Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Duratec Super Sports Exhaust Manifold

The rule of thumb is that the longer the trumpets, the more torque at low revs.

Chris, I don't think you can compare the Morgan with the MGB in that respect. In the MGB, everything is under a real bonnet. With the P4SS, it's not about the volume per se, but about the STBs cutting through the eardrum like a scalpel. This is not the case with the closed engine compartment of the MGB.

Thanks Heinz, hopefully I will not have an issue.

I have been told that Frontline fits a cover which cuts out the ITB sound for customers who don't like the sound that I can get fitted to my car afterwards. But I will not be telling someone there is an option for a quieter engine unless I get complaints. It also involves cutting a big round hole in the radiator support.

Chris, yes, you can try it first without the cover. It could be possible that when using the cover the ITBs get more cold air the way it looks. But I would also say it is not a must. Good you have this option, perhaps after the first years of roaring enjoyment you yourself could like it a bit more quite, we will see.

Frontline really do lovely work

Heinz, Yes you are right I can it without the cover for a year and buy it afterwards. I had not thought about the extra supply of cold air but you are right it could make a difference.

That is an Australian car using parts supplied by Frontline, but yes I agree they do great work.

Monty really flys now chaps, the Duratec engine is amazing, no wonder Caterham have used it for years and still use it today. But it is what I would term a high compression engine, so you need to be careful not to run too much ignition timing.

At the weekend I experienced what I thought sounded like some mild knock between 5,000 - 6,000rpm under full load and running this ignition table, the problem area is circled:



So to solve the issue I've pulled 2.5 - 4.0 degrees out in that area to keep the engine safe, the revised table is shown below



I'm also now achieving excellent VE numbers, as you can see I'm showing 100% volumetric efficiency at 7,500rpm at 100kPa (full load). The Bosch 440cc Green Giant injectors were clearly the right choice



I can also confirm the Ecumaster EMU Black really is an excellent aftermarket engine management system to work with, it offers really good control and is way more flexible than other ECUs I've used in the past

I still have it Richard and it goes like a dream, North Yorkshire by the way, not Scotland. I've done around 20k in it in 10 years, you'll recall I did the deal through Williams.
We've toured quite a bit in it and a couple of upgrades have been done, Hi Spec big brakes, ally rad' all courtesy of Mulberry Suplex front suspension mods complemented with Bilsteins on the rear. In the 10 years I've owned it it's never failed to please or missed a beat. However, time and tide waits for no man and it may be coming on the market this spring.

I just came across this thread so I missed all the discussion up until now.
My car was a standard 2012 Duratec Plus 4, mainly because, at the time the factory would not sell me a LH drive Plus 4 SS.
At my request it was the first Plus 4 Duratec that was fitted with a Plus 4 SS exhaust system. Other than a heap of suspension problems with that car due to incorrect front springs and the dreaded sagging leaf springs I also had continual emission problems.
First the factory supplied and Borghi fitted exhaust wrap. That helped but it was not the final solution. Under warranty a new cat was also supplied. I then fitted individual throttle bodies and an Omex ECU. That helped a lot but after about 50 to 60 thousand kilometers I started getting exhaust smell and realized that the catalytic system was failing.
I was then advised that the size of cat was suitable for, at the most, a 1600cc engine!
Following this advice I fitted a better quality and larger cat.
By the way I do not find the sound of the TBs too loud but perhaps the cam on the SS makes a difference.

The quality of the rear springs Morgan fitted to my 2012 Plus 4 was dreadful too, worse than poor tempering, I would put money on them never being tampered at all! A pair of BCC asymmetric anti-tramp springs paired with a set of Bilstein dampers from SSL sorted it, to finish the rear end off a Panhard rod was added.

The first owner must have hated the original front end because within just 3.000 miles he had spent £6k on a Mulfab front wishbone conversion, this works extremely well and combined with my rear end improvements gives fantastic handling and a lovely compliant ride


I have no idea where Morgan were sourcing their springs from in 2011/12 but they were absolutely atrocious!