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MG Midget and Sprite Technical - 1500 sports exhaust options?

Hi everyone. I'm was looking to upgrade the exhaust system on my 77 midget 1500 to something that sounds a little more sporty. The only option I've found so far is the stainless replacement system on Moss/Rimmer made by Bell. Has anyone come across any alternatives to this?
S Marshall

MGOC have Double S systems made in Devon at Cullumpton ISTR.

Also Maniflow do mild and S/S systems.
richard b

Thanks for the reply Richard I'll check those out.
S Marshall

i had a custom one fit its a bit too loud foe me getting another inline box fitted to take the edge of of it.


mark heyworth

Not sure how loud is too loud, but only the other week I managed to set the alarm off on the car I was parking next to, in my Sprite!
Daniel

Thats the way a spridget is suppose to sound/do as a classic sportscar in my honest opinion. :)

When I still had my 1500 engine in I had a maniflow 4-2-1 exhaustmanifold with single pipe(with flexible pipe in) and a single box.
All custom made in Stainles steel, loved it!

More or less the same setup with the Kseries and love it, maybe my neighbours not LOL!!
Im not deaf but it doesnt bother me, not on motorways or citydriving.
A de Best

As the later 1275 and 1500 share the same twin-box silencer arrangement, why not fit a single box silencer from the early 1275?
Dave O'Neill 2

I take it the single box set up is louder than the twin box?
S Marshall

Yes, it sounds much better.
Dave O'Neill 2

Maniflow offer a number of different exhaust systems for the MG Midget 1500: https://www.maniflow.co.uk/index.php?view=category&category=181 and an exhaust manifold: https://www.maniflow.co.uk/index.php?view=product&from=169&product=1149

Also an inlet manifold: https://www.maniflow.co.uk/index.php?view=product&from=162&product=1611

Cheers
Mike
M Wood

I have a Maniflow mild steel 3 branch and single box ‘across the back’ system the LS031 which is a slightly larger bore than standard on my mildly tuned 1293.
It gives a throaty sound but not overly loud and I have not considered it loud or an issue on longer runs.

The pipe and box are getting to the end of their life now - Maniflow consider mild steel gives a better sound - not tinny ISTR they said but I may consider Stainless for pipe and box.
richard b

Does a single box RC40 work on the 1500? Always been my silencer of choice for the A-series engine.
AdrianR

Second vote for an RC40 - if it fits. Agreed Adrian, it does sound good on the A Series.
Jeremy MkIII

Richard

Could you ask Manifow what wall thickness they are using - my guess is the MS system is thicker and heavier than the SS
Malc Gilliver

I had a single box RC40 on the Sprite but found it too loud so fitted the 2 box system and that worked great, 2nd box hung behind the tank. That's a 1420cc A series and a mild steel boxes but they were durable, I would make the rest of the connecting pipework in stainless next time though.

Regarding SS systems I recall in the past talking to people that mentioned them lasting well but getting louder over time as the packing broke down and blew out, that can be a matter of the quality of the packing. A mate repacks the silencer on his Caterham every few years but it's designed to be taken apart for the procedure. Anyone else have any thoughts on that?

David Billington

I went for the Maniflow single box straight through exhaust with their 4-2-1 manifold on my 1500, I was concerned that it would be too loud but found it was spot on, sounded far better and also gave a bit more power and a bigger bonus was that it was very straightforward to fit.

Tim Lynam

Custom made 4 into 1, then into custom 1.75" exhaust with twin straight through silencers, naturally! :-)

Tried a single silencer for a bit, too loud, I felt embarrassed to drive it.

Maniflow are commonly regarded as the best off the shelf option.

Malc.


Malcolm

David Billinton,

I used to work for a number of car companies on exhausts, last exhaust system job was at Gibbs Aquada, that had a fully enclosed exhaust system running at really high temps - well over 700C on full power and that used to destroy the exhaust packing - I do remember findind a really high temp packing material - I have a feeling they were in north Derbyshire, but this information dates back twenty years.

However in the mean time cars have added more and more emisions stuff, so there will be a greater range of high temp materials now - back then we were using E-glass.

One of the problems with exhaust packing is the balance - you need lots of holes for the noise to escape the pipe, but those same holes allow carbon in to the packing causing it to become less efficient and allow the packing out once it has broken down.

The alternative is to fit much larger multi pass silencers, but they are very difficult to package and can if badly designed reduce engine power.

My gut feeling is the best route is to have mulitple stainless steel repackable silencers that you can unbolt and repack when needed, if you plan on keep the car for years.
Malc Gilliver

Malc,

Maybe Maftec or Denka and IIRC there is another trade name. Basically a 1600C classification temperature mullite fibre blanket. One use is as a support material for the core of catalytic converters so can take the exhaust environment. Not cheap compared to other fibres but also not classified as a potential carcinogen. I have some Maftec blanket and gave a bit to a neighbour to patch his cat as the casing had partially failed and a replacement was more than the car was worth.
David Billington

David,

Sorry just spotted I dropped g from your name.

Cat blanket is different, that exists to swell when the canned cat is first used, to gently grip the brick without breaking it, not absorb noise.

It might well have been a stainless steel wool packing we were looking at - not these people, but this stuff - https://ekksol.com/stainless-steel-wool/exhaust-muffler-packing

But I left once I realised the whole company was bad for my health
Malc Gilliver

Malc,

That's OK, I didn't notice until you mentioned it, you've got a spare g you can use somewhere else.

The fibre blankets I was using were for high temperature insulation but there were related products which were engineered for high temperatures and their acoustic properties.

I'll mention the SS wool to my mate, might be a better option over the glass or mineral wool stuff he has used in the past.
David Billington

Thank you all for the info, interesting reading. It seems I have a few choices available that I'm going to explore further.

Cheers
Sean
S Marshall

I once put a 1500 twin box on a 1275. I cut the 1500 pipe where it deviates from the path of the 1275 and found the 1275 pipe slipped neatly inside the 1500 pipe so all I needed was a clamp and job done. The 1500 pipe is one size up from the 1275 pipe.
Rob
MG Moneypit

This thread was discussed between 09/07/2025 and 24/07/2025

MG Midget and Sprite Technical index

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