RA60/65 struts into KE70.

[gjgnz]

I’ve been doing a bit of searching and can’t seem to get a definitive answer on this. In theory everything should bolt in to my KE70 without any dramas. I know I’ll need to use the Celica LCAs and SA63 PS knuckles (same length as AE86, 125mm?). Will be converting to coilovers so spring perches etc aren’t a problem.

The issue I need to resolve is the effect on camber. A lot of people say that it will give horrible positive camber that can’t be dialled out with adjustable strut tops. Others say that it is fine.
I know that Cressida and MA61 struts definitely have this affect but I’ve read that the 4 cylinder 60 series Celicas (RA60, RA65, SA63 etc) run a different kingpin angle. It actually looks like some of the MA61 guys are using RA65 struts as an upgrade to give an extra 1.5° or so of negative camber.

From what I’ve read the MA61 and MX73 kingpin angle is around 10.5° and the AE86 / KE70 is about 8.5° so in theory the RA65 struts should have almost no affect on camber in a KE70? Can anyone shed some light on this? Are there any other problems I've missed here?

See below for some background:
http://www.toymods.org.au/forums/tech-conversions/50999-toyota-strut-king-pin-angle-database-2.html
http://www.toymods.org.au/forums/tech-conversions/401-ma61-ra65-struts-powersteering-arms-conversion.html

[Hako]

Subscribing for brake upgrade possibilities

[Javal]

Hi,

Kudos for doing your homework. I've done this conversion into a xT13x Corona - there are many similarities to what you're doing.

The problem in doing this conversion is not the KPI, nor the strut itself, but the steering arm. Steering arms for xA6x have the ball joint hole offset relative to the strut mount bolt holes. This pulls the bottom of the strut in (compared to an ae86 steering arm where the ball joint hole is in-line with the strut mount bolt holes) and does in fact give small loss of track and thus a bit of positive camber. I have experienced this firsthand, there is no hearsay here.

This is best remedy is simply to run longer control arms to correct the track loss from the steering arms. You can't just swap an AE86 arm on as the bolt spacing is different. I also ran in to issues with the steering arm / bottom of the strut touching on my swaybar (but only at full droop). This may be circumvented by using longer control arms.

Apart from that it was a pretty great brake upgrade. You get a strut that takes a 2" cartridge also.

I say dive in and report back.

[gjgnz]

Thanks for the reply. If the offset steering arm sits the bottom of the strut further inboard, would a set of NCRCAs correct it back so that the strut basically sat inline with the centre of the ball joint?

[Javal]

NCRCAs would be overkill. The offset is less than 10mm from my hazy memory. That and i'm not sure you'd be able to get NCRCAs for xA6x bolt pattern. Longer LCAs would probably be the way to go.

[Javal]

i.e. with an NCRCA you're going to be moving the strut out 25mm or so just so the second set of bolts can clear the steering arm. Using a 10mm longer control arm (like xT13x) would be a much more mild solution.

[Jacobxxx]

Do the t3 arms correct the steering arm issue?

[gjgnz]

Do the t3 arms correct the steering arm issue?

These ones?
https://technotoytuning.com/toyota/ae86/hybrid-steering-knuckles-ae86-corolla-using-ma60-mx73-and-other-strut-casings

[Javal]

It would appear so.

[patrickleslie]

i'm not sure you'd be able to get NCRCAs for xA6x bolt pattern.

You can, T3 do a set

RE camber, I swapped SA63 gear into a MA61. The kingpin angle negative camber more than compensated for the steering arm track decrease positive camber. Overall there was an increase in negative camber. Total track was about 14mm less. Fixed with wider -5 offset wheels.

Not 100% sure how that translates to KE70 but you should be fine if you use the Celica LCA.

Also, if you have lowered springs...you get bump steer and RCAs fix that. However, when I put RCAs in the camber went positive. Now I'm running maxed out T3 camber plates with custom spring hats to only get 1.5 degrees camber. Good for daily, and the RCAs come out whenever I want -4 camber :D

[Javal]

You can, T3 do a set

RE camber, I swapped SA63 gear into a MA61. The kingpin angle negative camber more than compensated for the steering arm track decrease positive camber. Overall there was an increase in negative camber. Total track was about 14mm less. Fixed with wider -5 offset wheels.

Not 100% sure how that translates to KE70 but you should be fine if you use the Celica LCA.

Also, if you have lowered springs...you get bump steer and RCAs fix that. However, when I put RCAs in the camber went positive. Now I'm running maxed out T3 camber plates with custom spring hats to only get 1.5 degrees camber. Good for daily, and the RCAs come out whenever I want -4 camber :D

That doesn't translate to xE7x at all, as all xA6x Celica (*note I am wrong about some things, MA61 use a different knuckle*) have the offset balljoint hole in the steering arm (even though there are variations of the arms throughout the chassis range). So basically the only thing that changed for your was the KPI, as where putting them in a corolla you lose track also. (*This statement is also incorrect as I was unaware the steering arms were changed to xA6x Celica items also*)

This whole post is useless.

[patrickleslie]

all xA6x chassis have the offset balljoint hole in the steering arm
Not true?...define offset balljoint hole then?

MA61 balljoint hole runs across the same axis as the strut bolts. IE it is not offset. I swapped in the SA63 arms where the balljoint hole is well off being on the same axis. IE is is offset, by a good 6mm or so. There is definitely a decrease in track when this swap is done in MA61 so the only thing that changed for your was the KPI isn't quite true either. Source: http://wilbo666.pbworks.com/w/page/52176416/RA6x%20vs%20MZ1x-MA6x#RA65BalljointTaperDimensions ... and I have the MA61 arms in my hand, trust me they aren't offset. I assume this point is important because the KE70 stock arms are not offset either?
With the decrease in track from the steering arm balljoint offset and the increase in camber from the KPI, this resulted in a small total increase in negative camber in the MA61. If it were just the struts and not the steering arms then it would be around -1.5* camber. When I did it with struts and arms I measured it to be around -1* camber

Now I'm on a roll, i'm just going to throw some figures out there and perhaps someone else can work out the answer :) or gjgnz can just do it and report back haha

The KE70 has a KPI of ~8.5 and the xA6x Celica has a KPI of around 9 from memory.
Celica LCA 300mm
MA61 LCA 302 (the 2mm difference being from the balljoint hole size, not the arm length)
KE70 LCA 290mm? I'm not 100% sure on this figure.
Considering that in the Supra I had 302-6 for track decrease, and the -1.5* camber due to KPI and the end result was ~-1 camber
So in a KE70 you would have the 290-6, and +0.5* camber. This will be around 1* positive. OP already knows to use Celica LCAs anyway so...

Now we have 300-6, +0.5* camber...my thinking says it's going to be borderline 0* camber change, perhaps a few 0.1s on the positive side. If gjgnz goes for coilovers like he says then he'll have camber tops anyway so that shouldn't be a big deal

[Javal]

Yes, sorry that's my mistake saying 'all xA6x chassis' have the offset balljoint hole. It would seem MA61 have a different steering arm to RA60/65 SA63 and the ST141 / RT142, which all use the same design. I assumed they were the same as the same RCA is listed for all of the above. I will edit my above post to reflect this.

Considering you'd have to swap in the MA61 LCA to make the MA61 steering arm work with the RA65 strut to negate the balljoint offset (and as such use a much longer steering arm losing steering speed and lock) it kind of makes it a bit of a moot point.


I assume this point is important because the KE70 stock arms are not offset either?
This is indeed correct.

And using the longer Corona arms to correct the effect of the offset balljoint hole will indeed bring it all back square and even. Combined with the increase in KPI from the Celica strut you will in fact end up with a little bit of negative camber.

TL;DR - T3 arms to negate the effect of the offset balljoint hole or Longer LCAs to compensate for it.

[patrickleslie]

And to add a little more confusion to the mix, the RCA is technically the same because they share the same strut bolt spacing but depending on the manufacturer and whether they have raised lock in bumps or just a flat surface will prevent them from working in every single case. Lol. I fixed mine with a file and a lot of swearing
Gotta be careful about using the MA61 arm in this Ke70 swap as the Supra arm takes a BJ314 and the Celica Steering Arm takes the BJ145. That's something that has been worked around before but you've got a simpler solution to that here which also fixes the possible track issues...


using the longer Corona arms to correct the effect of the offset balljoint hole will indeed bring it all back square and even. Combined with the increase in KPI from the Celica strut you will in fact end up with a little bit of negative camber.
...if I'm not mistaken, you mean xT13x? They are 310mm right? And take a BJ145? If so then YES perfect :D

I figure a change of 10mm lca length = 1*, and assuming the same mounting points for LCA and Strut Top, so...

XT13c LCA 310mm - xA6x Celica Steering Arm 6mm, +0.5* xA6x Celica Strut KPI = -1* negative camber and ~30mm total track increase from stock KE70

Or T3 arms like you said and then you can do, like, 340mm LCAs or whatever lol