Front a-arm & suspension weight discussion

phattyduck

New member
CMS-GT4":34mwyahi said:
I changed the thread topic so we might include more details in the respect of where this thread is heading. more or less fabrication and lightening of suspension components.

Here is some info from a thread I started on gt4dc about switching to the st205 rear hubs, and arms, which are lighter. At least the lower arm is 1lb lighter. It extends the rear track 20mm each side which reduces the need for a spacer.

From other thread:

I have an entire rear st205 suspension (less the struts) in my possession and I was considering swapping it into my st185. I took weights of the rear lower arms and found that they are ~1lb lighter.

I have read that the arms could be swapped but I measured them and the holes are ~25mm further on the 205 arms than the 185.

So I thought I might swap the entire assembly axles and all.

The only issue I am concerned about is the position of the strut top is in the same location yet I am moving the bottom further out. I am unsure of the strut top distance on the st205 and how it relates to the 185.

Being that the strut top is to remain in the same location and the bottom is moved out nearly an inch will this cause camber issues?

Has anyone does this swap, and can any alignment issues be sorted with rear camber bolts or is the st205 made to compensate for this?

From what I have read the st205 rear track is ~40mm wider than the 185.

Diceman":34mwyahi said:
I know of someone who has fitted an entire ST205 rear subframe, hubs & arms on to his ST185.

It does increase the rear track, he also found that one of the ST205 arms did not fit.

IIRC the increase in track is from the hub not the arms. The Driveshafts are I believe the same length. From what I understand the hub inner flange has the same track as teh ST185 but the outer flange/drive flange is 20-25mm further out per side.

If this is correct then it is likely that the strut mounting is in the same place and will not effect the camber/alignment.

Apparently teh reason for one of the ST205 struts being onger is more to do with teh chassis mounting point being in a different location on teh ST205 underside.

This is only what I have read and I do not have any first hand experience but it is also something I have been thinking of doing. The use of teh ST205 rear hubs will also mean teh rear calipers & discs bolt up without teh need for a very small shim/spacer to overcome the difference in drive flange centre bore of 54.1mm on teh ST185 & 55mm on teh ST205.

If you have the hubs - measure them up and please post the info to confirm if I am babling or correct :)

It also looks like the rear cross frame might be lighter as well for the 205. I wonder if this will mount up as well. It looks smaller than both the 185 and 165 models.
The increase in rear track on the ST205 compared to the ST185/ST165/SV25 comes exclusively from the longer arms. You will need to match your axles to do this swap.

You will gain about 3* of camber until you get some alignment bolts in there. The shop had to put 2 bolts on one side and one on the other to get back to 1* total camber (stock for my Camry Alltrac). I'm not sure what is different on the ST205 struts/chassis to account for this (different top mounting point or different lower mounting points).

I kept my stock hubs for the moment, but the ST205 hubs are essentially the same as far as I can tell. ST205 rear brakes bolt on to earlier hubs, aside from the well known 55mm vs. 54.1mm hub difference.

Also note that the part numbers for the rear subframes are the same across the years (ST205/ST185/ST165/SV25). The mount bushings and other minor parts may have different part numbers (the ST205 and SV25 subframe mount bushings are different but interchangable, for example).

Hope that clears up a few things.

-Charlie
 

CMS-GT4

Active member
So can the camber bolts adjust 5 degress of camber? I am already sitting at 2 degrees in the rear from lowering. If I add 5 to that, I might run into more issues. I wonder about strut top placement on the celica vs the camry. Does a 185 strut bar fir the camry alltrac? I know its not needed since its a sedan but that would give us an idea of strut top distance.
 

phattyduck

New member
CMS-GT4":8nlxoen3 said:
So can the camber bolts adjust 5 degress of camber? I am already sitting at 2 degrees in the rear from lowering. If I add 5 to that, I might run into more issues. I wonder about strut top placement on the celica vs the camry. Does a 185 strut bar fir the camry alltrac? I know its not needed since its a sedan but that would give us an idea of strut top distance.
The camber bolts generally give you a 2* adjustment range - adding a second will give you another 2* or adjustable range or so. The ST205 arms should only add 3* if camber, not 5*. Depending on what you already have in there, you should be able to get back to 2* (which is about right for performance) without trouble.

Rear suspension geometry is exactly the same Camry vs. Celica (alltracs) as far as I have been able to tell. Same subframe, same arms, same hubs, same axles, compatible (but not same) swaybars, etc. Even the exhaust mounts are in the same place. Think of it as a Celica with a 2" stretch in the middle (yay rear legroom!). I'm getting some Tein SS coilovers tonight, so we shall see if it works out like I hope.

-Charlie
 

CMS-GT4

Active member
I mis-wrote it. I have two, will be adding 3 for a total of 5 degrees of camber. So with two sets of alignment bolts I can get down to 2-1 degrees of camber in the rear?
 

Roundy

New member
gtfour77":kwzroern said:
Quick Wilwood part numbers that would work for our application:

Front Rotors: 160-7172 (right) 160-7173 (left)
Hats: 170-8132 (bolt pattern: 12x8.75")
Hat offset: 0.41"

All of this will fit the alltrac spindle without much trouble (simple single plane bracket like the one I posted in my autocross build)

Sorry slighty OT here.

What bracket are you talking about? I couldn't spot anything in your thread?

Also how do you go with the hat having 4.5" PCD? Just redrill for 5x114.3 in your case?

Cheers
Nathan
 

CMS-GT4

Active member
I just had another idea. Use the st205 rear lower arms, have them cut and a threaded section added with a locking collar nut then you could have adjustable camber via the arm instead of having to do the camber bolts. Save weight and gain function.
 

alex237

New member
just a thought- i know a person in the uk thats put a 205 subframe on his 185,he swapped the lot.bear in mind halfshaft lengths if you just swap the arms,ill try to find out more info for you :)
 

gtfour77

New member
Roundy":110kwjvv said:
gtfour77":110kwjvv said:
Quick Wilwood part numbers that
Sorry slighty OT here.
What bracket are you talking about? I couldn't spot anything in your thread?
Also how do you go with the hat having 4.5" PCD? Just redrill for 5x114.3 in your case?
Cheers
Nathan

Nathan,
I have converted to a camry/lexus front spindles/hubs so my front bolt pattern is now 5x114.3 (5x4.5). It's a Mustang Cobra rotor hat that is bolt-on. You can also re-drill it for 5x100...
Brackets are described here:
http://alltrac.net/phpBB2/viewtopic.php ... c&start=45

It's page 4 just in case it takes you to the 1st page of the thread... :wink:
 

Terracar

New member
I am a little hazy on the spherical bearing use in the A arms idea...

If I am understanding correctly (please forgive me - very little sleep in last few days due to thanksgiving prep) you would replace the bushing in the A arm with spherical bearings - you mention aluminum blocks also (I think) - might question is would the spherical bearing be the same size as the bushing and pressed into teh A arm or would it be two smaller spherical bearings pressed into the A arm?

The use of the bearings make sense to me to take out the slop from the bushings - but would be concerned over the stresses on the bearing caused by in/out & side to side forces (probably thinking about this reverse of what you are at this time lol)

Also to CMS what about lightening the axles? Not sure if any options for this exist for our cars - have seen them for the honduh crowd though.

Also somewhat OT - but also what about remaking engine cross members from lighter materials - not alot of savings but potentially some there.



-Terracar
 

CMS-GT4

Active member
alex237":30rtea27 said:
just a thought- i know a person in the uk thats put a 205 subframe on his 185,he swapped the lot.bear in mind halfshaft lengths if you just swap the arms,ill try to find out more info for you :)

Got any pics and details? I was wanting to swap over the 205 subframe and superstrut bits but everyone told me it was impossible.

Terracar":30rtea27 said:
Also to CMS what about lightening the axles? Not sure if any options for this exist for our cars - have seen them for the honduh crowd though.

That is an option but I imagine its an expensive option.
 

gtfour77

New member
I am still researching this whole idea but yes, that would be basically it. pherical bearings would remove any slop in the suspension which is ideal for racing purposes. All of the big guns at nationals run them and there is a huge reason for doing so... Talking to Mark Daddio, Vic Sias for 5 minutes will cause you to spend about $5000 in one weekend.. and that's the chea stuff...heh
Anyway, here is an example of what I mean. It's called a caster block as it prevents the a-arm to go backwards and change caster under braking/cornering... It just needs to be something solid to stop the motion.
http://www.blaszakprecision.com/Spheric ... _block.jpg

Here is another design:
http://www.powerhaus.com/usedcars/1987_ ... _strut.jpg

http://images.google.com/imgres?imgurl= ... %26hl%3Den

Thsi is very similar to our suspension so we might take some ideas from this setup...



Terracar":3dn0phoq said:
I am a little hazy on the spherical bearing use in the A arms idea...

If I am understanding correctly (please forgive me - very little sleep in last few days due to thanksgiving prep) you would replace the bushing in the A arm with spherical bearings - you mention aluminum blocks also (I think) - might question is would the spherical bearing be the same size as the bushing and pressed into teh A arm or would it be two smaller spherical bearings pressed into the A arm?

The use of the bearings make sense to me to take out the slop from the bushings - but would be concerned over the stresses on the bearing caused by in/out & side to side forces (probably thinking about this reverse of what you are at this time lol)

Also to CMS what about lightening the axles? Not sure if any options for this exist for our cars - have seen them for the honduh crowd though.

Also somewhat OT - but also what about remaking engine cross members from lighter materials - not alot of savings but potentially some there.



-Terracar
 

gtfour77

New member
Possibly, I am selling my daily driver within the next couple of weeks (need to do some maintenance on it) and then I will take the front and rear suspension apart and start thinking about some improvements.

Edit: I'll keep you posted, this will be actually quite simple project once started. Quick jig and good bar stock will go a long way... :D Plus adjustable lower ball joint will help out with caster and balance.
This is what I am thinking...
http://www.pdm-racing.com/products/imag/bvrlca.jpg

With one of the arms being adjustable, unless I can come up with a design that will let me reliably change the ball joint position, kind of like adjustable camber plates...

Also, and this is 100%, adjustable radius rods with spherical bearings will be put in the rear to replace the stock rubber bushings (in the subframe only) and to make alignemnt easy.
 

Terracar

New member
When you say caster blocks to prevent a arm going backwards - is my interpretation correct in the image below?

AArm.jpg


TIA

-Terracar
 

gtfour77

New member
Nope, it's the movement to the rear of the car... the movement you shoved in the illustration is the easier one to control and simple spherical bearical can be used. The other motion creates lot more stress on the bearing since it's a pressure that goes "through" the bearing opening rather than on the race. If you need more explanation I can try but this is the best I can do for now... :wink:

This can also be solved by positioning the rear bearing horizontally rather than vertically...
 

Terracar

New member
Ahhh - ok makes sense now. That was my concerns for using the spherical bearings - figured that movement would be hard on the bearings (the forces exterted on them).

Ok glad I am on the same page


Thank you for the patience :)

-Terracar
 

CMS-GT4

Active member
phattyduck":2a0xt2tq said:
The increase in rear track on the ST205 compared to the ST185/ST165/SV25 comes exclusively from the longer arms. You will need to match your axles to do this swap.

You will gain about 3* of camber until you get some alignment bolts in there. The shop had to put 2 bolts on one side and one on the other to get back to 1* total camber (stock for my Camry Alltrac). I'm not sure what is different on the ST205 struts/chassis to account for this (different top mounting point or different lower mounting points).

I kept my stock hubs for the moment, but the ST205 hubs are essentially the same as far as I can tell. ST205 rear brakes bolt on to earlier hubs, aside from the well known 55mm vs. 54.1mm hub difference.

Also note that the part numbers for the rear subframes are the same across the years (ST205/ST185/ST165/SV25). The mount bushings and other minor parts may have different part numbers (the ST205 and SV25 subframe mount bushings are different but interchangable, for example).

Hope that clears up a few things.

-Charlie

So I measured the 185 axles and the 205 axles today. Unless them being in the car changes the length somehow the rear 185 axles are shorter.

I measured both axles at the ends of the boot. The 185 axles came around 17.5" (444.5mm) and the 205 rear axle came to about 18.75" (476.25mm).

BTW: Both axles in the pic are 205's, I was just trying to show the reference points of where I measured. To the end of each boot.
photowy1.jpg
 
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