Rob_DOHC

iTrader: (4)

Yea thats what i was talking about earlier, about reading the set up notes to find out why they did it. I suspect it was to alter the roll centre at the rear of the car...

The datapost seems to have a more basic rear suspension set up too.

Rob,

vroooom ptssssh

This is the arm I have, feels pretty substantial but light. 2 of these per wheel I wouldn't be worried at all about bending or flexing, or about pulling the threads, they are fine threads so pretty strong, and as long as its made to the right length according to your setup there would be plenty rose joint inside the ally. will find out exactly what ally it is tomo.

muz

Doing a little research apparently the Brooklyn Ford (ECS) car was the more expensive car at Ł35k in race trim, where as the Datapost car was more in the region of Ł28k. I'm guessing the ECS car had a bit more R&D into it's build. You're probably right with altering the roll centre bringing it closer to the car. This would be easy to do as well.

They look the part.

Rob_DOHC

iTrader: (4)

Did a quick drawing couldn't be bothered to draw threads etc though.

Im not saying this would be the best way but its probably how i would do it.... this is using CDS tube with weld on insert and depending on how paranoid i was feeling i might sleeve the joint too.





Sleeve over the top




At the moment im going to keep my current bottom arms as i can't be bothered to strengthen the rear strut towers for coil overs, but would like some toe in/out adjustment, perhaps ill get some different top mounts for the rear so camber can be adjusted too.....

Rob,

Rob_DOHC

iTrader: (4)

Muz, found this pic. Its a corsa (or something) front arb... looks like it might be the good basis for an arb like the group A cars?

muz

Nice drawings.

I don't think you would need to sleeve them. I would weld the insert to the sleeve along the top seam but also drill two holes 10mm down the tube and plug weld the insert at 12 and 6 oclock to the insert as well.

I already want to run a concentric bearing top mount on the rear turrets like I have on the fronts (which the group A cars also had) so I'm cutting the front turrets out of my old Mk3 Ghia donor shell and running larger front turrets in the rear so I have more room for the coilovers and can get rid of the crap rubber and top hats.

From what I can gather from reading up the rear wishbone bars sort the toe in/toe out, the front wishbone bars sort the camber and the tie arms deal with the caster.

Group A rear turrets



I'd probably make a roll bar, it would be easier in the long run.

Rob_DOHC

iTrader: (4)

Mate you read my mind, typed it all out and then though i wasn't describing it clearly and deleted it

NutsRus (i think his name is) gave a pretty good explanation, he basically said the tie bars can be used to adjust toe in and out like on the s1 rst, but if you adjust it too much you effect castor.

He used the bottom arms for adjusting camber and toe in/out and the tie bars to correct castor....

I think for the moment i'll use the tie bar to adjust rear tracking and see how it feels. Going to get some tie bars made up i think. Going to have the welded at a certified place down the road.

Any one found some good suppliers of rose joints?

Rob,

Project_Bonus

I cant keep up with you lot i dont check it for a few hours and your on to a 3rd page lol

Rob those drawings are properly pukka!! Not that im an engineer of any sort but i also like the idea of sleeving the insert just for peace of mind.

So it seems that we have agreed on a design, well most of us, and it seems that CDS is going to win over ali because the benefits dont outweigh the costs and the effort so all thats left is to find some decent quality rosejoints as muz pointed out.

Onto the rear arb, whats wrong with a standard rs item?? and more importantly how would you go about fitting it with the multi link trailing arms, those pictures are nice but dont actually show very well how it is actually mounted to the setup, also i noticed in the photos of the group a setup it uses mini compression struts where the hell can you get them from and what spec etc.

Those concentric rear top mounts look awesome but are obviously custom aswell so how would we go about gettin a set of those made up?? Muz you seem to be a bit of a dab-hand at machining steel as your willing to take on pretty much anything so would and could you make up a set for the rear??

Project_Bonus

Just found this website: http://www.merlinmotorsport.co.uk/RO...184/index.html

They also sell them on burton power and they have the sizes and also the strength rating in lbs and there very well priced, pretty sure they would knock up a decent discount if we ordered enough to make 3 or 4 kits.

muz

There's probably nothing wrong with a standard item to be honest. Gus has said if deffo needs one. Just if I were going the whole hog to make it look Group A I might as well change that as well.

Mini compression struts? Where are these?

The top mounts seem to be used on the Datapost and Longman Engineering cars, so I'm guessing Longman made them. I would just use Compbrake top mounts Like I have in the front.



but I dont think they will fit the standard set up, and as the turret is very tight anyway and I have a shell here for scrap I might as well properly turret the rear. It has been done before.

I'm hardly a dab hand lol. I have a welder, grinder and not afraid to try something different.

Luckily my project is open ended and I have good storage for it so if it take another 2 years to be ready, so be it.

russ rs

Stu Collins has got adjustable rear top mounts. I guess Jamsport sorted it for him

gus

iTrader: (1)

just to ad a bit of cofussio to this post

spoke to ratboy

who also has the same sort of setup as minus the arb's ad his is fine
alot will come down to spring rates i guess

i thought while the car was where it was i would get the boys to add the adjustable arb's
as i would rather have and not need

just adds to my options

gus

iTrader: (1)

also i guess alot will come down to how you want your car to drive

Project_Bonus

I here you on that ive only just started mine so all of this is realli helpful in my planning and decision making.

Your definately braver than me then! i dont have the confidence in my "lack of" engineering skills to start producing one off parts. I am going to learn how to weld though as ive got a few brown issues on my bodywork and i want to weld in my own roll cage.

I may have confused myself with compression struts because after a second look they arnt, i was talking about the group a rear arb setup and the small linkage that connects the arb to the hub. I'm gonna go with a S2 rear arb for the time being and i feel a group item is needed later down the line then ill do it then.

As far as the rear top mounts are concerned im open to options, my rear left turret has started to rust so if i wanted i could put front turrets at the rear instead of replacing it with a standard item however i wouldnt realli know what im doing on that front so would definately need a help in hand. Alternatively i might send an email across to Compbrake and see if they will make up a set for the rear im fairly sure they could and would so thats an option, if not then if Stu has a set then maybe i could get a copy set made if he hasnt fitted them yet.

After all of this effort this car better handle like a go kart or i will probably cry myself to sleep at night

Project_Bonus

What would you guys say about front and rear strut braces aswell?

Bare in mind i will have a seam welded shell with a 10 point weld in cage do you think i will benefit from having them or will it make the car to stiff and just invite yards and yards of understeer??

Rob_DOHC

iTrader: (4)

Cheers mate, they were only quick ones to show what i meant. But i think once i've taken some measurements i'll get some tie bars made up. Was talking to a chap about welding and apparently you can get a brittle area near the heat effected zone if your not careful. But im sure a certified welder would be able to shed more light on it...

Also another conversation, the tie bar will be heavily loaded/in tension under braking, i hadn't considered this, and its likely this is why some break?

So if your using the ali tube as above i would feel much better (if it were mine) if even a helicoil etc was used....?

Rob,

muz

Have you got any pics, Gus? Or a roll bar size, as I imagine the diameter of the ARB is critical to the cars handling characteristics?

gus

iTrader: (1)

i have std front and s2 rear

will get pics later

muz

I may well be taking this a bit too far now, however, I'll throw something else into the mix. Would it be worth re turreting the rear suspension to complete vertical uprights? The standard set up doesn't have the rear shock perpendicular? I know it makes less of a difference as the the rear wheels aren't driven, but would it benefit doing this? I'm not too clued up on how all this changes bump steer and scrub lines (maybe it doesn't) etc so maybe Rob could shed some light? I

The standard set up is set at an angle.



The 'WRC' type setups and turrets people install set the shock purpendicular but those wheels would be driven as these are 4x4 or RWD.

Rob_DOHC

iTrader: (4)

Hiya mate, sorry i missed this. In all honesty i don't think you will gain any thing with an upright rear strut.

Scrub radius doesn't really come into play on wheels that aren't steered. You can get bump steer at the rear of a car but its pretty minor. As the wheel travels up in the arch the tie arm will change angle, in the rst the tie arm will straighten out and push the rear wheel into toe out (a little) if the car originally had neutral toe. But i think this will be pretty minor.

I believe the strut being at that angle is probably to combat the effects of the tie arm. As the wheel moves up in the arch it will move back slightly as well as up. This over comes the tie arm getting longer (well the angle change) and pushing the wheel into toe out. If that makes sense? If you look at your picture above and imagine where the wheel will go as it moves up in the arch, and dig out a bit of Pythagoras to imagine what the tie arm is doing....


I think with an upright strut you will get more roll/bump steer. Im not familiar with the rest of the WRC suspension set up so im not sure how they over come this, possibly with very little rear suspension travel, and geometry which would make it undesirable to correct for toe...... I was told a while ago that competition cars use a bit of rear toe out any way to help turn in..... but on a road car a tiny amount of rear toe in help with straight line stability...

Thats my guess any way lol

Rob,

muz

Cheers, Rob. I was just bored this morning at work and catching up from the weekend on various threads and the ol' brain started ticking when I was reading this and a WRC EsCos and MK's Fiesta build lol.

Rob_DOHC

iTrader: (4)

Lol, fucking mondays interesting thought though, never really noticed the rear strut was at an angle before!

gus

iTrader: (1)

sorry for the crappy picture was in to much of a hurry to mess about

should get the idea tho



std rear arb modded to accept the rose joint

Project_Bonus

Ahhh i was wondering how you would go about fitting a rear arb with the multi-link rear setup that picture explains a lot to me, How about the rear arb from a saph?? i know its rwd and probably has it setup differently but i can imagine its probably a bit stronger.

That rear strut looks awesome and i need a new nearside rear as mine has started to rust so where would i go about getting those?? will they take standard concentric topmounts aswell if so i might consider them.

Also on another point who knows of anyone who makes weld in rear strut braces and also any recommendations for a front strut brace aswell.

I know this is a bit off topic considering but ive just started to strip back the sealer so i can begin seam weldin the chassis and im not sure where to start or how much i should actually weld? Im gonna start my project thread tomorrow so ill get some pictures up for some advice.

gus

iTrader: (1)

strut braces i had made when the cage was done

alot easier if your welding as as you can place where you want / fits best

front

i used engine mount brackets to mount


rear

muz

That's the same as I was thinking, Gus, if I were to keep the standard ARB. I do love your car. Has so many nice touches.

No, a Cosworth rear ARB is completely the wrong size and shape. Wouldn't work. One could be made relatively easily though.

One the blue car, those are WRC rear turrets for a Coworth and I think are well over Ł1000! I think I'm just going to use front turrets off an Escort and put them in the back. I have a MK3 and MK6 shell to cut up and see which fit best.

I think Gus should add, for a nice fornt strut brace like his you will need a bespoke inlet manifold. No Ford manifold allows a brace like that, I tried
I also had my bay all nicely painted then bought a rollcage with turrets ties so that will need re painting.

Project_Bonus

Gus that looks awesome!! i can imagine its an absolute beast to drive aswell!! looks like a lot of hard work and thought has gone into the build how often do you get to track it??

Where did you get your cage from, ive been looking at customcages and to have one in T45 they want just over a grand and i dont know if thats pricey or not??

The strut braces look the part i might consider having an adjustable insert grafted into the front for even more adjustablility not sure if it will realli make a difference but cant hurt to have one.

The one thing puzzling me at the moment is how to work out what spring rating you should be using, i should probably buy a book on suspension geometry but everyone on here seems to have an answer to everything lol

muz

T45 is like a WRC spec material. You'll be fine with CDS. Slightly heavier but about Ł300 cheaper. Mines a Custom Cages, Gus' was X Sport IIRC. Dont need an adjustable strut brace IMO.
Spring rating depends on your dampers and driving style. I have 270LBS on the front and 180LBS on the back but the back is far too light for my driving style. I'm going to experiment with 350/400/450 etc LBS springs untill I'm happy. The Group A cars ran anything from 700-1200LB rear springs!

Project_Bonus

Ok i dont think im gonna be goin with the rear turrets at that price lol still might go with the adjustable brace though just for some experimentation cant hurt to try it out but u may be right probably isnt necessary.

I will be running bike carbs on a custom swept inlet manifold so that shouldnt be an issue but ill be going custom with the front brace anyway.

I couldnt decide on the material of the roll cage so i talked myself into T45 but when you put it like that ill probably go with CDS and spend the Ł300 on something else to be honest.

I was gonna go with gaz gold coilovers to start and then possibly trial out different rate springs but ill see how it goes thanks for the advice on the driving style i wouldnt of thought of that.

Just need to win the lottery now and buy everything!!!!

vroooom ptssssh

Spoke to the boy who done that arm I posted up, it is a higher grade ally but he can't remember what it was, has four numbers...thats all I know.

slimwynn

i'm thinking of running with no arb can you remember what lbs springs you were using at the time??
is anyone else running without a arb??

Versus_Creations

iTrader: (1)

O the hours I spent on this good on you all for having a re think and intresting thoughts and ideas etc.

took me ages to get it right. not just me but every person I have ever known as an engineer or machinist called in all my favours at the time.

Tbh your all thinking so much into it you will end up like I did. I wasted loads of effort and obviously $ overthinking then over engineering everthing.
Fact is the joints and hardened billet tie bars not seamless is where the money is at.

Once you have correct measurements for bars using the correct joints and hardened adjusters and lock nuts the links are easy to install and setup. Fitting rollbar is easy as there are tarmac rollbars from other cars that fit under rear of erst with boot floor removed. Now days there are even copy blades you can buy. When I done mine I had to buy 909 parts for the rollbar like nylon bushes and clamps etc.

Depending on what you do with your car it is a great mod. If you have all 4 corners upto this spec it makes driving your car on another level.

strip it to 900kg with a bit of power over 250bhp not much less than a 450bhp cossie wont keep up let alone over take.

gus

iTrader: (1)

No new ideas on mine.

Loosely based on old grp a wrc ideas

900kg!!!!

Versus_Creations

iTrader: (1)

ok a little over..