Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: ngrainqey on 14 April 2012, 19:09:40

Title: steering rack conversion...
Post by: ngrainqey on 14 April 2012, 19:09:40
Hello,
I've got a ZF steering rack sat doing nothing, has anybody swapped to a steering rack on an omega on here  :o ?
thanks
alex
Title: Re: steering rack conversion...
Post by: ngrainqey on 14 April 2012, 19:33:12
....just thinking in the land of V8 conversions  :y
Title: Re: steering rack conversion...
Post by: feeutfo on 14 April 2012, 19:56:32
So was I, on reading your title. Not heard of anyone doing it though. V engine would loose the servo tronic, as we know it anyway. Is servo tronic fitted to other vx models?
Title: Re: steering rack conversion...
Post by: ngrainqey on 14 April 2012, 20:14:25
think its possibly on such as insignia
but yeah i have a rack and tierods spare :P

thanks
alex
Title: Re: steering rack conversion...
Post by: ffcgary1 on 15 April 2012, 19:41:03
throwing a spanner in the works here guys, but omegas dont have a steering rack.
Steering box and link rod to wheels via steering idler arm. :'(
Title: Re: steering rack conversion...
Post by: Nick W on 15 April 2012, 20:19:55
think its possibly on such as insignia
but yeah i have a rack and tierods spare :P

thanks
alex

I don't want to make this too complicated, but you are aware of the steering geometry that a rack requires? It's not just a case of bunging a rack under the car and making some mounts.

The distance between the track rod pivots is critical to avoid bump steer, and is directly related to the suspension geometry.
The position and angle of the pinion is important for actually getting it in the car.
Racks are different for fitting in front of/behind the axle line. Get that wrong, and you turn the steering wheel left, and the car will turn right!
Power steering? You'd want it on an Omega.
Is it robust enough for a heavy car?

And they're just the obvious things!
Title: Re: steering rack conversion...
Post by: ngrainqey on 15 April 2012, 20:43:10
the rack i have is off an ex plod S60 T5 so about same weight as an omega and its also mounts rearward of the axle like the omega
thanks
alex
Title: Re: steering rack conversion...
Post by: dbug on 15 April 2012, 20:45:31
More trouble than its worth mate   ???
Title: Re: steering rack conversion...
Post by: Kevin Wood on 15 April 2012, 21:13:34
As said, there's an awful lot more to it than chucking on a rack from a similar sized car.

If the geometry isn't perfect (and that means the exact length of the rack and its' exact location, in all 3 planes) it will be undriveable. Of course, that correct location might have the rack passing through the engine, so it could turn into a bit of a headache.
Title: Re: steering rack conversion...
Post by: feeutfo on 15 April 2012, 22:23:46
Rats omega used a wrack from a Nissan Almera.
http://www.rats.no/omega_tg.html

Left hooker and a Lexus v8 though.
Title: Re: steering rack conversion...
Post by: feeutfo on 15 April 2012, 22:25:49
Ps, if you translate that lot via google you'll see they searched high and low to find a wrack suitable.... presume it had to sit lower to clear the sump... :-\
Title: Re: steering rack conversion...
Post by: aaronjb on 15 April 2012, 23:42:33
And for all we know it might drive like a bag of bolts and have frightening bumpsteer issues..
Title: Re: steering rack conversion...
Post by: feeutfo on 16 April 2012, 00:09:21
Your joking right?
Title: Re: steering rack conversion...
Post by: feeutfo on 16 April 2012, 00:14:17
Suely you've seen this?
http://www.youtube.com/watch?v=N__PXqzuyB0&feature=youtube_gdata_player
Title: Re: steering rack conversion...
Post by: 05omegav6 on 16 April 2012, 00:31:16
Fwiw, whilst under mine changing the oil filter, I noticed a slot and hole on both chassis rails. They are diagonally up and back from the tie rod and look like they could be used for mounting summat :-\

Ford did a similar thing with the Granada and Scorpio: the Granada had the roll bar mounted behind the sump whereas the Scorpio had it mounted in front of the subframe. Ford were that lazy they forgot to tell the factory not to weld the captive nuts into the chassis rails ::)
Title: Re: steering rack conversion...
Post by: 2woody on 16 April 2012, 20:09:17
it's something that I'd dearly love to do - the steering box has to be the thing I like least about Omegas.

It should go without saying that the geometry has to be absolutely spot-on, which means correct in all three planes as Kevin rightly points out. Further to that, the wishbone style on Omega means that the rack must go in front of the front axle to get acceptable turn-in. This means that it will then not clear the Omega sump.

It could be do-able with the righ gear, but would mean a new sump, new front subframe and wishbones, which complicates matters somewhat.

But definitely a worth addition to the "aims" pile.

p.s. "servotronic" is a ZF trademark, but they have different systems for rack and for box.
Title: Re: steering rack conversion...
Post by: feeutfo on 16 April 2012, 20:56:01
Looking at that thing belt round a heavily banked oval at up to 214 miles an hour with Zero corrections, I'd be more than happy with that set up. MORE than happy. ;)
Title: Re: steering rack conversion...
Post by: 2woody on 16 April 2012, 21:33:31
I suspect I wouldn't !
Title: Re: steering rack conversion...
Post by: feeutfo on 16 April 2012, 22:04:11
I suspect I wouldn't !
You reckon it's set for stability?
Title: Re: steering rack conversion...
Post by: 2woody on 16 April 2012, 22:10:34
reckon i'd set much tougher design goals...
Title: Re: steering rack conversion...
Post by: feeutfo on 16 April 2012, 22:18:28
Begs the question, why design the omega with a box at all IMO. Although racks can be notchy and pulse IME. :-\
Title: Re: steering rack conversion...
Post by: 2woody on 17 April 2012, 21:20:05
History really - Omega B is a very thinly facelifted Omega A, which itself is a very thinly facelifted Carlton - in fact the V-car platform was very similar from Commodore onwards in 1968.

as usual in the motor industry, the manufacturer can afford to change the bits you see, but not the bits you can't
Title: Re: steering rack conversion...
Post by: TheBoy on 17 April 2012, 22:29:15
a lot of mercs still use steering boxes...
Title: Re: steering rack conversion...
Post by: feeutfo on 17 April 2012, 22:57:51
a lot of mercs still use steering boxes...
Yeah, ask Wim what marque they invented that torsion bar for, to take the box play out during set up. ;)
Title: Re: steering rack conversion...
Post by: TheBoy on 18 April 2012, 20:31:31
a lot of mercs still use steering boxes...
Yeah, ask Wim what marque they invented that torsion bar for, to take the box play out during set up. ;)
I didn't need to - they told me when they first got it.  In good order, not sure I understand why there should be more play?
Title: Re: steering rack conversion...
Post by: feeutfo on 18 April 2012, 20:38:58
They used it on mine due to the constant issues with steering wheel off centre.

Can't talk for Mercs, but it made absolutely no odds at all. Still pissed.

Miraculously, steering wheel was instantly straight once they had the facility to heat up and free off rear track rods. Back was steering the front off line. Sigh...
Title: Re: steering rack conversion...
Post by: feeutfo on 18 April 2012, 20:40:45
To add, absolutely nothing to do with Tonys "accumulative play across the steering mechanism"

Sorted now though. :)
Title: Re: steering rack conversion...
Post by: TheBoy on 18 April 2012, 20:46:33
They used it on mine due to the constant issues with steering wheel off centre.

Can't talk for Mercs, but it made absolutely no odds at all. Still pissed.

Miraculously, steering wheel was instantly straight once they had the facility to heat up and free off rear track rods. Back was steering the front off line. Sigh...
Mine has always left dead straight.  MV6 is pissed again now, only done 2 months ago. But if you saw some of the potholes around here - I hit one the other day (fortunately at very low speed, but couldn't actually stop in time), and bottomed the car out.