Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Extra ground clearance on a Mazda boxed +4

Deejay, It changed the drive and ride quality of my plus 4 by an unbelievable amount. Yes, the tyres I removed were 10 years old and original fitment so wouldn't be at their best even though the car had only covered 7000 mls but nonetheless it was like having new suspension fitted. One down side is you need all five if you have a spare but the good news is you are in the VW polo tyre size and there's a huge choice and deals freely available, Think I paid about £350 fitted for premium tyres.

Just two years ago I replaced all five original and very wooden 12 year old 195/60 Yokos with 185/65s, thses gave me a 7mm lift over the tyres originally specified by Morgan. For my new 185/65 tyres I went with Continental Ecocontact 6s for their soft sidewall which make them ideal for an unusally light car like a Morgan, most tyres these days in 185 or 195 sizes are designed around modern small hatchbacks that tend to weigh at least 400kg (45%) more than Monty.

Choosing a tyre with a soft sidewall really helps with Monty's rear end ride quality on the road, I'm also able to increase the pressures significantly for a stiffer sidewall if I'm running up Presscot or having fun at the Curborough sprint track, the front end is a Mulfab wishbone conversion that continues to impress with its excellent abilty to smooth out anything that's thrown at it while delivering lovely compliance.

However, I then lowered the car by 20mm and ground clearance started to become an issue, I dont regret this for a minute as it dramatically improved Monty's look and included the added benefit of moving the axle back so the rear wheels now actually sit central in their arches, to redress the ballance and more or less get me back to where I started before lowering the car I tackled the problem head on

See my 'Nip & Tuck' post here:

https://www.talkmorgan.com/ubbthreads.php/topics/800136/monty-gets-a-nip-n-tuck#Post800136

The chassis & bellhousing shave was my answer to giving me back the full 20mm of ground clearance I'd lost when lowering the car plus 5mm, plus a further 7mm from the tyres so I've actually gained 12mm of ground clearance over a standard Plus 4, the countersunk screws will take this 17mm and its worth pointing out I never actually had a ground clearance issue when Monty was standard. Admitedly the chassis & bellhousing shave was not the cheapest approach, but I couldnt live with that awful bellhousing lip a moment longer and the crossmember was just crying out for some sympathetic surgery too.

I do aknowlege that going from 185/65 to 195/65s would give me a further 13mm, add this to my chassis/bellhousing shave and the countersunk gearbox fasteners and the taller tyres (less the lowering exercise) would actually leave me with a net gain in ground clearance of 30mm over than a standard factory spec Plus 4, all this while still retaining the lowered look and centred rear wheels I love so much.

However, as I've already solved the gound clearance issues and my Conti 185/65s are lasting well, I think for the time being and after fitting the countersunk gearbox screws that arrive tomorrow, I'll just leave it at that and call it job done for now

I find it odd that you guys put bigger tyres on to get more ground clearance. I agree moving the rear wheel back to centre it is essential for looks but I would think increasing the ground clearance a fraction and changing to small tyres for a smaller rolling diameter would make the car feel faster and more responsive.

On my Silvia the stock 15inch wheels had tyres that would have a 614mm diameter, when I got the car it had 205/55R16 tyres with a 611mm diameter and went well. After a small accident I needed new wheels and a shop fitted 17 inch wheels convincing me I would get much cheaper tyres in that size, they fitted 215/45T17 that had a diameter of 625 which would have increased my ground clearance by7mm over what I had before but the car felt so sluggish off the lights I hated it. I replaced the tyres with 225/40R17 with a diameter of 611mm so back to what I had before and the car felt great again. The 2% extra size was very noticeable in the gearing and basically ruined the car, it had 150kw so should have had enough power to not be noticeable but it really was.

Are Morgan's very under geared so you can get away with adding over 2% increase in gearing without the cars feeling very sluggish?

By the way this website is great for working out tyre changes. https://www.willtheyfit.com/

Chris .... maybe I've been lucky, but every car I've ever owned (including the Morgan) has had a first gear much lower than needed for day to day use .... you're through it almost before you can change up ..... and rare you'll find a hill on our modern road system (in the UK that is) that might be a bother with an extra few percent of upgearing.

K

Two cars I have had that have been transformed with smaller diameter tyres have been a Honda S600 that was very underpowered and the Nissan Silvia that was not really underpowered at all. I noticed acceleration, handling and steering felt much better. The Honda had new tyres put on by the previous owner based on price that were much higher profile than what the car had as new and the Silvia also had a shop do me a favour by fitting a size that was cheap, but cars performed badly with cheaper but larger tyres than what they were supposed to have compared to going close to factory. Every other car I have been lucky enough to buy the car with the factory sized tyres and keep to the stock size without any issues.

I always thought it was the diameter but I am now wondering if it was the weight of the larger tyres that caused the noticeably poor performance rather than the change in size.

Anyone know what load rating does to the feel of a car and any issues changing to a higher load rating? My wife's new Outlander has 255/45R20 101W tyres. I hope I will not need any for a couple of years but looking at new tyres it appears the same size but 105W is nearly half the price. All I can tell from googling 101W and 105W is 105W has a higher load rating so can carry more weight in the car without issues.

How do those mechanics in the F1 pitstops manage to lift a wheel and tyre as if it weighs nothing ? It's as much as I can do nowadays to lift a Roadster wire wheel + tyre, maybe I'm getting feeble as well as old.....

Even a big race wheel and slick is only around 10kg ish .... your road wheel/tyre is probably considerably heavier.

K

The Plus 4 as fitted with 195/65 R15 tyres has the lowest ground clearance of all the trad Morgans. This can present real problems, particularly if the car has been fitted with the sub standard saggy rear springs that were used around 2012.

some time back I prepared a table of the various options showing the tyre radius.

https://www.talkmorgan.com/ubbthreads.php/ubb/download/Number/16690/filename/Tyre%20Sizes.pdf

For fear of turning a ground clearance thread into a tyre thread, it should be noted that because Morgans are occasional use hobby cars many of them cover very few miles, so the best advice would be for us all to go out to our garages now where our Morgans are sleeping and read the date on our tyres. For example, when I bought Monty just two years ago he only had 10,000 miles on the clock, knowing how light cars also tend to have very low tyre wear I thought I'd better check my tyre dates.

Unsurprisingly I discovered Monty was still wearing his original Yokohamas Morgan had fitted 12 years previously when Monty first left Pickersleigh Rd making them a good 6 years overdue replacement! This experience left me wondering just how many Morgans are out there running on very old tyres?

I spent a lot of time deciding on what I was going to replace those horrible age hardened Yokos with, in the end and after much research I evaluated the pros and cons of my refined list of best options, a process that suggested a set of 185/65 Continental Ecocontact 6s would be ideal. The new Contis did give a small increase in ground clearance of 7mm, however the increase was not great enough to blunt acceleration and if anything my speedo reading actually became more accurate.

The slightly smaller section also gave better steering feel and the softer sidewall delivered a significant improvement in ride quality, I'm under no illusion that any new tyres would have delivered significant improvements over those 12 year old hard as wood Yokos, but I remain convinced the softer sidewall 185/65 Continental Ecocontact 6s were the perfect choice for Monty who spends most of his time on the road, not track. Combine this with the new and properly tempered rear springs made by Owen Springs in Sheffield plus a set of quality Bilstein dampers from Dan White at SSL and Monty's ride and handling was completely transformed.

I should also point out at the same time a Panhard rod was fitted and the car was lowered by 20mm, so despite the 7mm I'd gained with the tyres, Monty's ground clearance was actually reduced by 13mm which doesnt sound like much but it proved to be enough to start giving issues on speed bumps etc. Clearly I needed to get back the 13mm I'd lost and return to Monty's standard ground clearance, but I didn't want to lose the lowered look and the relocation of the rear axle that finally put the rear wheels in the centre of the arches.

The solution came in removing the ridiculous bellhousing lip and reversing the lip on the chassis crossmember, this gained at least 25mm so actually resulted in roughly 12mm more ground clearance than a standard Plus 4, all this while retaining the lowered and centralised rear axle look. To be clear, I really didn't have a ground clearance issue with the standard car, and now Monty has 12mm advantage over stock any nasty scraping sounds I suffered after lowering the car are now a distant bad memory.

However, I've now proved my low point is the gearbox mount bolts so given how cheap and easy it is to do the countersunk fastener mod, I may as well take the further 10mm advantage, this should mean I end up with at least 22mm (let's call it an inch) more ground clearance than a standard Plus 4.

Happy with that

Ramble alert, though just touching on tyres and ground clearance in places and a bit of repetion thrown for newer members to TM ...(-:

I am ever interested in the many different ways that Morgan ownership might be enjoyed..As I have typed I spent my yoof modifying much but on a very limited budget and there was no interweb back them... (-:

Over the years I was fortunate to own and work on a variety of old crocks...err...interesting sports cars, the quality of which improved in time with improving financial stability, until I arrived at a time when I had spent more than a decade of owning three different old Porsches, the newest of which was perhaps nine or ten years old at the time I bought it...and what a fine machine it was in so many respects, ultra reliable, fast and a very competent machine in all respects, providing relaxed driving in city traffic, demanding of drivers input while enjoying interesting B roads, or transporting one`s good lady dressed in her finest to an evening event.. a very competent all round machine.... What`s more to want...?

It seems that natural evolutionary processes can defy logic in the minds of some... (-: Having reached my late 40`s in the 90`s, it seemed my mid life crisis steered me towards an appreciation of much older machinery given the simplicity of design and construction, as well as perhaps more importantly their individuality, all at a time when it seemed increasing legislation had created a form of car design uniformity which came to be known as Euroboxes.... It seemed even Porsche were becoming easier, safer and more comfortable to drive, and to find the degree of driver involvement I enjoyed in my older 911, one had to be driving at much higher speeds, unless on a really challenging tight B Road... Hmm..?

Budgetary considerations ever present, a vintage and reasonably performant sports car in modern traffic situations seemed unlikely to be found, but a Morgan seemed an ideal substitute for a 20`s,30`s sports car... (-:

Unlike my yoof and those like me there were those who had come to Morgan ownership either later in life perhaps never having spun a nut, and looking to explore the basics in things mechanical, a Morgan might seem an ideal project, and one that might also be simple to improve upon, and after all it seems Morgans have ever been modified in that way, perhaps since day one..(-: whereas to deviate from originality in a Vintage Bentley, Bugatti and the likes, might be frowned upon, of course all in the days before Ivan discovered the internet and lifted the lid... (-:

Having bought a +8 and in search of a pseudo vintage driving experience encapsulated in beautiful hand crafted wood and alloy bodywork, I was not in search of more comfort or speed, and such was the archaic cart spring rear suspension and unusual vintage front suspension setup, attached to a minimalist chassis design where everything flexed in various different directions dependant on the loads placed upon the assemblige by a combination of road surfaces and the drivers desired pace, all of which added up to the requirement that I had to learn all of the many differences in technique to fully enjoy that which my Morgan had to offer...(-: Having been involved in the repair and restoration of my own old cars before ever parting with my cash, Morgan foibles were accepted as likely to be all just part of the Morgan ownership experience, though Kevin`s restoration of what was his +8 before it became mine, seems to have provided an almost foible free Morgan ownership experience over the 22 years I have owned it.

Given some of the rough roads my good lady and I have have travelled over in times past, the current trend seems to be to have the largest diameter wheels with the minimal aspect ratio of tyres possible the aspect ration of the tyres looking more like the thickness of rubber bands, which seems to be THE look that is desired and the less of the tyre visible in the area of the upper crest of the wheel arch, the more street cred likely to be accrued. Added to all that in many marques, removing any rubber bushings and replacing them with modern and less flexible materials to improve the "feel" through the steering would definitely seem likely manage a sense of more improved CONTACT with the road surface, as well as perhaps spending a bit more time in the air after traversing a bump in the road... etc.etc.etc..

As seems typical for thinking of one of my age, it also seems nothing is new under the sun..... There was I in my mid life crisis looking for more contact with the road in terms of driving experience and it seem`d something sporty and vintage was the logical (?) route to embark upon, whereas today those with a younger mindset are even "slamming" Porsches....the latest of whichcome as standard with quite the most technologically advanced, digitally controlled variable suspension steering and braking set-ups.. but then I have not totally forgotten how much style was far more important than practicality in my younger years....(-:

In the seventies Morgan may have sought to fit in to some degree with wheel styling and in the process increased not only the diameter of their +8 wheels from 15" to 16" but also the look, from the Milrace design to an improved quality wheel which could also increase the all important modern look of wider tyres as was in vogue at the time.. I have doubts if the wheel tyre changes caused the MMC to alter much if anything much in the way of suspension design, though happy to be educated otherwise..I do think they had to alter the width of the wings than those of the earlier +8..

By way of comparison in the same era Porsche too made available two different wheel diameters, though at the same time for 911`s dependant on the model designation of either sport with 16" Fuchs wheels, or comfort, with 15 inch cookie cutter wheels and larger aspect ratio tyres in order to provide the same rolling radius as the sport with it`s different wheel and tyre combination. Porsche also fitted Bilstine shockers to the sport and Boge shockers to the comfort option.... At the time my 82 SC had 15" wheels and on track it took longer to settle into a corner due to sidewall flex, thus in quick consecutive left and right corners it took longer to settle into each corner, whereas the sport logically provided more feel in the wheel relative to the road surface and directional change.. Who would have thought....? (-:

I feel fortunate to have a rather testing road near my home and perhaps more so than any hill climb course I have visited, or seen on TV....(-: there is no need whatsoever to break the speed limit to feel challenged by it`s many rising and dropping tight corners to feel fully engaged, be that in my old +8 with perhaps 150 horses, some of which may have gone off to graze elsewhere over the years (-: or my 991 Carrera 4S with its seemingly 400 digitally controlled horses, variable damper rates, and applying rear inside wheel braking as part of the process of maximising cornering speeds and handling... all of which in their own way require the need for a driver to be wide awake and concentrating, truth be told in dry weather, the Morgan experience is still favourite, but the Porsche can take it on in any weather, and no doubt if times were measured the C4S would be that bit faster and safer too.... But then, I suspect much depends upon ones personal priorities on any day, if one is fortunate enough to have alternatives to choose from...?

I do admit to thinking of perhaps finding a bit more comfort in the Morgan these days, and given the recent thread on TM related to seat webbing, I suspect my 11 stone in combination with the minimalist design and construction of the Mog have combined to reduce the cushioning effect of the drivers seat over time to the extent I am sure my rear end has more contact with the seat frame than in times past, and also my line of sight along the bonnet definitely seems a mite lower too...Hmm..? Time for a bit of modification methinks...(-:

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