Mk1 Escort (Ratspeed) project build....

[madragon199]

Not much of an update...before i get to carried away with the front end i thought id better work out the front suspension geometry..

I wrongly assumed that with all the aftermarket parts that getting the desired "CG"......."RC".....camber ...caster .ect....would be straight forward....and i want to keep my 15" wheels...

Camber and caster no problem....CG no problem...but with the car at 4" i cant get the "RC" where i want it...

ive moved holes up to max on crossmeber ect...

All of this is just theory using the string calculator on the living room floor....

i will post some pics up when i get in....

ive decided to test my results out on my old cosworth (which came back in my life again)..its an oval race car and if i can get that to go around a corner .with massive positive camber..massive negative camber..extra caster and an offset "R/S" to the n/s of the centre line...then my thery could be correct...

So i started working on the cosworth ...removing the front suspension measuring ect.
later ...cheers mark

[madragon199]

Need some updates mate.....

Matt

Been working on the suspension geometry....trying to get it to work with 15" wheels and 4" ride height...will post progress cheers mark

[Matt75]

Awesome, I'm using 15" wheels and want to run it super low too so will be watching with interest

Keep up the great work

Matt

[madragon199]

So Suspension just the front at this moment....

This is just my understanding of how it works and i could be very wrong...(hence the test mule ...)

First i am designing this as a race circuit car (i will add extra points for road use later) so no compromise on bushing ect...

The first thing i wanted to do was get the Centre of Gravity "C G" as low as possible so remove as much weight of the car and whats left move as low as possible...then lower the car as low as allowed, in my case 4" from ground....

that was easy...

next i looked at camber ..i wanted more...so we increase the control arm length...the main used arm is this.



next is caster adjustment...again i wanted more...so we use a stut "compresion or tension" this uses the anti roll bar fixing point on the above track control arm...this is an escort compresion strut.



and the two together..



so we have got "C G" as low as we can we got caster and we got camber...

I am using 15" wheels x 10 " with a 5" off set...my tyre overall size is 610mm..

now we can work out our Roll centre position, we plot all the new suspension pivot points on a big piece of paper and i used the string calculator method(as i dont have a computer programme)...

Like this (its not mine but its neater i will post mine next)



this is the calculations for the test mule (sierra 3 door)



What we find is that the roll centre goes below ground...this sounds good ...but its not...

The roll centre has actuactuly moved further away from the " C G " creating more "rotation" .

we actually need"rotationl" to create a downward force on the suspension tyres...( we could move the roll centre up to the "C G" point and have no body roll but this is bad as this would cause a side ways push on the tyres causing less grip) but we want to keep it under controll.

What we are looking at doing is moving the "C G" as low as possible , while keeping the roll centre 1" to 2" above ground so we now have a low "C G" and reduced "rotation"

To move the roll centre back up to above ground we need to move the lower arm pivot points...move them up at the cross member and down at the wheel....


we can drill the cross member and move the hole up,,,,and we can move the pivot point down at the wheel with some sort of extension...something like this



Looks like an accident waiting to happen..

Next i looked at my scrub radius with the new settings and the wheels i am using..





i am going to aim for zero scrub radius...

But with my pivot points its impossible...

I decided that as i need a complete new everything i would make the front suspension to suite my needs ....

i like the idea of a lower "A" arm but this solid arm is not adjustable ...so we move on to some thing like the front suspension on Duals zakspeed capri..

you can see its based on the compresion strut/control arm but wider pivot points and dedicated fixing ...





and kind of like this



I like this idea...

Ilike the length increase of the arms..this will help reduce the camber curves....

but i still have the problem of the scrub radius...

So im going to go Dual pivot point..this creates a virtual pivot point further forward....

kind of like this






This will help my scrub radius position...

next i started to take the test mules front suspension apart...(sierra cosworth)

cheers mark

[essy]

Madragon - Your the man, don't even understand the maths but love what your doing mate.

[2639]

The Fonz of Escort-bothering. :-/

I like the scrub radius diagrams. I'm reasonably good at feeling what is going on , but less then experienced at visualising what is happening. So many thanks for the effort you have put in to explain where you are aiming for, very useful.

[Deano1990]

Awesome!!

[escortinadriver]

Great informative post as always.
Looking forward to this.

[madragon199]

Before i can remove any more metal i need to finish the strut top and add the bracing and gussets ect...then i can cut the front and mod the chassis rail for the suspension..
So more cutting bending and welding...

Plug welded and stitched panels..






Next an inner gusset..so need to check wheel clearance..





this ties the strut inner and outer and the top panel together..





Next i made an A V O style top plate but i extended it down the inner wing to add some support where the new top inner wing meets the origonal inner wing i am just going to plug weld this on..











Also added a top gusset that ties all the top together.



Next replacing the wing rail and all the triangleation ! ..i will be making a removable flip front so dont need the wing rails as such..

So more cut and bend and hole punch...










I also replaced the rusty metal on the window quarters ect and then added a 2mm plate where the new (above ) brace will be welded to..



checked fit ready for welding



Thats all for now cheers mark

[alladdin]

[madragon199]

Finished making the other 2 gussets...then welded it all together..gave it a quick grind and file...then a coat of primer.(it goes rusty between visits)..

just the picks..






















next up is the lower rail ect and hopefully cut the front off...cheers mark

[Matt75]

Nice Mate, As always

Matt

[madragon199]

Nice Mate, As always

Matt

Cheers matt...

[GAZZAMK2]

Just read from start to here - mate your either mad or a genius!

I'll go with genius cos that is some inspirational work going on.

Keep it up it will be mind blowing

[madragon199]

Just read from start to here - mate your either mad or a genius!

I'll go with genius cos that is some inspirational work going on.

Keep it up it will be mind blowing

Id go with "mad" ..its a fine line between mad and genius.... thanks gazza... hope you enjoyed...cheers mark

[haadee]

Great project, something different then everyone.

One thing I was thinking about are the gussets, they have holes in, dirt and moisture can get trapped inside the gusset.
Inside the gusset might be a place for corrosion/rust to start building up.

[madragon199]

Great project, something different then everyone.

One thing I was thinking about are the gussets, they have holes in, dirt and moisture can get trapped inside the gusset.
Inside the gusset might be a place for corrosion/rust to start building up.

Yes it did cross my mind..but i kidded my self that as its going to have a removable flip front.i will be able to keep this area clean.... (im not good at clean)


cheermarks

[duel]

Hi mark,

I love what you're doing you know your stuff.

Cheers,
Ed

[madragon199]

Hi mark,

I love what you're doing you know your stuff.

Cheers,
Ed

Thanks ed..i love your zakspeed..its a great source of information for me..and will be a stunner...
cheers mark

[madragon199]

Time for the frame front build...

But first have to remove more rust...

so before i cut the front end of i wanted to make a jig for reference of the front grill position ect..

so jig made



then started to cut the front of i left the rails for now alough they will be cut and modded later..













This is the reference jig....





thats all for now cheers mark

[adldxg]

nice work mate, loving this build

[madragon199]

nice work mate, loving this build

thanks mate ..

[madragon199]

Trying to get the front tube frame started...but as always theres other things that need doing first.....

i need to no where im going to put the lower arms...as i mentioned earlier in the thread im going dual pivot point lower arms....

so first i cut the outer skin from the front chassis rail...its in better condition than i thought.. i will be tubig and boxing this later..but first i need to find my suspension points..





now i need to build my twin pivot hub...and trial fit ...take some measurments .and work out where i want my suspension pivot points..

So i decided to use bmw alloy twin hub...(5 series e60/61) they are cheap only £12 a side ...
the problem with using this hub is the stud patern is smaller than my wheel pcd...

i could get a wheel spacer adapter made...but i really dont like these..

so option 2 ..i decided to mount a stub axle on the bmw hub with a pcd to match my wheels and to give me the offset to use my wheels..
i found a pair of vitara front hubs complete with new bearings for £24...i think they have a removable stub axle..the pcd and wheel bore match my wheels..so half way there...then see if i need to make an adapter ect..

any way the bits arrived and i started dismantaling the hubs..











i removed the wheel bearing (with a grinder in the end..i dont need the bmw bearing)



Then i turned to the vitara hubs...luckily they do have a removable stub axle..so removed it..







i then measured the counter bores on both stub axles..and amazingly they were identicle(the car god was smiling today)







so i bolted the vitara stub axle to the bmw hub ..and tried it on my wheel..fits like a glove....and with room for the coilover....




[img]http://media2.turbosport.co.uk/2013/11/2016121615371057971WP_20161215_13_45_46_Pro.jpg[/img

i then made a cardboard tube shock and placed the wheel hub and shock in position and took my measurements...









When i get home i will put the dimensions on the string calculater and work out my suspension pivot point positions...
Cheers mark

[Matt75]

Awesome mate

What size and offset are your wheels and what tyres you running?

Cheers

Matt

[Matt75]

Awesome mate

What size and offset are your wheels and what tyres you running?

Cheers

Matt

[madragon199]

Awesome mate

What size and offset are your wheels and what tyres you running?

Cheers

Matt

Hi matt the wheels are 15" X 10" offset is central almost 5"....im running 265 x 40 x 15 pirelli tyres... but i could only find 2 off so might have to compromise on the front and go 235 x 45 x 15".....

Cheers mark

[Matt75]

Awesome, I'm runing 9" fronts and 10" rears and I too am having dramas getting tyres

I'm looking at Avon for some 245 / 50's I think

Cheers

Matt

[madragon199]

Awesome, I'm runing 9" fronts and 10" rears and I too am having dramas getting tyres

I'm looking at Avon for some 245 / 50's I think

Cheers



Matt

my problem is the higher the profile of the tyre the higher it will lift the car ...my 265 X 40 X 15" give me an overall tyre 0f 593mm...if i went with something like the 245 50 15 it gives me an overal tyre of 626mm...thats 33mm higher and lifts the car 16.5mm....i no it doesnt sound alot but i am already having to redesign the complete front suspension just to keep the roll centre above ground...i even looked at 14" wheels but thats even worse...

i think if mine was a road car it wouldnt be as much of aproblem(increase the ground clearance)...looks are as important as absolute handling...so as always it would be a compromise...

On i side note...can you give me a measurment of your new calipers origanal fixing centres...i am hoping to use them on the bmw hubs...cheers mark

[turbobossbo]

loving this thread. Really informative and great pictures. Thanks

[madragon199]

loving this thread. Really informative and great pictures. Thanks

Your welcome ..
as graham said earlier. its a good reminder of what i did.when im older and forget

[Matt75]

Hey Mate,

I assume you mean centre to centre which is 150mm

Let me know if you need more measurements

Cheers

Matt

[madragon199]

Hey Mate,

I assume you mean centre to centre which is 150mm

Let me know if you need more measurements



Cheers

Matt

Thanks Matt..thats great....cheers mark

[madragon199]

been busy...

I worked out where i want my suspension points..
i used the string calculator and did it full size...

results







not very clear so ive plotted over string ect..



so with this suspension pivot points i get all my desired camber/caster ect....the hardest thing was getting the roll center above ground i wanted 125mm

above ground this gives me a low center of gravity plus a good roll coupling it also has to tie in with the rear roll center which on average wants to be twice as high...so 250mm on the rear which should be achievable...

As you can see the lower arms actuall pass through the chassis rail....this is ok...

the bigger problem will be the steering rack position/bump steer

As you can see i took my arms as long as possible...

before i start cutting and fabbing i need to sort out the possibility whether i can get the steering in the space and bump steer ect..

so another line drg...for 0 bump steer(im ignoring akerman at the moment) you can match your inner pivot points or you can place your rack on the intersecting rc lines...i tried the intersecting line first because this would mean a lower rack position..



this gives me a good rack fitting position and a easy rack length...but the outer pivot point ends up 4" above ground which is where my wheel is...so no good..

The other option is match the inner pivot points...this gives me a short rack(which is easy to make) the bigger problem is the engine is in the way...alot..

but i have a plan ...so in need to check there is anough roon between engine and pivot point for full rack movement...

im going to make the rack out of a cosworth power steering unit ..they are 2.7 turns and are bigger shaft diameter..










ok so i have a plan.... time to start cutting the inner wing and rail...







The cut from to to bottom is cut on a taper ...wider at the base...and you can see the rail has been cut on the lower half upto the crossmember...(clearance for steering knuckle)

the next panel is the end closer and front frame fixing part..with holes..









trial fit






the tubed front will be removable and it will also mount the front lower arm pivot point so i need a good strong location ..

Checking lower tube location /fit




next the upper tube mounting ...i am tying the strut tower with the closing panel with a tube ..and the new frame will slide into this and be bolted to the closing panel once strengthed.















so its all tied together...now a top plate again welded to the tube...









all welded... now a quick check that the top and bottom tube frame will be parrallell to each other....other wise it wont slide together...









all good..

later cheers mark

[Matt75]

Im in awe as always.....

[madragon199]

Im in awe as always.....

thanks matt

[madragon199]

At home ive been getting the hubs ready...im using rose joints for the connections....

my plan was to use m16 rose joints...but BMW use a special size and the hole diameter is 16.6mm. which is to big for a m16 bolt in aluminium..you need an exact fit..or the bolt /hub will fail..

i thought m17 rose joint ...but you cant get that size of the shelf..

So we end up with m18 rose joints...i dont mind going up in size...they dont weigh much more and still use a 22mm adapter the same as m16...

time to open the holes up...i used a 17.5mm blacksmith drill ..luckily i only need to drill 6 holes .because my drill press is not really suitable for the job..
so many clamps ect...









All ready to be hand reamed to suite the shank of the bolts when they arrive...

Cheers mark

[madragon199]

started the tubed frame front....
i decided to use 38mm tube ...i went with erw rather than cds because im going to use it on the road as well and i want the tube to crush in an impact..

first part is the front controll arm rose joint mounting cross member...i am using 44mm tube for this...







This welds to both sides of the straight chassis tube and bolts to the existing cross member...

next the down tube ....

problem i dont have a former for 38mm pipe ....so used the old screw driver in the spanner trick...

placed a piece of flat 2mm steel on the pipe and formed the sheet and flat steel all in one ...worked a treat..

top and bottom bends to give me a good fit..
















i usede my belt sander to make the scollops...







the top and bottom tubes have a flange welded on so they can be bolted to the front rails..
3mm plate...





this is the low fixing brace its welded to the inner and outer tower and the new frame bolts to it ...as an extra brace..



put the wheel and hub assy in position to check clearances..mocked up a strutt...







im going to tig all the tube joints together...so iv borrowed a tig and got a day to learn and weld it all...
Cheers mark

[Matt75]

You're a freak.....I thought about space framing the front of mine for a bit. Now I wish I had. Great job as always.

[top cat]

looking good

[escortinadriver]

Yep, just in awe.

Always learning while reading this thread.

Shaun.