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MG MGA - Tuned Exhaust Performance

I have been thinking about installing a tuned exhaust (from Moss Motors). Can I expect noticeable performance increase?
gerard hutchinson

By itself no.

The best tuning you can do on a vehicle is to fully and timely service the whole vehicle which includes maintenance and repairs. Then the whole car has to be set up not just the carbs and engine. Only then will you have the best potential for improvements.

If the tuned exhaust is suitable and well made (not all are) then added with other changes from standard perhaps you may have a better feel to the performance but how much actual improvement the tuned exhaust gives would need to be checked on a rolling road probably. You will get a different sound which can make things feel better.

I have and have had non-standard exhausts but more for the sound, feel and longevity that any small increase they might give and to combine with the other small improvements to give a combined small improvement.

Best overall improvement, after proper whole car servicing and set, I think for the engine is to replace the mechanical dissy with a high quality (I'd not trust the cheap ones) fully (top and bottom) electronic dissy, better for starting, idle and running throughout the rev range. Best to pair this with good quality (not necessarily high priced) HT lead set and new spare plugs possibly gapped slightly wider to take advantage of the performance of the fully electronic dissy.
Nigel Atkins

I'd agree with Nigel, no noticeable difference other than perhaps a louder exhaust tone. I've attached two links to Barney's site which detail changes that will have an impact on engine performance:

https://mgaguru.com/mgtech/power/pp200.htm

https://mgaguru.com/mgtech/books/pdf/MGA_1500-1600_special_tuning.pdf

The first is basic commentary with recommendations; the second is the MGA Special Tuning guide.
Nick Kopernik

Peter Burgess tested several exhaust systems on the B-Series engine and only one gave any power increase. It was a whopping 2HP at the flywheel, which is barely over 1HP at the wheels. And this was on an 1800, so the power gains would in theory be even smaller on an A engine.

So assuming your engine is stock, better to choose based on materials and sound than performance.
Steve Simmons

I added the moss supercharger about 14 years ago. I had a Monza type muffler since 1982.

When my transmission (original) began to drop out of 3rd and 2nd gears, I decided to change to the T9, 5 speed conversion.

While the engine was removed, and supercharger off, the Moss tubular exhaust manifold was tuned, ceramic coated and fitted.

I could feel and hear the differences

The supercharger forces it to breath, the manifold let’s it fart and the muffler makes it growl. Interestingly, it seems quieter at speed. The new transmission definitely helps with that!

The suspension had been rebuilt prior.

Seem the prices for all of these have soared,

Paid US $75.00 for the muffler.
Ted Persons

The factory went to a great deal of experimentation and testing time to create the most efficient exhaust and intake manifolds that it could afford. Thus, for any "tuned intake system" or "tuned exhaust system" to offer significant improvement over the factory system, the vehicle must be significantly modified from factory form. Ted gives a thoroughly explained illustration of this form of modification which requires modification of the factory system.

More advanced tuning of the engine require modification of parts, not just the bolting of parts together. The cylinder head has to be modified to efficiently use the extra fuel that precision fitting the intake manifold to the head and carbs potentially offers, The exhaust system must not only allow the exhaust to be pushed into it, but must assist in move the gasses through the system. All of these things must be done in an integrated manner lest they not work as a harmonious system and the various modifications fight each other.

For these reasons, simply bolting on what someone describes, for advertising purposes, as a "tuned exhaust system" seldom works to any great extent and, in some cases, can cause problems due to the system becoming unbalanced.

Les
Les Bengtson

This thread was discussed between 22/06/2022 and 24/06/2022

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