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Want to build a corner carver

25K views 89 replies 18 participants last post by  Jsams 
#1 ·
Hey VMF, first post here but not new to Mustangs. I've got a 66 coupe, 4 speed manual with a 289 that I've owned for 10 years and would like to improve the chassis. Not pertinent to old Mustangs but I also own a 04 GT with a full Griggs Racing chassis. I've been doing research for quite some time and would like some opinions for the 66.

Not sure if I should go full blown modern chassis on it or do a mix of old school with a modern twist. First off I snagged a set of Global West uppers to do a Shleby drop, they were used so I don't have a template. I understand there is a one inch or a 1.75 drop, any opinions on which would be better? I've been exercising the idea of rack and pinion or doing a FR quick ratio box and rebuilding the factory stuff. I love how quick and easy steering is on any new car, I don't mind the effort of manual steering but if I decide to auto x or do driving events I want quick responsiveness. I'm open for any set ups or experience you guys have!

Thanks!
 
#2 ·
Don't do any drilling for the Shelby drop until you get a template. The new holes are not directly downward.
Global West has a website. Get ahold of them. I'm sure they will get you a template somehow.
 
#6 ·
Neither of those is the right drop template for Global West upper arms.
The drop on their arms currently is 1.5" ....... the reason I say currently is
because that number has changed at least once since 1984.
I'm traveling this week, so your best bet is to call them and see if you
can score one that way.

I really don't care for the R&P kits that are out. Too much compromise.
The only good one's I've seen are all custom rack setups.

ex-Global West GM
1991-1995
 
#8 ·
I was digging around my parts pile and realized I have the templates and some hardwear. I installed some new ball joints in my used GW arms and got one side installed already. I called GW just for grins and they said their drop is 1 3/8 apparently.

As far as steering goes Im not sure what to do. Quick ratio boxes run in 500 or 600 range plus other items I'll service while Im in there like tie rods or what ever. Not sure if I should also run a Shelby pitman arm or is that only for use with stock steering? Flaming River makes a steering rack/tilt steering combo for 1200. Thats tempting considering I'd like a tilt column and a new box would be 50 percent of the cost of a RP set up. Im sure with either set up I'll have to correct bump steer. Another consideration, IIRC, steering effort is heavily related to scrub radius so rack and pinion or not I've got some more figuring out to do...
 
#9 ·
I was digging around my parts pile and realized I have the templates and some hardwear. I installed some new ball joints in my used GW arms and got one side installed already. I called GW just for grins and they said their drop is 1 3/8 apparently.
That's just today (and depending upon who you talk to there), tomorrow maybe
different ;)
I have both 1 3/8" steel and 1 1/2" blue plexiglass in my tool box.

ex-Global West GM
1991-1995
 
#10 ·
Well, I ripped the pony around and seems to be better, I didn't have time to align it tonight so I'll do it tomorrow. Not sure what I think yet, I know it's an improvement but its hard to tell. Steering is sloppy and I'm sure there is zero caster because I lost all my self centering on the steering. I'm almost certain I have way to much negative camber also. I'd like to get adjustable strut rods from GW but I'm running 16x8 wheels with a 225 tire, IIRC it's a 55 side wall, but they rub like crazy. So if I add more caster through strut rods it will just get worse.
 
#14 · (Edited)
I'm running 16x8 wheels with a 225 tire, IIRC it's a 55 side wall, but they rub like crazy. So if I add more caster through strut rods it will just get worse.
You are fighting yourself.

16x8 wheels, to fit on a mustang have 4.5 backspacing, which is limiting factor number 1 (aka with a larger rim you could move everything inward another .25 inch.

A 225 55 16 is 26 inches tall and your car's ride height is 24.5 so where other people can live the backspacing on the 16x8 you can't which is limited factor number 2

You need more - camber to keep the tires from rubbing plain and simple with how you have it configured at this point.
You also need the adjustable rods not necessarily for the caster (that is a benefit) but for the solid mount and lose the deflection of the bushing in your stock strut.

You then need to install your upper arms either according to the global west instructions (best) or at least in the shelby drop location and then you need to take it and get it aligned with -2.5 camber, as much caster as you want and 1/8 toe. If it rubs after that roll your fender lips. If it rubs after than, go to -3.
 
#12 ·
Need either measurement or photo of front ride height.

225 is not max'd, but rim offset may not be ideal

Yes, if you just did the "Shelby" drop you are prob camber heavy. Get the camber eccentric eliminators.

Wouldn't have thought the caster would have changed remarkably unless you moved the lower arm too. But yes caster can change the rotation axis. Where is it rubbing front/back fender:frame

Don't forget in the end to compensate for bump steer. You'll never be happy with the lowering until you do. Neither of these mod's are pricey and there are several good strut rod solutions. Do NOT run Poly on stock type as it just binds and doesn't fix problems.
 
#13 ·
I have no idea how much it's lowered, I know the center of the wheel from the ground to top of the wheel well is 24.5 inches. I know that means nothing with out a pic but its tucked. It rubs the front lower part of the fender. I really like GW bump steer kit but I'm not sure if I'm going to run RP or factory steering so I want to make sure it's compatible with any bump steer kit I get. I'd actually like to get new springs front and rear with Bilstiens or some other quality shock. I'm sure with bump steer and the terrible rebound control of my tired KYB's that doesn't help either.
 
#16 ·
I had it up on the alignment machine and I set the toe for now. The caster is .4 driver and .8 passenger and camber is -1.5 driver and -2.4 passenger. Before I start messing with specs I'm going to do strut rods and get a bump steer kit. The steering effort is a lot better and I adjusted the slop out of the steering box as well. I think the part that's hurting the overall performance the most is the terrible bump steer.
 
#17 ·
If you think it's ok now, you should see it with the right alignment numbers.
(yes, I know why you have it aligned the way it is right now)
You shouldn't need to set much more than one degree negative camber because
the camber change with those upper arms is negative. Likewise, the caster
needs to be about 3 or so degrees positive.

ex-Global West GM
1991-1995
 
#19 ·
I did a lot of perusing on corner carvers and on here looking for info on BS. My plan of attack is get caster around 3, camber around -1 or so then adjust BS. So far I've seen a huge improvement in over all traction and road holding but it's very unsettled. I think I'm going to try the Baer Tracker set up, I like the tune ability of it and its nice I don't have to drill the knuckle out, that way I can always start from zero with another kit if needed.

The suspension seems pretty straight forward as far as tuning but there is such conflicting info for steering set ups. I'll worry about one thing at a time but I'm trying to plan my mods accordingly.
 
#20 ·
That's an excellent plan of attack.

One of the cars I have is the second car they did back in 1985.
I ran it at open track events from 1994 to 2005 and truth be told, didn't
see a big issue with bump. We routinely fixed bump on lots of stuff too,
some of which could be documented with a tape measure at the start.

For jmn444- As far as caster and bumpsteer, you can't "adjust out" the
bump but you can make the car more liveable. BS has to be addressed
by alterations in the pitman/idler, draglink, etc.

ex-Global West GM
1991-1995
 
#22 ·
Shaun at SoT runs like 5 degrees of caster. have you tried that much?
 
#23 ·
With less than a degree of caster, the car will feel unsettled. Caster makes the car track straight down the road. More is usually better until you run into the tire catching the front lip of the fender and/or steering effort increasing too much. Really, crank it up!

Really, don't come to any conclusions about your setup until you re-set it to -1 deg camber and at least +3 to +4 caster.

Also, your side to side spread is pretty far. I try and target +/- .25 camber and +/- .5 caster side to side.

Believe it or not, but uneven camber can lead to the car pulling to one side all on it's own.
 
#27 ·
Looks like I have a ton of trial and error to do. On my 04 GT I run 7.5 caster and neg 1.8 camber. Believe it or not on 200 tread wear tires I get perfect wear on them with mostly city driving and a few driving events. I do rotate them every other oil change. The 66 is a complete different beast, I know what I want and how to do things but I have no idea what to do or what works on old Mustangs.

Do you guys have any suggestions for a rear set up? I'm quite fond of pan hard bars and watts links but I'm freaked out having two roll centers. As far as I know they aren't recommended when used with leafs but I have no personal experience with them on older cars.

GT289, when you refer to pitman and idler for BS have you successfully made adjustments by modifying those components? This is one reason why I'm considering a rack and pinion set up. But, who is to say the rack is at the proper height and location to improve BS and Ackerman. I suppose a RP set up seems appealing because it looks like a simple set up but it might be a whole new can of worms.

Applejack I read some good info you wrote on another web site about BS, very interesting, I think it was on corner carvers...?
 
#29 ·
GT289, when you refer to pitman and idler for BS have you successfully made adjustments by modifying those components? This is one reason why I'm considering a rack and pinion set up. But, who is to say the rack is at the proper height and location to improve BS and Ackerman. I suppose a RP set up seems appealing because it looks like a simple set up but it might be a whole new can of worms.
A long time ago we bumped Rocco Gioffre's '65 in that manner. It was in CC mag's
Real Street Eliminator. That was the very last car I touched at Global as far as BS.
He had all the GW stuff and 70 or 71 drum spindles supporting a B302 T/A front
disc setup......and pretty significant BS. We slotted the idler arm bracket for
easy adjustment, built a custom pitman by sectioning, reinforcing and welding.
When we got all the numbers right, we welded up the slots in the idler bracket and
called it a day. It was a zero bump setup when we finished.

Rocco Gioffre: Los Angeles, CA | Flickr - Photo Sharing!

Most of the RP kits are compromises. Reduced turning circle, etc. The only one
I saw that was an excellent setup was Danny Bahn's (DB Performance), but it's
definitely not a DIY kit.

ex-Global West GM
1991-1995
 
#28 · (Edited)
Yeah, there is some old data out there that I measured in '05 in this thread:

It really comes down to just putting on the Bear tracker, setting the heim as low as you can and starting there. Lower than their design would allow would be better, especially if/when you switch to the '70 drum spindle for the stronger pin/bearings.

Then again, I use the Pro-Motorspoorts kit because I liked the quicker steering it offers, but I have a slower than stock steering box.

It's all about tradeoffs.

I had Maier leafs and a Maier panhard with Bilsteins. It worked great for what it was. I really think the theoretical discussion about competing roll centers is a bit overblown in it's seat of the pants impact. I never had problems with it. One trick to make it work is to put in a stiff front bushing and really soft stock shackle bushings. That way, if the panhard wants to control the position of the axle, it can push the shackles around, but you still have a nice fixed trailing arm condition with the poly front bushing. Maier had the front bushings iirc.

Personally, all of that is off the car and I'm in the middle of upgrading to the Street or Track 3-link, but I was also involved in developing and tuning it.

Being able to set individual ride height and have an easy to adjust rear roll center has proven really valuable in the two ESP cars ('99 Camaro and '12 Boss 302) that I autocrossed and trophied with, so I'm excited to get my old polished turd of a '65 to the same level of adjustment.
 
#30 ·
The street or track stuff looks legit. I'll be honest I cruised around the web site and I'm really digging it. Not in good or bay way but it reminds me a lot of Griggs stuff in how thoughtful the fabrication is, it looks very functional, down to business and it looks engineered in a positive way of making changes. I hate always referencing GR but I've spent a lot of time on the phone with them and I like his mind set of keeping it simple, functional and no holds barred for performance. With that being said their GR350 chassis for old school cars is REALLY expensive. ST looks pricey but from what I've seen it a lot cheaper then GR. Maier racing is nice as well, I know he always slaughters the Good Guys AutoX every time it's in town and he's a nice resource to have 45 minutes north of me. Some times I feel he's a little pricey for keeping it so old school but I can't argue with the reputation and performance so I digress. From what I know about cars as a hobby and profession I find GW really appealing for quality, price and performance but when it comes down to it I've owned my 66 for 11 years and have no real world experience tuning the chassis.

Do people change to a newer front spindle only for strength or is there advantages in geometric angles or brake kits?

Not sure if this it true or not but logic would tell me if I stick with a modified "stock" steering set up I'll have less issues with headers and clutch linkage clearances as well.

I also have a feeling I'll soon be regretting having my 16x8 Torque Thrusters...

Lastly is there a common or general tire size you guys run? Staggered set up or same all around?
 
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