TR4/4A TR4A Exhaust - Twin or single?

[Foura]

My 4A has the older style twin muffler twin pipe exhaust system with a Y branch after the centre mount. I am contemplating going to a single pipe of about 2 1/4 diameter with a straight through muffler and perhaps what we used to call an echo box to keep the noise manageable. I had that arrangement on my 3A many years ago.

Does anyone have any real world experience of performance improvement from getting rid of the Y branch? I recall reading somewhere that a better exhaust flow was why Triumph went to the single exhaust and cross mounted muffler on later 4As.

 

[trrdster2000]

Rocky, I have the same system as you on my TR6, as it's an early single manifold system and I can only tell you it works great compared to the stock single pipe and one muffler with two exit pipes. I will replace the whole system at a later date for the Ansa dual pipes, but for now all works well and sounds great, some small popping when letting off or shifting down.

Wayne

 

[sail]

Can't answer you question. My duel system was shot and I put on the later single set up for simplicity and to get rid of the muffler under the cockpit. I don't like the sound and am thinking of replacing the cross mounted muffler so I'd be interested in what you come up with.

 

[Gliderman8]

I will replace the whole system at a later date for the Ansa dual pipes, but for now all works well and sounds great, some small popping when letting off or shifting down.

Wayne

I have the ANSA dual pipes in my TR6... you won't be disappointed!

 

[HerronScott]

Does anyone have any real world experience of performance improvement from getting rid of the Y branch? I recall reading somewhere that a better exhaust flow was why Triumph went to the single exhaust and cross mounted muffler on later 4As.

Sorry no information on switching to the single later cross-mounted muffler as both of mine have the dual exhaust setup. I would have guessed that they switched to the later setup due to costs as I would expect it was cheaper to have 1 muffler.

When I restored my first TR4A, I replaced the front muffler with the later TR6 dual-to-single Y-pipe and used an Ansa exhaust for the rest of the system (single-to-dual Y-pipe and the 2 rear mufflers with dual chromed pipes for each). I don't recall it being too loud and I loved the look from the rear. Unfortunately they no longer make it for the TR4A.

Scott

 

[RJS]

The prior owner of my car did the restoration. I can tell from the photos it had the dual exhaust set up. However, he converted it to the single exhaust using the cross box muffler from a TR250 which has the twin pipes exiting the left side.

While I probably would have stuck with the original design I must say this fitment is simpler, cheaper, sounds very nice and has lasted me 13 years (mild steel)

Bob

 

[MichaelG]

Does anyone have any real world experience of performance improvement from getting rid of the Y branch? .

Rocky, I installed a single pipe system...... it came right off the center muffler and had no rear muffler or resonator, and had it on my 4A for many years. Not sure if the performance was actually any better...but it sure sounded faster . A few years ago I installed a new twin muffler system. I did not notice any performance decrease...it sounds great and is much more comfortable on longer cruises. That said any good muffler shop could bend a pipe to do this in an hour or two.....

 

[DanB]

it would be nice if you could hear the muffler sounds before you went to the trouble of putting the system on your car, wouldn't it?

 

[pdplot]

Years ago, I welded up an exhaust system for my TR3 using a Smithy deeptone muffler intended for a Ford or Mercury. Sounded great and would probably last for the life of the car as they were made from heavy gauge steel. I have a stainless steel setup on my TR6 now but I'm not thrilled with the sound although it should last forever. Too many harsh overtones. I don't know if they still make Smithys or "Smittys" as we used to call them back in the day. Sounded great on V8 Fords.