Jinx's Record of Improvement

The only problem I can see with shortening the upright is that you don't effectively reduce the suspension travel, so there is a good chance the wheel will hit some part of the car before the suspension hits the bump stop. Simplest solution to that would be to increase the size of the bump stop. :D
 
Now, why on earth would you want to reduce the suspension travel, Richard? I can feel a suspension tutorial coming on!

Chris
 
Ha ha...

I can see me ending up with an inch of suspension travel a this rate. :LOL:

To be honest I don't want to lower it that much, only as low as I've seen some sit anyway. My reasons are mostly for the visual effect and also to see if I can get it handling as well as possible. Thanks for the suggestions though guys, it gives me plenty of things to think about. My plan is to have the suspension sorted before the P6 National next year. Probably.
 
When you get to the point, Adam, we'll talk about handling - lowering the car has zero effect on handling or roadholding! Reducing the suspension travel makes both worse. What we are interested in is front and rear roll stiffnes in absolute terms and relative to each other. Neither has a lot of connection with ride height!

Chris
 
The problem I can see Chris is that if you retain the same amount of travel, but lower the car, there's a good chance the car will bottom out or the wheels will bind on the body before it reaches the full extent of travel.

By shortening the strut, you leave the suspension at the same point in the suspension movement range, so if for sake of argument you have 12 inch of travel each way as standard, if you shorten the strut say 2 inches you still have 12 inch of upward travel, but the car is now 2 inches closer to the ground, so it's more likely to ground before the suspension reaches the bump stops.

You don't really want the front crossmember or sump to become the new bump stop :LOL:
 
i have 2 mgbs both 78 , one original rubber bumper height and the other lowered to original , the lowered one looks better but to drive is like having a fight with it as the steering wheel jiggles about on every bump, i presume that they just fitted shorter firmer springs, if you look at a p6 now with our modern eye for fashion they appear tall and narrow and i think that i also would prefer the look of a lowered car but as my mate said when he drove mine over a speed bump remarked how his modern large toyota saloon avensis i think he would have felt the bump and the p6 just rolled over it smooth as you like , good luck rich
 
I don't quite follow where you're coming from here, Richard. I've got no problem with lowering the car, as long as everyone understands that it is a purely cosmetic excersise. If you think it looks cool, go for it! But it won't affect handling or grip in any way. That is affected by the suspension geometry (angle of tyre tread to road surface) and roll stiffness.

The reason you want long suspension travel is so as to keep all suspension movement within the linear portion of the spring response. If you shorten the spring travel you risk operating the spring close to its maximum compression, at which point you will have dramatically non linear response. So lowering suspension by shortening the spring is not a good idea. By shortening the pillar you retain maximum potential travel. Clearly you may need to adjust bump stops to suit the new suspension geometry. But the result is better because you stand a much better chance of operating the spring in the middle, linear, portion of its response curve.

I should mention spring rate, most people increase, stiffen, this at the same time as they lower the car. Not necessarily a good idea. For a track car, it is possible to assume extremely smooth tarmac. For a car to run on the road, easy suspension movement is key to allowing the wheels to stay in contact with the road at all times. That's the fundamental requirement for good adhesion! Stiff suspension does not equate to good handling and grip - it just makes your dentist very rich.

Stiff springs are often used as a cheap and cheerfull way of increasing roll stiffness (very desirable). But that's a cop out and risks violating the requirement to keep all the wheels on the ground! Better attack the basic causes of roll stiffness by adding roll bars and by lowering the centre of gravity of the car (eg carbon fibre roof panels or lead filled sills).

To illustrate - one of the better handling cars and with astonishing grip for its weight and tyre size is the Citroen 2CV. Its soft and it rolls but the result is excellent. You may need sea sick tablets and you'll definitely need a bucket seat and full harness if you intend using its potential regularely though!

Coming back to the P6, the principal problem is the variation of camber with roll at the front. This makes it impossible to get the optimum angle of the tyre tread to the road. So the first requirement is to increase the front roll stiffness to limit this effect. There's no problem at the back, thanks to the de dion, but an equal increase of roll stiffness will be necessary to preserve the already superb handling balance. The simplest way of doing this at the front is the uprated front roll bar. To change the rear by the same amount to retain the handling balance the only option available is to increase the spring stiffness. Even with the maximum size bar that will fit in the available space, front roll stiffness is still a tad on the low side. Others with serious cash to spend have therefore gone on to engineer a supplementary roll bar in the conventional Ford position across the front of the car below the rad. And have then gone on to balance the rear with a bespoke rear bar (I've not seen photo's of how these have been laid out, but it's going to be awkward - there's too much de dion in the way!).

If anyone fancies increasing roll stiffness by lowering the c of g of the car there are a few tricks it ought to be fairly easy to arrange. A roof panel in carbon fibre, aluminium or other lightweight material is a good start. Then the side window glass ought to be pretty easy to replace with a much thinner glass. Any further down the car than this starts to have less effect in relation to the effort expended. So perhaps all that remains is to make sure the spare wheel is either absent or laid flat in the boot well. It might be nice to try and get the battery a bit lower too. Perhaps under the rear seats?

Chris
 
Well... Like I say, the main thing is to get the stance right. It's mostly about the look, but the roll bar and lower/stiffer springs will without a doubt reduce body roll. Incidentally, not that it is the main aim, lowering a car is by far the easiest way to lower it's centre of gravity. By default every single scrap of it's sprung weight is lower in relation to the centre of the wheels. In my experience every car I've lowered (even if it wasn't stiffened) has rolled less. the simple physics of the thing are that the taller something is relative to it's width, the more it wobbles and leans... I'm a good example of that fact. :LOL:
 
An update! Somehow I managed to get myself a small Christmas bonus, which I decided would be good to blow part of on something I'd wanted for a while... A Moto-Lita steering wheel! I'd been after a 15" dished wooden wheel for some time, although some steering wheel know-it-alls insist these are semi-dished, something is either flat or dished in my opinion. Anyway, I'd been keeping an eye on evilbay but nothing was coming up, so I bought one new with the boss from Brian at Autoequip in Birmingham. But I had a problem, even though the boss is £50 to fit the P6 I was undecided about the cover on it;



I couldn't decide whether it really let the wheel down given the quality of the wood, or if it just looked like utter cr*p. Either way it needed to go.

The first thing to do was have a look at the old 3500S centre, which had a good badge but flaky black paint on it. With a small sharp screwdriver I popped the badge out and then stripped the paint off. This was followed by successively finer grades of wet and dry sanding, very fine wire wool (0000 grade) and then finish of with autosol for a shine. I re-glued the badge and this is where I was.



Much better, now to make it fit. The Moto-Lita boss has about an 83mm diameter hole for the centre, the 3500S centre fits in the 1 1/2" diameter centre of the old S steering wheel. That's some difference, so I needed a way to space it out... Cheaply! This eliminated all ideas I had about getting a metal spacer machined up and after all it's only a wheel centre, so it doesn't need to be held on in such a well engineered way. All I had kicking about to make one was an old Pickguard off my Fender Telecaster, a dremel and a marker pen. I drew out the shape, attacked it with the dremel and got roughly what I needed. Not as round as my ego would have liked, but functional...





Don't bother with the three holes, they were put in to clear the three raised sections on the wheel centre, but it works better without them.

Then it was just a matter of sitting in the car and filing the home made ring until it just fitted snugly into the boss, whilst trying to keep it as round as possible. When it fits in just slip it onto the centre and push your shiny piece of work in place. Much better than the Moto-Lita one, I know you can buy a plain chrome centre for £30 but I think that is a waste for plain chrome cap.



I'll have to put the finished pictures on the next post, five is the maximum!
 

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So it's finally on there, I'm pleased with how it looks and being a 15" wheel it isn't that much heavier than it was before (if at all). The feel is improved and it's much nicer having something thicker in my hands... erm, yeah... So here's the finished article anyway!
 

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MM, very nice detailing. I think it gives the wheel a bit of a connection to the car, instead of just another aftermarket wheel. I think the three spoke design is probably the most attractive steering wheel for cars. Though to be fair to Rover I think the two spoke 'S' wheel is more than acceptable. The standard black one-spoke thin-rimmed wheel is just so so futuristic. Brilliant imagination and forward thinking from the Rover design team, and still looks fantastic nowdays, much like the whole car.
 
I do really like that Adam! You may be interested to know that polishing the holder for the centre badge is actually correct! That's how the early ones were when they were first fitted to '66 NADA TC's with the 17" wood rim wheel.

Chris
 
I've always been a fan of the Mota-Lita wheels - and that looks very nice indeed, especially with the new centre badge.

It's such a shame that all the airbags and electronics make it virtually a non-starter now on new cars. I always liked to personalise my cars and a decent steering wheel which, after all, you are in contact with all the time you are driving, has to be at the top of the list.
 
Haha, I see you finally ponied up for a genuine one then. Good work on adapting the the wheel centre to fit, that plastic one is awful.
 
testrider said:
Haha, I see you finally ponied up for a genuine one then. Good work on adapting the the wheel centre to fit, that plastic one is awful.
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Yeah... You'd know because I dragged you all around Stoneleigh looking for one!

I can't believe Moto-Lita supply that god awful centre with their wheels, I'd be ashamed if it was my company.
 
I can't believe Moto-Lita supply that god awful centre with their wheels, I'd be ashamed if it was my company
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Agreed, Shamelessly Awful, BUT:

A Rover P5B hubcap badge can be adapted fairly simply to the ( 3 1/2 ") Moto Lita center, + I think it looks great !

Do like the "3500S" Badge too!!

motolita14.jpg


http://www.moto-lita.co.uk/

GW
 
TokyoP6B said:
A Rover P5B hubcap badge can be adapted fairly simply to the ( 3 1/2 ") Moto Lita center, + I think it looks great !
Click to expand...

Now that is a classy solution, it looks really good in there, nice work!
 
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