rear suspension choice

[Spider69 16]

Hi,

I have to replace the rear suspensions on my mach 1.

I have currently std koni, front and rear.

I'm a normal driver, no race track.

What is the best choice between std and gas shock absorber?

 

And what is the difference in behavior?

 

Spider69

[SA69mach 39]

How do you find the suspension now with the koni shocks?

 

I ask in terms of compression and rebound.

 

When you hit a pothole or a bump, what happens, how does it feel and sound.?

 

Does the car bounce UP after the initial bump?

[SA69mach 39]

I did a full stock suspension rebuild on my 70 last year. New rubber, new ball joints, new bearings, new disc brake upgrade, new stock 5.0 Mustang springs (one coil cut off to keep the stance and height I wanted)

The only 'new' item was the shocks. My builder, Steve McClennon form Hotrods to Hell suggested Bilsteins, firmly. He rates them over Koni for the following reasons

Koni have high gas charge and very stiff compression, and mild rebound.

He says you need mild gas charge, with softer compression and stiff rebound.

I went with Bilstein RCD series, 55-RO54 and 55-RO56 (front and rear, if forget which is which) and they are amazing. Even without the front sway bar installed the car handled long sweepers and bumps with ease, total control at all times.

Cant say enough good things about the Bilsteins, I love driving that car now.

 

I have never had Koni and will not make any negative remarks, I only know what the Bilsteins did for a car that went form evil handling to amazing. Considering everything else was bone stock Ford parts, it was the shocks that made the big difference.

 

They are not cheap, but at 375 for all four, they are a good investment. I will never have anything else on my Mustangs, and have a set on the way right now for my 69 Mach1.

 

The Konis should be giving you superior handling right now. If you have any issues or complaints it may be time to replace them, either with new units or different brand. Y

[Spider69 16]

My konis are without gas.

No special sound after hitting pothole or bump and the car doesn't bounce up after initial bump.

I was quite satisfied with the koni shocks, but since some weeks I have a strange noice coming from the rear end of the car when I'm turning left or right. Not easy to explain, its like a 'klong'.

I don't know which part of the car made this sound,but I guess it should be the shocks or the leaf springs.

So I start with replacing the shocks and therefore my question, with gas or without gas shocks?

I heard some comments about gas shocks which are too harsh for the mustang chassis.

 

Spider69

[prayers1 153]

SA69mach- Any pictures with the new suspension?

[mustangstofear 608]

I've heard good things about the Bilstein Shocks.

[Brian Conway 264]

Probably should find out what the 'Klong' is ? Brian

[SA69mach 39]

I've heard good things about the Bilstein Shocks.

 

I never considered such expensive shocks before last year. I figured there would not be much real difference. But I was rebuilding a car at a hot rod shop and kinda got drawn into the fancy Bilsteins on a 70 Mustang that was truly horrible to drive. Handling was poor. So, rebuilt the suspension with replacement stock items, LCA, reversed the spring perches, ball joints, rear spring rubber mounts. Stock front springs with one coil cut off

AND the Bilsteins. Even waiting for the 1 1/8 front anti-sway bar to arrive the car handled great. Sweepers, bumps, whatever, it was amazing difference. Wheel alignment was 3 degrees castor, 1/16 inch neg camber and 1/8 toe in, which is fairly stock for radial tired Mustangs now.

 

Just ordered my second set for my new 69 Mach1. Money well spent, and you have to feel it to believe it. Bilstein work on the principle of mild compression and stiff rebound control, with very large shaft and valves. it works. I have their Street valved versions and they are a great investment and worth every penny.

[SA69mach 39]

SA69mach- Any pictures with the new suspension?

 

You already have this pic, but here you go....

 

this is stock Ford springs at rear with new rubber. Stock Ford springs form NAPA with a coil cut off, and stock rebuild. The only thing different is the shocks. RCD 55 RO-5X series Street valving.

Sits kinda high, but the way that car handles is amazing, and the stock height is handy over street furniture, speed humps and driveways. Got a heavy duty 1/18 inch sway bar on the front.

You can do a lot with a stock rebuild and some good shocks. I have a lowered car, Big /block and all the fancy stuff. It is a pain to drive anywhere.

 

The Mustang goes anywhere, and it handles great. Cant beat it for a DD.

 

The 69 Mach will be treated to the same in a day or two-waiting for the Bilsteins to arrive. I guess I have put my money where my mouth (opinion) is. I regard the extra cost as a good investment. I am really happy with the shocks, and will be putting them on all my cars in time.

 

It sounds snobbish, and 18 months ago I would have balked at buying Bilsteins for the cost factor alone. I guess we all change when given the proof.

[SA69mach 39]

My konis are without gas.

No special sound after hitting pothole or bump and the car doesn't bounce up after initial bump.

I was quite satisfied with the koni shocks, but since some weeks I have a strange noice coming from the rear end of the car when I'm turning left or right. Not easy to explain, its like a 'klong'.

I don't know which part of the car made this sound,but I guess it should be the shocks or the leaf springs.

So I start with replacing the shocks and therefore my question, with gas or without gas shocks?

I heard some comments about gas shocks which are too harsh for the mustang chassis.

 

Spider69

 

Konis a re good quality shocks. I am not a hater.

If you are happy with them then stick with them. Worth tracing the knock in the rear. You may have a loose or broken fitting on either the car mounting point, or the shock itself. Or it could be a number of other things not related to the shock absorbers.

 

Your Konis will have a gas charge inside it. The amount of charge determines Street/Track/Race kind of definition. It is a factory charge at the time of manufacturing. You may be thinking of Air adjustable shocks, with a air line to input a charge of air to adjust to loads, driving conditions etc.

Those shock absorbers are regarded as not suited to Vintage Mustangs, and reports of the shock mounts inside the trunk area breaking are numerous, but somewhat dubious. I have never seen evidence of that, but it may be true.....

 

I would surmise and assume that any Koni unit designed for a 69 Mustang will be well suited. You seem satisfied with the Koni except for the clunk. Lets find out what that is, and then work out if the Konis are a problem. They are considered a superior shock absorber.

[rwcstang 201]

I've heard good things about the Bilstein Shocks.

 

I have SOT Coil overs with Bilstein sport shocks front and rear and what a difference on how the car drives.

[RPM 1,190]

Hey Spider, did you ever get the klong fingered out? Just read this page. This is a great thread, with experienced driving feel, components used and alignment specs. Nice job guys.

[Rsmach1 71]

Koni's are a great shock, and rebuildable. If you have the "Red" shock, they are adjustable, the "Orange" shock is not. If unsure you can simply get the part # off the shock and check. If you decide to go with new shocks let me know, if they are the Reds, I would be interested in them.

[SM69Mach 68]

I have SOT Coil overs with Bilstein sport shocks front and rear and what a difference on how the car drives.

+1 here as well.

 

Could not be happier with my set up.

[Spider69 16]

Hi all,

Klong is an old story.

I have changed the rear leafs, grab-a-track 4 1/2.

Wonderfull :-)

 

Konis are still on the car and everything is working and driving well