Exhaust upgrade - Go for header first?

  1. My model of MX-5 is: NC1 2.0 Sport
  2. I’m based near: London
  3. I’m looking for technical help or recommendations on: Exhausts.

It seems that most people will go for a backbox first but I was wondering if it would be better to just get a set of headers? Would it alter the sound of the car at all?
I was looking at I.L Motorsport 4-1 headers. They seem better value than the backboxes.

Would there be any reason not to go for an aftermarket header with the rest of the exhaust being fully standard?

Seems like a lot more of a faff to fit, fingers crossed the studs/bolts on the original header are not rusted and seized.

Be aware that changing from the standard exhaust can seriously - I mean seriously - affect the usability of the car. I tried this a few years back - the new exhaust lasted 2 days, and one outing of about 60 miles round trip. Much too noisy!

It’s the most effective part to replace by a long way as far as power and response is concerned. Slightly more noise, nothing bad at all.
But then read here:

2 Likes Exhaust emission control equipment

This inspection is only for vehicles that must have a full catalyst emissions test (disregarding the basic emissions test). You only need to check components that are visible and identifiable, such as catalytic converters, oxygen sensors, and exhaust gas recirculation valves.

Defect Category
(a) Emission control equipment fitted by the manufacturer: missing, obviously modified or obviously defective Major
(b) An induction or exhaust leak that could affect emissions levels Major

This is also something to be aware of ,
Lifted straight out of the MOT testers guide .

Disregarding all the emissions arguments, the IL 4-1 is a well made and regarded choice and will give you a useful power hike with a map upgrade.
A back box will only give you noise.
If you fit the IL you can budget for the cable extension and bung required to move the post manifold O2 sensor into the standard midpipe after the 2nd cat.

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Yes, get the IL header to start with and work back from there.

I have the IL header too.
Just “Be careful” which rear box you go for.
I swapped my standard for the “Go Perform” which indeed was far too loud, droned, boomed and actually hated it in the end. (Different hearing, different opinion of course).
Currently have the Cobalt which is very good. Surprisingly quiet at normal cruising speeds, not much different at all from stock really. Acceleration gives you what you probably want to hear!
But currently unavailable sadly.
At the end of the day a sports exhaust has a different tone etc etc which is the whole point.
If you have a mate, or try and find someone that has what you want and try perhaps?
Just an opinion. :+1: :slightly_smiling_face:

Exactly why I am asking about headers. Asked Moss about 6 months ago about the redesigned Colbalt exhaust and they kept saying soon, got bored of waiting. :blush:
I just want to add something to the NC to make it more enjoyable, it’s a bit dull as standard.

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Yep agreed.:+1:
When I looked I brought the short list down to 2.
The IL Motorsport and the Racingbeat one.
Swings and roundabouts to be honest.
Both very good and as they say you get what you pay for.
I decided I was going to pay a good tuner to do it.
Rodders (uses the RB) one.
Skuzzle at the time used the IL one.
Skuzzle was just much closer but would have travelled to Rodders.
If any of this helps. :slightly_smiling_face:

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Just don’t buy one of those Toyosport manifold things, they’re bloody awful.

BBR have a selection of used headers on offer in their clearout bbr_gti on eBay
The longer primary 4in1 are favoured either IL or Racingbeat. If you wanted a new one they obviously sell there own as well that they get good results from when mapping. My current car has a 4-2-1 IL which BBR mapped without any noticable differences in power and curve. I have a Racing Beat backbox and it is loud, although the rest of the system does lack the normal restrictions so would be more acceptable on a standard mid pipe.

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Thanks, I did see those ones and watched them, they have some good bits on ebay.

The catted headers are like £800 and I reckon that’s better spent on MeisterR’s.
I’m on SE London so not too sure where is the nearest MX5 tuner so I would probably be running stock map with headers for a while which might seem a bit pointless.