Looking at new shocks/struts and springs, would like some advice.
03-28-2018, 10:48 PM
#1
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Location: Florida
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Looking at new shocks/struts and springs, would like some advice.
I have a 1994 Z28 that has the original shocks and springs (original owner, 64K miles). I know they need to be replaced and will be doing that while I am dropping the fuel tank to replace/fix the fuel pump. The car has been sitting for about five years due to family constraints, amongst other things. But now I am itching to drive it again. I know I need to change all the fluids and tires. I am just taking this all on at my own time.
But I need some suspension help as the choices are many.
So I think I have narrowed it down to Bilstein SLP 70008 shocks/struts along with the BMR SP001R lowering springs. While reading reviews for the springs, one person recommended the UMI adjustable on car panhard bar, 2029-B. Another review recommended rear control arm relocation brackets.
I can see needing the adjustable panhard bar but why would I need the relocation brackets?
While looking around I also found the Bilstein shock/spring kit at Classic Industries and Hawk Motor Sports. It appears the springs in that kit are Eibachs.
What are some other choices I should look at? Should I just stick with the factory springs and the SLP Bilstein shocks? I don't think I want the Bilstein B6 HDs as I want better handling but not a stiffer ride. I don't have any interest at this point on changing sway bars or anything else like that. All the bushings and rubber bits all still appear to be in really good shape. I can see needing to upgrade to a polyurethane bushing kit in the future. I will still be running the original rims and original sized tires.
Getting new shocks and springs isn't like trying on a new pair of shoes. Because once these are on, they are on. Cannot just easily return them so I want to make sure I get it correct the first time.
If anyone has advice, I certainly would appreciate it.
But I need some suspension help as the choices are many.
So I think I have narrowed it down to Bilstein SLP 70008 shocks/struts along with the BMR SP001R lowering springs. While reading reviews for the springs, one person recommended the UMI adjustable on car panhard bar, 2029-B. Another review recommended rear control arm relocation brackets.
I can see needing the adjustable panhard bar but why would I need the relocation brackets?
While looking around I also found the Bilstein shock/spring kit at Classic Industries and Hawk Motor Sports. It appears the springs in that kit are Eibachs.
What are some other choices I should look at? Should I just stick with the factory springs and the SLP Bilstein shocks? I don't think I want the Bilstein B6 HDs as I want better handling but not a stiffer ride. I don't have any interest at this point on changing sway bars or anything else like that. All the bushings and rubber bits all still appear to be in really good shape. I can see needing to upgrade to a polyurethane bushing kit in the future. I will still be running the original rims and original sized tires.
Getting new shocks and springs isn't like trying on a new pair of shoes. Because once these are on, they are on. Cannot just easily return them so I want to make sure I get it correct the first time.
If anyone has advice, I certainly would appreciate it.
Last edited by AccessBowtie; 03-28-2018 at 11:27 PM.
03-28-2018, 11:27 PM
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Re: Looking at new shocks/struts and springs, would like some advice.
What is the main use of the car - 1) just a daily driver, that you would like to handle better; 2) more hardcore use like auto-x or road racing; 3) straight line / drag racing?
The intended use will determine the best components. You mention both “lowering springs” and “factory springs”. Do you want to lower it or not? That will determine the necessity of things like an adjustable panhard rod and/or LCA relocation brackets.
Just to add to confusion, look at the choices available from this 4th Gen suspension specialist, and SCCA champion.
Do you plan to upgrade the wheels and tires?
Strano Performance Parts - Parts Catalog
The intended use will determine the best components. You mention both “lowering springs” and “factory springs”. Do you want to lower it or not? That will determine the necessity of things like an adjustable panhard rod and/or LCA relocation brackets.
Just to add to confusion, look at the choices available from this 4th Gen suspension specialist, and SCCA champion.
Do you plan to upgrade the wheels and tires?
Strano Performance Parts - Parts Catalog
03-29-2018, 12:19 PM
#3
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Re: Looking at new shocks/struts and springs, would like some advice.
No autocross or drag racing. Just a 5k miles a year daily driver. I will be keeping the 16 inch factory rims. As for tires...not much of a selection in the 245/50/16 size so I'll probably be going with the BF Goodrich Sport Comp 2 (Maybe the Hankook Ventus V2 Concepts).
I cannot say with certainty I want the car lowered or not. I'm kind of 50/50. While I think I would like the handling and more planted feeling that comes with the lowered car (1 inch drop is more than fine) I do not want to spend a ton of extra money just to do it. I think if I stuck with the factory springs then would I want to go with the Bilstein B6s? Factory springs are 24 years old. Car has been sitting on the ground for the past five years with the springs being compressed (not on blocks or anything). Not sure if there is any long term damage to the springs with that.
Upgrading to lowering springs isn't that much more money. Another $150-ish for an adjustable panhard bar. I don't know if control arm relocation brackets are mandatory. Will I need some kind of relocation bracket for the front end of the car. New panhard bar and relocation brackets aren't that expensive so it's not the cost. Just trying to do it right. I'm very much a factory/stock appearing kind of guy but want to replace worn out parts with better parts as those opportunities present itself.
I just don't want to have to replace a lot of still mechanically good parts if they do not need to be replaced just to get the vehicle lowered an inch.
And one thing I need to save money for is getting the a/c compressor fixed. I thought I wanted to tackle that job myself but decided against it.
Reading reviews on Summit Racing about the springs and SLP Bilstein shocks really impresses me and I feel I want to go that way. But again, I want to get it right the first time and am not sure of all the things I will need to make it happen.
I cannot say with certainty I want the car lowered or not. I'm kind of 50/50. While I think I would like the handling and more planted feeling that comes with the lowered car (1 inch drop is more than fine) I do not want to spend a ton of extra money just to do it. I think if I stuck with the factory springs then would I want to go with the Bilstein B6s? Factory springs are 24 years old. Car has been sitting on the ground for the past five years with the springs being compressed (not on blocks or anything). Not sure if there is any long term damage to the springs with that.
Upgrading to lowering springs isn't that much more money. Another $150-ish for an adjustable panhard bar. I don't know if control arm relocation brackets are mandatory. Will I need some kind of relocation bracket for the front end of the car. New panhard bar and relocation brackets aren't that expensive so it's not the cost. Just trying to do it right. I'm very much a factory/stock appearing kind of guy but want to replace worn out parts with better parts as those opportunities present itself.
I just don't want to have to replace a lot of still mechanically good parts if they do not need to be replaced just to get the vehicle lowered an inch.
And one thing I need to save money for is getting the a/c compressor fixed. I thought I wanted to tackle that job myself but decided against it.
Reading reviews on Summit Racing about the springs and SLP Bilstein shocks really impresses me and I feel I want to go that way. But again, I want to get it right the first time and am not sure of all the things I will need to make it happen.
Last edited by AccessBowtie; 03-29-2018 at 12:33 PM.
03-29-2018, 12:36 PM
#4
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Re: Looking at new shocks/struts and springs, would like some advice.
For a daily driver, I don't personally feel like a lowering (the cars are already really low) will help you feel more planted. I would only lower the car in this case if you prefer the look of the lower stance. Also consider the impact to ground clearance.
Outside better shocks/struts, if you want a more solid feel in the car in corners around town, I would first spend money on sub frame connectors and a strut tower brace. This will stiffen the chassis and make the car feel really flat through turns.
Outside better shocks/struts, if you want a more solid feel in the car in corners around town, I would first spend money on sub frame connectors and a strut tower brace. This will stiffen the chassis and make the car feel really flat through turns.
03-29-2018, 12:44 PM
#5
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Re: Looking at new shocks/struts and springs, would like some advice.
For a daily driver, I don't personally feel like a lowering (the cars are already really low) will help you feel more planted. I would only lower the car in this case if you prefer the look of the lower stance. Also consider the impact to ground clearance.
Outside better shocks/struts, if you want a more solid feel in the car in corners around town, I would first spend money on sub frame connectors and a strut tower brace. This will stiffen the chassis and make the car feel really flat through turns.
Outside better shocks/struts, if you want a more solid feel in the car in corners around town, I would first spend money on sub frame connectors and a strut tower brace. This will stiffen the chassis and make the car feel really flat through turns.
I wouldn't mind the lower look of a 1 inch drop. But it's not something I need.
03-29-2018, 02:20 PM
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Re: Looking at new shocks/struts and springs, would like some advice.
03-29-2018, 07:39 PM
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Re: Looking at new shocks/struts and springs, would like some advice.
Even if you lower the car, an adjustable panhard bar may not be necessary. If you make an assumption or two and do the math, dropping the chassis 1” moves the chassis ~1/10th” to the side, relative to the rear axle assembly. Best thing to do if you lower the car is to measure the rear of the car to determine if the chassis is still centered side-to-side over the rear axle. If it is, you don’t need an adjustable bar.
The LCA relocation brackets are very important to straight line traction. As the chassis is dropped, the front mounting point of the LCA can drop below the rear mount on the axle assembly. On hard acceleration the LCA pushes down on the chassis, and the resulting “equal and opposite” reaction produces an upward force on the axle assembly, traction is lost, the driving force on the LCA is lost, traction is regained, and the cycle repeats. This can result in massive rear axle “hop”, resulting in the car going nowhere.
I’m not aware of the extent to which this phenomenon would affect cornering and general handling. I have only experienced it with hard acceleration in a straight line. I used the Eibach Pro-Kit springs, which resulted in a 0.7” drop in the rear, and about a 1.8” drop in the front. The fronts were combined with QA1 adjustable ride height springs, and I tried to match the stock spring seat height, but the drop was more than the springs were supposed to produce.
With the front that low speed bumps became a major obstacle, trash in the road would get caught under the car, and driving on asphalt roads that were heavily rutted by large trucks resulted in various under chassis pieces rubbing on the road surface. I used the height-adjustable fronts to raise the front up, almost back to stock, and replaced the rear Pro-Kits with a pair of Eibach Drag Launch springs, which have the rear sitting about 1/4” higher than stock. But that works well with 28” slicks.
If you are just looking for a good handling daily, the right shocks should be a major improvement. Since you have to separate the front coil-over spring/shock assembly to replace the shocks (they are not struts) might as well replace the springs. The front upper spring seat/shock mounts should also be replaced.
For solid cornering, upgraded sway bars are critical to reducing body roll. I wouldn’t pass them up.
The LCA relocation brackets are very important to straight line traction. As the chassis is dropped, the front mounting point of the LCA can drop below the rear mount on the axle assembly. On hard acceleration the LCA pushes down on the chassis, and the resulting “equal and opposite” reaction produces an upward force on the axle assembly, traction is lost, the driving force on the LCA is lost, traction is regained, and the cycle repeats. This can result in massive rear axle “hop”, resulting in the car going nowhere.
I’m not aware of the extent to which this phenomenon would affect cornering and general handling. I have only experienced it with hard acceleration in a straight line. I used the Eibach Pro-Kit springs, which resulted in a 0.7” drop in the rear, and about a 1.8” drop in the front. The fronts were combined with QA1 adjustable ride height springs, and I tried to match the stock spring seat height, but the drop was more than the springs were supposed to produce.
With the front that low speed bumps became a major obstacle, trash in the road would get caught under the car, and driving on asphalt roads that were heavily rutted by large trucks resulted in various under chassis pieces rubbing on the road surface. I used the height-adjustable fronts to raise the front up, almost back to stock, and replaced the rear Pro-Kits with a pair of Eibach Drag Launch springs, which have the rear sitting about 1/4” higher than stock. But that works well with 28” slicks.
If you are just looking for a good handling daily, the right shocks should be a major improvement. Since you have to separate the front coil-over spring/shock assembly to replace the shocks (they are not struts) might as well replace the springs. The front upper spring seat/shock mounts should also be replaced.
For solid cornering, upgraded sway bars are critical to reducing body roll. I wouldn’t pass them up.
Last edited by Injuneer; 03-29-2018 at 07:44 PM.
03-29-2018, 11:32 PM
#8
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Join Date: Jun 2003
Location: Florida
Posts: 26
Re: Looking at new shocks/struts and springs, would like some advice.
Even if you lower the car, an adjustable panhard bar may not be necessary. If you make an assumption or two and do the math, dropping the chassis 1” moves the chassis ~1/10th” to the side, relative to the rear axle assembly. Best thing to do if you lower the car is to measure the rear of the car to determine if the chassis is still centered side-to-side over the rear axle. If it is, you don’t need an adjustable bar.
The LCA relocation brackets are very important to straight line traction. As the chassis is dropped, the front mounting point of the LCA can drop below the rear mount on the axle assembly. On hard acceleration the LCA pushes down on the chassis, and the resulting “equal and opposite” reaction produces an upward force on the axle assembly, traction is lost, the driving force on the LCA is lost, traction is regained, and the cycle repeats. This can result in massive rear axle “hop”, resulting in the car going nowhere.
I’m not aware of the extent to which this phenomenon would affect cornering and general handling. I have only experienced it with hard acceleration in a straight line. I used the Eibach Pro-Kit springs, which resulted in a 0.7” drop in the rear, and about a 1.8” drop in the front. The fronts were combined with QA1 adjustable ride height springs, and I tried to match the stock spring seat height, but the drop was more than the springs were supposed to produce.
With the front that low speed bumps became a major obstacle, trash in the road would get caught under the car, and driving on asphalt roads that were heavily rutted by large trucks resulted in various under chassis pieces rubbing on the road surface. I used the height-adjustable fronts to raise the front up, almost back to stock, and replaced the rear Pro-Kits with a pair of Eibach Drag Launch springs, which have the rear sitting about 1/4” higher than stock. But that works well with 28” slicks.
If you are just looking for a good handling daily, the right shocks should be a major improvement. Since you have to separate the front coil-over spring/shock assembly to replace the shocks (they are not struts) might as well replace the springs. The front upper spring seat/shock mounts should also be replaced.
For solid cornering, upgraded sway bars are critical to reducing body roll. I wouldn’t pass them up.
The LCA relocation brackets are very important to straight line traction. As the chassis is dropped, the front mounting point of the LCA can drop below the rear mount on the axle assembly. On hard acceleration the LCA pushes down on the chassis, and the resulting “equal and opposite” reaction produces an upward force on the axle assembly, traction is lost, the driving force on the LCA is lost, traction is regained, and the cycle repeats. This can result in massive rear axle “hop”, resulting in the car going nowhere.
I’m not aware of the extent to which this phenomenon would affect cornering and general handling. I have only experienced it with hard acceleration in a straight line. I used the Eibach Pro-Kit springs, which resulted in a 0.7” drop in the rear, and about a 1.8” drop in the front. The fronts were combined with QA1 adjustable ride height springs, and I tried to match the stock spring seat height, but the drop was more than the springs were supposed to produce.
With the front that low speed bumps became a major obstacle, trash in the road would get caught under the car, and driving on asphalt roads that were heavily rutted by large trucks resulted in various under chassis pieces rubbing on the road surface. I used the height-adjustable fronts to raise the front up, almost back to stock, and replaced the rear Pro-Kits with a pair of Eibach Drag Launch springs, which have the rear sitting about 1/4” higher than stock. But that works well with 28” slicks.
If you are just looking for a good handling daily, the right shocks should be a major improvement. Since you have to separate the front coil-over spring/shock assembly to replace the shocks (they are not struts) might as well replace the springs. The front upper spring seat/shock mounts should also be replaced.
For solid cornering, upgraded sway bars are critical to reducing body roll. I wouldn’t pass them up.
Okay so I guess I'll keep the factory ride height, which I am actually fine with. I think I'd like to stay with Bilstein shocks. Which would be preferred, the Bilstein SLP or the Bilstein B6 HD? And what springs would be recommended with the recommend Bilstein shock?
I'd like to thank both of you for your time and information so far.
03-30-2018, 09:04 AM
#9
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Location: Hell was full so they sent me to NJ
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Re: Looking at new shocks/struts and springs, would like some advice.
I have no experience with either shock set. Strano has a description of the SLP version that sounds good to me.... “comfortable yet firm ride on the street.” He sells both sets but unfortunately does not describe the HD's. If you plan to buy from Strano (his prices appear to be the same as Summit), he might be able to point you in the right direction. However he is known to get a bit testy if he senses you are just getting free input, but plan to shop elsewhere.
03-30-2018, 11:54 AM
#10
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Location: Lansing, MI via Bowling Green, KY: Dalton, GA: Nashville, TN & Atlanta, GA
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Re: Looking at new shocks/struts and springs, would like some advice.
There are lots of options. How much are you willing to spend?
Personally, I would call Sam Strano and also check out his site.
I recently put his springs & Koni Sport shocks on my '94. I haven't driven the car much since, perhaps 100-200 miles, but the ride seems really good and perhaps better than ever. I hadn't driven the car in 17 years, so maybe I just missed it.
Most people will probably tell you that shocks are the most important component. The Koni shocks aren't cheap, but are considered one of the best shocks available for these cars.
If you have headers on your car, ground clearance can become an issue with lowering springs. I said to heck with it and did it anyway. I think it looks better lowered and I suspect handling is improved quite a bit due to lowering the center of gravity.
Personally, I would call Sam Strano and also check out his site.
I recently put his springs & Koni Sport shocks on my '94. I haven't driven the car much since, perhaps 100-200 miles, but the ride seems really good and perhaps better than ever. I hadn't driven the car in 17 years, so maybe I just missed it.
Most people will probably tell you that shocks are the most important component. The Koni shocks aren't cheap, but are considered one of the best shocks available for these cars.
If you have headers on your car, ground clearance can become an issue with lowering springs. I said to heck with it and did it anyway. I think it looks better lowered and I suspect handling is improved quite a bit due to lowering the center of gravity.
03-31-2018, 08:40 PM
#11
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Re: Looking at new shocks/struts and springs, would like some advice.
I would agree - Koni Yellow Shocks - I have them on my Subaru and they are perfect for sporty daily drivers - I also don't know how I haven't lowered my 96 yet..... There's so much wheel to fender gap compared to cars now and it sits extremely high and feels like a barge in corners compared to my Subaru (and Audi).....
FYI - I also have the SLP shocks with stock springs on my car - and they are nothing special - Konis will blow them away without question
I would suggest Koni Shocks/ Strano Springs / Sway Bars - then talk with with Sam Strano and let him suggest the additional needs based on your expectations and those parts as a starter.
FYI - I also have the SLP shocks with stock springs on my car - and they are nothing special - Konis will blow them away without question
I would suggest Koni Shocks/ Strano Springs / Sway Bars - then talk with with Sam Strano and let him suggest the additional needs based on your expectations and those parts as a starter.
Last edited by 96 Z 28; 03-31-2018 at 08:45 PM.
04-06-2018, 09:51 PM
#13
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Posts: 26
Re: Looking at new shocks/struts and springs, would like some advice.
Cost is always a factor but I am the original owner of my Camaro and it sat for 5 years so now is the time to treat the car right. After getting new shocks, swapping all fluids, new tires and then getting the a/c fixed I know I am already going to be spending at least a few grand.
The reason I was thinking lowering springs is because the car does appear to sit high and there is a lot of fender/wheel well gap. So now maybe I'll look at Koni shocks. I'll call Strano Performance once I get to the shock/springs part of the car.
I'm still working on dropping the gas tank to repair/replace the fuel pump. Have never done anything like this before but I'm slowly getting there. Thought I could get away without lowering the diff but that does not appear possible.
Gas tank drop questions...
Above the left rear wheel is a black canister that has several fuel hoses attached that run between it and the fuel tank. What does that canister do? Where do I disconnect the hoses to drop the tank? At the canister? At the tank or somewhere in the middle? Watched a video on Youtube and just cannot figure it out.
Again, I thank everyone for their recommendations. So many choices, that I cannot say with certainty which way I am going to go with the shocks/springs.
The reason I was thinking lowering springs is because the car does appear to sit high and there is a lot of fender/wheel well gap. So now maybe I'll look at Koni shocks. I'll call Strano Performance once I get to the shock/springs part of the car.
I'm still working on dropping the gas tank to repair/replace the fuel pump. Have never done anything like this before but I'm slowly getting there. Thought I could get away without lowering the diff but that does not appear possible.
Gas tank drop questions...
Above the left rear wheel is a black canister that has several fuel hoses attached that run between it and the fuel tank. What does that canister do? Where do I disconnect the hoses to drop the tank? At the canister? At the tank or somewhere in the middle? Watched a video on Youtube and just cannot figure it out.
Again, I thank everyone for their recommendations. So many choices, that I cannot say with certainty which way I am going to go with the shocks/springs.
04-06-2018, 11:53 PM
#14
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Location: Hell was full so they sent me to NJ
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Re: Looking at new shocks/struts and springs, would like some advice.
The canister is part of the EVAP emissions system. Carbon granules adsorb hydrocarbons venting from the fuel tank. During certain engine operating conditions, intake manifold vacuum pulls fresh air through the canister to strip the hydrocarbons from the carbon and burn the air/hydrocarbon mixture in the engine.
There is a flex line from the fuel pump sending unit to the canister, and a flex line from the canister to the EVAP purge valve on the passenger side of the intake manifold. The line from the sending unit has a pressure regulating vent valve. You disconnect that line by pulling it off the pipe on the sending unit. There are also fuel supply and return lines that connect to the sending unit. They have GM Buick connect fittings (3/8” on supply; 5/16” on return) that mayrequire a release tool.
From Shoebox
http://shbox.com/1/evap_system.jpg
http://shbox.com/1/quick_connect.jpg
Again, the factory service manual includes detailed instructions:
https://www.mediafire.com/?40mfgeoe4ctti
There is a flex line from the fuel pump sending unit to the canister, and a flex line from the canister to the EVAP purge valve on the passenger side of the intake manifold. The line from the sending unit has a pressure regulating vent valve. You disconnect that line by pulling it off the pipe on the sending unit. There are also fuel supply and return lines that connect to the sending unit. They have GM Buick connect fittings (3/8” on supply; 5/16” on return) that mayrequire a release tool.
From Shoebox
http://shbox.com/1/evap_system.jpg
http://shbox.com/1/quick_connect.jpg
Again, the factory service manual includes detailed instructions:
https://www.mediafire.com/?40mfgeoe4ctti
04-07-2018, 10:56 PM
#15
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Location: Florida
Posts: 26
Re: Looking at new shocks/struts and springs, would like some advice.
Thanks for the diagrams, Injuneer.
Got all the fuel lines disconnected, tank is out. Getting the fuel filler tube out of the fuel filler opening in the body sucked. What a pain.
After opening the tank up, unfortunately the inside of the tank is dirty, rusty and in pretty bad shape. The fuel pump assembly is also rusted/very dirty. While parts move freely, I do not want to re-use any parts.
I already have a new Delphi fuel pump (I can take it back if I need to).
Where is the best place to get a new tank and where can I get a quality fuel pump assembly or new fuel pump and assembly already together and ready to install?
Got all the fuel lines disconnected, tank is out. Getting the fuel filler tube out of the fuel filler opening in the body sucked. What a pain.
After opening the tank up, unfortunately the inside of the tank is dirty, rusty and in pretty bad shape. The fuel pump assembly is also rusted/very dirty. While parts move freely, I do not want to re-use any parts.
I already have a new Delphi fuel pump (I can take it back if I need to).
Where is the best place to get a new tank and where can I get a quality fuel pump assembly or new fuel pump and assembly already together and ready to install?
