How to get a Quieter Exhaust? Loud MX-5

[ChasR]

I'm considering trying to get a quieter exhaust for my MX-5 but would not want to go back to stock levels either. Something a little louder and no more would be fine.

ATM my 1990 MX-5 1.6 is on a Raceland 4-2-1 manifold, MX-5 Parts Dual Exit exhaust system with the "silenced" decat - this does sound a little empty when tapped if I am honest. If I am honest, it is loud! OK, there are louder cars but when all you can hear inside is a booming sound at 55MPH and around that speed despite trying to whack the stereo volumne up it does get a little grating on a daily after a while! I'm sure my RST wasn't this bad with a Mongoose exhaust inside and TBH even the Porsche 944 was on when in the 'non-silenced' mode.

Anyway I am weighing up my choices which include:

-Reinstating the Cat
-Adding another silencer into the mid-section
-Replacing the exhaust for a Twin-box system - Didn't Racing Beat or IL Motorsport do one of these?

However, just how much difference would these have? I know on a 106 GTi the Cat made a massive difference but it add a little bit of boominess despite deepening the exhaust note. For you MX-5 peeps, what differences have you noticed?

And yes, I may be willing to swap the exhaust if the above options regarding working with what I have got are a lost cause, even if it does look good on the car .

[qwerty]

I had a similar problem with a Saxo VTR I bought. Turned out that the PO had specified too big pipe and dropped the middle box. I swapped the exhaust for a twin silencer Magnex system and a de cat, it was quieter and faster!

Tom

[bigearmuffs]

Have you looked into the Varex systems, we have a Mitsubishi Evo that had a 3" through pipe as an exhaust, clearly this was very loud, it now has a Varex backbox on that can be flicked over by a switch on the dash.

With the back box on it is probably a tad quieter than a stock system, with it open it is back to loud, although not as loud as before.

We didn't buy the full system just the back box, also didn't use the remote just hard wired it to the dash.

www.xforce.com.au/

[Curtis]

^ I always liked the idea of a varex, a lot of money for a backbox. Chas, I've got a stock exhaust save for a Cobra back-box, and was considering going a bit louder. We could swap a few bits if that would be something to interest you? Mines a 1.8 MK2.5 though, I don't know how much of it is interchangeable.

[ChasR]

Aug 8, 2016 18:03:21 GMT bigearmuffs said:

Have you looked into the Varex systems, we have a Mitsubishi Evo that had a 3" through pipe as an exhaust, clearly this was very loud, it now has a Varex backbox on that can be flicked over by a switch on the dash.

With the back box on it is probably a tad quieter than a stock system, with it open it is back to loud, although not as loud as before.

We didn't buy the full system just the back box, also didn't use the remote just hard wired it to the dash.

www.xforce.com.au/

I used to have a Wortec on the 944 Turbo previously which also had a switch for changing the exhaust. That has to be one of the best exhausts I have had on a car. Loud when you want it to be but also quiet when required, all at the flick of a switch. You can just about tell when it went from loud to quiet in this video. I do have a video of how loud it was somewhere:



If the car becomes a keeper I may well get the Varex and keep it in mind for future cars ; I was looking similar to go onto my now sold Escort RS Turbo. Something on the M3 like this would be superb. At this time I was hoping to not spend alot of making it quieter but selling my current exhaust may help with that if I go for something else.

Cheers for the headsup on these system

Aug 10, 2016 8:11:20 GMT Curtis said:

^ I always liked the idea of a varex, a lot of money for a backbox. Chas, I've got a stock exhaust save for a Cobra back-box, and was considering going a bit louder. We could swap a few bits if that would be something to interest you? Mines a 1.8 MK2.5 though, I don't know how much of it is interchangeable.

Thanks for the offer Curtis. I shall look into it and see what is interchangeable. I know being an early car my cat will be shorter than yours. As for loudness I'll get a video up if you didn't hear it at the MotoFest. Mine sounds similar to this:



With a cat one seems to sound like this. I'll have to try and hear one in the flesh, but sounds like it may be tamer:

[welshpug]

add a turbo

[ChasR]

Aug 10, 2016 12:41:04 GMT welshpug said:

add a turbo

Lalalalalalala *fingers in ears*

You're not the first to mention it to be and you won't be the last. These Early 1.6s do lend themselves very well to turbocharging thanks to their 323 origins.

I do fancy turboing it, as it would also have that nice side effect as well. But I know I would want to take it 200BHP+, where things start to get expensive with ECUs, injectors (I *may* have the injectors but I need to check), manifold and the other gubbins required.

That and I already have one quick car ; I really need something vaguely sensible :lol:

[welshpug]

quieter = sensible, ergo adding turbo is sensible

i know a guy that has done as you mentioned, TD04 of some kind, megasquirt home tuned and over 200bhp at a guess.

[ChasR]

Aug 11, 2016 13:57:37 GMT welshpug said:

quieter = sensible, ergo adding turbo is sensible

i know a guy that has done as you mentioned, TD04 of some kind, megasquirt home tuned and over 200bhp at a guess.

Hmmm, while trying to stay off this road, what is his MPG like? My MPG seems to have improved quite a bit (more than I was expecting!) since fitting the new lambda, and I was seeing 31MPG most of the time before.

[logicaluk]

Id try refitting the cat and see how it goes, if not put the lot back to standard as you said you've already got a fast car.
Dan