TA22 + rack and pinion

[oldcorollas]

i'm going to read this thread a bit later, but a quick comment regarding LCA pivot and rack width..

it depends crucially on any change in steering arms also.
what you need to maintain, is the (rackend->steering arm) : (LCA pivot->balljoint) geometry (when looking from the front of the car).

effectively this means that for a given rack, if you take into account the difference between the donor/recipient steering arms (height and offset from balljoint), and maintain that difference when relocating the LCA pivot (or shortening rack), it should be hunky dory....

next is fore/aft rack positioning for ackermann.. that depends critically on steering arm length as well..

[Sam_Q]

Can you confirm how much further out the LCAs sit on the AE71 compared to the TA22?

30mm per side by memory

[Matty]

Subscribed, would love to get R&P in my 22. Especially now the bay is free of an engine...

[shelldrake]

I bolted in one of sams setups in my ta22 running a 4age 20v. Everything is looking good. Just need to give it a test run in the next few weeks...

[The Real Roadrunner]

30mm per side by memory

So completely illegal for any road going vehichle in this country.
unless of course you are shortening your Lcas to reduce the track or running +40 offset rims, all of which will cause other problems.

And please explain to me how shortening the crossmember increases bumpsteer? it won't if you shorten the rack by the exact same amount.

Another question i have is how can you confirm that your setup has 0 bump steer? im yet to see a single car built without it, it can actually be a good thing if designed in correctly.

BTW those Lock spacers you suggested cause a fair whack of bumpsteer, how favourable it is depends alot on your pivot point hight differences and what toe settings you run but by the looks of it you have alll the bases well covered

Cheers
Linden

[Sam_Q]

shortening the LCA's yes, I don't want the Celica equivalent of sigma arms in ae86's. The length of the tie rod ends in a crossmember is matched to the pivot points of the lower control arms. If the crossmember is shortened then the steering arms get proportionally longer and therefore the wheels will change toe through the suspension movement due to the a different arc of axis, much like the pinion angle change on the diff in a 4 link rear suspension. It will not happen when the rack is also shortened to match so it sounds like you know about these points above already. I am still going to look into shortening the racks. The reason I have avoided such an option till now is because I thought it might increase the amount of work required and right now there is already heaps to do. Lock spacers shouldn't affect the bump steer because they just let the tie rod ends travel further into the steering rack than normal, so the geometry is not changed.

Now I better change my statement on having zero bump steer, how about I declare it will no more dialed in bump steer than the ae71 or ke70 these are coming from. So what ever Toyota decided was the best I am just using, because quite frankly we can't know everything they came up with on their modeling so why mess with it?

I am guessing though I have just confirmed these points to you though than anything else but I explained in details for everyone else's benefit

[Rob KE25]

[QUOTE=Sam_Q;

Major Clod: Interesting point, I can't see how would be easily possible but I did plan on taking a rack apart regardless so I can assess that option. Apparently theres some nylon bush thats inside a rack that can't be bought that I was thinking of making on a mass scale.[/QUOTE]

Hi Sam. I heard the same. If I recall correctly, some similar racks (AW11) have the same part as the AE86/ KE70 ones. They have the same bush, but one is in nylon, the other rack has it in metal.
I ordered the bush, which is in metal from Toyota Co-op. Part number 45522-10021.
Check it out, it is probably what you want, and in metal.
Rob KE25

[Sam_Q]

well nothing quite like some hard facts vs hearsay, thanks Rob

[sauceman]

Found this dude's attempt. See what you experts think of it. http://www.classic-celica.com/nuke/m...wtopic&t=18943

[Sam_Q]

Edit: found out about front crossmembers, so yeah is safe.


Hmm he its using a KE70 rack which is the wrong length and no good unless it is shortened

[sauceman]

Its very totally. My approach is not to alter the donor crossmember but to alter the chassis frame. Quicker.

[Sam_Q]

hey I made signed up and made a post:

"a very unusual design, I think it's clever how you made the brackets off the original idler arm mounts.

does that bar replace the original crossmember?

what do you think about the difference between the length of the steering rack and the original idler arm pivot points?"

I wonder how he will respond.

[bigmat]

have a good look at this guys thread. hes running a full house 9 second ta22, tubbed and all the fruit. read the whole thread as it seems to be a good conversion.

cheers mat

[stidnam]

The engine crossmember in the american celica cureves towards the front to account for the rearr sump that the 21r motors that they had so it is not replacing the crossmember. All this is for is to hold the rack.

The rack is not shortened which isn't good though

[Sam_Q]

wow thats a releif, imagine the stress on it with a 1J on that. Anyway typical of me to find a grumble with someone revered on a forum, seems to be a tradition with me