Koni FSD shocks installed and reviewed
12-21-2006, 12:47 AM
#1
Burning Brakes
Thread Starter
Koni FSD shocks installed and reviewed
I finally got the time to install them. A friend of mine let me use his lift and lent a hand. I also added Zinc Plated Brembo/OEM Z51 rotors, Raybestos Ceramic pads and Z51 F/R sway bars. As I posted before I painted them black and added OEm deacls to them to keep my car looking OEM. My car also has an ABS of steel 3/8 aluminum tunnel plate. I added the rotors and FSD's first and took it for a thorough road test before adding the Z51 F/R bars. I'm on the fence about the Z51 sway bars due to their ride quality, oversteer and tail happy feel. One turn I normally take at 60 mph with the FE1 OEM setup, or the FSD's now sends my car sideways with the Z51 bars at 45 mph. I will probably swap them back to stock, but will drive the car a little more first. My feeling is the Z51 bars need stickier tires.
FSD on FE1 springs and BASE FE1 Swaybars Road test:
The first thing I noticed is the car sits about 1/8 of an inch lower and my dash does not creak when transitioning in and out of my driveway. More than likely due to a little less preload vs the OEM Shocks. The overall ride feels very close the OEM FE1 shocks but the control over rough surfaces is much improved and the car corners much flatter. Turn in feels more precise and there is significantly less wheel shudder, dive and squat. They still have that silky but firm Koni trademark feel like the sports, just a little softer. I also notice a lot less wheel hop under hard off the line acceleration.
I tested the car under the following road surfaces:
1) Sectioned washboard freeway 75+ MPH
2) rough split uneven pavement 45-75 MPH
3) rough uneven paved off camber turns 45-65+ MPH
4) Mixed bag of smooth and rough high speed turns 50-75+ MPH (HWY 17 in Santa Cruz, CA) Those who live here know what road I'm talking about
Results by road surface:
1) Sectioned washboard freeway 75+ MPH: The FSD's ride much better over sectioned freeway surfaces and over wash board bumps. One sectioned area I tested had a high section right in the middle of an off ramp turn. Before I installed the FSD's this would really unsettle my rear end under acceleration, Now I can hardly feel it! Washboard bumps feel reduced by 50% or more.
2) Rough split uneven pavement 45-75+ MPH: This is were the FSD's really shine. One section of road I drive on a lot was repaved on the left had side only, the right side is a mess of pot holes and it slopes to the right in some sections. This Road would really upset my C6 with the OEM setup, causing pulling. With the FSD the car tracks almost as if it's on a smooth surface.
3) Rough uneven paved off camber mid-high speed turns 45-65+ MPH. Again the FSD's shine. One particular turn I normally take at 65 -75mph has two large dips almost at the apex. before I would hear my airdam scrape and the dips would really unsettle the car. With the FSD's the car stays much more platted requiring less steering input through the turn. Overall grip and control in much better on high speed turns. I also noticed less steering wheel shudder and cowl shake as well.
4) Mixed bag of smooth and rough high speed turns 50-75+ MPH (HWY 17 in Santa Cruz, CA) This Road is really the acid test as far as diverse road conditions. It's a wet, rough high speed windy mountain road. The FSD's add a lot of control and confidence on this road and many bumps, dips, washboard sections I just can't feel anymore. I also noticed the car does not wander at higher speeds as much and overall traction also seems improved as well.
Summary:
They live up to their advertising and are a great mod for the money. Again the Z51 bars are a pro/con mod and I will post a followup after I remove them and put a couple 1000 miles on the FSDs. My experience with Koni sports has been that they break in a little after a 1000 or so miles. I'm happy to answer any questions.
Sneaky FSD install painted semigloss black with OEM decals. Auto X tech inspectors and the stealership will never notice
FSD on FE1 springs and BASE FE1 Swaybars Road test:
The first thing I noticed is the car sits about 1/8 of an inch lower and my dash does not creak when transitioning in and out of my driveway. More than likely due to a little less preload vs the OEM Shocks. The overall ride feels very close the OEM FE1 shocks but the control over rough surfaces is much improved and the car corners much flatter. Turn in feels more precise and there is significantly less wheel shudder, dive and squat. They still have that silky but firm Koni trademark feel like the sports, just a little softer. I also notice a lot less wheel hop under hard off the line acceleration.
I tested the car under the following road surfaces:
1) Sectioned washboard freeway 75+ MPH
2) rough split uneven pavement 45-75 MPH
3) rough uneven paved off camber turns 45-65+ MPH
4) Mixed bag of smooth and rough high speed turns 50-75+ MPH (HWY 17 in Santa Cruz, CA) Those who live here know what road I'm talking about
Results by road surface:
1) Sectioned washboard freeway 75+ MPH: The FSD's ride much better over sectioned freeway surfaces and over wash board bumps. One sectioned area I tested had a high section right in the middle of an off ramp turn. Before I installed the FSD's this would really unsettle my rear end under acceleration, Now I can hardly feel it! Washboard bumps feel reduced by 50% or more.
2) Rough split uneven pavement 45-75+ MPH: This is were the FSD's really shine. One section of road I drive on a lot was repaved on the left had side only, the right side is a mess of pot holes and it slopes to the right in some sections. This Road would really upset my C6 with the OEM setup, causing pulling. With the FSD the car tracks almost as if it's on a smooth surface.
3) Rough uneven paved off camber mid-high speed turns 45-65+ MPH. Again the FSD's shine. One particular turn I normally take at 65 -75mph has two large dips almost at the apex. before I would hear my airdam scrape and the dips would really unsettle the car. With the FSD's the car stays much more platted requiring less steering input through the turn. Overall grip and control in much better on high speed turns. I also noticed less steering wheel shudder and cowl shake as well.
4) Mixed bag of smooth and rough high speed turns 50-75+ MPH (HWY 17 in Santa Cruz, CA) This Road is really the acid test as far as diverse road conditions. It's a wet, rough high speed windy mountain road. The FSD's add a lot of control and confidence on this road and many bumps, dips, washboard sections I just can't feel anymore. I also noticed the car does not wander at higher speeds as much and overall traction also seems improved as well.
Summary:
They live up to their advertising and are a great mod for the money. Again the Z51 bars are a pro/con mod and I will post a followup after I remove them and put a couple 1000 miles on the FSDs. My experience with Koni sports has been that they break in a little after a 1000 or so miles. I'm happy to answer any questions.
Sneaky FSD install painted semigloss black with OEM decals. Auto X tech inspectors and the stealership will never notice
. The first thing I noticed was how much larger the diameter of the pistons shafts are; FSD 18.5 mm vs 11 mm for the OEM Z51. Below are pics compared to a set of OEM Z51 shocks I purchased from another forum member. The overall length and travel appear to be identical. The body diameter is close 50 mm for the FSD vs 48 mm for the OEM. When compressing them by hand they feel a little a lot more compliant than the Z51 OEM. I painted the FSD's semigloss black and removed the OEM decals with a heat gun and applied them on the FSD's to fly under my stealership's radar. I will have to drill the mounting holes out a little on the factory dust covers. They should look stock once the are installed. I can't wait get them on! I should have a chance to get it on a lift on Tuesday or Wednesday. Stay tuned!
Note the Piston Shaft size vs OEM
FSD and OEM Z51 shocks can you tell which one is which?
Note the Piston Shaft size vs OEM
FSD and OEM Z51 shocks can you tell which one is which?
I want everythng to look OEM under my car not just for warranty reasons but for Auto X purposes as well. The OEM bushings look a little beefier than the Koni's as well, material seems similar, but either will work the same. The picture below shows how the bushing hardware would mount to the piston shafts. With the OEM hardware the dust cover also acts as support on the bottom of the bushing. Note the difference in size of the factory bumb stop vs the FSD. I'm not sure which one I will use, RSL if you have any input I'm all 
. I may call Koni's tech support and ask them, my feeling is to go with the Koni.
OEM hardware on the left, FSD on the right.
. I may call Koni's tech support and ask them, my feeling is to go with the Koni.OEM hardware on the left, FSD on the right.
Last edited by torch2000vert; 12-23-2006 at 12:47 AM.
12-21-2006, 02:05 AM
#2
Burning Brakes
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wow now thats what i call a thorough review!
Im glad to hear they lived up to the hype, I would love to hear how they feel back with the stock swaybars so we get a completely before/after comparison to your stock setup, thanks for sharing all your results!
Im glad to hear they lived up to the hype, I would love to hear how they feel back with the stock swaybars so we get a completely before/after comparison to your stock setup, thanks for sharing all your results!
12-21-2006, 03:41 AM
#3
Melting Slicks
How did you manage to do the decals? Is there a part# for them or did you somehow manage to remove and restick them?
12-21-2006, 09:04 AM
#7
Safety Car
Not meaning to hijack the thread, but I'm curious how long you've had the tunnel plate on? I just installed the 3/8" model, with no other changes. Some of what you attribute to shocks, I am experiencing as a result of the tunnel plate. The over the road rigidity I'm feeling likely has a handling benefit, I just haven't driven it enough to quantify yet.
12-21-2006, 09:46 AM
#8
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FSD Eval
torch2000vert,
Wow! Thanks for the thorough review! Well, they did for you on your roads what I observed on our test vehicle in northern Kentucky, so great. Pretty good "bang-for-the-buck", I think.
Wow! Thanks for the thorough review! Well, they did for you on your roads what I observed on our test vehicle in northern Kentucky, so great. Pretty good "bang-for-the-buck", I think.
12-21-2006, 10:10 AM
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FSDs vs Bilsteins
Interesting. Another forum member just PM'd me asking the same thing. I'll tell you what I told him.
From our experience on many different vehicles, Bilsteins are pretty easy to beat on ride quality. Their monotube construction works well for some things, but less so for ride. Its the nature of monotubes, not the manufacturer. So how would KONI know that? We make monotubes also; in fact, our rebound-adjustable Sports for the C5/C6 are monotubes, with inverted bodies and easy-to-access adjustment windows. The Sports are designed for owners who do serious autocross or track days and want the ability to change the setup to suit track conditions.
Rather than have our overloaded-with-work shop do a Vette comparison, we're waiting for some of you club members to do that instead. I think this thread's FSD report should give someone here enough confidence in the results to do just that. After all, isn't that one of the reasons you frequent the marque websites, to find out which mods work well (or not)? I know I do.
From our experience on many different vehicles, Bilsteins are pretty easy to beat on ride quality. Their monotube construction works well for some things, but less so for ride. Its the nature of monotubes, not the manufacturer. So how would KONI know that? We make monotubes also; in fact, our rebound-adjustable Sports for the C5/C6 are monotubes, with inverted bodies and easy-to-access adjustment windows. The Sports are designed for owners who do serious autocross or track days and want the ability to change the setup to suit track conditions.
Rather than have our overloaded-with-work shop do a Vette comparison, we're waiting for some of you club members to do that instead. I think this thread's FSD report should give someone here enough confidence in the results to do just that. After all, isn't that one of the reasons you frequent the marque websites, to find out which mods work well (or not)? I know I do.
12-21-2006, 11:27 AM
#12
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I Just ordered a set from LTB Motorsports. They've got them in stock!
http://ltbmotorsport.stores.yahoo.net/konifsd.html
888-346-7266
http://ltbmotorsport.stores.yahoo.net/konifsd.html
888-346-7266
12-21-2006, 09:46 PM
#15
Burning Brakes
Thread Starter
Not meaning to hijack the thread, but I'm curious how long you've had the tunnel plate on? I just installed the 3/8" model, with no other changes. Some of what you attribute to shocks, I am experiencing as a result of the tunnel plate. The over the road rigidity I'm feeling likely has a handling benefit, I just haven't driven it enough to quantify yet.
BJK[/QUOTE]
I had them on my C5 and they were better than the OEM, but I did not have Koni's to compare them too, I did however try a set of Edelbrock IAS. I hated them, way too soft. I did a write up on the OEM Z06 vs Bilstein Sports VS IAS on the C5 forum, you maybe able to find it
12-21-2006, 10:57 PM
#16
Safety Car
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FSD on FE1 springs and BASE FE1 Swaybars Road test:
The first thing I noticed is the car sits about 1/8 of an inch lower and my dash does not creak when transitioning in and out of my driveway.
The first thing I noticed is the car sits about 1/8 of an inch lower and my dash does not creak when transitioning in and out of my driveway.
Also, what kind of warranty does Koni offer?
One of the local speed shops seems to have a very negative veiw of previous Koni products and I am wondering what history is out there on Konis that makes them feel that way.
BJK
Last edited by 07MontRedcp; 12-22-2006 at 04:12 AM.
12-22-2006, 12:18 AM
#17
torch2000vert:
I may have been reading too fast, but it seems like you have the base FE1 suspension but replaced the shocks with Z51 shocks prior to getting the FSDs?
You say you used the OEM bushings and hardware less the nuts, with the Koni Bump Stops -- which pieces are those in the picture you posted? Aren't bushings = bump stops?
Thanks!
I may have been reading too fast, but it seems like you have the base FE1 suspension but replaced the shocks with Z51 shocks prior to getting the FSDs?
You say you used the OEM bushings and hardware less the nuts, with the Koni Bump Stops -- which pieces are those in the picture you posted? Aren't bushings = bump stops?
Thanks!
Last edited by MYVetteBy25; 12-22-2006 at 12:26 AM.
12-22-2006, 01:13 AM
#19
Burning Brakes
Thread Starter
torch2000vert:
I may have been reading too fast, but it seems like you have the base FE1 suspension but replaced the shocks with Z51 shocks prior to getting the FSDs?
I purchased a set of Z51 shocks with the Z51 Swaybars from another member. I never installed the OEM Z51 shocks, I may sell them down the road
You say you used the OEM bushings and hardware less the nuts, with the Koni Bump Stops -- which pieces are those in the picture you posted? Aren't bushings = bump stops?
No bushings are the black rubber pieces at the top of the picture. The bump stops are the white pieces that mount onto the piston shafts. They are what limit the shock travel.
Thanks!
I may have been reading too fast, but it seems like you have the base FE1 suspension but replaced the shocks with Z51 shocks prior to getting the FSDs?
I purchased a set of Z51 shocks with the Z51 Swaybars from another member. I never installed the OEM Z51 shocks, I may sell them down the road
You say you used the OEM bushings and hardware less the nuts, with the Koni Bump Stops -- which pieces are those in the picture you posted? Aren't bushings = bump stops?
No bushings are the black rubber pieces at the top of the picture. The bump stops are the white pieces that mount onto the piston shafts. They are what limit the shock travel.
Thanks!
12-22-2006, 04:08 AM
#20
Safety Car
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Note the Piston Shaft size vs OEM
This may give better perspective to those who do not see your first posting. Looks like there is alot of travel control via the bump stop on the OEM shock and I am concerned as to why they did that.
On closer look at the bottom photo it does appear that the Koni FDS piston shaft is shorter than the OEM by about the amount of the larger bump stop used on the OEM. If that's true then that may be why the Koni bump stop is no more than a washer and the bump stop might in reality be the top of the shock.
Am I out to lunch on this one???
BJK