So… I decided that my nc2 mx5 (2.0) was lacking character from the rear… so off hunting I went for as much feedback as physically possible to carefully select a suitable exhaust.
I have owned / driven cars with loud exhausts in the past and made the decision that this was something I didn’t want again, but nor did I want zero sound from my little 2 seater.
So … after MUCH deliberation I settled on the moss cobalt backbox which moss themselves and many many owners state is barely louder than standard with just a bit more excitement when driving the car hard…no drone / boom etc etc
Fast forward to today, my cobalt has been delivered and bolted up by some trusted dudes, my untrained eye can spot no leaks etc but… I am not impressed with the result…
The volume difference is muchhhh bigger than expected and the overall result is a boomy low pitched note out the back especially with the soft top up… I am genuinely questioning whether something is up with my setup given the reviews I read before buying… I am genuinely wondering if I will be able to put up with it for long…
I have just been on a 100+ mile run and ok…if I am FEATHER light with the throttle it’s not all that loud, but anything more and the boomy boring noise is there again…
I know exhaust notes alter when carbon build up kicks in bit so far it’s all miserable boomy bass noises with not even any character such as pops or anything more than very quiet burbles to make up for it …
Can anyone relate? I’m close to contacting moss, I feel silly but I’m really not exaggerating here…
Got one on my RF 2.0 ND sound like a sports car should the nd as hight tickover on start up mazda way of making it sound sporty on start up with the standard exhaust it always sounded a bit like a diesel but now nice sound on acceleration no boom quiet when cruising
I was in a similar situation to you, had loud exhausts before, just wanted something with a nice rasp/burble but not too noisy on the motorway, ordered the cobalt and on first start up was disappointed that it was too quiet !!..My MX5 is a toy only as my main car is a company Mondeo. Have done around 500 miles in the MX5 since i fitted it in Feb and it has now just bedded in…nice subtle sporty note on acceleration and pops and burbles very quietly on over run and not noticed much difference when cruising.
i absolutely love mine so maybe there is a fault in the exhaust. Very happy with it but if I really had to critique it i would want more noise.
I too have a cobalt that I find booms like a ********.
1500rpm either accelerating or decelerating gently it’s really uncomfortable in the cabin. Above 1500 it tails of and above 2500 it sounds good but when you drive anywhere other than the open road 1500 rpm is hard to avoid especially in the 20 limits that are everywhere these days.
I disliked it so much I had to take it off. Went back to standard. I miss the noise in the tunnels
If anyone wants it they can have it for £60. Not new but in good nick, have the original receipt from the original owner too. 2016
Interesting. I’ve had Cobalts on both my NB and NC. I found initially the sound was a bit tinny but once everything bedded in the note lowered. Now it has a lovely growl when you put your foot down but otherwise it doesn’t rattle windows. Might just be, as someone else said, that you have to live with it for a fee weeks/months until everything beds in.
i hate booming exhausts so i wouldnt put up with it
i fitted the cobalt after having a cobra exhaust which i absolutely hated drowning booming and just plain nasty
there does seem to be a couple of differing opinions here is it maybe there quality control isnt up too par and some are good and some obviously are not ?
I think that Charliefarlie has nailed it. Everyone’s hearing is different and that is probably the core of the problem, to one a pleasant “sporty” note to another is an unacceptable “blare”, and a nice “burble” a unpleasant “drone”. It’s a pity that you can’t listen to a variety of exhausts in a custom made “listening assessment room” similar in purpose to those for choosing hi-fi speakers before buying.
I fitted a Cobalt over the winter lay up. Love it’s looks and although I’d say it’s not noisy per say, it does drone around town if the engine is under load which is mildly annoying. It’s fine everywhere else and I feel the car is a bit more peppy through the gears… maybe my imagination. Took my mate out for a drive to get his thoughts and he now wants one for his Z Sport.
when I bought my NA Eunos it had a recently fitted Cobalt single exit exhaust fitted, I thought it was a little loud
a year later i decided to try to quieten it so had a looksee and eventually chopped the tailpipe off & replaced it with smaller plain pipe of the same diameter as the silencer & it’s much better
removed
the tailpipe is 59mm id from the backbox to75mm id inside the tailpipe and thats inside the outer ‘shroud’. the size increase acts like a ‘megaphone’ and the outer can help amplify - something I do not think is needed
I had some 2 1/2" id steel pipe so welded that in place - sorry no photo’s as it’s under the car (okey, I know its a schyte ‘dissimilar’ weld of Cobalt’s Chineeseium stainless & mild steel with argoshield light ‘shield’ gas but it’s just a tailpipe extension to get exhaust gasses outside the rear bumper )
as to noise, I’ve been playing with rallycars & working in heavy engineering for ~30 years so not afraid of a loud exhaust but the cobalt was not that pleasant untill 'modified’
Totally agree that everyone’s ears are different, but I genuinely got out of the car feeling like I had been to a mild rock gig ; that slight muffled sound after being next to speakers yaknow??
I wouldn’t say I’m sensitive to the point that I’m exaggerating as I love the right kind of racket from a car it adds to the experience, but boomy is absolutely the word I’d use…
I really like the tail pipes on the cobalt but not the noise. I was thinking of lopping the cobalt tips off and attaching them to the standard silencer to have silent good looks.
Just fitted a Cobalt exhaust to my new GT Sport Nav on Thursday and for me the sound is just about perfect. The standard was so quiet but now a nice sporty note on acceleration especially at around 6,500rpm, but very quiet burbling under normal load. On previous ND Sport Recaro had the twin centre exit exhaust from MX5 Parts with diffuser, which looked great but for me was too booming. Have previously had BBR Super Sport which was too loud and BBR GT box which was very similar to the standard exhaust sound. Cobalt in recent Moss sale was also around half the price of BBR and similar from MX5 Parts. I agree however what may sound perfect to one person can be too loud or too quiet to another.
Yeah I’m not sure all is as it should be with mine… There is no way people would disagree, after a day of winding around country roads , the in gear deceleration has literally given me a headache top up / down booms like crazy both ways… look forward to getting out of the car the opposite to how I felt before fitting
If it helps explaining the volume it totally drowns out any of the piped induction sound in my 3.5 that is gone totally…
Really unhappy - a friend has an mx5 parts box which I find way too boomy and if my memory serves correct, this is not much / any better
