Suspension Ideas

for the front suspension i would go with the V8 gt springs, they are rated at 480lbs/in os while they are stiffer than stock your ride wont be too stiff. remember that the six is much lighter than the V8 so you dont need as much spring rate. next while you have the suspension apart do the shelby drop, lower the upper arm pivot point down an inch and back 1/8", to change the camber curve. dazecars.com has the template and drill bit you need to do the job. run a 1" sway bar on the front. i would also use adjustable strut rods and a roller bearing on the lower control car. also step up and install roller bearing spring perches, dazecars.com and opentracker racing products both have the needed parts to convert your perches, or you can buy the already done perches. i would also use a roller bearing to replace the stock idler arm bushing. again opertracker can be a help here.

as for the rear suspension, since you have the six i dont recommend using a rear sway bar as that would cause over steer issues that can be severe. i would however recommend using V8 rear springs.

for shocks i would recommend using the kyb gas adjust shocks, remember to use a large, thick fender washer in the underside of the upper rear shock mounts to spread the load and prevent the shocks from punching through the sheetmetal. if you have the money though, run koni shocks as they are adjustable.

for brakes again since you have the six you dont need huge brakes, and 11" front disc brake will do nicely. scarebird, master power brakes, and others have a variety of kits you can use. my advice though would be to upgrade to V8 spindles as the six cylinder spindles were suspect to begin with. you can use any V8 drum brake spindle from 1965-1969 with no problems. if you happen across a pair of 1970 mustang spindles grab them as they have even larger spindles.

i would upgrade to an 8" rear end and 5 lug wheels.

as for wheels and tires, i recommend running a 15x6 or 15x7 wheels and 205/60-15 tires. with the six that is all you really need.

as for lowering the car, you can use a mid eye rear leaf spring, and take the front springs and cut the coils down until you get the ride height you are after. cut a 1/4 coil at a time.

the only thing would be to add the correct wheel spacers if you use late model wheels. otherwise everything works just fine.

cjperry81 said:

Thanks for the advice. Would there need to be any modifications made to those recommendations if i were to go with a larger wheel such as 17's with a lower profile tire?

Click to expand...

There are also plenty of 17" wheels that fit properly without spacers. Here's a couple:

Don't limit yourself on tires to little 15s althought tires are a lot cheaper...

Go with a 16 or 17 inch wheel. 6 cylinder or not, the more rubber on the road the better you'll be able to do.

One thing that hasn't been mentioned yet is steering. Have you got manual or power? Not something you'll need immedietally, but if you want to keep autocrossing it, you'll very quickly find out the stock steering ratio is going to be way too slow. Lots of options (and opinions) are out there on what to do, but go out, have fun and see how you like it before spending a bundle.

Look at getting one of the shelby "quick steer" links. It'll up your effort somewhat, but will make slaloms and quick transitions a little easier.

I don't have first hand experience with the Air over Leaf set up, but it looks like something you would put on a "cruiser" where you wanted ride hide control. I'd never put it on something I wanted to handle well. You MIGHT get it to work, but there are waaaay too many variables to play with until it was right.

You've been given some excellent advice on how to make your car handle well.
I'll add you should stiffen the chassis. Good sub frame connectors, export brace (a good one, not a $25 chinese knock off), and a monte carlo bar should be on your short list along with what's been mentioned. Keep an open mind on shocks. It's a matter of prefference and VERY important. Get the best you can afford.

I don't know if anybody mentioned that 6 cylinder 1966 Mustangs had four lug wheels and none of the wheels mentioned will fit unless he changes to 5 lug front and rear.

On my 66 i've got 620 front coil springs KYB gas adjust shocks, a 1 1/8 inch sway bar, 5 leaf mid eye rear springs, and a 3/4 inch rear sway bar. This gives me about one 1 inch lower ride height in the front and an inch and a half in the rear (after the rears settled more than the front). I'm also running a monte carlo bar. I bought all of this from Mustangs Plus, most in a kit form. I've made no other changes to steering or suspension angles and I havn't noticed any bumpsteer. As far as ride goes, it is a night and day diff. It's firm without being overly stiff or jarring and their hasn't been a girl yet who's complained.

Now i'm sure that the 620's on the front of a 6 cylinder like yours might be a little tall, but if you don't mind cutting a coil out to get the height right they are damn good springs for auto crossing/spirited driving. Or go with the shelby control arm relocation if you don't feel like cutting the springs, this will also give you much better camber angles for cornering. Really the 6 cylinder and a small block V8 are only 100 lbs different in weight, and 50 if you've got aluminum heads.

This all being said, and knowing you said something about a budget, i'd go with the monte carlo bar for 50 bucks (no more front end wondering in hard cornering) and a larger sway bar for 100 bucks (the bigger the better). This should give you all kinds of predictability in the corners.

adam, 620's are way too stiff for a six cylinder car on the front, which is why i always recommend no stiffer than the stock GT spring which is rated at 480

as for sway bars, no bigger than 1" on the front and no rear bar with a six powered car. remember that balance is the key to a good handling car.

Guess you are probably right about the springs being too stiff for a six cylinder, but when I was putting mine together I left the stock swaybar on with the 620's and it still rolled badly on hard corners. I guess I just think that if the car sits flat when turned hard it's the right way to go.

What do you mean by balance? I assume you don't mean a front to rear weight balance, but something more like build for the particular car and type of driving style.

No, I have never taken my car to an actual road race track, just open parking lots and freeway on ramps. I'm sure that my idea of good handling will change when I do.

Balance should mean that the car will neither understeer or oversteer.

However without addressing the roll stiffness of the rear, the combo above will understeer horribly.

All cars will benefit from an adjustable rear roll bar.

Yes, there are other ways to limit roll at the rear, but a bar is the cheapest and most adjustable method.

Good luck...

A pet peeve of mine is that Mustangs Plus sells springs rated at 525, but markets them as 620. The 525 crush rate number is from their catalog. They say the 620 is the wire diameter. Others like Maier sell 620 springs that have a crush rate of 620 lbs/inch. Two totally different springs. It's no wonder you get differening accounts of "what is too stiff". Throw in different shocks, road conditions etc, and opinions are all over the place.

Adam, You really should relocate your upper arms. You'd be surprised at the difference it makes (then drive hwy 9 or 17 sometime ). It doesn't lower the car more than a 1/2" because the spring perch isn't lowered much compared to the pivot point of the arm.

putch11 I havn't had a problem with understeer just yet, but could you explain how having a stiff rollbar in the rear would cause my set up to understeer.

S-Car-Go Would you recommend the classic shelby drop with moving the arm down just one inch or also moving it back with the drop. I think shelby only moved it down and not back, but I'm probably remembering wrong.

better suspension

i undersrtand what u mean i wanted my 68 to handle better, i can truly say it has almost no body role i have a monte carlo bar the one piece strut tower brace which you might have to jack up the car cuz mustangs have a tendency to have the shock towers caved in alittle or warped i went with the upper and lower control arms from mustangs plus which were crap absolute crap so i went with the blue printed ones from Marlo's Frame & Alignment much better original casting but blueprinted and reinforced i have the 1 1/2 inch sway bar in front and also the tie rods new and the idler arm with poly perches and all poly urethane bushings oh and 620 pound drop springs with kyb shocks. the rear i haven the 5 leaf springs with poly urethane bushings reverse eye which lowered the car to much i would recommend mid eye also with kyb shocks with the rear sway bar which has performed great most my suspension from mustangs plus but i would not get the control arms from grab a track they are useless thin and warp also the ball joints crap as well but every thing else good oh and also in the rear i have the welded traction bars and i have the global west subframe connectors

I'd avoid the KYB shocks, have them now, not much fun to count every piece of gum and small change I happen to run over. If you can, save the extra money and get the better shocks.

change to a t5 . . .