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

Being on holiday sat bored on the beach has finally given me the time to properly study the torque and horsepower differences between Stage 2 Monty & Sage 3 Monty. Before I start, I'd like to point out Stage 2 Monty went really well and was already a vast improvement over a standard Duratec Plus 4, but power and torque did drop off dramatically from 5,700rpm as shown by the white arrow below.



After our more recent tuning efforts I was pleased to discover that from idle to 5,700rpm, Stage 3 Monty has basically the exact same torque rich Duratec we created for Stage 2 Monty, and this means he's retained all that lovely flexible drivability I value so much.

But that all changes now when I wind out Stage 3 Monty beyond 5,700rpm and on to 7,300rpm, at which point he is serving up an additional 44 lbs/ft of torque & an even more impressive 50 more horsepower than Stage 2 Monty achieved at the same engine speed. That's a mighty 40% uplift in both torque and horsepower at 7,300rpm, now push on further to 7,700rpm and you're 2,000rpm above where Stage 2 Monty previously fell over.

This additional 2,000rpm gives so much more time in each gear, which ultimately translates to a lot more fun

On the road, I've actually found it's the first additional 1,000rpm of increased power delivery from 5,700rpm - 6,700rpm where Stage 3 Monty's bigger lungs are proving most useful for overtaking, but once you've completed the manoeuvre he will also happily go on to give you another 1,000rpm on top of that. Finally, if do I choose to wind Monty's Stage 3 Duratec out even further to 7,900rpm, he's now delivering a whopping 63 more horsepower than Stage 2 Monty achieved at that same heady engine speed.

While Stage 3 Monty's power currently stays flat from 5,700rpm - 8,000rpm, I have to say staying flat is a huge improvement over Stage 2 Monty's 'fall off a cliff' at 5,700rpm power delivery. OK, so Stage 3 Monty isn't making the headline grabbing 213hp we predicted (yet!), but while we're fixing that I hope you'll all agree what we've already been able to achieve is pretty impressive?

The way I'd summarise Stage 3 Monty is he's way more than a 182 hp Plus 4. From 5,700 rpm onwards, his Duratec now behaves like an entirely different engine producing around 40% more torque and over 60 hp more than Stage 2 at the top end, and importantly he does this while giving away virtually nothing in low and mid-range drivability.

For me, that's a far more significant improvement than the modest 9 hp increase in peak power alone would suggest

I always find these postings of interest, and tend to notice that the empthasis is mainly on generating bhp and less so torque, I've always basically understood it as while torque measures the turning force produced by a vehicle's engine and the engine's ability to perform work, horsepower measures how fast the engine can perform the work. Therefore, basically high torque makes an engine accelerate faster from a stop, and high horsepower makes for higher top speed.

WIth higher revs introducing greater stress and wear on an engine, I've always thought it was important to keep an engine in its highest torgue band at the lowest revs possible, in fact even short shifting to keep it there, and therefore with an eye to engine longevity.the pursuit of acceleration was having the greatest torque band at the lowest possible revs,.Having very high top speeds is potentially academic on public road use.

My CX PLus Four has 20% more torque than the manual, it has the same bhp and final drive ratio and therefore same top speed, but mine has a quicker 0 to 60 speed, and in gear acceleration, I know helped by an auto but it also has 2 more gears to change compared to the manual. You can feel the difference in the power and its delivery when compared to the manual.

In theory, with the suspected exhaust restriction removed, Monty should do this