Stainless steel exhaust advice please

Short_Shift · 22 June 2017 20:13

saz9961:

Short Shift:

saz9961:

Short Shift:

saz9961:

Mongoose makes a good system, with lifetime warranty. I brought mine in 1999, and the warranty has been needed a few times along the way. Racing Beat systems are extremely well made systems, and one of the few that are actually dyno-proved. I had the pleasure to visit Racing Beat’s Anaheim outfit in 2000. They pretty much do everything in house, and are Mazda North America’s tuner of choice.

1995 was a cross-over year; part way, Roadster exhausts changed, by deletion of a hanger by the catalytic converter. I’ve heard of cars failing MOTs when the tester sees an unattached hanger bracket on the exhaust. Mongoose makes this bracket detachable. On other exhausts, its probably worth getting the fitter to cut off the bracket. The later exhausts were fitted to Phase 2 NA8C cars; these can be spitted by having a green Roadster badge on the rear, and VIN NA8C-4******.

The danger of getting a fitter to source and fit the exhaust, is that he might attempt to fit an exhaust intended for a later UK Mk1, which is a different system. You need the same system as fitted to any 89-93 1.6, but mechanics can be pigheaded in this respect, when told to fit parts that the “book” tells them are wrong.

The old school exhaust of choice for BHP gains was the Borla exhaust; these systems made the most power by eliminating the mid-pipe silencer.

Out of interest what does the Mongoose sound like and can I conclude then that there is a genuine performance benefit?

Did you fit this one yourself and if so how long did it take?

Cheers

Matt

The system has moved between cars. A 1.8 takes a little longer than a 1.6, because you have to feed the exhaust parts around the subframe braces. You can remove the braces, but I’d be a bit wary of the longitudinal braces; they have been known to be so seized, the captive nut is broken. The cat studs will likely snap off, so you need to make sure you have the facilities to drill out the stud if necessary, or have a new cat to hand. The rubber hangers can be a bit stiff to prise off the original exhaust; soapy water helps, but you may need to cut some hangers off. So have to fresh Mazda rubber hangers; forget about aftermarket generic hangers, none of them are any good. Use high temperature silicone as a jointing compound, not exhaust paste. Some small fuel hose clips are handy to adjust the exhaust on the hangers, so it sits right. 30 minutes on/off is extremely optimistic, unless you have a lift. And if you have a lift, you would not be asking these questions.

Its not a hard job, but there is enough things to wrong first time, that you wished you threw £50 at your local garage to fit it.

Its debateable whether any of these exhaust any performance benefit; the Borla, because it has no mid pipe, has fewer bends.

Someone else’s Mongoose:

https://www.youtube.com/watch?v=AqaFmFTrDuc

Thanks and apologies for delay in responding - the website repeatedly failed to load yesterday and I gave up near midnight when I lost wifi completely

The Mongoose sounds really good although it would be helpful to know if it is doesn’t drone too much when cruising at speed. Interestingly I looked on the Mongoose website and the only listing for an MX5 is a decat. There are listings online for decat back systems via other companies (presumably old stock). I rang Mongoose who tell me they no longer make systems for MX5s (not enough demand apparently).

Your advice re the potential pitfalls of trying to fit an exhaust myself makes a lot of sense. I remember having an exhaust fitted to my first car a 1962 straight 6 rover P4 about 30 yrs ago. The garage qoted £10 for the fitting and due to some complications it took them over 4 hrs and a lot of swearing but they honoured the price and I was very glad not to have attempted this myself. The mention above of a potential 30 minute job made it sound very straightforward and tempting but may be discretion is the better part of valour Particularly as the cost of getting one fitted might not be that great!

Cheers

Matt

The MX5parts systems tend to drone, as do the Cobalt. Both are ok, but are at the lower end of the spectrum for a stainless steel system. Racing Beat are top notch, though you have to pay a bit more for them. The slight problem with Racing Beat is that they are designed for the US market, so have an additional downstream fitting for a second O2 sensor. Not a huge problem, as a bung is supplied.

Its academic now, but Mongoose systems don’t drone, and were a control exhaust a few years back on one of the MX5 Race Series.

Reasons why you would want a long warranty on a stainless steel exhaust:

You’ll never have to buy another exhaust again.

Some systems have hangers welded to the sides of silencer boxes. Stainless welds can be brittle; if they crack, the entire weld comes away leaving a huge, non-reparable hole.

Most systems use silencer parts that are pressed, not welded. After about 10 years, the joints start to loosen up and leak. Again, not repairable.

If you are just into car ownership for the short term, then a cheapie from MX5parts or Cobalt makes sense.

From what you have said I am tempted to purchase the Mongoose systems from one of the companies which have old stock as Mongoose tell me they would continue to support the product long term even if they don’t still make them - You get what you pay for and I do want to keep the car long term. Your detailed advice has been extremely helpful

Thanks

Matt

Rusty_Wheels · 23 June 2017 08:49

I fitted a Cobalt exhaust myself, and whilst it ‘should’ have been very quick, actually took me three days from start to finish!

It was just one of the cat nuts that caused the problem. The nuts used are a special self locking nut, that have a tapered thread at the end. Even though my previous exhaust had only been on for a mere 9 months, it simply wouldn’t shift! In the end, I cut a groove in it and used a chisel to tap it loose after a couple of days of penetrating oil:

I do like the Cobalt exhaust but the Mongoose looks excellent. Cobalt is well made, and when you can get it in, is actually a really good fit. Oh, and the other advice when removing/fitting the hangers, use silicon oil. Slippery stuff!

Short_Shift · 23 June 2017 13:25

Good ol’ penetrating oil!

Thanks for the advice

Thanks

Matt

Short_Shift · 24 June 2017 13:10

Despite being advertised on line the Mongoose is in fact no longer available even through other suppliers. I am a bit worried about potential drone from Cobalt or MX5 parts exhausts particularly as planning a long trip down to Italy next year. May have to consider the Racing Beat option!

ast · 24 June 2017 13:42

Get along to some owner club events, and hear others setups. Things like a 4-2-1 manifold can quieten things down. A decat can add a sporty note to a standard exhaust, but can sound awful with a stainless exhaust.

A new brand, Go Perform, is highly rated by the garage I use to service my MX5s |(who are doing rather well in the MX5 championships)

Racing Beat Europe:

Note, you need the connecting pipe as well

There is Japspeed:

https://www.japspeed.co.uk/mazda-mx-5-mk2-5-cat-back-exhaust.html

MX5city’s, note, no mid pipe silencer

Jetex

http://www.jetex.co.uk/performance-exhausts/Mazda/MX5-(NA)-(90-97)/

Short_Shift · 24 June 2017 16:53

saz9961:

Short Shift:

Despite being advertised on line the Mongoose is in fact no longer available even through other suppliers. I am a bit worried about potential drone from Cobalt or MX5 parts exhausts particularly as planning a long trip down to Italy next year. May have to consider the Racing Beat option!

Get along to some owner club events, and hear others setups. Things like a 4-2-1 manifold can quieten things down. A decat can add a sporty note to a standard exhaust, but can sound awful with a stainless exhaust.

A new brand, Go Perform, is highly rated by the garage I use to service my MX5s |(who are doing rather well in the MX5 championships)

Thrussington Garage

Racing Beat Europe:

MX5 NA/NB Exhaust Systems

Note, you need the connecting pipe as well

There is Japspeed:

https://www.japspeed.co.uk/mazda-mx-5-mk2-5-cat-back-exhaust.html

MX5city’s, note, no mid pipe silencer

Stainless Performance Exhaust System for MK1 | MX5 City

Jetex

http://www.jetex.co.uk/performance-exhausts/Mazda/MX5-(NA)-(90-97)/

Thanks again “Saz”

Yes, if I am going to spend a few hundred pounds on one of these systems probably worth investing the time hearing some different set ups. My current exhaust is a Fonos (which I have never heard of before) and I have little idea how this compares to the others mentioned in real world conditions. You get some idea listening the internet clips but not quite the same as sitting in the car. I probably wouldn’t go for a decat system due to the potential MOT “hassle” factor

Cheers

Matt