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MG Midget and Sprite Technical - Maniflow single box with resonator?

Hi all, a bit of advice needed.

I have a Frogeye with 1275 bored out 60 though, 286 kent cam, MG Metro head and HIF44 carb. At the moment it has standard exhaust manifold and single box 1275 exhaust system. The exhaust note has gradually got louder over the last 5 years so I suspect whatever silences the sound has deteriorated over the years.

I have a Maniflow LCB I want to fit so would like a Maniflow exhaust system to go with it but I'm over the thundering exhaust sound period of my life and want the exhaust note to be a good deal quieter.

I don't want to fit a later 2 box system with silencer across the back. The Maniflow website shows a small silencer that can be fitted in front of a single box (a resonator?).

Has anyone had any experience with this sort of setup?

Rob
MG Moneypit

I put one of these on my A35 - similar engine spec to yours except for MG Metro cam and 1.5 rockers. It was to replace an existing Maniflow box and resonator but I found it too quiet. After 50 miles I took it off and decided to stay with the old one. The Frogeye has a single RC 40 and to me sounds nicer - though it's certainly not quieter. I'd have thought having a resonator under the floor would compromise the already tight ground clearance, so suggest you do some measurements first.
f pollock

Rob,
I've got s/s Maniflow LCB, s/s custom centre pipe and what should be a s/s Maniflow back box but it's got noisier over the years, now too noisy. When funds allow (probably never as other issues take priority) I'll get a s/s (re)packable back box made up, that way you can have it as quiet as you like. Lots of these places that make up exhaust systems for the youngsters cars seem to be very good, use very good materials and reasonably priced. A small back box would be an easy job for them.
Nigel Atkins

I run a Manifold LCB + single back box system (not s/s) on my mildly tuned 1275 and I find it very quiet at low revs, becoming pleasantly resonant with foot hard down. Much more neighbourly than the previous Peco system I had for many noisy years - but I do miss the popping on overrun! But that's the subject of another thread.
Peter Blockley

My 1293 's' spec Frog also has a Maniflow LCB running into standard 1275 SS pipe and Special Tuning SS back box. Quiet burble at low revs but more lively hum at 3500 revs. Wife often goes to sleep on longer runs, its quite soporific
Bob Beaumont

Thanks for the comments.

Magic midget do a re-packable SS box, I may look into this. What is it packed with? SS pan scourers?

The current exhaust is much too noisy until you pass 3500 rpm. 2500 to 3500 sounds like Thor with a big hammer per cylinder!!!!

Rob
MG Moneypit

Aren't they usually packed with glass fibres? The exhaust runs straight through but is perforated. The glass wool is packed tightly around the perforated tube and disrupts the wave forms of the noise. The glass wool eventually breaks up and is ejected out the tail pipe.
Mike Howlett

Another vote for Maniflow LCB and back box (in my case an RC40). As others have said a nice burble at low revs (almost MGBish) and to quote Bob, 'a lively hum at 3500 revs'. Mild steel coming up to 10 years old now.
Jeremy MkIII

I'd forgotten Kim Dear's Magic Midget does packable rear box but it's in a kit, if sold separately that would be the place to buy from. Ask Kim and I'm sure he'd give details.

http://www.magicmidget.co.uk/exhaust.htm
Nigel Atkins

I do have the LCB with the maniflow "resonator"now. At first I only had the single green Maniflow box. I always had to wear ear plugs. Especially on motorways. With the resonator I do not need them. The ground clearance is no problem. Speed bumps (lying policemen) affect the front end of the LCB. I also have some dents in the fuel tank after rallying in rough terrain but no problems with the resonator with is placed just before the rear axle.

Flip


Flip Brühl

This thread was discussed between 17/07/2019 and 21/07/2019

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