RA28 stering rack conversion (need advice)

[bullitt]

Hi all...
I like to know,it is posible to use RA60 Xmember into RA28..I'm after stering rack conversion into my RA28, i see lot of forum member use xmember from AE86 and KE70..the reason i go for RA60 Xmember is no modification for engine mounting..I know this topic have pro and con..
Hope you all can give me an advice....thanks.

[TurboRA28]

I looked into this option and it could be made to work. But the front track would be very wide! Probably illegal, need flares? the rear would be skinner than front. etc etc.

I went with the KE70/AE86 as even though it was wider, it wasn't extreme and with +32 offset wheels (Silvia offset which has a huge range) it fills the guards nicely.

Cheers
Joel

[thechuckster]

would suggest measuring/comparing:
psteer unit and associated control arms
Xmember (mount-to mount-bolt)
position of lower control arm mount points
length of control arms

can't find the data at the moment, but compare the track of an RA28 and RA60 - will give you indicator of width of the overall unit.

[TurboRA28]

I had all that data somewhere but buggered if I can find it..

From memory the RA60 would have made the track a good 50 - 60mm wider each side. Can you say negative camber?

The KE70 was around 20 - 30mm wider..

[o_man_ra23]

Im looking into this option atm for both an RA23 and a TA22. The main concern is the lower control arm mounts. The extra distance on these wont affect your track as much as it will your camber. So, to solve this problem you have a few options. Either re-position the lower control arm mounts, or elongate the holes and put an XF falcon style camber adjust pin in (if you dont know what i mean, go to your local ford wrecker and ask to see the front suspension setup on a XA through XF falcon) You may need a combination of both these tasks to get a perfect result, but this gives you camber adjust at the same time, and a good way to explain to your other half that the whole conversion will reduce your tyre wear and so cost less

[TurboRA28]

Be careful.. If you start moving the lower control arms around, you'll just introduce bump steer problems.

[o_man_ra23]

perhaps another way around this is to use the TA23 xmember, and butcher the rack mounts off the RA60 xmember to put on there... just gotta be careful where you place the rack mounts, as you dont want them off centre.
TurboRA28 - what kind of placement of the control arm mounts would be likely to induce bump steer?? Is it when you make the mounts closer/further from the rack, or is it movement in the other direction, or rotation of the mounts that will be likely to cause this?? This is something ill need to know for my conversion so i can avoid making a mistake.

Cheers, Owen

[TurboRA28]

Mate just out of interest, did you read my rack n pinion conversion writeup on the old forums? As a lot of this is covered..

But..

The first rack n pinion conversion I did was using a TA23 xmember, with custom mounts to hold a KE70 rack. I had to move the control arms outwards in this instance to get rid of bump steer.

This is something I wrote up when doing the TA23/KE70 rack setup...

I hope this info will help in setting it up correctly.

For zero bump steer the control arms and steering arms need to be identical in length. Also they need to be in a parallelogram with each other.

The ratio of the difference in height between the control arm inner pivot point and the steering arm inner pivot point, needs to be the same, as the difference between the control arm outer pivot point and the steering arm outer pivot point.

All measurements are taken from the relevant pivot points :
Control arms are from the centre of the bush mounted on the cross member to the centre of the ball joint. This is 300mm.

Steering arms set with 0 toe are from the centre/pivot of the joint at the inner rack end to the centre of the ball joint/outer tie rod. This is approx 275mm – need to confirm.

With the above measurements the steering arm would need to be lengthened 25mm on each side. This increase will happen when the pivot point of the control arm is moved outbound 25mm.

[TurboRA28]

Also I had problems with ackerman angles with the ta23 xmember.

If you were going down this path, have a look at MWP's information as he has refined the setup and it seems like it will be improved from mine. He fixed the ackerman problem by cutting into the xmember and moving the rack forward more. Also used a AE82? I think. rack that was the correct width and didn't need to modify the positioning of the control arms.

Cheers
Joel

[o_man_ra23]

Righto, i do remember reading that, but didnt make sense at the time as i was not seriously looking at a rack setup then. So... i need to find a narrower rack... one which will be the correct width once i have made my camber adjustments. Thanx heaps for the advice.

Cheers, Owen

[bullitt]

look like i have to find AE86 or KE70 xmember to do this conversion..and front 18r sump too,to get clearence 18rg engine into xmember...

thanks for all advice..

[Pube]

heres what i did in my RA23





Consists of a cut down commodore manual steering rack mounted on a TA23 crossmember and using a KE70 steering column. I used a Borgeson universal joint to join the two together.

[MWP]

Righto, i do remember reading that, but didnt make sense at the time as i was not seriously looking at a rack setup then. So... i need to find a narrower rack... one which will be the correct width once i have made my camber adjustments. Thanx heaps for the advice.

Now i have approved in these new forums....

The AE92 rack is the shortest i could find in a huge pile of honda & toyota items and is what im using.
The AW11 rack is also very short.

The AE86/KE11 racks are a little be longer... cant remeber how much.

[takai]

20mm longer from memory. I had them sitting in my boot together a while ago, should have taken better photos.

[willwal98]

I know this thread has a little bit of age on it so sorry folks.

I just have a quick question on the mounting for the rack. From what I have read you all seem to go for a rear cross member (supports a front sump) and just weld on some tabs and bolt in the rack. Just say for arguments sake that you already have a car setup with a mid/rear sump and a forward cross member, could you not weld on some sort of mount to the cross member and still have the rack in the same place?

I guess from the fact that I have not heard of this being done there must be some good reasons for it

Please excuse my completly out of scale pic.