lets talk suspension

[3-0-II]

Like alot of folks my Cobra II is a never ending project. I'm in the middle of an EFI 5.0 swap right now, but that doesnt stop me from daydreaming about the rest of the car.

I was sniffing around fleabay some and I always see things like tubular front suspension, coilover kits, things like that. I'm wondering... does anyone have any experience with this stuff?

I plan on eventually getting some of stumpy's SFCs and traction bars and I have a set of 425lb/in springs in the garage waiting to be put on.

I would love to make a corner carving beast out of this car. So what would you guys recommend? I saw some QA1 coilover kits on fleabay.. Would I be able to use stock A Arms? Or will I need tubulars. And if I DO need tubulars, which ones? there are so many options..

Also, what rebuild kit should I look into? My bushings are in terrible shape.

and if it matters the car was originally a V6 car. the only changes i've made mechanically are the V8/C4 swap

I'm sorry if this seems like a huge amount of things to ask. I just want to figure out and learn as much as possible. There are alot of wonderful windy roads that I love driving my 01 bullitt through. I want to get that same exhiliration out of driving the II when she's alive again

 

[Mstng2]

Do you have the full V8 Sway bars front and rear? If not those are a for sure need.
for a start I would recommend:

Stronger front springs
Sway Bars
SubFrame Connectors

 

[3-0-II]

I know I have sway bars front and rear, but I didnt know there was a difference between V6 and V8 cars..

i do have those stiffer springs that need putting on, but I was thinking, if I'm taking it all apart to do the springs and to replace all the bushings and ball joints with a rebuild kit, I might as well weight a little longer, save up a little more and go all out on the suspension

 

[Wart]

I know I have sway bars front and rear, but I didnt know there was a difference between V6 and V8 cars..

There is also a difference in front bars between IIs that came with and without rear sway bars.

I believe the front bar on my V6 Mach (factory rear bar) is the same diameter as the bar on my non rear bar V8, 7/8 or 1" diameter.

The front bar on a KC is 1 1/8", I believe, and KCs came with a rear bar. I believe the rear bars were the same diameter as my V6 Mach.

Hope this confuses you, I am.

 

[Wart]

i do have those stiffer springs that need putting on, but I was thinking, if I'm taking it all apart to do the springs and to replace all the bushings and ball joints with a rebuild kit, I might as well weight a little longer, save up a little more and go all out on the suspension

BTW, if your taking the rear springs apart make sure you have healthy spring packs or leaves for a rebuild. More often than not you'll find broken leaves.

 

[3-0-II]

I don't think I can convey how lost I now am... lol

and I hadn't really thought about the rear springs at all... i wonder how much a new set would help handling if at all? I know Alcino has some fiberglass ones.. hmmm

 

[Wart]

First time the rear springs are unbolted or worked on the best bet is to take it to a spring shop. All major metro areas have at least one.

I don't mean a "Tuners-R-Us" kind of place, I'm talking a truck kind place that does car springs. More than likely it will be cheaper than "factory replacements" and if your tuning the suspension for turning you'll want to play with the back springs anyhow.

Definitely cheaper than buying your own torch to get the damned things off the car.

 

[Wart]

A large part of making a car turn is balance.

What happens at one end effects the other.

Take a V8 car with no rear bar, add a stab, and it will handle better. Allot of people are happy with that. But add the heavy front bar and it handles even better. Or it should, because the car has brought more into balance.

And it seems the front bar is sized by the amount of engine between the wheels.

I have a set of bars from a KC and a set on a '78 V6 Mach1. Both cars came with a handling package. The rear bars are the same size, I believe (long time since I measured them). The KCs front bars are either 1/8 or 1/4 inch larger than the Mach's. Like I say, long time.
>
If your changing the front spring rate you almost have to change the rear or you'll end up with a front that wants to track flatter and a rear that wants to roll (sort of the same as mis matched bars, but different).

And, heck, if your car has the original springs, front or rear, it's probably a bit of a low rider and need changing anyway. Probably.

 

[78CobraII]

Weld in the subframe connectors (with the car level!) and install those front springs.

Get the largest factory front and rear sway bars you can find (1" front? and 3/4" rear?) and install them with poly bushings in the pivots and endlinks.

Install low profile tires (60 or 50 series) with Summer tread.

Your MII should now handle like its on rails.

If its too jarring, go back to rubber bushings.

The coil over shocks will require special lower control arms to mount. If you're going to that much trouble, spring for the tubular control arms. There are lots of suppliers these days, but you'll have to dig a bit to find the ones that fit the stock suspension...i.e. you need the broad "D" shape on the upper and the strut rod mount on the lower. Heidt's (Heidts Hot Rod Shop - Custom Suspension Systems) has these. Or you can buy the lowers that eliminate the strut rod but require a new mount point to be welded in.

 

[3-0-II]

Just went out and measured, I've got the 1" sway bar in the front and .75" in the rear, so thats good.

So I saw the tubular lower control arm's I'd need for the coilovers. I figure if I'm spending that kinda of cash I might as well get the tubular uppers too. I could even get a bit of wheel clearance that way. I assume I need the normal un-narrowed tubular uppers? I'm pretty sure that's right.

also, what kind of bushings are in the off the shelft heidts stuff? I don't care how rough the ride gets in this car. if its just rubber I want to upgrade it to polyurethane or polygraphite. Polygraphite isnt a must, but if it doesnt hurt performance theredoesnt seem to be a reason to not use them

edit:

one last thing i'm wondering... what spring rate would be ideal for the coilover conversion? they've got coil springs available anywhere from 375lb-700lb springs. I don't want to just grab the stiffest ones I can find because I know coilovers have alot more stress exerted on the rest of the car than normal setups. I plan on converting to coilovers on the bullitt as well and I'm not going to go past 300lb/in springs.. they do have suggestions on which to get based on front end weight of the car, but I have no idea what that is

http://cgi.ebay.com/ebaymotors/QA1-...itemZ350166768039QQptZOtherQ5fVehicleQ5fParts

 

[kcobra302]

make sure you get the standard width mii uppers. many companies sell uppers that are 5/8" narrower.

i found out the hard way. bought a set through ebay and could not return them. supposedly the seller did not know they were narrower than stock. i was lucky to be able to resell them on ebay.

 

[78CobraII]

I would call Heidt's on their bushing material. I'm not sure I've ever seen it listed.

If you want *no* deflection, get these:
Circle Track Products from Day Motor Sports ~ STEEL UPPER CONTROL ARM BUSHINGS

They would be really harsh because of the steel construction, but would have the benefit of not "binding" the suspension like the press-in bushings do. On the other hand, the pressed-in bushings probably add to the spring rate somewhat, so additional thought would have to go into your coil selection.

Since the MII front suspension or some derivative is popular with the circle track racers, they might be a good resource to go to for advice. They would also be a good resource for finding the front weight of your car as most will have access to a 4-corner scale. Other than that, the best I can tell you is to have the whole car weighed, then figure your front weight from the published MII V8 front/rear weight distribution of 59/41. Of course if you have taken some weight off of the front end (removed the AC, replaced iron parts with aluminum like brackets, heads, and water pump), your weight distribution may be different.

You might contact Alcino on this forum for his advice. Also, I have seen an SCCA road racer and a Solo I racer that were runing MII's, that might be helpful.

More racing parts suppliers:
Day Motor Sports ~ Circle Track Racing Parts
TSM MFG. CO., INC.
Speedway Motors - Street Rod Parts, Race Parts, Ford Flathead Parts, Sprint and Midget Racing Parts, Pedal Car Parts

 

[kcobra302]

i picked up mine from speedway motors and they came with poly bushings. they have both the tubular and stock stamped versions. i went with the tubular and they are nicely built.

 

[a351Must2]

since I used to like to spend money on suspension stuff...

I've been through some combos of suspension and would have to say the best I've had was my '74 Mustang when it had 150lb/in rear springs, 900lb/in front springs, 1" front, 3/4" rear sway bars, urethane everything bushings, but stock control arms.

In it's current form as a '78 T-Top with subframe connectors and everything the same except for ssm lift bars, it oversteers a litle, but is a fun drive.

My '78 I'm currently building is following my orginal "best" setup and getting urethane bushings everywhere I can put them, sticking with the stock size sway bars, 600lb/in front springs and the old 150lb/in rear springs.

The biggest desire is trying to get a minimum of neutral steer, but at worst a little understeer...

The '78 T-Top currently has a formidable amount of oversteer...which is fun to me, but not always desireable.

 

[KH!]

I followed the link in your sig, is SSM even alive anymore?

 

[Dano78]

No, I believe they went out of business a few years ago. However I believe that Stumpy's Fabworks still offers them. They are pretty much knock-offs of the SSM bars. Here's a link to his site-
Stumpy's Fabrication Works : Home

If you search E-Bay I believe he still sells them and the MII subframe connectors on there.

 

[78CobraII]

I came across this weight diagram on the web a while back...it might be useful in deciding on spring rates. It may have originally come from a spring or suspension parts manufacturer. I recall seeing something like it years ago.

 

[Dano78]

Find a local warehouse that deals with big rigs, or asphalt or gravel business, or even a highway weigh station and run just the front tires onto the scale to get your nose weight. Do it all the time in the Peterbuilt when hauling asphalt/gravel. We're only allowed so much weight on the front axle of the dump trucks or you'll get a big stinky ticket for being overweight even though you're not on the back axles.