Raising the top arm pickup points
Turbo Mini Forums

Ok, posting here rather than my usual haunt as im sure atleast some of you gents have experience with this on very very low cars (i recall a light blue hillclimber many years ago with this modification though the name of the owner escapes me :( )

basically in order to try to reduce / eliminate torque steer as part of a whole barrage of improvements this winter i am aiming to reduce the scrub radius. but i aim to do this while keeping my awesome deep dish 7*13's.. so have came up with a weird concoction of suspension components:


mini top arms, early a-series metro ball joints, mgf front uprights, mgf(not TF) lower ball joints, home made lower arms. Am not the first person to do this however there is a problem that i have never seen anyone address. the mgf hub is taller than the mini and a-series metro hub. so to maintain the same ride height the car must be lowered. if that makes sence. two problems arise, first teh top arm starts to sit at a daft angle where the bump stop ought to be, and secondly suspension travel becomes less linear and there is less travel to full bump.

i wish to raise the upper arm and its pickup points, without disturbing any other subframe/engine/ suspension pickup points. has anyone done this? if so any pictures? was thinking of simply cutting a half inch or 3/4 inch out the tower, shortening the hi-lo appropriately and welding in new material beneath, after cuttign below the top arm mounts obviously. should put hte top arm at a sensible angle..

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

i can't see there being any insurmountable problems, ,
you need to move both holes up exactly the same in both planes ,
then you will need to reset/ remedy any bump steer you have just built into the new setup but moving the top arm up.

opps just re read your looking to lift the whole frame, this meens the bott arms will come up too.

carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

nah just looking to moove the top arm! the bottom arm position is as high as itll go without fouling the gearbox/sump/driveshafts. and mooving the whole frame will leave me with issues elsewhere. only wish to relocate the top arm mount. bump steer i will worry about after the fact,hopefully wont be drastically out and an easy solution found. my lower arm is 1/2" lower and almost 1" firther to the outside than a line drawn through the centre of the origional lower arm/tie bar mount. it is still longer than the top arm though so get camber gain on bump, albeit slightly less, which ought to be better with my low profile tyres anyways lol

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

i wouldn't go to the trouble of sectiononig the towers, i would as previously mentioned accuratly mark up the towers and redrill .


carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

certainly makes sence for the rear most hole, the front hole however will be a touch more tricky, but your totally right, got to be teh best way, certainly the least fuss in terms of accurately mooving the hole centres.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

could you induce some torque related downward force on the wheels by creating a top arm than is high at one bolt hole than the other ?

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

ooh interesting subject Robert has touched upon and I need one of you keen drag racers to jump in and try it - I don't have the time!

my old friend John Miles, ex Lotus F1 - look him up for his suspension design credentials!advised me years ago to look at re jigging the mini front suspension to promote positive hub movement - ie it moves forward from the car on take off rather than the normal "regression". Apparantly he had a dabble with this on the BTCC Honda cars a while back with very good results.

In theory it sounds very simple but may not prove that way. Essentially the front tie rod pick up point needs to drop in relation to the pivot point in the subframe - ie closer to the ground by 25mm or so. The supension kinemtaics upon torque application will force the hub to move forwards under hard accel as the nose rises, changing the contact patch position.

If someone is going to do it I'd make it adjustable so you can go back to stock position if it gets scary.lol!

JK

If Carling made Mini engines
it would probably be like this one!

Team www.sheepspeed.com Racing

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

EDIT found pics of pauls frame and clearly visible.. jimster any pics of the miglia setup atall? really appreciate the input/knowlege.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

yes as I alluded to its not a simple task, and a different problem to solve on the mini suspension compared to strut arrangements

nice to see something different - if you can accurately measure the hard points it shouldbe possible to run a kinematics model to look at what the wheel is doing

JK

If Carling made Mini engines
it would probably be like this one!

An ugly and agricultural solution, but could you not make a stepped top arm? Weld one on top of another (obviously hacking off the irrelevant bits from each), if nothing else but to prove your thoughts work.

Then get Carl to make you some nice Ti ones!

I have thought about moving the top arm up many times, it looks simple, but it is not as simple as redrilling the hole. One side of the subframe has a big hile to get the shaft through, this makes fabrication a bit of a pain.

The idea of getting the top arm back to the position (angle) it was designed for must be a benift though.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

I did build anti lift into my new front subframe. There are two videos of my car on You Tube before and after (before was my fastest 13.4 at Pod and other was my fastest 13.2 at Avon). You can clearly see the diference in the launch and upto half track. Its very easy to do, it envolves lowering the front mount of the bottom wishbone and fabricating a top wishbone with a lower front mount than rearmost mount. It took the best part of 5 years on and off to design it though. I do believe its the anti lift that helped it go quicker - and it would have been quicker still if the clutch pedal hadnt stuck down on the launch and if I hadnt missed 3rd gear.

Paul

I seriously doubt it!

got any links to youtube?

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

13.4 at Pod before http://s169.photobucket.com/albums/u210/sp...nt=MVI_0511.flv

13.2 at Avon after http://www.youtube.com/watch?v=_5-yGxNwXsM

You can hear the difference and see the lift in the first video and see that the car is perfectly flat in the second. Its very evident after the first gearchange

Paul

Edited by paul wiginton on 28th Jan, 2010.

I seriously doubt it!

Did you do this in the end? Did it work as expected? I'm looking at doing it to fix some of the geometry issues from running the car low, together with a balljoint spacer on the bottom.

I did, raised the arm about 25mm iirc. Drove real nice but literally finished the frame, drove to shakespere county ran a 12.4 cracked a liner and the mini hasnt turned a wheel since, due to me deciding to start my own wee buisness. Didnt get time to see how effective it was and changed far to much about the suspension to say any one thing helped sorry..

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

I believe nick has done this to his clubby?

Yer he has, cheers, just checked out his instagram. Looks loads better.

Just been doing some reading on anti lift, sounds interesting,but nothing i'm keen to get that into. However, if anyone knows, I'd be interested to know what you think the effect of raising the bottom arm mount would be, without moving the tie rod mount? It was an idea i had in order to save using a ball joint spacer, but i decided against it as i didn't want to mess around with the angles of things i don't really know much about. The result would be an axis in side view between the lower arm and tie rod mount that is closer to being parallel with the top arm. What would be the benifits and drawbacks of such a set up?

Dan

Edited by JetBLICK on 24th Sep, 2016.