counter with what I would consider and justify as unsuitable alternatives.
There is no debate about my business. I don’t pay for advertising because the business does not turnover enough to justify it. That suits me because generally speaking as busy as I want to be without it. Having said that as I don’t pay the Owners Club for advertising, I think it inappropriate to court free advertising with an obvious business name, blatant advertising, etc when other businesses do pay. Not many of these businesses or certainly not my competition contribute by posting on the forum so I will promote myself when reasonable and usually privately.
There is no question about the MX5Parts supplied cat - IT IS INFERIOR. Unfortunately I say this from indirect personal experience. No axe to grind with MX5Parts as I buy from them myself but as stated they need to change their cat supplier.
I have a 97 /98 mk1 with the bigger CAT and got an exhaust made by MiJ in Walsall (as seen on Car SoS a few times) last year for not much more than an off the shelf one. The fit is brill obviously as it was made for the car and sounds very nice you have a choice on how much noise it makes.