Steering Ratio

[Callumgw]

Does anyone have a book that confirms what the steering ration (number of turns lock to lock, or gear tooth etc) of the ASTRA N12 power steering rack?

or of the n13 power steering rack?

My manuals/books don't list power steering at all.

Cheers,
C

[boosted]

hi,
for the N13 powersteering PR24SA, i found out 2 different values: 2.7 and 2.9 turns from lock to lock

[Callumgw]

cool, the turning cycle is all I can find for the Exa (10.6) and ET (10.2m)

C

[Callumgw]

The lock to lock on the ET (from a 1984 'modern motor' mag) is 3.8

C

[Callumgw]

hi,
for the N13 powersteering PR24SA, i found out 2 different values: 2.7 and 2.9 turns from lock to lock

Did you put one into an n12?

C

[boosted]

Did you put one into an n12?

C

no, i also own a n13 hatchback.


greets
martin

[Callumgw]

ahh, any chance you could stick you head under both bonnets and see that they look similar? Just a check there is nothing obviously different?

Cheers,
C

[tassuperkart]

Basic layout is identical C. I have a seaking suspicion that dimensions of the asteering arms are slighty different (wider) in the N13.

Cant comment on bolt spacing tho..... All easy enough to get around if your keen.
L8r
E

[Callumgw]

Basic layout is identical C. I have a seaking suspicion that dimensions of the asteering arms are slighty different (wider) in the N13.

Cant comment on bolt spacing tho..... All easy enough to get around if your keen.
L8r
E

you sure? just wanted to confirm they have a sloped input drive and mount on the isolated D brackets, etc...otherwise it might be worth hunting for an Astra powered unit, its just that the n13's seem more common.

C

[boosted]

ahh, any chance you could stick you head under both bonnets and see that they look similar? Just a check there is nothing obviously different?

Cheers,
C

i will take a look, but it could take some time and not to forget, they are LHD cars.....

greets
martin

[Callumgw]

not to forget, they are LHD cars.....

Understood,
Thanks Martin

C

[Timmzy]

Hi Callum,

I would guestimate that the differece in turning circles between the ET and EXA might actually be related to the wheelbase and that the actual steering setup is identical.

Also - Why wouldn't you just use on of those speedway racing racks with the universal mounted pumps? You could put it anywhere and have infinite amounts of ratios? You would just have to get the pivot points and end of arms correct for the steering geometry.

Darren.

[Callumgw]

I would guestimate that the difference in turning circles between the ET and EXA might actually be related to the wheelbase and that the actual steering setup is identical.

Probably something like that.

You would just have to get the pivot points and end of arms correct for the steering geometry.

I reckon this could take a bit of fiddling and fabrication...If we can find a good rack with minimal fiddle then it stays with the theme of most of my other mods, in that they are easy for lay people to do and cheap for noobs.

C

[Callumgw]

Well I spoke with a nice bloke up in Queensland this afternoon at a power steering restoring company (I'll post his details tomorrow, cause there at work). He gave me some great info. Firstly the n12 and n13 power racks have the same part number and are a TRW rack. He was fairly sure the ratio was about 2.7 for the power rack. So they should bolt up.

Then the less good news. The power racks uses a torsion system to load the fluid and this requirement for 'pre load' means theres a bit of free play - about 1/8 to 1/4 turn. This can be removed by making that torque tube rigid. This can be done by wedges, or by silver soldering the mechanism. Both of these approaches are considered to make the car unroadworthy (track work only).

The internals of the power rack don't fit into the standard rack, so a quick swap won't beat this issue.

C

[Callumgw]

The guy was from:

http://www.ultimatepowersteering.com.au

Unit 31
193-203 South Pine Road
Brendale Qld 4500

As I said above he was knowledgeable and helpfull, good traits to find when you do what we do
Their part number for the Power rack was PR0002.
$525 for a fully reco'd one and if you bring in your own they can mod the power steering torsion bit for about $350.

C