Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) +8 exhaust system - which way to go?

I have finally got a +8 again after many years without and now have a problem over the exhaust! My last +8 many years ago was a 3.5 with Librands exhausts which sounded lovely but would raise the dead. My new car, a 1997 3.9 has brand new stainless steel single exhaust fitted by Allon White which is a very much quieter system.

I feel a twin system with proper manifolds would increase horse power by letting the engine breath and give more of a V8 burble - however, too much noise can make the whole experience a bit tiring on longer journeys.

Welcome views from +8 owners please, especially those who have tried both the standard single system and twin pipe system. I especially am after opinions on; noise / sound quality, performance and ground clearance please.

I'm biased but consider twin side exhausts. Better ground clearance and less likelihood of exhaust fumes with roof off. A system with decent silencers shouldn't be too intrusive.

With a 1997 car you will have cats?

The options for cat-equipped cars are slightly more limited, but the best route is the Librands manifolds to start. The old type used to cross over under the sump (the benefit being much longer primary pipes and so better torque , the big negative being the hot gases under the sump making the oil hot which is no problem in winter , but not good in summer) The newer type exit through the chassis rail on each side which is doesn't loose a lot and is better for the sump oil. This is quite an expensive piece of kit , but well worth it , due the release of power and the cleaner look inside the engine bay.

Then you have the cats , you could swap these for sports cats , but this will shorten their lives and make more noise . The standard cats do provide quite a lot of silencing in themselves.

Now form the cats back you have more choice , firstly the silencers , Librands make them in loud, medium and quiet (or at least they used to ?) , if you want to tour then only go for medium or quiet, loud is really very obtrusive.

From there, the tail pipes are almost a free option. Richard's suggestion of side exit pipes is worth exploring and is definitely the cheapest and does away with the clearance problems around the rear wheels and chassis. Otherwise straight tail pipes could be made up by almost any exhaust manufacturer with the right equipment. Do not go for resonators as tail pieces, they are not necessary and will rob the system of some of the nicer exhaust notes, a simple flared tip is much better.

The only ground clearance issues come from the tail pipes extending back too far , the rest of the system is above the gearbox crossmember.

RELATIVITY and EXPECTATIONS would seem to be THE key words when a description such as tiring might be used when seeking advice from others..? When I look at the list of machines you have or had available listed at the bottom of your post, it seems that you perhaps have a wide enough experience of old to new(ish) tec in both m/cycles and cars, also suggesting you have the option of horses for courses in terms of efficiency or something a tad more raw..

Back to exhaust systems and choices. Sorry I do not have experience of a single pipe system, however circa 20 years ago when I bought my 3.5, having spent many years messing with 911`s I was in search of a bit of a vintage driving experience to enhance my enjoyment of local roads and was advised that a +8 Morgan was THE way to go by some of the folk who still lurk around here.. and they were not wrong..(-:

It seemed that my rear tyres could polish the stainless exhaust pipe on occasion perhaps as the result of enthusiastic cornering. On looking for a work around that situation it seemed the diameter of the rearmost mounted silencers required the exh pipe connecting to them to be closer to the tyre than might be the case if they were removed and thus the pipe allowed to run closer to the chassis rail..? Job done and as the result the rumble, roar pop und bang, was amplified while bringing the old V8 to life.... exactly what I was after... (-: Though it seems while enjoying such youthful antics the tyres still rubbed the pipes on occasion..!

Tiring of the sound of a V8 Morgan... Relativity seems to come back into play..? When cruising along my +8 burbles away contently, though if I step on the loud pedal it barks, or with a bit more encouragement it roars, and on lift off in the roaring phase it can pop and bang.. Myself and my good lady covered a few Southern European trips from Central Scotland down as far as driving the Amalfi coast one Summer. Tiring, yeah well some days we perhaps pushed too far and in the heat of Italy in June in an old Morgan...did it feel like an adventure... you bet. Would it have been less tiring in a more modern sports car... I don`t doubt it..

As for speed bumps and ramps of all sorts, yeah tail pipe length is worth consideration, long enough to avoid odours being sucked back into the car, or blackening up the rear of the bodywork, side exit may avoid the ramps issues..

Good luck in your choices.

I had the single exhaust on my ‘96 Plus 8 replaced with a straight through twin system. I’m not sure that I can tell the difference as far as horsepower is concerned but it sounds great (to my ears), it pops and throbs wonderfully and I never tire of it, even on the long drive from Kent to the Isle of Man. I guess it’s all relative and down to personal preference, a friend has side exhausts on his ‘89 Plus 8 and it’s even louder than mine!

I have had both on different cars, my earlier car having the single sided and you are fully aware of the nice rumble and occasional pop but quite a muted experience, a 3.9 as well.

My present car came with the Librands Sport dual system but standard cast iron manifold, I can't say I have noticed any difference in performance but the sound is full on rumble with lots of popping on over run at around 1,500rpm. Ground clearance not an issue.
It suits me perfectly being a dual hearing aid old boy and haven't found it a problem on longer runs but can see that if your hearing is good it could become intrusive.

I would advise meeting up with someone that has the system you fancy and give it a listen as sound is such a subjective thing.

Good luck with your choice and good to hear you have a Plus 8 again to enjoy.

Richard

The most restrictive part of the standard set up is the cast iron manifolds , the design is absolutely dreadful, just using the tubular exhaust manifolds will release about 15 bhp and a better torque curve.

You won't need to measure it on a dyno , believe me , you will notice it the very first time you arrive at a corner much faster than you expected.

The +8 tuning regime I would follow is

1 Better exhaust manifolds and decent silencers

2 Better intake system (K&N or foam type air cleaner to replace large box and trumpet

3 Tornado chip for ECU

Those will give you about 20 bhp . Mine went from 162 to 182 (measured on the same chassis dyno) , but the torque peak moved from 4,700 rpm down to 3,600 which meant the power was much more usable.

I have no experience of single pipe. But have run Librands big bore manifolds (1980s vintage & most recent) with both side pipes and rear pipes with no back boxes for 200k miles. 1980 +8. I run mine on Librands big bore stainless, stainless boxes with side pipes but no catalysts. Had blown all the stuffing out of the boxes, it used to flame on the overrun. Part filled boxes again. And I do wear ear plugs on long journeys. Also over the years had problems with exhaust blow back when running rear pipes. No ground clearance issues.

Andy,

Thank you very much for your tuning tips and I shall bear them in mind if I feel the need for a little extra power.

I have the single exhaust system on my 94 +8, straight through side pipe from the cats back I run a modified air intake with Tornado Chip tune. As with Richard I am a two hearing aid chappy and I love the sound which I do not find intrusive, 8000 miles on Morgans Over America was a delight in my book. The high altitude winding mountain roads here in the Alpine Colorado Rockies mean lots of throaty burbling and popping coupled with great acceleration/braking. They say this is Gods country, driving all my Morgans in it makes it even more heavenly.