Minor frame pulling DIY questions - Tweaked strut tower in race car
03-25-2014, 04:29 PM
#1
Minor frame pulling DIY questions - Tweaked strut tower in race car
Working on our 944 Race car for the chumpcar series. We picked this thing up incredibly cheap and are making a few tweaks here and there before getting out to a race.
One of the things we noticed is that the alignment is a bit off, looks to be caused by a slightly tweaked frame. The driver side shock tower sits a bit higher, about an inch, than the passenger side. Additionally, the main cross member sits about an inch higher on the driver side than it does on the passenger side. This all correlates to the fact that the PO described an off-track incident where they hit something on the ground, and the witness marks exist in the form of gouges on the drivers side of the crossmember right at the frame/control arm mount point the corner. There is also a very small crinkle in the box structure just aft of the very top of the strut tower, near the hood.
TL-DR - upward hit on the crossmember right below the shock tower.
The car still drives pretty decent but has a little pull. We'd just like to do what we can to tweak the frame back a bit. We're not going to be spending the money taking this to a frame shop, at least not yet. This is chumpcar.
After looking at it a bit this is what I came up with. My idea was to disconnect the control arm and stick an aluminum pin through the control arm mount point. Jack from the frame rail and use a comealong to pull down the crossmember (see the red arrow marked '3'), which should hopefully true things up a bit. This doesn't have to be perfect. My biggest concern is that I do not want to tear the threads that are a part of the unibody. I would rather shear/rip something aluminum thats easily replaceable than further damage the threads in the unibody which will cause me to have to cut and weld. If I decide I don't want to pull on the crossmember, I also thought about welding on a tab near the crossmember and pulling on that instead.
As a way of distributing the load a bit more, I also thought perhaps I could tie down the front at 2 points - the control arm mount point and the top of the strut tower, as shown in the last diagram. That should distribute the force a bit more.
An alternate method I came up with was to strap down the crossmember to the ground (or the frame of our race trailer) and use a floor jack on label marked 'jack stand'.
Anybody have any pearls of wisdom for my backwoods redneck plan? Of the different methods, any stand out to you guys that have done this before as the best? Taking this thing to the frame shop is likely not in the budget for this project I'm afraid.
One of the things we noticed is that the alignment is a bit off, looks to be caused by a slightly tweaked frame. The driver side shock tower sits a bit higher, about an inch, than the passenger side. Additionally, the main cross member sits about an inch higher on the driver side than it does on the passenger side. This all correlates to the fact that the PO described an off-track incident where they hit something on the ground, and the witness marks exist in the form of gouges on the drivers side of the crossmember right at the frame/control arm mount point the corner. There is also a very small crinkle in the box structure just aft of the very top of the strut tower, near the hood.
TL-DR - upward hit on the crossmember right below the shock tower.
The car still drives pretty decent but has a little pull. We'd just like to do what we can to tweak the frame back a bit. We're not going to be spending the money taking this to a frame shop, at least not yet. This is chumpcar.
After looking at it a bit this is what I came up with. My idea was to disconnect the control arm and stick an aluminum pin through the control arm mount point. Jack from the frame rail and use a comealong to pull down the crossmember (see the red arrow marked '3'), which should hopefully true things up a bit. This doesn't have to be perfect. My biggest concern is that I do not want to tear the threads that are a part of the unibody. I would rather shear/rip something aluminum thats easily replaceable than further damage the threads in the unibody which will cause me to have to cut and weld. If I decide I don't want to pull on the crossmember, I also thought about welding on a tab near the crossmember and pulling on that instead.
As a way of distributing the load a bit more, I also thought perhaps I could tie down the front at 2 points - the control arm mount point and the top of the strut tower, as shown in the last diagram. That should distribute the force a bit more.
An alternate method I came up with was to strap down the crossmember to the ground (or the frame of our race trailer) and use a floor jack on label marked 'jack stand'.
Anybody have any pearls of wisdom for my backwoods redneck plan? Of the different methods, any stand out to you guys that have done this before as the best? Taking this thing to the frame shop is likely not in the budget for this project I'm afraid.
