Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Plus 4 GDI Aero Racing Manifold & Exhaust Upgrade

After much deliberation, the Plus4 Club Sport upgrade was selected as the option to go for. Cain at Wolf Performance, with his vast GDI experience, was entrusted to undertake the required work.

At my request the Librands EXA041 silencer was retained, together with a side exit tailpipe. A short 40 degree stainless tailpipe was welded to the silencer. A bespoke stainless bracket arrangement was fabricated and welded to the tailpipe. The bracket was suspended from the existing rubber mounts and eliminated the ungainly stock U-bolt assembly.

MMC had no existing stock of CATs for this conversion and subsequently manufactured a couple to Cain's pattern.

While not having as yet partaken of a dyno session, I have been delighted with the result. From the off, there is noticeably more urgency from the engine and overtaking acceleration is much improved. The burble on the overrun is now perhaps a little more pronounced and accompanied by an occasional chorus of barks. One of my concerns had been the possibility of rev hang being introduced, but there is absolutely no trace of this. My Plus4 had never suffered from a hair trigger throttle and this has not changed.

The cost of this upgrade including labour, new spark plugs and various other refinements was just over £3.5k. As regards "Grin factor per pound", I think that's a good investment.

Very happy bunny


:

I look forward to seeing it in it's glory soon. Will bring ear defenders

Good move - I've been delighted with mine. Plenty of pops & bangs for your buck.

Is this with the Clubsport Re Map?

Yes the ECU remap is included with the Clubsport upgrade

A question regarding a Plus 4 GDI with the full factory Club Sport Update (manifold, catalyst, exhaust pipe, ECU flash):

My 2018 Plus 4 GDI has a rather rough idle, which made it fail the exhaust gas inspection because it is required to run within a certain window; I think it had to be somewhere between 650-840rpm for 20 consecutive seconds. It always exceeded the 840rpm for only a second, but long enough to fail the test.

Moreover, the catalyst seems to only work properly (and enough to pass the emission test) once you make it glow red hot - unsure if that was intended with the Club Sport Update.

So, any ideas how I can pass the MOT? I am out of ideas, it was all good before the Club Sport Update...

Hi Robert

I had the Clubsport upgrade done in 2018. Each year when the emissions test is done against the clock between 2500 & 3000rpm it is always marginal. It usually takes 3 or 4 attempts, and as the cat gets hotter the emissions slowly reduce.

My manifold & cat are wrapped, but to be honest it is still marginal. Your tickover shouldn't be rough, so get the O2 sensors cleaned. If you decide to replace the sensors, they need an extension to the leads.

I had a recent conversation with a GDI owner with rough running, and although this is not a fix, he discovered that by unplugging the upstream sensor, the idle improved. His upstream was sooted up and so he replaced it.

When I replaced my exhaust, my upstream sensor was clean, but the downstream sensor after the cat was sooted up. That makes no sense to me but is apparently due to the cat combusting what is left over in the exhaust.

Last year my +4 Duratec almost failed on Hydrocarbons, this year I drove her 11 miles to the MOT station flat out in 2nd sailed through with low Hydrocarbons.

It helps to prebook an MOT slot ie while you wait and arrive on time with a stinking hot engine. Ask them to do the emissions test first.

My local garage gave me this advice and ever since the GDIs emissions results have been in the middle of the scale.

That's what I do, it's always worked so far.