Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Reducing Gear Ratio on Diff

I get what you're trying to achieve and why, but the uncomfortable truth is a Rover V8 is the wrong starting point. The positive is it sounds like you've understood a Morgan is a small light classic car that's fun on the fun roads, but only if you can wring it's neck. In my experience, a big lazy V8 (with too much torque) shoved in a very light car is simply not the right engine ingredient to create a fun back lane scratcher.

I say "in my experience" because I owned a 4.0 litre TVR Chimaera for 12 years, it was great for motorway cruising and touring, it would rev to 6,250rpm but there was little point. When pressing on the 233hp V8 really wanted to be pulling from 3,250 - 5,250rpm so a quite small 2,000rpm window before I was looking to select the next gear up the box, by which time road speed was higher than ideal for having fun on the fun roads.

It's a shame as in the 1,060kg Chimaera that 233hp equated to 220 bhp per ton, which landed the car nicely in the 200 - 300 bhp per ton sweet spot. Understanding and accepting that less can genuinely be more was a profound moment in my long passionate petrol fueled life, this realisation finally dawned on me when in my unyielding pursuit of ever greater power I found myself in a 4.7 litre Bamford Rose tuned Aston Martin V8 Vantage, it did rev to 7,000rpm but with its 470hp it was entirely unsuitable for having fun on tight twisty UK B roads.

So I sold it and bought a 2012 Plus 4 (Monty), everyone in my circle of petrolhead friends thought I was completely mad, but I knew the port injected Duratec was a great little engine and I wanted to get back to the real essence of what a sports car should be, I also wanted to go back to my passion for the true classics I grew up with. The 2.0 litre Duratec is a light, rev happy, and easy to tune engine with fantastic reliability too, so perfect for a small light Morgan.

To this day I still swear I had more fun in Monty in the first year of ownership than I had in all my way more powerful hobby cars that came before, and all this with only 143hp! Of course I couldn't help myself so I tuned Monty, he now offers what I estimate to be a very similar/slightly higher power to weight ratio as my TVR Chimaera, but Monty now revs to well over 8,000rpm! He will still happily pootle about at 1,500rpm, but the TVR's 3,250 - 5,250rpm acceleration zone is now 3,250 - 8,250rpm in Monty. I've gone from a small 2,000rpm acceleration window, to a huge 5,000rpm 'zone of joy' making Monty almost three times the fun of the Chimaera when enjoying those winding B roads that make driving such a pleasure.

Finally, and on your point covering fuel economy, I did fix this issue on my Chimaera by making it dual fuel, on LPG I would regularly achieve the petrol cost equivalent of 40mpg. However, it did start to become tricky to find gas towards the end of my ownership so I really don't think it would be a practical option today. On the flip side, while Monty now has the same power to weight ratio as my TVR, his tuned Duratec still delivers 38mpg on a run, so that's basically the same pence per mile my LPG burning Chimaera achieved.

If you're after more revs and fun which it sounds like you are, but you feel you might miss the power and performance of your Plus 8, then you could do a lot worse than selling the Plus 8 and replacing it with a port injected Duratec Plus 4 from around 2008 - 2013, then tuning it a bit.

https://www.talkmorgan.com/ubbthreads.php/topics/839547/monty-takes-a-deep-breath#Post839547

Alternatively, if you want to achieve more or less the same end result without all the fuss of tuning a standard Duratec Plus 4, then a 2012 Plus 4 Supersport would be an ideal choice.

Enjoy