418 replies to this topic

[Toranamat69]

G'day Matt,

I am still chipping away at this - have been really busy on other things recently.

Very frustrating as I have lots of parts here, just not enough time but I am pretty keen to finish it. I have done a few hours testing and measuring this week.

M@

[Toranamat69]

I have just put a few charts on my cardomain page with the camber and bumpsteer curves for the UC setup if people are interrested.

New stuff is right at the bottom.

http://www.cardomain.com/ride/480776/2

I'll try to get some pics up later today.

Anyone have a set of HQ to HZ stubs they want to sell? If not I'm off to the wreckers on Saturday.

M@

[Toranamat69]

I should have mentioned in those charts, The positive suspension travel is bump travel, the negative is rebound travel so you can work out which way is up and down

The range covers the whole suspension travel from bump stop to bump stop so once you have your Torana front end more than 1"lowered - you are getting a little close to the bump stop in bump travel.

The standard camber curve explains why these front ends wear the tires out on the outside edges if you ask me.

M@

[axistr]

Hi Toranamatt I have been watching you progress with intrest on the p/s as my lxss hatch is going through full restro and also want to add p/s. I'll just put a few ideas into the debate, I'am sure you will know most of the steering geomertry but keep in mind that bumpsteer has two main factors 1: the steering rack, tie rod bar and steering arm should be kept in a straight line in normal driving configuration. 2: If you use a string line or straight edge from the centre of the front lower control arm pivot bush to the centre of the front top control arm pivot bush, your steering rack inner tie rod joint should be smack inline, (ie) the 3 of them should be inline in the straight ahead position, if not, raising or lowing the rack can help depending on the angle of the tie rods and steering arms. Just to add further confusion if you drop in shims to correct caster & camber this will affect this rack alignment. My experiance is to set the cambers to 15min neg on the left O on the right and caster 2 deg-2.30min + even on left & Right. 1.2mm toe this is a good set for road use with a bit of hard driving thrown in. All so check your toe out on turns 1.5-3 deg at 20 deg lock, and check the steering arms in relation the the centre on the drive axle. Check that the drive has no side thrust, if all this is spot on there will be no bump steer, and we havent touched on k.P.I or neg & pos scrub radious and wheel offset and there effects, Hope this may help and I havent just confused you. sorry to through a spanner in the works. Keep up the good work

Thanks Len

[Toranamat69]

Thanks for the suggestions guys, the feedback is good.

I have just updated the cardomain with a few more pics (nothing major) - mainly changing my comments on the Cortina rack as I double checked it and it appears I was a bit out on my measurements for rack travel and centreline. The Cortina one look like it could line up and give good bumpsteer figures, it is the ackerman effect of the steering which will be the compromise with this system I now believe.

Axistr, I am with you on most of that stuff and agree but I don't quite follow with this bit - are you talking FWD here?

and check the steering arms in relation the the centre on the drive axle. Check that the drive has no side thrust, if all this is spot on there will be no bump steer

Salazar, my reasoning with trying out the polygraphite fully floating ones are for 2 reasons
1. To see if it stops the squeaking you get with polyurethane
and
2. To see if it makes a diff to handling to have no (or little) resistance in the pivots.

The control arms on my test jig certainly move very freely compared with the ones on my car with the bonded type poly bushes.

I read in a write up on the Ferrari F50 a while ago, they made a big improvement to the handing that they put down to the reduction they managed to achieve in the friction/drag in the suspension bushes so there is a point where it does become relevent.

Holden used rubber in the rear trailing arms and front lower control arms because the bushes need to compress sideways slightly as well as pivot and the rubber allows this to happen (and rubber gives a nice ride). The front lower control arm bushes only compress a tiny bit sideways whereas the rear upper bushes have to squash heaps.

M@

Edited by Toranamat69, 10 July 2006 - 10:24 PM.

[axistr]

Hi toranamatt, the thrust angle is the position of the diff housing(rear wheel drive) in the vehicle or thrust centre line. If the wheels are both off set to the right this will push the front of the torrie to the left, I have fixed many cars and trucks over the years with major bumpsteer problems, and the fault is down the back not allways up front. Many so called wheel aligners correct the vehicle pull to one side by adding more caster on one side to counteract a fault elsewhere. I have a four head wheel aligner for our car section so it shows up every time, (must to front and rear) To put it in simply if you have a billycart with two planks of wood and four old bearings the only way to get it to turn is to move the axle front or rear it does not mater which end it will turn. The other point I was trying to get across was that the front steering arms with the centre of the rear diff centre, if you get a string and place it on the steering arm where the tie rod goes through and extend it to the centre of the rear diff centre housing the string line should run through the upper and lower ball joint centre line this is hard to check on cars (drop line the chassis and mark on the floor) but on heavy trucks if the truck has had a chassis extension this throws the toe on turn out, beleave me it makes a lot of differance or if the steering arms have had a bad knock, hard to see by eye. In truck there are three differant angle arms available with rockwell steer axles, so for them to go to the trouble it must make a differance. To be quite honest most wheel aligners don't know these facts. By the way HQ-WB where never good handling cars from new, if you did a slow full lock turn you could here the front tyres squealing and see rubber behind you. The lower the K.P.I the higher I set the caster but on torries I set them as I stated before, Hope this helps understand some more steering geometry. Len

[axistr]

Hi Toranamuk, If you understood the last bit of my post you would know that extending the chassis will effect toe out on turns, to correct this problem on your torrie you will need to bend the front steering arms out this should give you more toe out on turns, but may be limited due to clearance of the disc rotor and it's also trial and error on how much you need to bend the arms. Or maybe you all ready have a bent steering arm.

[axistr]

Hi toranamuk, the closer the rack and tie rod bars are to level the better she will handle the bumps, toranamat has been doing all the graphing of torana front ends so he would have some figures to go by, but as you have all different components you may have to start right from the beginning and do a full suspension dropline onto a level surface, paying attension to the steering arms and to the centre of the rear diff housing as I have stated previously. Do you understand how to carry out dropline's as it's hard to tell you on this thread, would need to use pen and paper and 5 pages. If you get stuck PM me and i'll try to help you.

[enderwigginau]

axistr whereabouts are you located?

Just wondering whether a working group get together is possible?

Grant..

[axistr]

Hi Grant, I live in the hawkesbury district 80km north west of sydney.

[enderwigginau]

You wanna commute up to Brisneyland to meet with Toranamat and I? hehehe

[axistr]

I'd love to if I could get away from work, and it's bloddy cold down here this time of the year. My wife and I own a truck/car repair workshop and time is very limited, but if I get a chance count me in. What suburb are you and matt situated in brisvagas ?

Many thanks Len.

[Toranamat69]

Mine is slowly progessing - between time and $$$, only slowly unfortunately.

My G/F had surgery about a month ago and I have been in carer mode pretty hardcore.

The poor girl still won't be able to walk for another 4 months or so either.

M@

[GML-31]

I spoke to Grant at our club meeting Monday night about a guy on the coast fitting a whole supra front end to his torana, apparently the bolt holes line up perfectly but the track is wider, am trying to get some pics this week.

[Toranamat69]

Hey GML-31,

Keen for any further info - I like the sound of it. I would have tons of Q's for the guy obviously.

I have been chipping away at my setup a bit more- I have managed to get a full 2 days on it last week between jobs - some interresting things starting to surface.

http://www.cardomain.com/ride/480776/2

I have revised some of the previous stuff - in the bottom half of the second page.

Sorry if I am taking ages on this for those who are hanging out for my results but I really believe this needs to be done as a whole suspension/power steer upgrade in 1 go, not just the PS.
It is actually adding up to a fair cost too - I try not to think about these things though.
I think my next purchase is going to be a pair of CRS 2" HR drop stubs.

M@

Edited by Toranamat69, 21 August 2006 - 11:03 PM.

[Bart]

In the latest performance buildups magazine there is an lj torana which is fitted up with an appleton power steering rack, belongs to steven coad. quite interesting read.
www.appletonrackandpinion.com

any pics and info on the type of Applton, specs etc?

[Toranamat69]

Does anyone have details of the Appleton setup above? Sounds interresting.

I have never found a power rack I thought would be suitable for the LC but the 19.25 " long racks shown on the Appleton site look like they would be suitable.

Those remote servo valves are very interresting too. I wonder how easy it would be to fit one of those hydraulic servo's to the Torana rack rather than changing the whole rack over. I like howyou can get diffrent ratio racks and different servos as well.

If you look under the what's new tab, there is a road race power rack which I reckon is a viable contender for an LH/LX front end going by the width of the rack.


GML-31, any update on the pics of the supra stuff?

M@

Edited by Toranamat69, 17 September 2006 - 05:22 PM.