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 Post subject: Boxing and Extending 240 Lower Control Arms
PostPosted: Tue Jul 07, 2015 8:35 pm 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Jun 14, 2006 4:19 pm
Posts: 2983
Location: Lethbridge, AB
The lower control arms on 240's are meant to fold up in the event of a front end collision which means that they are pretty flexible and it seems that everyone boxes them to increase the steering sharpness. My car also had no ability to have camber - so I decided to just lengthen the ball joint mounting point as this is the cheapest way to get a lot of camber. With my recent foray into the world of autocross, I either lengthened my LCA's or buy new front tires a couple of times a season (yes, it was that bad).

After chatting with a few people about this, the magic number seemed to be 40 mm. So with this as the basic design, on I went with the fabrication.

First up, build an extension piece to TIG weld onto the front of the existing LCA. This required some metal origami in my press - getting it perfect is a matter of patience, practice and measuring twice. The flange (short return at the base of the bracket) was considerably longer, I then cut it to match the width of the existing. This made fabrication easier.

Image

I then mocked up a ball joint to reference the holes and move them the required amount out. Drilled the holes and created a stud for the rear ball joint mount. Then I cut boxing plates from 16 gauge steel and welded them on. It looks like this when done. Don't forget to give yourself a generous hole to bolt on the rear of the ball joint bracket.

Image

For the front ball joint mounts - you need to cut the boxing plate back a little to get full nut access.

Image

Send the finished product out for powder coat and they're done.

Image

Image


This moved my suspension from zero camber to -3.3 degrees. This is as little as I can get, so the 40 mm is probably a little too much. I've got the original LCA's and may fix this little issue to get around -2 degrees as this may be a little too much camber.

Image

I can tell you that the front end grip at this angle is very good. Only tire temps will tell and we're racing this weekend. Wish me luck.

Oh, and I changed out the tie end rods to a new set that I cut and lengthened...don't try that at home with a little buzz box - that's a job for TIG welding.

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 Post subject: Re: Boxing and Extending 240 Lower Control Arms
PostPosted: Tue Jul 07, 2015 9:45 pm 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Thu Dec 29, 2005 12:29 am
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Location: Eating tofu and legumes in my hippie shack
Wow! That's a lotta camber. How is it driving around town? Looks awesome!

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 Post subject: Re: Boxing and Extending 240 Lower Control Arms
PostPosted: Wed Jul 08, 2015 8:37 am 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Jun 14, 2006 4:19 pm
Posts: 2983
Location: Lethbridge, AB
volvoshredder wrote:
Wow! That's a lotta camber. How is it driving around town? Looks awesome!


It is fine driving around - it tracks straight and doesn't feel different at normal speeds. When pushed it's a completely different animal. We'll know better on Sunday when I push it harder, but over my little local "race track" (the roundabouts on the way to Paradise Canyon) - the tendency for the car to understeer is gone. It finally has front end grip. Now, it may be even better at -2.5 - but with the body roll caused by the lack of rear bar, I suspect I might just be fine. I really wish I could tune it, but my towers just won't allow tuning as one side is more upright than the other and I'm not going to build a frame jig to reference that and pull it all out of the car. Though as I think about it, it wouldn't be that hard to fix...so when it goes back in to the garage after the 122 is done, it's on the upgrade list. I do have a frame jig.

Anyway - it felt great (for a 240). We'll see what the tire temps tell us - thankfully Matt's running in a different category this Sunday, so he can be waiting for me in the pits with the tire temp gauge.

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 Post subject: Re: Boxing and Extending 240 Lower Control Arms
PostPosted: Wed Jul 08, 2015 11:01 am 
Haha, I just built a W24 Octo-Turbo, now what?!

Joined: Wed Dec 21, 2005 8:03 pm
Posts: 2852
Location: T2C
122_Canuck wrote:

Anyway - it felt great (for a 240). We'll see what the tire temps tell us - thankfully Matt's running in a different category this Sunday, so he can be waiting for me in the pits with the tire temp gauge.


Uhhh...there will be others there too... :D

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'67 123GT
'67 122s
'99 AMG E55T


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 Post subject: Re: Boxing and Extending 240 Lower Control Arms
PostPosted: Wed Jul 08, 2015 12:20 pm 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Jun 14, 2006 4:19 pm
Posts: 2983
Location: Lethbridge, AB
Pylon wrote:
122_Canuck wrote:

Anyway - it felt great (for a 240). We'll see what the tire temps tell us - thankfully Matt's running in a different category this Sunday, so he can be waiting for me in the pits with the tire temp gauge.


Uhhh...there will be others there too... :D


I figured you'd be taking pictures or video of our efforts :lol: .

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 Post subject: Re: Boxing and Extending 240 Lower Control Arms
PostPosted: Wed Jul 08, 2015 1:24 pm 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Thu Dec 29, 2005 12:29 am
Posts: 1786
Location: Eating tofu and legumes in my hippie shack
122_Canuck wrote:
volvoshredder wrote:
Wow! That's a lotta camber. How is it driving around town? Looks awesome!


It is fine driving around - it tracks straight and doesn't feel different at normal speeds. When pushed it's a completely different animal. We'll know better on Sunday when I push it harder, but over my little local "race track" (the roundabouts on the way to Paradise Canyon) - the tendency for the car to understeer is gone. It finally has front end grip. Now, it may be even better at -2.5 - but with the body roll caused by the lack of rear bar, I suspect I might just be fine. I really wish I could tune it, but my towers just won't allow tuning as one side is more upright than the other and I'm not going to build a frame jig to reference that and pull it all out of the car. Though as I think about it, it wouldn't be that hard to fix...so when it goes back in to the garage after the 122 is done, it's on the upgrade list. I do have a frame jig.

Anyway - it felt great (for a 240). We'll see what the tire temps tell us - thankfully Matt's running in a different category this Sunday, so he can be waiting for me in the pits with the tire temp gauge.


Interesting. I'll be very interested if the increase in front track width increase oversteer as well? I really wonder if you're gonna need at least some rear bar now to compensate for all the extra front end grip.

The Smurf had assymetric front towers too. Never could get a proper alignment. And yes, I'm sure Dale or I can get tire temps for you.

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 Post subject: Re: Boxing and Extending 240 Lower Control Arms
PostPosted: Thu Jul 09, 2015 8:12 am 
Haha, I just built a W24 Octo-Turbo, now what?!

Joined: Wed Dec 21, 2005 8:03 pm
Posts: 2852
Location: T2C
I've said it many times but perhaps not in type...when Matt and I modified the upper mounts in the 122 we ended up with way more camber than we anticipated. Even with that amount of camber...as seen here...

Image[/URL]

tire wear didn't seem unusual and the car drove down the road relatively straight. It would get a little twitchy at higher speeds but it literally pulled itself around corners.

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Dale

'67 123GT
'67 122s
'99 AMG E55T


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 Post subject: Re: Boxing and Extending 240 Lower Control Arms
PostPosted: Thu Jul 09, 2015 9:07 am 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Jun 14, 2006 4:19 pm
Posts: 2983
Location: Lethbridge, AB
volvoshredder wrote:
122_Canuck wrote:
volvoshredder wrote:
Wow! That's a lotta camber. How is it driving around town? Looks awesome!


It is fine driving around - it tracks straight and doesn't feel different at normal speeds. When pushed it's a completely different animal. We'll know better on Sunday when I push it harder, but over my little local "race track" (the roundabouts on the way to Paradise Canyon) - the tendency for the car to understeer is gone. It finally has front end grip. Now, it may be even better at -2.5 - but with the body roll caused by the lack of rear bar, I suspect I might just be fine. I really wish I could tune it, but my towers just won't allow tuning as one side is more upright than the other and I'm not going to build a frame jig to reference that and pull it all out of the car. Though as I think about it, it wouldn't be that hard to fix...so when it goes back in to the garage after the 122 is done, it's on the upgrade list. I do have a frame jig.

Anyway - it felt great (for a 240). We'll see what the tire temps tell us - thankfully Matt's running in a different category this Sunday, so he can be waiting for me in the pits with the tire temp gauge.


Interesting. I'll be very interested if the increase in front track width increase oversteer as well? I really wonder if you're gonna need at least some rear bar now to compensate for all the extra front end grip.

The Smurf had assymetric front towers too. Never could get a proper alignment. And yes, I'm sure Dale or I can get tire temps for you.



Wait - you're coming to the AutoX! =D> =D> =D> We'll have a full crew - so stoked. Don't forget that I also have a wider rear track. Hasn't felt tail happy at all - but we'll see Sunday.

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 Post subject: Re: Boxing and Extending 240 Lower Control Arms
PostPosted: Thu Jul 09, 2015 9:10 am 
Haha, I just built a W24 Octo-Turbo, now what?!
User avatar

Joined: Wed Jun 14, 2006 4:19 pm
Posts: 2983
Location: Lethbridge, AB
Pylon wrote:
I've said it many times but perhaps not in type...when Matt and I modified the upper mounts in the 122 we ended up with way more camber than we anticipated. Even with that amount of camber...as seen here...

Image[/URL]

tire wear didn't seem unusual and the car drove down the road relatively straight. It would get a little twitchy at higher speeds but it literally pulled itself around corners.


Still one of the best car days of my life so far. Oh and it's hard to believe that I was ever that fat...we should crop me out of that picture.

Seriously, given my outside tire wear, a little inside tire wear would make things even. These are 5 year old tires anyway, so if I burn them this year, I'm not sad.

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