Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Exhaust question

Just remove the baffles, I absolutely love the improved sound track and the reduced pinking, pretty much the same deal as the Stage1 exhaust for $30. Cats removal does not really affect the sound/performance much, the pipes run a little cooler though.

Agreed

Hi Lightspeed,

I’m currently running stock exhausts with the front baffles drilled out and the holes in the rear baffles drilled to a slightly larger diameter, intact cats, S&S Stealth high flow air filter, Stage 2 cams from Garage 56, and the Garage 56 ECU mapped for stage 2.

I originally installed the Morgan Aero Racing Stage 1 exhausts when I went to stage 1. Garage 56 reassured me their Stage 2 ECU would work fine with the Morgan Aero Racing Stage 1 exhausts claiming the Morgan stage 1 exhaust is similar in design to their Garage 56 exhaust which was used to map their stage 2 ECU.

So my engine still seems to run well with no loss of performance with the change to the modified stock exhausts.

My final recommendation for anybody wanting to go to stage 1 is to save some money and modify the stock exhaust by drilling out the front baffle, leave the cats alone, install a high flow air filter like the S&S Stealth, and use the stock ECU. I think you will be very happy. You only need a remapped ECU for the stage 2 cams.

I went to MMC Stage 1 on my car, with the performance benefits already mentioned by others here.

What really did it for me was the sound, entirely subjective of course, Morgan AR exhausts not only look the best and neatest , but sound absolutely wonderful.

I would do the same again every time.

Heads up the Stealth Air Filter has been discontinued by S&S and they have no more stock.
If you want one then your only chance is to find one in a dealers stock.
Roller Rockers have gone the same way.

This discussion goes back a few years.

For some of you who are new to this forum most people did not go to stage 1 because of increased horsepower/torque performance expectations but to make the engine run better. With my original stock exhausts they were so restrictive the header pipes would glow red after driving for awhile and the engine would run rougher with more vibrations created throughout the vehicle. This was substantially improved going to stage 1. And yes there is a modest horsepower/torque enhancement.

Sportster, thank you for the detailed description on your setup.

When you drilled the two rear baffles on each side how large a hole did you make in th center of those baffles?

I went for MMC Stage 1 for the same reason. In 7,000 miles on the standard exhaust I doubt I hit the rev limiter more than a handful of times as it was so strangled at the top end. Fitting the air filter alone made no discernible difference.

On my first drive after fitting the Stage 1 exhausts I inadvertently hit the limiter about 20-30 times as it just revved so freely and was so much smother. I think opening up the standard exhaust or going for any of the stage 1 exhausts is the best single modification for the M3W bar none.

How many who have done the mod on their exhaust have removed the cats as well?

Contrary to what others have said, I found that removing the CATs worked wonders in fact. Just look at the restriction they present to flow - those are full fat 400-cell structures that to flow need massive volume (which is why effective, efficient stock CATs are huge in modern cars), but in the M3W they are stuffed into a tiny 2" header. I removed them first, before any other mod and immediately noticed the difference. Most M3W's fail the UK emissions test anyhoo even with the CATs (when tested as a Class-4 4-wheeler, as in theory they have to be, weighing over 450kg), so my car at least was better off without them. But yes, everyone's comments about Stage-1 minimum are entirely valid - this is not a performance mod, but an engine life expectancy mod in fact.