Looks neat,looking like a smiley face now
Looks neat,looking like a smiley face now
Well done Clint for remembering what this thread was actually about,
anyway aren't superchargers best?
Good idea that
Smart Ass ! :-) Tops M8
IT WONT BE SMILY AFTER CLINT'S LASHED IT ALL OVER
is it ganna be a road car clint or just for the track? i like the way your not going along the usual cossie conversion route ganna be a little differant from the rest by the looks of things but not better than mine of course
looking good
This car i was talking about is in Fast ford this month,nice feature on itheres the business end of things in the sapphire
I decided as my car wont be going near the rough stuff that I wanted a tarmac setup for the car and after seeing Gary @ retromotorsports 'special' tarmac watts setup I knew it was the way to go.
Clint it looks like its comming on nicely mate,Should handle as well with that set up.....very nice
woah, never seen one like that before. Is that whats known as a Mumford link? i.e. an inside out watts linkage... very neat though - top stuff.
wheres the petrol tank going to go?
Tom
Nice that Clint. Put the panhard on mine but saw a similar one to yours on a mk2 racer and wish i'd fitted that instead
saw your car on sautrday clint - it looks very inpresive. the arches look super.
gearbox mounting is smaller than i thought it would be for the aston gearbox mind you
Jon
That looks interesting,not seen it done like that before.
Mick.
Its not a "Mumford Link" the mumford use's 2 pivots linked by a short adjustable link, these are mounted on the chassis, from the pivots are 2 arms that go to the axle. The mumford is mounted very low and is only suited to pure track cars that have small suspension movements as it is only inches from the floor. The 2 pivots on the mumford mean the pivots can go in a shorter height, which helps with the ground clearence. The rear roll center can be as low as a couple of inches from the ground.
My link is still a "Watts Link" just with the ability to have a a variable height roll center by raising or lowering the pivot. The pivot on a 'rally type' Watts is quite a heavy lump to hang on the axle, where as with this link the unsprung weight is kept to a minimum, with just a total of one arm and two small mounts added to the unsrung weight.
If i get time I'll draw out a Mumford link and post it here.
Here you go Gary, hope this helps
Cheers Paul, saved me doing a paintbox drawing.
Cheers Paul, saved me doing a paintbox drawing.
But i will do this quick non detaile one to show how low the Mumford is normally fitted, it can go higher but the you can have one pivot and an adjustable height tower to compensate for different ride heights just like what Clints got.
Why don't you see the Mumford and my one more often? Cost. You can buy an off the shelf watts link which has simple brackets and is cheap to produce in large numbers. The other and more common reason is, "hes got that so I'll have that" The rally type watts link has been fitted to thousands of cars.
Well i'll be dipped in shit, you learn summit everyday. Do i get half a point for mentioning the mumford since it looks pretty similar!?
I can see why people use that on kit cars - where you have some framework behind the axle already, must make it easier to hang the pivot bracketry.
Thanks for the drawings/explanations.
cheers
Tom
With all the linkages what are the benefits of this system then ?
Cheers
Brian
With the diff mounted pivot the roll center is fixed at that point, it never moves, a 23" tyre will give you a roll center height of 11 1/2 " i.e the centerline of the axle, no the front RC can be as low as a few inches below the tarmac, which gives you skewed roll. Get a fag packet and put a pin it at the bottom center and another pin the other end at the top center, now roll it, you will see that the end with the pin at the bottom lits the front inside wheel of the ground,,,,, all the pics of threewheeling Escorts.
Put the pins level and you can see the car (fag packet) corners flat, all 4 wheels in contact. This can be very important with a car cornering at very high speeds as the air flow under the car isn't changed as much, with skewed roll the car looks like it is going to take off. And Clints car will need to be planted.
Thought this was a good friends car?I decided as my car wont be going near the rough stuff that I wanted a tarmac setup for the car and after seeing Gary @ retromotorsports 'special' tarmac watts setup I knew it was the way to go.
Looking good, as tom says you do learn summik new every day, still only sort of sussing out watts linkages meself
Thought this was a good friends car?
"no thats what he told the mrs"
What bush you using in the pivot Gary?
A poly one
I know that M8, But what from?
They go on a Cossie somewhere I trim them down and they give years of sterling service
How is your design adjustable for height Gary? Does the box slide up inside another box section?
Yep, i'll get some better pics of it when its done with the bars showing the heights and axle travel.
Whats the idea with the tubes Gary?
Strength/stiffening/they look good
There is another way of lowering the roll center and thats called a "woblink" not seen very much as it creats a lot of roll stiffness in my experiences and experiments. But it does lower and fix the roll center to the chassis.
The "woblink"
Why are we so concerned with roll center (RC) ..... here goes, differing roll center heights will cause whats called skewed roll.
To show this get a flatish box and stick a rod through as shown, now roll it and you will see that one corner goes down as the other raises, now the end with the more grip will be the dominant end, and in an escort this is the rear as we drive out a corner. In a front wheel drive car which has a beam rear axle the dominant end is the front under braking, hence a front inside lift on an Escort and the rear inside lift on a FWD car.
Now the front RC at the front of an Escort is is low, and gets lower the more the car is lowered.
While at the rear the RC is is along the at the center of the axle, and can only change height by changing wheel diameter, the is because of the links that hold it.
The front RC gets lower as the car gets lower, the rear stays the same, we get more skew the lower we go.
Now be using one of the describe links we can lower the rear RC height, which means the car will corner flatter, with all 4 wheels on the ground and hopefully somewhere near equal grip between front and rear tyres on either side (more grip on the outer pair of tyres).
Great info gary. I understood a bit before, but now i think i understand most of it which is great!
Your better than my teachers at school
Obviously not suitable for an escort (in their normal guise at least) but do you work out the rear roll center of an IRS equiped car in the same way as the front roll center shown above?
Jake
There is a lot of different IRS's what sort do you need to know, because some(trailing arm) you need to plot in plan as well as end on, where as double wishbones are done end on, and without double checking I wouldn't want to plot the wrong way for you.
Also with most production IRS you are stuck with what you have. If your thinking Sierra then you need to do an RS500 geometry fit and put up with the ride height at the rear. best lap times Iv'e got with a standard 3 dr was with a 5mm raise at the rear, and a 25mm drop at the front, could have been the driver though
Oh and if you thinking of doing an IRS on the rear of an escort, Ford did it with the RS1700 and a lot of money, and the live axled copies where quicker I belive.
Biglee had a Escort Cossy rear beam setup on his Mk2 RS2000.
gary you are the man ! its like being at school but this time i am paying attention whats your fealings on a sliding wishbone
give it to me straight i can take it i think
Is that what your one looks like? they can work quite well but the lighter way of doing it is by forming the a frame with the lower links of the 4 bar
I wasnt thinking of IRSing my escort. a panard rod would be a good start! just interested.
If i want to know more ill go get a nice fat book. Although im hopefully starting an automotive engineering degree in 18months so im sure someone there could show me if i ever want to put one on a car i was building.
Keep going with the diagrams, were all keenly waiting the next rear axle installment
Jake
Well you learn something new every day
This car is turning into a work of art
you certainly know your stuff when it comes to chassis work Gary
just one question though, would it not be better with a bearing in the middle rather than a polybush like the off the shelf watts kits??
Steve
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