278 replies to this topic

[TerrA LX]

IMO bump steer will vary with spring height, in relation to the horizontal alignment of the inner and outer tie rods.

[royalplumss]

After hours and hours of reading and asking questions from some of the more notably experienced members on here, I decided to install a simple Torana/HQ combination that was easily sourced without any expensive mods (except for the Harrop arms).

HQ stubs

HQ calipers (PBR Steel - smaller ones)

HQ discs

UC upper control arms - fitted to redrilled lower point on UC Kframe

LX lower control arms (didnt have thicker LH on hand)

Harrop steering arms

 

All in all - I am pretty happy with how it all went together, but am yet to test it on the road - and wont be able to for some time (it has been 16 years so far)

 

Have to revise this!

After getting back to the car and having a closer look (as per Reds query) - the caliper is touching the lower control arm - seemingly way too early for normal steering requirements.

It will take some time before I can have a proper look and see if I put something together wrong though.

I am thinking the UC top arm has brought it closer quicker in the turn.......

At least I am getting used to pulling these things apart - and attempting to put them together correctly

[v6 torana]

Thanks for the info guys, dont worry about the measurement Toranamat69 (huntsman spiders are creepy). I have found a set of UC steering arms from old mate in QLD for $25 each + postage to NSW.

 

Once i fit the UC steering arms I will add another post and let you know how it finished up.

 

I have fitted UC steering arms to the LC with HZ stubs (I wanted to drop the angle of the tie rod arms). It has dropped the steering arm by 4 cm comapred to the hz steering arms. The steering rack tie rod arms are now parallel with the rack, however because the tie rod ends mount at the top on UC arms (not the bottom) I am back to square one.

 

Has anyone done a reverse taper on steering arms ??

 

 

HZ

 

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UC

 

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[TerrA LX]

^ you might want to start a new topic for yourself asking specifically about the taper, this is a sticky thread for HQ brake conversion.

[snickersbar]

I fitted hq cast iron caliper to Torana stub axle, the caliper sits sort of in side of tie rod. Should swap over the steering arms to UC??

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[dattoman]

When the cars sitting on the ground at normal ride height what sort of angle are the rack ends on ?

[snickersbar]

I'm still using lx torana stubs and arms so it should sit fine but the tie rod needs to be tilt back so I can get the caliper on.
Just one last thing how bad is the bump steer with hq stubs with uc arms??

Edited by snickersbar, 24 October 2014 - 10:56 PM.

[76lxhatch]

The UC steering arms are lower to counter the effect of greater positive caster as tilting the stub axle raises the outer tie rod end; the A9X ones are lower again and allow even more caster. If you can get at least 2-3 degrees of caster then the UC arms will be good, and the bonus side effect is a little more clearance to the caliper.

Bump steer is greater when the outer tie rod end sits too high or too low for the arc of the tie rod to follow the arc of the stub axle closely.

[snickersbar]

Hey Im trying to fit my pbr cast iron caliper to my torana stub axle it wont fit.

the rotor has been turn down the size is 270,

back of the stub has been grand flat,

if I remove the out side pad I can bolt it on

can anyone help me

[SS hatch]

DBA 014       276mm new od   270mm would indicate 3mm off radius most state 6mm of radius. Although I have only just finished this conversion machining on the weekend. Disk is 270mm. Hq pbr cast calipers 2mm removed from inboard of caliper to where outside radius of disk runs. Caliper to disk clearance 2mm. All fitted prior to machining of caliper problem disk touched inside of caliper slightly, disk still was able to be rotated. Torana stub uc steering arms.The simplest thermal expansion gap remove more off disk.I was trying to keep as close as possible to standard Od. Is the pad touching hub of disk I had to remove some material from pad backing to allow pad to have clearance to hub  

Edited by SS hatch, 30 October 2014 - 09:01 AM.

[ribz0]

Luv this mod... well worth doing!!! Have had it on my LC for a while now and its the best thing I have done to it!!! had to have another read of the thread myself....
Cheers

Edited by ribz0, 05 February 2015 - 11:20 PM.

[gtrboyy]

You reckon on lc-j it be better to fit A9X arms?

 

Is it worth doing for square torries? curious

[TOERUNNER]

when you put the hq rotor onto the torana stub does it change the mounting point for the wheel, as in changing the track.

cheers Rodney

[Bigfella237]

I did the math in another thread and the front hub-to-hub width of an L34 (with HQ stubs and rotors) came out 14.6mm wider than the standard SL/R, so obviously the HQ bits added 7.3mm per side.

 

As Mark pointed out, the biggest difference will be the wheels, standard factory rims can often be set inward around 70:30 (%)

 

HQ GTS rims are set inward 57:43

 

L34 (& A9X) rims are set inward 53:47

 

The reason for these offsets (and the regulatory allowance in track increase) is of course to keep the load in the proper place over the wheel bearings, the wider the offset, the more load is placed on the smaller outer wheel bearing (and on the thin end of the stub axle), where the intent from the factory was to have the larger inner bearing carry more of the load.

[76lxhatch]

Personally I would fit them to the front and check out the clearance - those calipers should fit with little to no work and you will have better clearance to the cross member itself. However if significant grinding/machining is required then move them to the back where you can take the clearance out of the cross member rather than the calipers or steering gear.