Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Monty Takes A Deep Breath

OK chaps, with the important but dull idle quality tuning and fuel economy testing complete, let's get back to the fun stuff.


To properly understand the Stage 3 gains we must first study the torque and horsepower Monty produced (and where) when he was in Stage 2 tune, at this point I should stress Monty already produced excellent torque in this tune. First let's look at the 4,000rpm - 6,000rpm window as this is where you're typically asking the engine to really deliver on the road.

Specifically let's look at what we've really added in that all important 4,000rpm - 6,000rpm window by changing the Newman Phase 2 cams for Newman Phase 3 cams, and adding the A.L Developments ported big valve head with its exhaust ports brought out from 38mm to 40mm?


Stage 2 Horsepower

In this 4,000rpm - 6,000rpm window Stage 2 Monty went from 112hp - 170hp


Stage 3 Horsepower

Over the same 4,000rpm - 6,000rpm window Stage 3 Monty goes from 145hp - 175hp


Stage 2 Torque

While the peak of figure 158 lb/ft at 5,250rpm is impressive in itself, what stood out was the way Stage 2 Monty made 150 lbs/ft at 4,000rpm, and held onto that number all the way out to 6,000rpm where Monty's Duratec was still making 150 lbs/ft! That wide 4,000rpm - 6,000rpm window where the engine consistently served up around 150 lbs/ft is what made the estimated 930kg Stage 2 Monty fast in the real world.


Stage 3 Torque

This is where it gets interesting, in Stage 3 tune Monty replaces the Stage 2 158 lb/ft at 5,250rpm with 170 lb/ft at 6,400rpm. In the 4,000rpm - 6,000rpm window Stage 3 Monty starts out with the same excellent Stage 2 figure of 150 lbs/ft, but now the torque is a rising line! This means at 6,000rpm rather than just holding on to the 150 lbs/ft as before, Stage 3 Monty is now producing a full 18 lbs/ft more torque to give 168 lbs/ft. Better still Monty holds onto that advantage all the way out to 6,400rpm where he's still making a very healthy 170 lb/ft .

If you look at the Stage 2 torque line you'll see Monty's 150 lbs/ft torque falls off steeply after 5,250rpm, at this point Stage 3 Monty is now already making 10 lbs/ft more (160 lbs/ft). However, he doesn't give up there, Stage 3 Monty then goes on to pile in another 10 lbs/ft all the way out to 6,400rpm which is 1,150rpm more revs than where Stage 2 Monty gave up making torque. Stage 3 Monty not only adds 10 lbs/ft at the same 5,250rpm where Stage 2 Monty's torque peaked, he now keeps piling on more and more torque all the way out to 6,400rpm where the new peak figure of 170 lb/ft arrives.

Back in the real world, what all this means is under hard acceleration I can now hold onto each gear for a lot longer, a full 1,150rpm longer! You really do notice this because while I'm staying in gear longer Monty is not only holding peak torque as before, he's actually pilling on more and more which is really what pushes you back in the seat.


Final Analysis of the 4,000rpm - 6,000rpm Acceleration Window

At 4,000rpm Stage 3 Monty is actually making a whopping 33 horsepower more than Stage 2, at the same time he's also delivering the same excellent 150 lbs/ft of torque as Stage 2. From there on Stage 3 Monty piles in another 20 lbs/ft all the way out to 6,400rpm, at which point there's also a small 5hp advantage over Stage 2 Monty.

Hopefully this further illustrates why I have never been too fussed about outright peak horsepower comparisons, as we can now clearly see such a short sighted evaluation and measurement of the success of Stage 3 would be to completely ignore all the meat in the sandwich!

Although I must admit, Stage 3 Monty's new party piece of spinning rapidly towards 8,000rpm, and then all the way to 8,250rpm is an absolute riot too!