Front suspension musings. Using SN-95 arms on an F/Z

[Chuck W]

I'm getting all the bits together to do a 5-lug swap on the 80 Z7.

I'm going to use the 99+ 11" PBR stuff on the front and am going to use some of the 16 x 7.5" waffle-stars all around.

I've been slowly going through the general suspension stuff and have replaced/upgraded sway bars, shocks, rear springs, etc.

On the front I'm going to use C-kits, and while I was installing the 1 5/16" front bar I scoped out the front control arms...needless to say at 25 years old they are in dire need. I do however, have 2 sets of brand new SN-95 front control arms sitting on a shelf.

My thoughts are to go ahead and use a set of those since I have them and I'm planning on SN-95 spindles as well. The only issue is to mod the current K-member, or get another and mod it, to move the control arm mounting points in to compensate for the difference in arm length from the originals.

It's going to be tight enough as it is with the new wheels/tires with stock-length arms, and the longer arms will probably cause me clearance issues with the fenders. The onther option would be to refurbish the originals, but then I'd be temped to install poly bushings, and while I've used them on two of the other cars, I don't want them here on this one...

[Chuck W]

I'm getting all the bits together to do a 5-lug swap on the 80 Z7.

I'm going to use the 99+ 11" PBR stuff on the front and am going to use some of the 16 x 7.5" waffle-stars all around.

I've been slowly going through the general suspension stuff and have replaced/upgraded sway bars, shocks, rear springs, etc.

On the front I'm going to use C-kits, and while I was installing the 1 5/16" front bar I scoped out the front control arms...needless to say at 25 years old they are in dire need. I do however, have 2 sets of brand new SN-95 front control arms sitting on a shelf.

My thoughts are to go ahead and use a set of those since I have them and I'm planning on SN-95 spindles as well. The only issue is to mod the current K-member, or get another and mod it, to move the control arm mounting points in to compensate for the difference in arm length from the originals.

It's going to be tight enough as it is with the new wheels/tires with stock-length arms, and the longer arms will probably cause me clearance issues with the fenders. The onther option would be to refurbish the originals, but then I'd be temped to install poly bushings, and while I've used them on two of the other cars, I don't want them here on this one...

[Marz]

I'm not sure... but I think they'll work.

DeanT has upgraded his 78 Futura to the SN95 stuff... and then some.

Check out his Futura site:

http://www.geocities.com/MotorCity/3573/FZ/CrazyFZ.html

[Marz]

I'm not sure... but I think they'll work.

DeanT has upgraded his 78 Futura to the SN95 stuff... and then some.

Check out his Futura site:

http://www.geocities.com/MotorCity/3573/FZ/CrazyFZ.html

[Chuck W]

Well, he used the stock-length arms and just used the spacer under the castle nut since the Fox ball-joint studs are longer.

Not a big deal, other than finding another K-member to go ahead and mod, which should be cheaper than buying or refurbishing stock-length arms.

[Chuck W]

Well, he used the stock-length arms and just used the spacer under the castle nut since the Fox ball-joint studs are longer.

Not a big deal, other than finding another K-member to go ahead and mod, which should be cheaper than buying or refurbishing stock-length arms.

[Marz]

Well, he used the stock-length arms and just used the spacer under the castle nut since the Fox ball-joint studs are longer.

Not a big deal, other than finding another K-member to go ahead and mod, which should be cheaper than buying or refurbishing stock-length arms.

He used a Maximum Motorsports K-member. He has a section on fitting that as well.

[Marz]

Well, he used the stock-length arms and just used the spacer under the castle nut since the Fox ball-joint studs are longer.

Not a big deal, other than finding another K-member to go ahead and mod, which should be cheaper than buying or refurbishing stock-length arms.

He used a Maximum Motorsports K-member. He has a section on fitting that as well.

[Chuck W]

Well, he used the stock-length arms and just used the spacer under the castle nut since the Fox ball-joint studs are longer.

Not a big deal, other than finding another K-member to go ahead and mod, which should be cheaper than buying or refurbishing stock-length arms.

He used a Maximum Motorsports K-member. He has a section on fitting that as well.

Right, but he doesn't specifiy, but MM does offer ther front control arms with the Fox length and geometry...ie shorter. My buddy has the same set-up on his '87 Mustang.

I'm just going to mod either the existing K-member or another one if I can get my hands on one so it's all done and ready to install.

[Chuck W]

Well, he used the stock-length arms and just used the spacer under the castle nut since the Fox ball-joint studs are longer.

Not a big deal, other than finding another K-member to go ahead and mod, which should be cheaper than buying or refurbishing stock-length arms.

He used a Maximum Motorsports K-member. He has a section on fitting that as well.

Right, but he doesn't specifiy, but MM does offer ther front control arms with the Fox length and geometry...ie shorter. My buddy has the same set-up on his '87 Mustang.

I'm just going to mod either the existing K-member or another one if I can get my hands on one so it's all done and ready to install.

[onebad93LX]

Hey Check.. maybe this post will help...

http://www.corral.net/forums/showthread.php?t=598955

a quote from the thread...

"I did this same swap to my 82 GT with a lot of time invested in researching the differences not only between Fox and SN95 parts but also early Fox vs. late Fox.

I started out building the car with Fox length control arms, SN95 spindles, Cobra rotors / calipers, and 2000 Cobra R Bilstein struts. Goes together fine except you won't be able to achieve much more that - 1.5 deg camber. This is because the older Fox k-members are ½" per side narrower for a total of 1" narrower track width vs the later model Fox. I believe the change happened in 87? I'd have to dig out my notes.

Next phase of the build was to add the mysterious 87-88 Turbo T-Bird arms said to be ¾" longer to add additional neg camber adjustability. Thought this would be the hot ticket, not. Laying a set of T-Bird arms next to SN95 arms they come out to be the same length. Many people also believe the SN95 arms to be ¾" longer than the Fox arms, wrong again. If true, we should be able to put the SN95, or T-Bird arms, on our cars with 1/2" per side further inboard lower control arm mounting holes and only gain ¼ " per side in track width over a stock late model Fox. The SN95 arms are actually 1.33" longer than the Fox parts. This creates major fender clearance issues and more neg camber than desired.

So.....what I did was to find another k-member and move the control arm mounting holes inboard to allow for SN95 arms. ½" for old fox k-members, 1" for newer fox k-members, net gain in track width = .33" per side compared to a late model Fox. Much more manageable from a clearance and camber adjustment standpoint.

While I was at it, I moved the mounting holes up .80" to improve camber gain and roll center height. I believe I now have ¾ degrees of neg camber gain through compressive travel, would have to check the notes again for exact numbers.


Hope this helps...."

[Chuck W]

Hey Frank-

Yeah, that's pretty much what I was going to do. I'll be taking measurments and all to determine what's the best option/location for me. Hell, I may even through the numbers into the Mitchell Geometry program :lol:
The primary thing is keeping the track width managable, but I'm sure I won't be able to help myself from "fixing" other geometry issues.