RA28 stering rack conversion (need advice)

[brett_celicacoupe]

with a midsump 1g, there is practically no part where there is room for a rack. the sump is still "bulging' where you would put the rack. furthermore the gbox brace is in the way a little. the sump buldge and brace overlap a little too.

the red part is the sump, the green part is the gbox brace.

[willwal98]

I think it would fit. Don't forget it's in an RA28 so I already had to modify the sump to clear the original steering bars. And this is where I was planning to put the rack, right where the existing steering bar goes. There is room underneath for the steering rack crossmember and the rack itself would go where the bar is now. I think this would work but I don't have any sizes on a rack to say for sure and I also haven't got confirmation on the placement of the rack (whether that area is suitable).

[MWP]

The important thing is when the rack is in place and the steering wheels are straight, the tie rods point slightly backwards (not a long way forward like in your drawing).
When you turn the steering wheels say 25%, you want the tie rods to be straight.

Ill draw a diagram later.

In my experience doing this will give you a decent ackerman angle.

[willwal98]

please don't go too much on my diagram, it's definitly not to scale or anything, more just a rough representation of how I want to mount it, not really where.

If someone could give me a measurement from say the engine x-member bolts (as this will be the same no matter what member you have) to the rack, i'll see if it's doable.

I'm definitly no expert on this but I would have thought that if the wheels were straight, the rack would have to be where the steering bar is, and the ends of the rack would be where the inner tie rods are?? The only thing would be when you turn the wheel the position of the bar changes due to the arm comig off the steering box moving in an arc, but since there isn't much room forwards and backwards under there now, it musn't be too much, Thoughts on this??

[MWP]

If someone could give me a measurement from say the engine x-member bolts (as this will be the same no matter what member you have) to the rack, i'll see if it's doable.

I cant do this as im overseas.
Anyone else?

I'm definitly no expert on this but I would have thought that if the wheels were straight, the rack would have to be where the steering bar is, and the ends of the rack would be where the inner tie rods are?? The only thing would be when you turn the wheel the position of the bar changes due to the arm comig off the steering box moving in an arc, but since there isn't much room forwards and backwards under there now, it musn't be too much, Thoughts on this??

Oh.... no, youll loose the steering bar and inner tie rods completley.

Look at this photo:
http://www.overclockers.com.au/~mwp/...&x=1280&y=1024

With that setup the tie rods are pointing very slightly backwards.
Idealy you want them a little further than that (ie, the rack further towards the front of the car).
Although im pretty sure my engineer is going to pass it as is in that photo. The ackerman and bumpsteer measuments are good enough (still could be better though).

I think if i were in your situation i would change to a TA23 or KE70 xmemeber and get/make a new sump.

[willwal98]

Oh.... no, youll loose the steering bar and inner tie rods completley.
.

Hehe, yeah I gathered that

Look at this photo:
http://www.overclockers.com.au/~mwp/...&x=1280&y=1024

With that setup the tie rods are pointing very slightly backwards.
Idealy you want them a little further than that (ie, the rack further towards the front of the car).
Although im pretty sure my engineer is going to pass it as is in that photo. The ackerman and bumpsteer measuments are good enough (still could be better though).
.

Yeah that's what I'm not sure of, if I can get the rack forward enough. I haven't really had that hard a look. I'll take some photos and see what they tell me.

I think if i were in your situation i would change to a TA23 or KE70 xmemeber and get/make a new sump.

If I had to go that far, it will never happen. TA23 x-members are hard to find. A front sump and pick-up for a 1g is a piece of pie to get a hold of though.

[barned01]

is there more trouble than it is worth to make a custom crossmember?

[TA-022]

if its old try Celica Spares 02 9756 6606

im buying myself a TA23 xmember tomorrow.

[brett_celicacoupe]

is there more trouble than it is worth to make a custom crossmember?

i dont think any engineer will approve this easily. the factory xmembers are manufactured to certain standards. toyota would have had a large machine back in the day that would bend/twist to see how much it deflects etc.

he would have to make sure the custom xmember is structurally as good as the old one. so then you'd need to know exact measurements/steel grade/thickness etc.


well thats what i would think anyway

may be wrong

[willwal98]

To make what I am describing wouldn't be too hard and wouldn't have a HUGE load on it. As long as the steel was think enough and designed properly it would be fine.

MWP

I have had a look under the car and I think it would be a tight squeeze to get the rack forward of the steering arms. I see a few possabilities though, I think with a little bit of modification to the sump I could get slightly more forward and depending on the diam of the rack it may be enough, the other thing that may be possible is longer steering arms but I don't know where I would get some to bolt in. Getting some made would be no different to buying a TA23 x-member and a front sump.

[Major Clod]

I'd still look at the KE70 option, parts are plentiful too.

[willwal98]

so what's that option? Ke70 rack and engine x-member? How similar is the x-member to an RA28 one?

[Major Clod]

You'd have to talk to TurboRA28 to get the details, but the idea is that the rack is already the correct width if you use your lower control arms in the KE70 mounting holes. From what I've read, it will increase your front track by about 20-30mm either side if I can remember correctly, so you'll need to make sure you have enough room with your rims. It will also remove the stock positive camber and give you a little bit of negative camber.

The KE70 crossmember is also not swept back quite as far as the TA23 crossmember, so the rack is in a better position from the start. Need a front sump engine still and you need a custom front swaybar.

Again you might have to give him a PM to get the details. I recently did a fair bit of searching on the old forums, but I could really only find it writeups on his TA23 crossmember version.

Perhaps a good idea would be to purchase a dunger xA23/28 for a couple of hundred and use that as your development car if yours is on the road. That's what I have done, and aside from the bunch of spare parts I have stolen from it, I can strip it back and use it to plan my rack & pinion + 1G setup later in the year without having mine off the road.

[MWP]

the other thing that may be possible is longer steering arms but I don't know where I would get some to bolt in. Getting some made would be no different to buying a TA23 x-member and a front sump.

You wont find any to bolt in... i tried.
The only longer arms i could find on toyota's were in crowns and they used a different bolt pattern.

You also cant lengthen standard items (very illegal) and it would be very difficult to get an engineer to approve custom made jobbies.

The KE70 xmember runs pretty much straight across from the mounts (its doesnt curve backwards or forward).

[willwal98]

I don't see that working too well with a 1g-gte. I believe a front sump requires the rear x-member to fit and a mid or rear sump need the forward facing one (actually never heard of anyone using the rear sump).