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[chrisgixer]

Can't get the engine high enough to give the correct rack position. 

[davieboy0312]

A v8 project. That's sounds great any pics?

can you not use different mounts? Or alter subframe mount by chopping and extending?

[Spireite]

Anything is achievable Chris.

Have a look at "project binky" on youtube, the guys at bad obsession motorsport have fitted a toyota gt4 engine and 4x4 running gear in a mini!

[Marks DTM Calib]

Can the rack not go lower 'into' the subframe

[chrisgixer]

I need a u shaped steering rack effectively. []----\______/----[]

There are some pictures of modified racks on google images, where the rack body is lowered from the desired position, then end plates added to the rack and the tie rods added to those, to get the correct tie rod pivot point.

But I suspect that will cause flex in the rack shaft and cause it to bind. Plus there's the problem of the rack shaft possibly rotating in the body and binding on the pinion gear.

[davieboy0312]

Could you move engine forward and up? And lower steering box and idler mount lower?

[chrisgixer]

Can the rack not go lower 'into' the subframe

Subframe is clear. For and aft, the rack sits nicely where the centre drag link is on an oe car. The centre drag Link has a u shape vertically to clear the v6 lump/gear box join.

Even if modifying the v8 sump, its touch and go, and it would mean removing some of the sump webbing that strengthens the engine to gear box join.

[chrisgixer]

The rack needs to sit 50mm higher than the centre line of the centre drag link.

It looks like the Pictures of the rats omega steering rack show an incorrect position.

Pictures could be clearer though.

http://translate.google.co.uk/translate?hl=en?sl=no&tl=en&u=http%3A//www.rats.no/omega_tg.html

Or, a rack fitted 40mm lower than the wishbone pivot point does actually work.


Note; I'm using an ls1, not a lexus lump.

[davieboy0312]

Could you not cut the centre tie bar at the angled section and extend lower?

[chrisgixer]

They have extended the tie rods of the Almera rack I'm using, but the position looks too low, compared to the wishbones, and hence the wishbone pivot point.

[davieboy0312]

In the old Astra the steering rack was above the gearbox is that not possible or am i talking crap again

[Gaffers]

There are ways of modifying the steering rack and ensuring sufficient torsional strength.  Mark will certinly know much better than I but the shpe you suggested is very much in the realms of the possible.  Just needs some custom welding and manufacturing

[chrisgixer]

Here's the sort of solution I mean. You can see the end plates on the rack by the oil filter. Pointing rearward though, where as I would need them to,point up vertically.



The sliding bar to the rear, I presume, is to stop the rack shaft twisting/rotating in the body.

Pick taken from here. I haven't read it yet, just plundered the pic.
http://www.build-threads.com/build-threads/speedhunters-one-year-on/

[chrisgixer]

Btw that's a front mounted rack, omega needs to be rear mounted, but you get the idea...?

Question is, would it work without binding etc?

[aaronjb]

I think you might find a compromise (inducing some bump steer) the easiest way around it, assuming you're happy with a compromise (which you kinda are by definition on the Omega seeing as it has mac strut suspension)..

This is a good read: http://www.modified.com/tech/0508_sccp_making_it_stick_part_3/suspension_geometry.html?__federated=1

In order for a MacPherson strut suspension to have no bump steer, the tie rods must lie in line with the lower contol arm with the inner tie rod end in plane with the inner pivot of the control arm (see illustration on this page).

However, most production cars have the steering rack placement compromised by packaging constraints so steering tie rod location is often less than optimal. Lower the car and the problem gets worse.

Are you in a position (everything mounted up) to measure the real world bump steer to know how bad it actually is?