Vintage Mustang Forums banner

1 - 20 of 47 Posts

·
Registered
Joined
·
2,486 Posts
Discussion Starter #1
Well I love the sound of my new exhaust so I've been getting on it a lot lately. My car handles reasonably well (not as tight as I'd like it, but I feel like I'm in control) until 85-90mph. Then the car starts rocking side-to-side and feels unsafe.

Is this just because I'm using stock suspension? I have a '67 289 C4 with torque boxes on both sides. No SFCs yet and haven't done the shelby/arning drop yet. It has a scott drake export brace. I have a monte carlo bar but it's not currently installed.

Power steering car with the belt removed from the power steering pump because my system leaks like crazy.

I'd like the steering to feel a little tighter everywhere, and the car to stay put when I get up to high speeds. Roller perches are next on the list, and I plan to do the shelby drop at the same time.

Thanks
-Matt
 

·
Registered
Joined
·
571 Posts
I recently posted a similar question in this thread. I got some good feedback, you might check out some of the suggestions.
 

·
Registered
Joined
·
2,486 Posts
Discussion Starter #3
I recently posted a similar question in this thread. I got some good feedback, you might check out some of the suggestions.
Thank you, sir.

You have better steering components than I do and my car sounds like it handles a lot better. Get it aligned!

-Matt
 

·
Registered
Joined
·
35,836 Posts
The drop is much more important than roller perches. Do it now, before you try to drive high legal speeds again.

Arning/Shelby Suspension Drop

Oh, and if you do this stunt again

Power steering car with the belt removed from the power steering pump because my system leaks like crazy.
you'll probably die. When you remove the 800 psi of the boost system, you get about an inch of play in the pittman arm.

Leaks are generally caused by cheap generic hoses that don't fit right, or missing the clamp that goes around the valve and secures the steel hose tubes, the hose bracket bent or missing, or the hoses routed wrong. Often all of these at once.

You could probably fix the steering for what the roller perches will cost you. Me, if I had to choose, I'd rather have good steering than roller perches.


 

·
Registered
Joined
·
9,208 Posts
Well I love the sound of my new exhaust so I've been getting on it a lot lately. My car handles reasonably well (not as tight as I'd like it, but I feel like I'm in control) until 85-90mph. Then the car starts rocking side-to-side and feels unsafe.

Is this just because I'm using stock suspension? I have a '67 289 C4 with torque boxes on both sides. No SFCs yet and haven't done the shelby/arning drop yet. It has a scott drake export brace. I have a monte carlo bar but it's not currently installed.

Power steering car with the belt removed from the power steering pump because my system leaks like crazy.

I'd like the steering to feel a little tighter everywhere, and the car to stay put when I get up to high speeds. Roller perches are next on the list, and I plan to do the shelby drop at the same time.

Thanks
-Matt

Wow. I particularly like the part about your P/S system. Lemme feel your forehead.
You know what happens when (not if) the stud pulls out of your p/s control valve?
 

·
Administrator
Joined
·
13,017 Posts
Maybe don't go 90 miles per hour! Hopefully you're not doing that on public streets.
Stan
 

·
Registered
Joined
·
2,834 Posts
The drop is much more important than roller perches. Do it now, before you try to drive high legal speeds again.

90? Legal? Maybe in rural Montana or something. :)
 

·
Registered
Joined
·
35,836 Posts
90? Legal? Maybe in rural Montana or something. :)
Well, I would never accuse anyone of lawbreaking without evidence.

Of course, with the belt off the PS, I wouldn't go over about 15 mph, because a) the lack of precise control would make me liable to hit things, and b) banging an unpressurized valve like that doesn't do it any good at all.
 

·
Registered
Joined
·
1,657 Posts
Doh. Get that belt back on ASAP. If you want to go to manual steering, use a conversion kit. That is incredibly unsafe.

Now once that is taken care of, notify us if the problem persists.
 

·
Registered
Joined
·
9,104 Posts
Sometimes on the highway I hit the 80-90mph range in my '98 Sunfire. I get nervous about it because it is getting to be an old car and I don't usually drive it that fast. One time I hit 95mph because I really wanted to hit 100mph at least once, but I ran out of space.

You're wondering why your 44 year old car feels uneasy at 90mph? You're young like me and didn't grow up when these cars were new cars. The stock suspension today is much better than a stock suspension in the 60's. If I drove my friend's new Lancer at 100mph it would probably feel like my Sunfire at 40mph.

It sounds like you have been working on this car a lot. Is this the one you bought a while ago and it was torn down pretty far (I think it was green). I understand that you still probably have some kinks to work out and are determining what upgrades to do, but please, be safe. Otherwise, see this post:

http://forums.vintage-mustang.com/general-discussion-non-vintage-mustang/625039-do-you-have-anyone-would-tell-forums-you-passed-away.html#post4082651

We don't want anyone coming on here and saying that lemonshindig won't be posting anymore!
 

·
Registered
Joined
·
120 Posts
Power steering car with the belt removed from the power steering pump because my system leaks like crazy.
I love it. That's the type of repair my dad would have done.

Yep, I learned a lot from my old man. Mostly what not to do.
 

·
Registered
Joined
·
3,129 Posts
squirrely

lemon, my first two guesses would be poor alignment and the front of the car is higher than the tail. The front end too high lets air stack up under the nose at high speed and makes steering feel vague. The alignment being off makes things generally feel unstable the faster you go. If you go to most alignment shops, they'll give exactly what the factory specs are, which is exactly what you DON'T want. I like positive caster and lots of it, but some folks get nervous where I am ( 6~8 ) but if you get the front end lower than the tail and run 3 or 4 degrees positive caster and 1 or 2 negative camber and as close to zero toe in as you can get, it will feel like a whole differant car. try it and see



LSG
 

·
Registered
Joined
·
2,486 Posts
Discussion Starter #13
I had no idea that removing the belt was unsafe in any way, shape, or form.

I've been driving it that way in town and on the highway for 6 months plus.

This car's driving 90 miles to Spokane Saturday morning, and it's going to have to do it without that belt. Even if I special ordered the new pump tomorrow, it wouldn't get here by then.

I'll check what the car was aligned to last year.

Thanks
-Matt
 

·
Registered
Joined
·
353 Posts
Well, you get two inches of slop in the stock power steering whether the pump is running or not, it's just not quite as bad if it's working.

At 90mph in a stock Mustang you're getting quite a bit of aero lift up front, particularly if the springs have done their normal 45-years-of-sag thing and the back end's dragging. They were never very good high-speed cars to begin with.
 

·
VMF Ambassador
Joined
·
6,655 Posts
The drop will definitely help a lot. I've got stock suspension aside from the drop and have taken my pony up to 90-ish (on a large, empty highway on the day that I went to look at it, when the PO was driving!) without any problems. Straight and true all day long.
 

·
Registered
Joined
·
2,487 Posts
You should not drive an old mustang with stock type suspension, at 90mph IMHO.

If you want to drive that fast, you will need serious suspension upgrades, and please take it to the track.
Not only is the suspension inadequate, so are the brakes.
 

·
Registered
Joined
·
2,486 Posts
Discussion Starter #18
You should not drive an old mustang with stock type suspension, at 90mph IMHO.

If you want to drive that fast, you will need serious suspension upgrades, and please take it to the track.
Not only is the suspension inadequate, so are the brakes.
It has disc brakes, my friend. new two months back.

I love them :)

-Matt
 

·
Registered
Joined
·
9,844 Posts
Add as much caster as possible, problem solved.
Yep. 3 degrees at least.

If the suspension is tight and the alignment is right and you have radial tires it will be stable as a rock at 90. Or 120. Ask me how I know.
 

·
Registered
Joined
·
353 Posts
Yep. 3 degrees at least.

If the suspension is tight and the alignment is right and you have radial tires it will be stable as a rock at 90. Or 120. Ask me how I know.
A stock Mustang was never very stable at high speeds, crappy shocks and prone to lots of aero lift. The stock power steering is never going to be very positive, either and will never be as good as, say, a modern Corolla, though caster will help. Forty-plus years of wear and leaf-spring sag will just make things that much worse.
 
1 - 20 of 47 Posts
Top