Front Pin Drive to wide?

[rlampman]

I think I am missing something. I think with the setup I have pin drive wheels would stick out too far. Please check my math and any other suggestions. My goal for the pin drive front is to bring the tire inside the fender and still have a deep dish wheel not to run actual pin drive wheels but they should fit.

I have a MKII with FFR pin drive lower control arms, pin drive spindle adapters, and '99 spindles. Both sides are set up and measure out the same so the body is centered. Full alignment done with -0.7 degree's camber, 3 degree's castor, and 1/8" total toe. 4" ride height in the front and 4 3/4" in the rear. Oh and a TriStates body but the front should be the same as a standard MKII FFR.

My test wheel is 15X7 with 4" backspace, 235/60-15 tires.
http://i1349.photobucket.com/albums/p751/rlampman/Cobra/20140805_113328_zpsk7eqgcbc.jpg (http://s1349.photobucket.com/user/rlampman/media/Cobra/20140805_113328_zpsk7eqgcbc.jpg.html)

Suspension pictures where taken before alignment but is only mockup so I know about no boots. It is only tightened, not torqued, and different wheels.
http://i1349.photobucket.com/albums/p751/rlampman/Cobra/20140708_192051_zps9swpeoo9.jpg (http://s1349.photobucket.com/user/rlampman/media/Cobra/20140708_192051_zps9swpeoo9.jpg.html)

http://i1349.photobucket.com/albums/p751/rlampman/Cobra/20140708_192105_zpsafn4ry9a.jpg (http://s1349.photobucket.com/user/rlampman/media/Cobra/20140708_192105_zpsafn4ry9a.jpg.html)

http://i1349.photobucket.com/albums/p751/rlampman/Cobra/20140708_192124_zpsmau0dldj.jpg (http://s1349.photobucket.com/user/rlampman/media/Cobra/20140708_192124_zpsmau0dldj.jpg.html)

With a level set plum the bottom is against the tire and the top is against the fender lip with 1/2" from the top of tire. Sets nicely and really is where I want it but... If this was a pin drive wheel it would be 7.5" wide with a 3.5" backspace (listed on FFR site). There would also be a 3/8" adapter. So here's the math. 1/2" less backspace moves the wheel out and would also be 1/2" wider (to the outside) plus 3/8" for the spacer. That would move the wheel out 1 3/8" ! The tire would be outside the fender and rub when the suspension compresses. From the pictures of pin drive wheels I have seen on FFR's they are not that far out.

I have tried a 1/2" spacer on these wheels and it does clear the fender with the top of the wheel even with the fender lip. Another 7/8" (for a total of 1 3/8") would be outside the fender. I have verified that I have 13" pin drive LCA's, I know I have the right spindle adapters because I also have the standard width that are wider. I have only one set of frame holes for the LCA's (instead of inner and outer like MK3).

I can make the wheels I want work but would like a deeper dish (It would be a standard width FFR front wheel, 15/8 w 5"BS). It just seems like I am missing something. Any idea's?

[Todd Buttrick]

Wrong thread.

[rlampman]

Todd, that is exactly what I found trying to go underneath. I ended up putting that mod on hold for now.
How far out is your front wheel from the fender? Wondering if I have something wrong.

[Todd Buttrick]

Rod,

The lower CA for pin drive from FFR is not adjustable. It position the wheel/tire only dependent on backspace plus hub adapter. When I purchased my pin drive wheels from Vintage Wheels there was only one choice and I need to dig out the receipt to see what backspace I have as now I see they have many more options. I'm running SN95 spindles as well which throws another variable into the equation. Don't know about 99 spindles. Again, whatever upper CA configuration you have,it makes no difference so long as you have proper caster/camber ranges available. This is what I have now:

http://www.ffcars.com/photopost/data/500/2014-08-12_20_06_04.jpg

[rlampman]

Todd, thanks for the picture. That really clarifies it. I agree about the length of the LCA being the main factor. From what I understand the '99 spindles are 8mm wider than the 94/95 spindles and they have a strait arm for the tie rod. I have a set of '95's that I can use but even with installing them I am about an inch out from where your wheels are. That is assuming the FFR pin drive backspace of 3.5". Really would be curious what your backspace is if not to much trouble to look up or measure when you have the wheel off. I can't believe that is what FFR expected.

Wondering if you go back to the SAI frame bracket if you can extend the inner tie rods more to make up or is the position of the outer the problem. Maybe the newer SN95 spindles, '96 and up, with the strait arm would put the outer tie rod in a better spot. This is one of the reasons I was trying to keep the '99 spindles. Then I could change to the '95's with a spacer if needed for bump steer.
Rod

[Todd Buttrick]

Rod,

I've confirmed that the only offer Vintage Wheels had at the time in 5 pin was 3.5" front and back so that's what your seeing in my above pic.

When I moved the upper CA back to it's original frame location, I effectively lengthened the rack. Now the upper CA, lower CA and tie rod inner pivot points are in the same plane and bump steer actually got worse. That's a head scratcher. Increasing caster to raise the stearing arm end had very little effect on bump steer. I think I'm going back to the SAI adapter plate and remove the extenders on my rack (which means new tie rods) :mad:

[rlampman]

Todd, thanks for your backspace measurement. That is what I expected and confirms to me that my wheels are about 1"+/- outboard than they should be for pin drive width. The spindles only account for part. I am out of town for a week so when I get back I will measure the width of my body in the front. I got a measurement of 67 1/8" wide from wheel lip the wheel lip. Not sure if that's right yet. Still wondering what I am missing.

I am thinking of modifying my frame to make the inner holes for the LCA's like the MK3's have. That should bring my wheels in to where I want them. Can someone measure a MK3 and tell me where the inner holes are in relation to the outer. 3/4" inboard and same height as the outer hole?
Rod

[skullandbones]

On my MKIII, the outboard hole and inboard hole center to center is 1 inch. It is 3/4 inch from the center of the inboard hole to the inside edge of bracket (level horizon). The holes are not level with the ground. I would say the inboard hole is about 2 o'clock to the outboard one. This will be a case of indirect measurements to get to the solution. Of course, there are no square reference points so it is a little tedious. Also, I'm not sure if the brackets are exactly the same between MKs. I remember reading that one of the forum members is planning on moving his pickup point on the LCAs as well. I thought it was David Borden or maybe Bill Lomack (chotis bill). I don't know how much you can move the hole but if you could go inboard and down a bit, it would probably be good. You would have to check on the frame clearance to go down any. Hope you are able to get all the needed changes for your wheels. Good luck, WEK.

[rlampman]

WEK, Thanks for the measurements. I thought it looked like the inner hole was higher. The MKII rear UCA mount hole is centered on the bracket and I think I will have to add something to make an inner hole. I think the front mounts will just need drilling but my sway bar mount (VPM) will have to be relocated as well. I'm wondering, if I have the clearance from the frame, if it is better to leave the hole at the same height to keep the geometry of the suspension or move it up?

I will probably follow what you did on the UCA as well and mount it with a wedge on the bottom of the frame mount. This will help with the bottom of the shock moving in with the LCA.
Rod

[Todd Buttrick]

Rod,

Sorry, but I just realized this was I different thread than the one I had started. Didn't intend to hijack.

[rlampman]

No problems Todd. It's all good conversation :cool:
Rod

[skullandbones]

Rod,

Here are the pics of the MKIII front LCA bracket. The rear bracket looks identical to the front. Hope that helps. As of now, I won't be doing any other movement of the LCA position but in the future when I've learned a little more about how this front suspension is working for me and I'm able to get more accurate measures on the roll center and other parameters, it could be something to look at.

Good luck,

WEK.:cool::cool:

[Jim Schenck]

Rod,

The pin-drive front lowers are 1-5/8 inch shorter than the standard lowers so if you subtract that number from the backspace (5.0 in. on an 8 in. wheel) you would get 3-3/8 which leaves a little extra for the adapter. Also you have the older pin-drive IFS brackets which really are only designed for Fox spindles, the new ones have two sets of holes and fit the SN95 spindles as well. (94-95 are the best of the sn-95 for width and bump steer)

[rlampman]

Jim,
Thanks for the input. That is what I understood and was my plan. Not sure if you saw but I already have pin drive LCA's installed. From what I measure the standard 8" wheel with 5" back space fits just under the fender. If I install a 7.5" wheel with a 3.5" back space (would be 3 1/8" BS after installing the adapter) the outside of the wheel would move out 1 3/8" and be outside the fender. Changing to the 94/95 spindle would help (8mm or 5/16") but not enough. As for the spindle adapter, I have the pin drive spindle adapter and I thought there was only one. I know the new standard width spindle adapter has 4 holes for different spindles. Either way the camber is set so that may change something with the geometry but wouldn't change the outside position of the wheel. I am planning to change to the SAI adapter.

Am I following what you suggested correctly or am I still missing something? I know something is not be right.
Rod

[rlampman]

I have re verified the length of the lower control arms and they are 13". Defiantly pin drive length. I measured my body width and that may be part of my issue. Mine is 66 1/2" wide at the front fender lips. I have seen 67 1/8" referenced many times for a MK4 and Bill thinks that is what his MKI is so looks like my body is 5/8" narrower than a FFR body.
So...
5/16" each side for body width
5/16" per side (8mm) if I went to 94/95 spindles
I have another 1/2" I could move standard 8" wheels w 5" BS out
Total of 1 1/8". About what I thought I was missing

So little by little this is what I have lost... Now to decide if welding new brackets for the LCA's to move in like the MK3 is worth the deep dish rims...
Rod