serious suspension upgrades

[superchargedfool]

I currently have mk4 cortina front anti roll bar with mini oil shocks at the front and mini vertical shocks at the rear using the bolt/weld on cross bar.

While the handling is ok it isn't exactly great.

I am contemplating 5 link rear using an escort aimed kit with homemade panard rod and vertical coil overs into turrets. Now I know this has been done, but my point is with this at the rear what would be sensible up front.

I don't want to get the rear superb but leave the front not on the same page, if you know what I mean.

Opinions from those in the know sought. Don't forget I don't mind fabrication and going the difficult route but I also like simple things as well.

I am thinking also of going a bit lower on wider wheels of small diameter, say 7 x 13 under standard arches with 185x60 tyres. I know this isn't popular but I think it would be in keeping with the theme of my car as a sort of 70's street racer look. But having said this the wheel thoughts are not set in stone.

[wibble_puppy]

I am thinking also of going a bit lower on wider wheels of small diameter, say 7 x 13 under standard arches with 185x60 tyres. I know this isn't popular but I think it would be in keeping with the theme of my car as a sort of 70's street racer look

Hi S-CF,

Can't help you on the suspension thing, but lots of peeps here will have a view and helpful advice.

Just wanted to say, though, that IMO your car is your car, and if you want to lower it and put smaller wheels on then do! and I look forward to seeing the result

wibble

[StaffsMoggie]

whatever you do, dont fit poly bushes! All they do is knock and creak, as well as ruin the ride and stress the body.

[Stig]

whatever you do, dont fit poly bushes! All they do is knock and creak, as well as ruin the ride and stress the body.

I think you might be in the minority there, I'm very happy with the poly bushes I fitted to the rear, the ride is very slightly firmer and they don't knock or creak (I used white grease when fitting). There are different types around and it sounds like you've come across the harder ones or ones that don't fit.

I didn't fit them as a performance upgrade but for their improved life over the rubbish rubber ones I'd fitted before.

[Pyoor_Kate]

I also like(d) polybushes that're on the rear of my mog. The ride is slightly firmer, but they didn't creak or knock either

[bigginger]

Thirded. I too fitted them mainly because the modern rubber ones are so poor

[wibble_puppy]

perhaps it depends on the type of polybushes you use - I gather they vary in quality quite a lot?

[ndevans]

I also like(d) polybushes that're on the rear of my mog. The ride is slightly firmer, but they didn't creak or knock either

I agree on the poly bushes. Had no problems with the rear ones which have been in for about 5000 miles now, the front ones have only been in for about 200 miles, but no squeaks or knocks so far. The ride is a bit harsher but if they last longer they've got to be worth it.

[superchargedfool]

I've already got some polybushes and I don't see any negatives about them.

My point is if I go whole distance and five link the rear with coil overs what should I be doing at the front to make the handling feel sorted.

[bigginger]

...cue JLH, he's the expert
a

[Innovator]

I did what you are on about on my Minor van and it handled well.

http://www.beardmorebros.co.uk/website%20pages/van.htm

At the rear I had a 5 linked coil over set up. Your biggest task here is to get suspension travel. You need soft springs and lots of travel. It is worth the effort.

At the front I fitted coil overs. The damper was a bit small and I used to fade them on really rough roads when pushing on. I strengthend all pick up points and had about 1 degree neggy camber. No ARB was fitted because under steer is generally a problem on all Minors.

The van drove and rode really nicely without feeling harsh or crashing over bumps. When really pushing on hard it would under steer but I couldnt soften the front any more or it would bottom out excessivly especially when jumping.

[polo2k]

Hey all, one thing that i saw the other year (which really surprised me) was an audi quattro with upgraded rubbers everywhere, he was brakeing for the first chicane at castle coombe and because of the forces transmitted through the rubber into the mounting somthing sheared and he went sledging as the suspension collapsed.
a couple of weeks later I heard about another that had been there that day, while parking he turned the steering wheel and a suspension link snapped as it had been stresses by the bushes (again poly).
Obviously the quattro would be travaling a lot quicker, but its mounts are probably a bit stronger than a minor.
Please dont take this as scaremongering, maybe the devils advocate
has anyone seen this or are minors exempt?

[bmcecosse]

The problem with Minor front suspension is that the outer wheel goes POSITIVE camber on roll (see my old rally minor below!) - which is bad!! So you really need to modify the whole set-up to give good wheel geometry. McPherson struts may be one way - or double wishbones - designed to give slight increasing negative camber on bump. If the top link (as standard the damper arm) could be pivoted lower on the chassis so the top arm sat at a downward angle that would help considerably!

[MartinB]

Coil over shocks can work well on the front of a Minor with the Minor front suspension although the front and rear suspension should be considered together. The coil over mounting point on the front wishbone needs to be as far out (near the wheel) as possible making brake caliper clearance critical on full lock.
When I modified my minor for hillclimbs and sprints many years ago I found that the front roll centre ended up about an inch below ground level (low ride height) whilst the rear roll centre of the live axle was on the middle of the diff. The car's Cof G then acts about these roll centres during cornering meaning that the car then leans diagonally through the corner usually lifting an inside rear wheel. The lower the car went, the stiffer the roll bar had to be to counteract the roll centre getting lower. The fact that the engine sticks out in front of the front axle line only compounds the problem. To overcome this I fitted a very stiff front anti roll bar (made from a shortened torsion bar) with drop links going to the upper king pin/leverarm pivot. I ran 400 lb springs with torsionbars as well. You also need to make sure the tyre sidewall is stable enough to make your set up work, 185/60s on 7"rims was ok on my car.
My car ran a 16 valve fiat engine producing around 190BHP at the wheels (ran on slicks at events) at that time so was fairly heavy in the engine department and actually lifted an inside front wheel during cornering allowing full throttle to be used through the corners with the occasional 4 wheel drift (4th gear). It was also driven to and from events at that time and clocked up around 8k miles a year then, so wasn't just a race car. It was pretty firm on the road but I still used it for longish trips at that time ok.
To control the wheel angle (to stop it from going positive in cornering) you need to control the car through springs and roll bars along with the ride height etc.etc...

I would suggest you read a book on suspension geometry (one by Allan Staniforth is pretty good) which should point you in the right direction.

Sorry if this post is a bit long and heavy but suspension is complicated and needs to be done right if it is to be safe and fun.

Martin Baker