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

I have a 2000 +8, and by the time I 'm ready to change gear in 3rd I'm going a bit too fast for the lumpy bumpy roads I normally drive on. I wouldn't mind it to accelerate a bit quicker too!

Can anyone give me some advice on what to expect, where to go etc.

I don't use the car for touring, so the higher rpm isn't a problem, fuel efficiency is already atrocious, I just want to rev up the red line a bit easier in 2nd & 3rd.

.... and does it make a difference that I have an LSD?

TBH mate I don't think a Rover V8 is ever going to be fun to rev to the red line. If you want a screaming back roads racer you'd be better off with a 4/4 Sigma or a +4 Duratec. Dead easy to tune the bollocks off it and there's nothing quite as fun as a lightweight 4-cylinder at 7k rpm!

If you drop the rear differential ratio… you’ll find both 1st and 2nd a bit pointless. 1st is already a bid daft on such a light car - the gearbox ratio’s were intended for a heavy 70’s saloon.

But - if you do consider a change - an LSD would be helpful to control this a little.

I’d also suggest considering an aftermarket gear set to shift the gear ratio’s up a bit to compensate.

https://jb-engineering.co.uk/

These folks can help with both, but getting another rev happy Morgan is probably easier/cheaper.

There’s always the T5 gearbox swap …. (Slippery slope)……. #quick-get-the-spanners-out

In my 2002 Gems car it felt as if it came to life in 3rd at 3k rpm. It could be both docile and exillerating depending on how driven. Getting to know how it responded through gears and revs resulted in a great drive. I took my time. Getting the rear to waggle was fun. That Renault tv ad comes to mind...."shakin' that ass...".
My first Mog was a 1993 4/4...Ford 1.6 efi. Great fun car.

I have a John Eales 3.9 in my 1980 +8. Happily revs past 5k. But I don't take it past 5k these days in any gear. Have had it at 5.5k in 5th on a rolling road over 140 mph on the speedo. Chained down and 10 ft from the wall in front!

I am very happy with the performance of my bog standard Plus 8, have revved it to six a few times , and seen 132mph (on Mulsanne straight playing with a French Plus 4 Supersport) But I feel their happy place is lolloping along in the countryside. In fact I am amazed how revvy the standard 3.9 is compared to the old Holden and Ford V8's I knew from years ago.

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

Spot on Murray how long can you spend needing the additional ratio I ask you🤣

Well done on the Straight 120 ish is my top so far in Germany, the noise was something else 😎

The little Buick 215/LR/Rover V8 is analogous to referring to your claret as "Bordeaux" or saying "cheese" to specify your favourite, specially aged Gouda made only by a single personally-known-to-you Dutch family along with Kraft-sliced. When you understand the very different Rover V8 engine iterations and the changing car weights of Rover Plus 8s over their 36 years in various continents, a generic term becomes meaningless. I have played with 5 of these V8s engine variants and counselled on others All rebuilt differently. None the same. I have even gone so far as to swap these my own variants V8 engines mid-season to have different fun.....from a screaming 3.5 (6500+ rpm) to my long distance mogging ones (tuned 4.6L & 4.8L)

And yes, the MMC Rover stock transmissions used are silly for that much torque (made for a 4x4 truck) I keep meaning to move from my updated R380s, but something keeps stopping me. However, adjusted as they should be, the R380 provides a VERY smooth shift in a VERY hefty unit. Yes, 1st gear is useless. But I win competitions from 2nd gear. Richard..acceleration is how fast your torque comes into play. However, you are also using a sadly heavy flywheel and a non-exciting rising rate fuel regulator..

Aside from its iconic status, the great joy of these engines is the number of variants and their incredible torque at low rpm. What is the point of having a power band that can only be used at non-legal speeds? 10 years mogging Europe 5-6 months a year taught me that! Using a trad on Autobahns in Germany is a sad waste of time IMHO. That being said, at legal or near legal speeds (under 110mph) , a Rover Plus 8 can be prepared to a point where it comfortably it runs circles anything in the modern line up. (in coming!!!!!! ) For me fun is all about acceleration not speed. There are so many Rover V8 options that 95% of Plus 8s can be personalized to suit YOU. Morgan than 30 years ago, when I was itching to get deeper into things I knew nothing about 😂 I asked famous trad racers what camshaft I should use The answer was the pretty much the same on both sides of any ocean. "Tell me the roads you like best and I will answer you".

Codicil 1: Trads kept getting heavier. And some trads for some continents even heavier to meet local regs. They cannot achieve the same performance as the UK stock ones.

Codicil 2: Some block variants are weaker, than others. Actually, the 3.5s are the most solid. The cross-bolted seem fine but they do not replace the stock removed between the cylinders. (tsk) However, all Morgans are so light that they do not produce enough load to self-damage as has been the case in other vehicles.

Codicil 3: Rob Wells was right. You cannot get more than 275 bhp to the ground with stock tyres. Fat tyres are too much of a sacrifice in handling to interest me.

[b]Best to deal with each owner, what he has and what they want individually.[/b] There are also more ways to skin that cat than one.

Lorne