lowering 1 inch

[1968shelbygt350h]

hey guys I am running the correct repro speedway 15 inch tires none radials what a mistake any I want to drop the nose on the car at least 1 inch and I was talking to John at opentracker and he suggest I cut a 1/2 a turn of the front spring and dont even bother with a shelby drop since it wont really lower the car down by much I am thinking of putting these tires away since I want to drive the car and get some goodyears eagles also John sent me some new roller perches which are way nicer and closer looking to originals I just want to enjoy the car since I restore midyear and straight axle vettes its hard to drive the shelby any advice appreciated

[JD]

I did the "Shelby drop" on the '67 Shelby I had and it did lower the front and dramatically changed the handling. 

Also, the front end settings to more aggressive spec's helps too.

If you do decide to cut the springs, suggest not cutting your originals (if you have them) and cut repro's or buy after-market lowering springs.

[shelbydoug]

I've done it both ways and to two relocation dimensions, 1" and 1-1/2".

First off, what the lowered upper arms does is keep the tire tread closer to flat when the car leans into the turns.
Normally what will happen with the stock location is that the tire would lean out on top, putting the tire on the outward edge of the treads.

Optimum lowering was debated but is somewhere around 1.75".


The Shelby drop of one inch was done simply for one reason. It uses the stock ball joint without any modifications.
To go more then 1 inch, you need a wedge shaped spacer under the ball joint to prevent the stud from bottoming against the slot in it's hardened metal cover.

I use the wedge spacer. 1-1/2" drop works well.


Second. Springs. The "Shelby" drop was originally done with the stock Mustang HP springs without cutting them. Also, be aware that there are two "Shelby" patterns. A late and an early.
It DOES lower the front of the car not exactly at 1" but somewhere around there.


The springs that I am using are the ones recommended in the Boss302 chassis modification booklet. They are originally sourced from a Ford truck and in order to get them to 680lbs/inch of compression, you need to cut them. That means hacking off around one full coil.

Now initially I did that and it made the car WAY too low in the front. You couldn't make a fist and slip it under the front radiator support. For a Trans Am car, using the Bud Moore oil pan with the built in skid plate, that's probably ok?

What I did was take a 1" Mr.Gasket doughnut rubber coil spring spacer and install that to shim up the spring .

This combination gives me adequate fender to tire clearance with a BFG 235-60-15 on a 15" 10 spoke wheel.

Here's a picture.


Now in all honesty, Jim Cowles was the only one to notice the car being lower in the front and that was only because it was at a SAAC car show with all the other 68s lined up against it.

I missed my opportunity to measure the difference that day but it seems to be about 2-1/2" lower at the header panel in front then stock.

My recommendation would be to go my route. It's will save you a lot of unnecessary work and disappointing discoveries and put the car just about where you want it to be both in looks and performance. Granted I'm prejudiced about my own work and solutions but let me just say I've been doing this stuff since I got the car in 1972 so there were a lot of dead ends I had to run down on my own since no one would readily share information back then?


Let me just add one more thing, the combination of this lowering combination AND the radial tires IMPROVES the ride quality of the car DRAMATICALLY! OH, almost forgot, you need to do a "bump steer kit" with this otherwise the bump steer can be SO BAD, the car will change lanes just hitting seams in the pavement. Sometimes, it will want to do a 45 degree turn into the guard rail...all by itself without even moving the steering wheel.

OH yea! It hated the Merit Parkway in CT most of all!

[98SVT - was 06GT]

If it's going to be a street car or show queen just do the springs. If you are going to do some track days go for the Arneg drop you can go 1 1/8 without having ball joint problems. For a serious track toy I'd go 1 1/2+ and use the wedge or go all out and cut/reweld the A arm to change the seat angle. One thing to remember is you are talking of drilling holes in what has become a valuable collector car. For myself it's my toy and I'll do what I want to it. If you are looking at resale at some point it may detract from the price since it's not the day 1 original that everybody seems to want today.

[Bob Gaines]

If it's going to be a street car or show queen just do the springs. If you are going to do some track days go for the Arneg drop you can go 1 1/8 without having ball joint problems. For a serious track toy I'd go 1 1/2+ and use the wedge or go all out and cut/reweld the A arm to change the seat angle. One thing to remember is you are talking of drilling holes in what has become a valuable collector car. For myself it's my toy and I'll do what I want to it. If you are looking at resale at some point it may detract from the price since it's not the day 1 original that everybody seems to want today.

+1 on just the springs given the mentioned usage. It s easier to put back stock that way also. Considering that when it is time to change care takers originality is typically the #1 consideration for buyers. Also consider using a pair of donor or after market springs as the coil springs (wire size and spring rate)are unique to the competition suspension/handling  option on the Shelby.   

[shelbydoug]

If it's going to be a street car or show queen just do the springs. If you are going to do some track days go for the Arneg drop you can go 1 1/8 without having ball joint problems. For a serious track toy I'd go 1 1/2+ and use the wedge or go all out and cut/reweld the A arm to change the seat angle. One thing to remember is you are talking of drilling holes in what has become a valuable collector car. For myself it's my toy and I'll do what I want to it. If you are looking at resale at some point it may detract from the price since it's not the day 1 original that everybody seems to want today.

+1 on just the springs given the mentioned usage. It s easier to put back stock that way also. Considering that when it is time to change care takers originality is typically the #1 consideration for buyers. Also consider using a pair of donor or after market springs as the coil springs (wire size and spring rate)are unique to the competition suspension/handling  option on the Shelby.

If you are an investor, then yes, originallity is important.

I've had this car since 1972. Even in 1980, if you said $5,000 for it, people would laugh and walk away.

I can tell you that you may think that you are King S hit zooming along in your original car but the first time that you get blown away by Mad Max you will either dump the car and buy something else or start thinking about making what used to be known as a "sleeper".

If you wanna' talk the talk, you gotta' be able to walk the walk. Yes it is satifying and you'll be able to tell your grandkids how you would scare the crap out of yourself every time. But that's up to you.

All of these cars have histories unique to themselves. If you want a virgin, well...why? 
By the same token what's the point of having the Playmate of the year and just looking at her? To me the answer is obvious. Have one of each!

[jk66gt350]

When I bought my 66 GT 350 35 years ago, it had spring clamps on the front springs that compressed two of the coils together.  Seemed to work the same as cutting part of the spring off to lower the front, but was obviously reversible.  When I restored the car after purchasing it, I took the spring clamps off and the springs went back to their previous / original height. 

[Bob Gaines]

If it's going to be a street car or show queen just do the springs. If you are going to do some track days go for the Arneg drop you can go 1 1/8 without having ball joint problems. For a serious track toy I'd go 1 1/2+ and use the wedge or go all out and cut/reweld the A arm to change the seat angle. One thing to remember is you are talking of drilling holes in what has become a valuable collector car. For myself it's my toy and I'll do what I want to it. If you are looking at resale at some point it may detract from the price since it's not the day 1 original that everybody seems to want today.

+1 on just the springs given the mentioned usage. It s easier to put back stock that way also. Considering that when it is time to change care takers originality is typically the #1 consideration for buyers. Also consider using a pair of donor or after market springs as the coil springs (wire size and spring rate)are unique to the competition suspension/handling  option on the Shelby.

If you are an investor, then yes, originallity is important.

I've had this car since 1972. Even in 1980, if you said $5,000 for it, people would laugh and walk away.

I can tell you that you may think that you are King S hit zooming along in your original car but the first time that you get blown away by Mad Max you will either dump the car and buy something else or start thinking about making what used to be known as a "sleeper".

If you wanna' talk the talk, you gotta' be able to walk the walk. Yes it is satifying and you'll be able to tell your grandkids how you would scare the crap out of yourself every time. But that's up to you.

All of these cars have histories unique to themselves. If you want a virgin, well...why? 
By the same token what's the point of having the Playmate of the year and just looking at her? To me the answer is obvious. Have one of each!

Since you quoted me then you may be under a misconception. My post was not meant to cover the entire spectrum of usage . I guess you missed the part where I said given the mentioned usage (street car or show queen).

[shelbydoug]

No, I didn't miss it.

It was intended to be an "in addition" add on to your post, not a criticism of your view.

[calspcl]

Interesting, I am running the same size tires with 10 spokes and am having issues with the stainless fender trim getting caught by the tire during hard cornering and bending it.

I bought the arning drop template, but, have not moved forward with it since my tires catch the trim. I am considering a smaller/narrower tire in front, thinking this will stop the issue.

Should I try a tire size narrower or tire size with less sidewall. Suggestions appreciated based on your experienc. Although I am thinking not all 10 spokes have the same back spacing which could be another issue...

[calspcl]

I will measure the  back spacing tomorrow...

[shelbydoug]

Look at the caster. If you go more then 2 degrees +, the tires have more opportunity to catch the FRONT of the fender arch, BUT remember, stock a-arm mounting leans the tire out more on top.

The lowering changes the arch of the tire IN TURNING and you need a better spring then stock to reduce the body roll.

There have been a few "chassis tuners" that recommend different castor settings on the left then the right. I never fooled with that and really is a NASCAR "trick" to encourage the car to turn to the left of right more easily under load.

Maybe something that Bud Moore would do but too specific for me.



As far as exactly what to do on your car, every car is a little different. No two are EXACTLY the same.


Ten Spokes. There are three original ten spokes. Two have the S7MS id cast into the back of one of the spokes. The earliest version does not. I have all three.

The first "67" version does not have a spacer needed to clear the disc brake calipers. The last version intended to clear the '68 calipers does have a spacer cast into the back of the mounting flange.

IF you can find just a pair for the front WITHOUT the cast in spacer, those are the ones you want to work with.



Front wheel moldings. There is a void in the original '68 wheel well opening moldings that is intended to fit over the part of the fender that has it's lip rolled.

I found that sometimes it is the sheet metal screw that isn't seated  deep enough. You may need to leave the screw at 10 o'clock on the driver side off as well as the corresponding one on the driver side.


I posted those pictures for a reason. You can see the clearance on the tire.

Maybe the answer is that you can't go in half way to make it work?



Lowering. Not only do I have the A-arms lowered, but in addition I have the "Big Ford" "Trans Am" brake calipers and rotors and '69 big spindles. It all works like a charm but you need to get the "orchestra" to all play together in unison AND NOT FIGHT EACH OTHER. 


I went past the Arnig design. I used one done by Pro Stock Engineering in Utah that goes to 1.5". It changes what is essential a wild and crude "buckboard" into a smooth engineered machine.

[2112]

Something else that is now available is Progressive rate springs.

https://opentrackerracing.com/product/progressive-rate-small-block-coil-springs-1967-1973-mustang/

Description
These springs allow your Classic Mustang to take advantage of the latest suspension technology and perform more like a modern sports car. They really do give you the best of both worlds. A fairly stock smooth ride during normal driving, but as the springs compress under load (primarily during braking and cornering) they progressively become firmer very quickly to offer the handling characteristics similar to our 600 pound performance springs, but without sacrificing ride comfort. Made in the USA by a premier OEM supplier (for strictly race car applications we still recommend our Performance Springs). Our Progressive Rate Coil Springs feature: Hot wind from SAE5160H, oil quench, temper, water quench, shot peen, preset, 100% load test, ground flat and black powder coating.

I am not affiliated with this vendor, just a customer