Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) 4/4 Sigma 1600 Sports manifold and cat.

Following a Wolf performance re-map of the ecu on my Sigma 4/4 1600 some time ago,I thought I'd treat the engine bay to a sexy 4 branch sports manifold.

I know Librands sell a version and that has some impressive Dyno figures - giving a useful mid-range hike in power and Torque. However Morgan also sell an upgraded 4 branch sports manifold and 200 cell cat through the Aero Racing division. I figured the genuine Morgan AR manifold would be even better and was pleased to find it costs less too.

Its now sitting proudly in the engine bay and what a brilliant bit of kit it is! Not only does it look great but it has really given the engine a new feel. Always keen to rev, it now heads for the red line with a new found urgency. In gear pick up is noticeably stronger with more power lower down the rev range. Motorway inclines are dispatched in 5th without the need to drop to 4th. The sound is improved too - slightly louder but with a deeper burble on over-run and a addictive howl at higher rpms. It definitely adds some more character and makes the car even more fun to drive.

Fitting was straight-forward really. Removing the old manifold was only possible by removing the aux-belt tensioner - not a huge issue really. The 2 O2 sensor wires on the original exhaust are not long enough so its a case of extend the wiring ( possible but not ideal) or replace the sensors with new. With luck Cain had the correct Bosch replacements in stock which have slightly longer connecting wires - job sorted.

Yet to work it out - but gentle driving seems to need hardly any throttle so I'm expecting economy to have improved. I guess that's down to the higher torque figures from the better breathing engine. Right foot dependant as always.

That sounds like a great mod and good to hear the factory kit coming out at a good price.
Craig will be getting creative with the household budget

Andymot your insightful write up confirms my own experiences. All the points you describe I have done also even if with other parts in detail concerning the manifold and exhaust system as well as the mapping of the ECU but the resilt seems comparable in terms of performance.
Regarding another zone of tuning namely the intake section, after an extended trip last week and short before driving home today I would like to add that I may go one step back regarding the open air filter. It is a good feel on short distance blasts to have an open one with even more high rev willingness but concerning a 2.500 km vacation I will go back to the standard airbox, safe my nerves a bit and sacrifice some high rev HP. Low and middle torque is not worse in my experience using the standard airbox.

Sounds great andymot. Thanks for sharing your experience.

Richard, the household budget went out the window years ago! (kids at Uni etc) I wish Andy never posted that about the Manifold, it’s really got me thinking now

Craig, I know what you mean we had 3 go that route and everything financially sort of goes into freefall for a few years.
That mod sounds really worthwhile though.

I had the Librands manifold fitted on my 4/4... the difference in performance before and after was very noticeable even without an ECU re-flash. That's coming shortly!

I believe LIbrands use 'Janspeed' to manufacture their product... it's a very nice quality exhaust with smooth welds in and out. And car had no issues getting through the MOT emissions test either with the accompanying 200 cell catalytic converter.

Just get it done lads !!!!

The librands (along with sports exhaust and remap) made a big difference in performance and a deep throaty sound.




Installed in my 4/4...

Great photos of the Librands system - I hadn't seen one before. I had imagined the Factory version would be very similar but it turns out they are not copies of each other. What the longer individual pipes achieve, if anything, I don't know.







As you can see the factory AR version extends into the under wing area. This version has both the lambda sensors in the Cat - not into the base of the manifold. The side repeater wire shown isn't touching the exhaust as the picture suggests!

https://www.dropbox.com/s/kr9g78uaez1gcuk/IMG_8694%20copie.jpg?dl=0
Here is the aero racing exhaust with
The small cat.The car has passed the belgian mot .I had to keep the catalisator
Very hot.