Suspension decisions are killing me...

ok for what you want keep the stock front suspension but make some changes to it. my recommendations will be conservative, but will fit what i think you are looking for.

1: since the engine you are building is going to be 351w based, use a 1 1/8" front sway bar, and a 3/4" rear bar. this is a balanced settup for sway bars, and wont be tail happy in the corners. you will get enough of that with the power you are going to make

2: use a 540 or 620lb spring rate in front depending on whether you use aluminum heads or not(lighter springs with aluminum heads). if you think the 620 are going to be a bit harsh in ride, then use the 540lb springs as they will do just fine. in the rear use a 5 leaf leaf spring, i prefer the standard eye design, preferably with a military wrap in your case(the second leaf wraps around the front spring bushing as well as the main leaf). ride height is up to you, but dont go too low.

3: lower the upper control arm pivot point like shelby did. in the case of your stang 1" straight down.

4: reinforce the upper and lower arms according to opentracker's design specs. you might get a set of his modified upper arms and bolt them in.

5: use a set of roller spring perches like opentracker sells.

6: i recommend using a set of adjustable aftermarket strut rods that use a spherical bearing in place of the rubber bushings.

7: for wheels and tires i recommend using the 15x7 magnums like you plan, and wrap them in a good set of 225/60r-15's on all four corners. yes this is a convervative tire combo, but they fit well, and with the right tire they handle well also. i like kuhmo's personally, but use your favorite brand. this size is also easy to find when making long road trips if they are needed.

8: i would use 4 wheel disc brakes, but you can also use big rear drums. cobra automotive has a kit that puts 11x2 1/4" drum brakes on the rear.

9: something people dont consider when building a car that handles well, gearing. since this is a street car, and since that motor you plan will make a bunch of torque, you dont need a steep rear gear. i recommend using a 3.00 rear gear. it will keep your rpm down on the open road, and it will help prevent you from spinning the tires everytime you stand on the gas.

10: if you want a rack and pinion steering system, go for a good one. otherwise a new flaming river steering box with the 16:1 ratio will work real nice, and be less than 1/3 the price.

actually since the 69 is a heavier car than the earlier models and the 351 adds even more weight to the front i'd use at least a 620 spring, i'm running a 750 with 1" bar and KYB gas-a-just shocks, also for the back i have 5 leaf mid-eye springs and kyb GR-2 shocks can't say yet what the back rides like as i don't the rear stuff installed at the moment but i've been running the front combo for almost 20 years now and it's great. i also recommend the opentracker roller spring perches www.opentrackerracingproducts.com for a street car the reinforced control arms aren't necessary but it won't hurt to have extra strength. i also recommend a better strut rod but i don't really like heim joints for street use i'm looking at the new design TCP strut rods personally.

for the rest of the suspension i pretty much agree with Rbohm. either a 1 1/8" or 1" front sway bar and 3/4" rear bar. i highly recommend the rack and pinion kit from www.randallsrack.com i plan on running that unit when i get the cash. i've been researching the options and randalls has the best system for the least amount of money. stay away from the flaming river rack and pinion kit it's bad news. the flaming river original style gear box is fine if you don't want to do the rack and pinion however. 15x7 magnums are a good choice but i would use a 235/60-15 tire so it won't mess with your speedo if using a stock gear ratio plus it gives a slightly better ride and is a little bit wider. but the great thing about the 69/70 cars is that you can run a 15x8 front and rear and can run as wide as a 295/50-15 in the rear.

rbohm said:

2: in the rear use a 5 leaf leaf spring, i prefer the standard eye design, preferably with a military wrap in your case(the second leaf wraps around the front spring bushing as well as the main leaf). ride height is up to you, but dont go too low.

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I found the 5 leaf springs (standard eye) to be quite harsh. I ended up removing the second leaf and now my car is much more passenger friendly. I really don't see much difference in the handling on the street.

dennis112 said:

I found the 5 leaf springs (standard eye) to be quite harsh. I ended up removing the second leaf and now my car is much more passenger friendly. I really don't see much difference in the handling on the street.

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again, the 69 is a much heavier car so the 5 leaf probably isn't anywhere near as harsh.

Brad...

Just go with a modified stock setup... what stance are you lookin for?

Tim
<---8mpg on dfwstangs

STANGGT40 said:

i'm just wanting a nice lowered stance for the most part. i want to be able to run a larger wheel...maybe an 18" mag 500... i'd like the thing to drive like a newer vehicle when i'm done...i just don't know one single thing about suspensions. you want to take on a restoration project?

brad

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Id offer to help you out if I wasnt so busy with all the cars I have over here... There is seriously a line of cars.

For your suspension.. Id so something like a mid eye or reverse eye 4 1/2 leaf in the back and some progressive rate springs in the front. Get some roller leaf spring perches and if you want to go all the way, the upper and lower control arms would be a nice addition. KYB shocks are hard to beat, especially for the price. The shelby upper control arm mod would be good too.

Tim

All of the above is good advice I will add my .02cents, do your homework. The stock suspension is pretty good but it can be improved upon by using the rollerized “Opentracker “type components. I for one do not like the MII stuff it does not perform any better than a well built stock suspension and has many potential problems weld failure being the most dangerous. I like the global west arms but they are pricey but if you are replacing the stock with after market, it is a nice upgrade. I do not like the TCP for the fact they are to adjustable, this is a streetcar not a racecar and that adjustability can get you in trouble. On the other hand, I do like the TCP rack and pinion steering. I like the progressive springs for the front as they take some of the harsh ness out of the heavy springs but under load, they perform almost as well as the heavy jarring springs. On the rear, I like 4.5 leaf mid eyes. I for one plan on keeping the drums on the back for a while they will perform well disk are better but drums will get the job done and free up money to do other things. Disk on the front is a must and should be one of the first upgrades it is a safety issue. In addition, as mentioned above get an adjustable strut rod they are worth the money IMHO.

uh you have ifs stock non ifs would mean you have a solid axle up front.

what rbohm and others have said

roller spring perches, shelby drop, subframes, TCP or Randall's rack, but here's where I differ:

-Get an IRS. You mentioned that money was not as much of a concern has having a great-riding street car. IRS will smooth things out in the back. The Heidt's is a great-looking unit (I love the trick Jaguar-style inboard brakes, and that decreases unsprung weight) and it supposedly rides very well. An IRS will perform great on rough roads, solid axle better in drag racing and on a smooth track, but for street, the IRS will be comfy and predictable on bumps.

http://www.mustangdepot.com/OnLineCatalog/Suspension/heidts-irs.htm

This will require a little bit of fabricating, but any decent resto/hot rod shop should be able to do it.
I went a little more spendy on the front suspension (Unique Performance TCP copy coilovers) but am going cheaper and more track-worthy with a 3-link rear suspension. Pro-touring style, I guess.
Good luck and keep us posted!

70vert said:

roller spring perches, shelby drop, subframes, TCP or Randall's rack, but here's where I differ:

-Get an IRS. You mentioned that money was not as much of a concern has having a great-riding street car. IRS will smooth things out in the back. The Heidt's is a great-looking unit (I love the trick Jaguar-style inboard brakes, and that decreases unsprung weight) and it supposedly rides very well. An IRS will perform great on rough roads, solid axle better in drag racing and on a smooth track, but for street, the IRS will be comfy and predictable on bumps.

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Also, be realistic with your end objective. These are ancient platforms that were never rigid when they were new, let alone after 40 years of flexing and spot weld popping. You can make up for some of this with full seam welding, subframe connectors, and an export brace. But even with roller and heim-jointed everything in the front and IRS in the rear, you will easily notice cowl shake and frame flexing. It might corner flat and stick like glue, but it won’t feel like a modern car doing it. Modern cars are very, very good in the noise, vibration, harshness department, and the torsional rigidity of even a bottom-feeding Kia would likely embarrass us all. This all translates to the “modern feel”.

This is not to say “don’t bother”, and it didn’t stop me either. I run a TCP rack, roller perches, heim strut rods, Shelby drop, lowered 620s and nice Bilstein shocks, Baer tracker bumpsteer kit, and 1’ sway bar in front, with Maier leafs w/ poly bushings and Bilsteins out back, too. But you can’t hide that chassis; in fact, it becomes even more noticeable once all the slop is removed from the stock crap and the driver-feedback is improved from the new components.

Great post!

.

will agree that if money is no object, then go with the IRS, or a good 3 link rear. On the wheels, 18's are the biggest I'd do just because any bigger and theres not enough sidewall to give a nice ride on a street car, just my opinion of course, but I like the 17" for a magnum 500, heres a picture of mine just to give you and idea. This is on a 69 fastback.

gsxrken makes a good point. the stock mustang chassis is rather flexable, and a good set of subframe connectors will make a difference, along with an export brace and monte carlo bar. but those really dont go far enough if you want a really stiff chassis, but dont want a 10 point roll cage. start with the subframe connectors, add stringers that connect to the rocker panels, as well as a pair of bars to triangulate the stringer(much like kenny brown does with his extreme matrix brace for the fox body mustangs does), and add a center cage much like tcp made. this will really stiffen up the chassis, and make ALL other suspension mods extremely effective. in fact you may find that the 540lb springs might be too harsh for a daily driver when the chassis is properly stiffened up. that is because the chassis doesnt flex to absorb some of the spring rate.

the areas to really concentrate on are the chassis stiffening, and the rear suspension as these are the places where you are going to get the most results with the least overall effort and money invested. the front suspension does prety well even in stock form.

STANGGT40 said:

i meant to say "aftermarket" before the ifs part...i guess that i wasn't paying attention to what i was typing...

brad



tim, just make me a shopping list, and that's what i'll get! (you've pretty much done that already! lol) i want to get this thing started, but it seems like this is where i'm stuck...i just want to get it behind me so i can get some other stuff done. i also need to swap to discs in the rear and larger discs in the front...it already has front discs by the way. if you know of a good kit, post that too! i want to get all of my parts together, then send it off to get stripped down and painted. know any good paint shops?

brad

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Brad..I will try and get a list of parts I recommend and some places to buy them. As for paint..I know a couple places...but its going to depend on how much money you want to spend, how much work you want to do and how much time you are willing to give up the car for.

As for disc... SSBC makes a great 13" brake setup but its EXPENSIVE. I really suggest going with MustangSteve's cobra 13" setup. He had a complete kit for $750 or so but I think hes out of calipers and rotors (you can find them on ebay and stuff). Im all about helping the enthusiest instead of a huge corporation. MustangSteve started makin some cool stuff.

For the rears, you can do the Ultrastang conversion kit using MarkVII stuff or get something like a wilwood setup or SSBC. You can save a lot of money by scavanging parts instead of buying a whole kit.

Tim

Resurrecting an older thread.. but did you ever build the new suspension? How did it turn out??

I'm curious too... also wondering, does the mustang steve kit work on the shelby drop spindles? if not, what are the options for a lower stance with his kit?

Booksix said:

I'm curious too... also wondering, does the mustang steve kit work on the shelby drop spindles? if not, what are the options for a lower stance with his kit?

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shelby drop spindles? what? there is a "shelby drop" but it involves drilling new mounting points in the "frame" of the car and lowering the upper control arm an inch. has absolutely nothing to do with the spindles and anyone can do it. there is a guy that goes by Degins here on the forum that owns www;discbrakeswap.com that is working on a dropped spindle that will lower the car by about 1.5" but those aren't quite ready yet but once they do become available they will work with any of the aftermarket disc brake kits that use the stock drum brake spindle.