Shelby drop

[Grabber70Mach 107]

My next project on my 70 mustang is to lower the car, and improve the Suspension and handling of my car. It's just a weekend driver street car, but if I can get it to handle better I would like to take it to a few track days as we'll.

 

I'm not going to get super crazy and buy coilovers or a expensive 3 link rear end, but I would like to get the most I can out of a basic coil spring in the front and leaf in back. I'm also looking for a good amount of drop. 2 1/2-3 in front and 2-2 1/2 out back. So far I bought grab a track 620's with a 1 inch drop for the front and was thinking of doing the negative wedge kit as we'll. and do a reverse eye 4-5 leaf out back, maybe a 1 inch block as we'll. I'm also thinking about changing the front sway bar out to one of the mustang plus bigger sway bars and adding a rear sway bar.

 

Who make the best negative wedge kit? Or should I stick with the 1 Shelby drip? Anything else that anyone suggest I do to the suspension?

 

Any info or suggestion will be appreciated.

 

I would call John or Sherri at Opentracker racing products. Great people to deal with that know there stuff.

[podiver 10]

Thanks for all the information you presented. Didn't mean to start a war, but the technical info was really educational. I don't profess to be a math wizard, but you taught me alot and gave me enough to put the drop in my car. I am planning for street use (mostly). But I want to be comfortable pushing it through corners it was designed for a little faster and feeling I have control. No mountain passes. Maybe a little track.

[maxum96 32]

Contrary to what someone else was saying about bottoming out with .620 springs, I run them and I'm lowered about 3 inches front and rear. And I have no issues with bottoming out the front end. I use Global West Tubular upper control arms.

[970fizz 19]

Contrary to what someone else was saying about bottoming out with .620 springs, I run them and I'm lowered about 3 inches front and rear. And I have no issues with bottoming out the front end. I use Global West Tubular upper control arms.

 

Did you cut your 620's to get the extra 2" drop to make a total of 3"?

 

One of my ideas was to cut 1/2 coil on the 620's and do the Shelby 1"drop. I was thinking that may give me a total of 3" up front.

[barnett468 418]

.

hello 970fiz;

 

. . just to clarify my previous comment for you i did not say you would absolutely, positively, bottom out with 620 springs, and to the contrary, i actually said 620's would be fine for general cruising..

...if you drive half way aggressive you will likely bottom out with the 620 if you lower it that much but it would be ok for general cruising for sure....

 

shock damping has a huge affect on the ride and potential for bottoming . . if you have weak springs and shocks and your car bottoms, installing shocks with high compression damping will reduce the bottoming.

 

setting up a suspension PROPERLY is a matter of balancing the shock damping to the spring rate and intended use.

 

the most practical shocks to use for high perf apps or high spring rates are ones with individual damping adjustments, for comprression and rebound however, unfortunately, any quality shock with this feature is around $1,000.00 each. There is however dual adjustable shocks currently avail for around 800.00 for 4 i think are from china.

 

if someone claims they do not bottom with a particular spring, the info is not very helpful unless you know the type of driving they do and if they hit pot holes or dips at intersections with no problems AND you know exactly what shock they use and the setting they have it on if it is adjustable, and you know if they have a 302 engine with aluminum heads and intake and no ac, or a 428 engine with ac etc...

 

i have actually done hundreds of hours of suspension/shock telemetry testing for a major vehicle mfg on tracks and on an MTS machine, so i am fairly familiar with the affects of shock damping.

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Edited November 11, 2014 by barnett468

[barnett468 418]

Did you cut your 620's to get the extra 2" drop to make a total of 3"?

 

One of my ideas was to cut 1/2 coil on the 620's and do the Shelby 1"drop. I was thinking that may give me a total of 3" up front.

 

different springs from different mfg;s can vary slightly even if they are all the same rate . . also it depends on how heavy your car is . . a car with a 302 with aluminum heads and intake and no ac will need the same springs cut more than the same car with a 428 and ac so its best to install them as is first then cut a little at a time until you get there . . the springs will also settle a little so in my experience, it's best to set it around 5/8" higher than you want then get it aligned then drive it for a month.

.

Edited November 11, 2014 by barnett468

[1969_Mach1 333]

Hard to say if a stock upper control arm in the original location will hit the bump stops with 620 springs trimmed enough to lower the car 2-1/2" to 3". Without seeing it I would lean toward yes. Actually, a 620 cut that much with a stock suspension may not stay in the spring saddle when the suspension is fully extended. I guess a shorter shock could cure that. There is also the possibility of not being able to obtain the correct camber angle.

[970fizz 19]

My brother has a 67 coupe 289 with aluminum heads and intake, no ps, no ac with a 620 up front. We cut 3/4 of a coil out and it sits and rides great, but he does not drive the car aggressive. I may lean towards doing the same, but I would like to add the Shelby drop and just do 1/2 of a coil cut. Or maybe even the negative wedge kit.

[barnett468 418]

My brother has a 67 coupe 289 with aluminum heads and intake, no ps, no ac with a 620 up front. We cut 3/4 of a coil out and it sits and rides great, but he does not drive the car aggressive. I may lean towards doing the same, but I would like to add the Shelby drop and just do 1/2 of a coil cut. Or maybe even the negative wedge kit.

 

you may have thought of this but in case you haven't, i would consider a shelby/export brace and rallye bar.

 

roller spring perches are also nice but a bit pricey.

.

[maxum96 32]

Did you cut your 620's to get the extra 2" drop to make a total of 3"?

 

One of my ideas was to cut 1/2 coil on the 620's and do the Shelby 1"drop. I was thinking that may give me a total of 3" up front.

 

I cut a 1/4 turn out of both springs at a time. Then drive the car for a few miles and see how it sits. I think I ended up taking out about 1/2-3/4 turn. And cold cut the springs. No torches or plasma cutters. The heat screws up the temper of the springs. I cut mine with a die grinder.

Edited November 11, 2014 by maxum96

[970fizz 19]

I cut a 1/4 turn out of both springs at a time. Then drive the car for a few miles and see how it sits. I think I ended up taking out about 1/2-3/4 turn. And cold cut the springs. No torches or plasma cutters. The heat screws up the temper of the springs. I cut mine with a die grinder.

 

Good to know, I like the way your 70 look in the pic! I'll most likely have a

Spring shop cut my coils for me.

 

I'm from western Colorado, do you ever take your car to the steamboat show?

If so maybe I'll run into you some time.

[970fizz 19]

And thanks to everyone for the info,