Talk Morgan Forums Community The Malvern Arms Sports Exhaust

Some here ?




https://www.wolfperformance.co.uk/exhaust-components.html

Pure petrolhead porn.

When I ordered the Plus 4 the Plus 4 SS was in production. Morgan, I believe for reasons of homologation, refused to make me a left hand drive version of the Plus 4 SS and also refused to put the Mazda engine in a bespoke Plus 4. They did however agree to supply, via Aero Racing, the SS exhaust system.

Before I comment I would say that the sports manifold with the standard cat etc. That you describe as being a no-cost option would be quite different to the system fitted to my car. My manifold is quite long and the cat is under the right hand running board just in front of the silencer. This is said to be good for torque but has issues with getting the cat up to working temperature.

My experience is as follows.
Within 50km of picking the car up we had our first MIL (Malfunction Indicator Light). We were still at Malvern so we returned to the factory and they reset the error in the ECU. I must say that while we were running the car in I quite liked the sound and appreciated the bark when under acceleration. Around town it was quite acceptably muted but to too much

We continued to have MILs which I then reset myself using an app and a Bluetooth OBD2 dongle. We also had quite a bit of exhaust smell coming into the cockpit (a problem well known to Plus 4 SS owners before they received the ECU map upgrade). Various efforts were made by Morgan to resolve this problem including sending what was supposed to be a 400 cell cat which later turned out to be another 200 cell cat! They also supplied and paid to have fitted manifold wrap. Nothing really worked but I started to realise that the exhaust sytem, whilst providing a noticeable increase in power, was just too far outside the parameters that the ECU could cope with. The only answer would have been a re-map.

In the end I fitted individual throttle bodies and with careful tuning of the Omex ECU (that replaced the engine management of the original ECU) I was able to get the emissions to where the car would pass an MOT.

At this point jump forward 50,000 km and the exhaust smells returned. At this point I turned to an Italian cat maker that had been recommended by Heinz who uses one of his 300 cell cats on his 4/4, https://brainkat.it/en/

I was originally expecting to upgrade the existing cat with a new core however the owner of Brain advised me the the size of the Morgan supplied cat would, according to their standards, only be suitable for a maximum engine size of 1600cc. I then started doing a lot of calculations to work out the diameter of 300 cell core that would provide a similar gas flow to the existing 200 cell core. In the end I also opted for a higher quality coating on the core that would start to function at lower temperatures.

Amazingly I seem to have got it right and after the new cat was fitted I noticed a slight increase in mid range torque plus the exhaust note under acceleration and at touring speeds was slightly lower in both volume and tone. Definitely a bonus for touring where a load exhaust can be tiring. The fuel map was still within the correct parameters as with the smaller 200 cell cat.

After all that my opinion on the fitting the AR Racing Exhaust system with the standard cat is that because they are using the standard cat, and I must assume either the standard or a similar to standard manifold, you will avoid the problems with exhaust emissions, MILs and excessive noise. You probably only get slight or no noticeable performance increase but you will probably get a very enjoyable roar when you decide to put your foot down. Since it is a no-cost option I would go for it and at some point get one of the re-maps of the ECU that is offered.

The exhaust note is obviously a personal consideration. When we first got our Roadster it seemed very quiet and one of us was always surprised when the other returned because we never heard the car. We were used to the very distinctive note on the 89 Plus Four with side pipe which incidentally was never intrusive but which howled once 4000 rpm was passed. You have received good advice: I do remember being horrified when the P4 was first fitted but it settled down, mind you I remember being similarly discombobulated when I first changed from my Lotus to the Mog.

Mine has the librands manifold and exhaust
it has "presence " lovely burble

Because I have been playing with Caterhams for the last 30 or so years, I had a spare 6" round Caterham straight through silencer with, by chance, exactly the correct sized pipes at either end. It originally came off a 2l. Vauxhall 16v engined HPC Seven. I had the tail pipe, which had a bend in it for side exit fitting, straightened and lengthened slightly and it was a perfect fit, with a nice burble instead of the aggresive bark that the standard shorter oval silencer had.

Peters experience is most interesting and it will be interesting to see what the cat. fitted to my own Cosworth Duratec, manages to do when it comes up for its' first MoT in the spring. Maybe the mapping is better than Omex, although, interestingly, they blamed the exhaust system that Morgan later fitted after the mapping was done, on the SS + 4's?

Omex did the original map, or one should really say calibration (because there are two maps, fuel and ignition, and a whole lot of other settings) based on the Plus 4 SS prototype. This car was eventually purchased by Richard Wragg the MD of Omex. Between the development of the prototype and the final configuration of the car as delivered to clients something changed. The only component the Omex supplied was the programmed ECU. I do not know the details of what was different however I do know that the problems surfaced at about the same time that I was having trouble with my car that was fitted with the same exhaust system.

I should mention that, at Morgan's request, the calibration was password locked. One can understand this but it did stop individual owners and tuning workshops from working on the calibration.

Unfortunately there was a period in which Morgan and Omex did not see eye to eye on resolving the problem. Eventually Williams arranged for Omex to hava a customer's car for sufficient time to come up with two solutions. One would have involved completely new firmware and calibration that would have required the ECU to be sent back to Omex. The other involved a new calibration that could be loaded by the dealer. In the end this was the solution chosen and I understand that the relationship between Morgan and Omex was then improved with Morgan distributing the new calibration and instructions to dealers.

Plus 4 SS owners owe a vote of thanks to both Williams and Omex for eventually resolving the issue. I understand, from a couple of Plus 4 SS owners that I have had contact with that they are now very happy with their cars.

If anyone is curious as to what is involved in calibrating an Omex ECU you can download a pdf manual here.

This and a lot of other info can be found on http://omextechnology.co.uk

PS. I have no connection with the company. I'm just a happy owner.

"Between the development of the prototype and the final configuration of the car as delivered to clients something changed. The only component the Omex supplied was the programmed ECU. I do not know the details of what was different"

If I understood correctly, Richard said that Morgan changed the whole exhaust system after the mapping had been completed, this would obviously have needed remapping, but Morgan blames Omex for the problems and didn't admit that changing the exhaust system was the cause.

Thanks you for the responses and advice. It seems the 110 +4 option is the sports exhaust from the CAT back only and does not include the manifold. On advice I've decided to order the standard system and see how I get on. I can then look at the options once I'm up and running and see how others compare.

Very much appreciate the feedback - Now all I need to do is select a colour and try to consider how each option will enhance the car. - Happy days! - Sleepless nights.