NB Exhaust

Technical Area Engine, Transmission, Exhaust etc
2

Hi,

 

I’m looking to upgrade my 2001 1.8VVT Mk2.5 exhaust system

 

I’m after some recommendations for manifold and mid pipe as I can’t find a lot of information on them. If I remember correctly the mk2.5 has 2 cats, one on the manifold and one in the mid pipe. if anyone can recommend me a mid pipe and manifold which will give me an overall 30% noise increase. (links appreciated)

 

Of course the more free flowing it is the better but want to keep it mot compliant. 

 

https://www.japspeed.co.uk/mazda-mx-5-mk2-5-cat-back-exhaust.html - Was maybe looking at this, anyone had any experience with jap speed.



Thanks,

Freddie

3

Hi Freddie. I think you are confused about two cats on the NB, there is only one (the 98/2001 workshop Manual confirms this) The cat converter is there to reduce emissions (you probably know this) but it it’s not meant as a noise limiter. Instead the NB has two silencers, one between the cat and the actual real exhaust, and this is know as a ‘Presilencer’ while the main (rear) silencer does the real job of silencing the exhaust note and sound. The Japspeed 'Catback@ is exactly that, it replaces the existing silencers after the Cat - hence the term ‘Catback’ (after the Cat) No experience of how effective (or expensive) the Mazda speed system is, though it appears to be stainless.

There is NO cat converter straight after the exhaust manifold, just a coupling between sets of exhaust pipes. The only cat is after the downpipe. (under the car)

If you check out silencers on www.mx5parts.co.uk you should find a stainless exhaust silencer to suit your needs - e.g - 30% more sound. A google search for MX5 silencers will also bring up loads of replacements, mainly stainless. If the midpipe and presilencer, plus the pipe between Presilencer and final silencer are still in good shape, then replacing the rear silencer should be all you need to do (IMO) I bought a single exit S/S silencer from MX5 parts several years ago - for my NBFL, and it changed the purr to a deep rumble, with which I am very happy. Just check it is the right exhaust for an NB.

4

This is very useful, Just to confirm this information stands correct for NBFL also? As Mine is a FL?

 

But I will then look into a quality backbox thanks,

 

Freddie

 

5

Freddie - sorry for delay (just logged in) Yes, as far as I’m aware it is the same for an NBFL, except I don’t think there’s a pre-silencer on mine - never noticed one anyway!
The car will be in the garage shortly, so when it’s up on the lift I’ll double check that, and I will correct that if I do have one (coming up to MOT time!)

Since Christmas, my back box has changed from a lions growl to a full fledged roar, so not sure what’s changed. Bit embarrassing now! - I’ll soon find out.

6

 

Ahh great, just ordered an Il motorsport mid pipe and backbox so hopefully, all goes well.

 

Thanks for your help! :slight_smile:

 

Freddie