[67_LS1]

I went with a full Hotchkis suspension, front and rear. Springs, control arms, sway bars, everything. When I hit a sharp bump in the road with the front wheels it sends the shock throughout the entire car as a very hard, sharp jolt. It’s like the shudder goes through the entire frame.

I‘ve mentioned in some earlier posts that I’m contemplating either lighter springs or a smaller sway bar. I’ve got to do something, it’s just to harsh. My frame is not boxed either. Would this help or hurt?

I’ve also got 17” wheel with 225/45/17 tires. Not super low but not tall and cushy either.

I’m also running stock replacement body mounts if that makes any difference.

I drive this car most days and I’m looking for smooth and flat. No auto cross or any other racing.

Suggestions?

 

[Blackhawk]

How much room do you have until you hit the bump stops? You may be low enough that the bump stops are before the bottom of your normal suspension travel.

 

[modern malibu]

Check to make sure you are not riding on the bump stops I dont know if the springs you have would have lowered the car to that point, but it can't hurt to look. Shocks not the correct length?

 

[67_LS1]

How much room do you have until you hit the bump stops? You may be low enough that the bump stops are before the bottom of your normal suspension travel.
[/QUOTE

Good question. I have tons of pics of the stops but all while the suspension is hanging while on a two post lift. I’ll take a pic with it on the ground.

Check to make sure you are not riding on the bump stops I dont know if the springs you have would have lowered the car to that point, but it can't hurt to look. Shocks not the correct length?

The shocks came with the Hotchkis kit so I’m assuming they are correct.

 

[senna]

Remembering some of your earlier posts on this, how low is your car? Springs, spindles?

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[67_LS1]

I currently have 2” dropped spindles. The springs are 1” lowering but that turned out to be too low so I have spacers (from Hotchkis) in the bottom pocket so they are equals to stock height springs.
Hotchkis says the springs are rated 515 lbs. I’m running a featherweight V6 so the springs might be to still for the load they are supporting. Could the frame be flexing some where the springs are not?
I have no idea if this is possible, I’m just thinking out loud.

 

[senna]

I currently have 2” dropped spindles. The springs are 1” lowering but that turned out to be too low so I have spacers (from Hotchkis) in the bottom pocket so they are equals to stock height springs.
Hotchkis says the springs are rated 515 lbs. I’m running a featherweight V6 so the springs might be to still for the load they are supporting. Could the frame be flexing some where the springs are not?
I have no idea if this is possible, I’m just thinking out loud.

515 lb spring shouldn't be ridiculously harsh.

What about your shocks? Are they adjustable?

Are you able to remove the shocks without separating a ball joint?

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[67_LS1]

515 lb spring shouldn't be ridiculously harsh.

What about your shocks? Are they adjustable?

Are you able to remove the shocks without separating a ball joint?

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I might not be harsh for a SB or BB but it seems pretty stiff. The stock springs are rated 260 lbs for a SB.
And if only one wheel hits a bump, isn’t the sway bar part of the equation?

 

[senna]

So, what ever distance your springs are compressed to at current ride hight is what it takes to hold your car at that hight.

If they were compressed two inches that would be 1030 pounds.If you put 350 lb springs compressed three inches would be 1050 pounds. So maybe stock length springs @350 lbs with the one inch sparer would be close.

If it were mine I would either test drive it without front shocks or buy some cheap Monroes. Same goes for the sway bar, its easy to disconnect and secure for a test drive.



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[-SS454-]

are you running poly body mounts?

 

[senna]

BTW, I just this weekend changed my front springs from 750 lb (talk about hash) to 550 lb springs. With an LS, I was working in that same 1050 range at ride hight. It does ride firm but in no way would I call it harsh.

Let's be clear all of our Individual assessments are subjective.

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[amx364]

Springs hold the car up and shocks dampen the ride. You have a very light weight engine and maybe too much spring. The lowered spindles may not be helping either. If you have the standard spindles maybe reinstall those first and see if that helps, if not might have to change the springs.

 

[67_LS1]

Body mounts are rubber, not poly.
I do not have the stock spindles any more, plus I like it low.
If I got new springs, I would get t stock height and take the shapers out. The spacers are just 1/4” aluminum plates the lie flat under the springs bottom rubber seat. I could trim from there.
The shocks can easily be removed through the bottom of the control arm. Same for the sway bar. I’ll try different runs with/without these items in various combos.

 

[BillyGman]

Body mounts are rubber, not poly.
I do not have the stock spindles any more, plus I like it low.
If I got new springs, I would get t stock height and take the shapers out. The spacers are just 1/4” aluminum plates the lie flat under the springs bottom rubber seat. I could trim from there.
The shocks can easily be removed through the bottom of the control arm. Same for the sway bar. I’ll try different runs with/without these items in various combos.

AFIAC the best and most relevant question in this thread was asked by two different members here in post # 2 and #3 about the possibility of the rubber bump stops on the front upper and lower control arms possibly hitting the frame during suspension compression. I didn't see anywhere in this thread where you replied or answered that question. Did I miss it? You can always cut those rubber stops down with a sharp blade. They're usually double the height of what's needed anyway. That's a common trick that us drag racers use to gain a little more front suspension travel. But you don't have to be drag racing the car to benefit from that. Especially when the bump stops being so tall might be the reason you're experiencing what you have been.

Just remember, when you modify the car with aftermarket parts, although there are certain performance advantages to that, with those advantages often comes the domino effects of the modification in question. You have to become your own engineer at times to make the aftermarket parts work correctly, and/or make then play nice with the rest of the vehicle. And I can assure you that many aftermarket parts manufactures are NOT always going to make you aware of those domino effects. I've learned that the hard way in the past myself. The aftermarket parts places, ( distributors, retailers and manufactures) main priority is to sell you parts. That's it.

 

[Droptop72]

I‘ve mentioned in some earlier posts that I’m contemplating either lighter springs or a smaller sway bar. I’ve got to do something, it’s just to harsh. My frame is not boxed either. Would this help or hurt?

Since you asked this question, the general rule is that the stiffer the chassis is, the softer you can go on springs and shocks amd smaller on sway bars and get the same level of performance, with a much more agreeable ride. All that big stiff stuff is just a crutch for a chassis with too much give in it.

 

[Bob Tiley]

Can you press down on the fender and bounce the front end up and down or is it too stiff to do that?

 

[67_LS1]

I did mention the bump stops in my reply (post 4) but it’s kinda buried in the post. I’m going to look at them tomorrow.

Can you press down on the fender and bounce the front end up and down or is it too stiff to do that?

I cannot budge the fender with my 200 lbs.

Since you asked this question, the general rule is that the stiffer the chassis is, the softer you can go on springs and shocks amd smaller on sway bars and get the same level of performance, with a much more agreeable ride. All that big stiff stuff is just a crutch for a chassis with too much give in it.

Yes, I wished I had boxed the frame. If I could find another frame at a good price I would box it reinforce it and swap it in. I need the car for transportation so I can’t have it down to remove and box my current frame. I’d box this one after and resell it.

 

[1966_L78]

How does it act in the rear?

I have had several Chevelles with poly bushings in the upper rear control arms, and it created a very harsh ride... Doing nothing other then swapping out those upper bushings with rubber or arms with spherical bearings actually improved the feel and handling of the cars... The factory upper arms actually flex, along with the bushings. "boxed" uppers with still poly bushings are too stiff to flex when trying to articulate, and end up increasing the spring rate significantly by acting similar to "torsion" bars...

My latest project isn't set up to handle, but I did add Edelbrock adjustible upper arms with Spherical bearings at one end, and Currie Spherical bearings in the rearend housing uppers ears...

 

[Bob Tiley]

I cannot budge the fender with my 200 lbs.

If you can not budge the fender then the springs are way too stiff for your application. Assuming you are not sitting down on the bump stops.

 

[Jayhawk500]

If you can not budge the fender then the springs are way too stiff for your application. Assuming you are not sitting down on the bump stops.

My sentiments exactly. You beat me to it.
Modern "featherweight V6" as you call it weighs less than a SBC, which weighs less than a BBC.
Sounds to me like like your front suspension is sitting on the UPPER bump stops, not the lowers. I suspect you need lighter weight springs. Especially, if you cant move it when leaning on the fender.