Tips on Shocks/Sways/Lowering the C5
Cruising
Joined: Feb 2010
Posts: 13
Likes: 0
From: Houston TX.
Nice work Socalman, thanks for doing your homework and research !! Wish I would have found this before doing Ebach kit. Front was fine at 26.5 but rear was too low at 25.5 and poor quality ride and handling also. I used 6 in. bolts with Ebach bushings and ended up with 27.5 and excellant ride. Thanks for your help.
Melting Slicks
Joined: Aug 2004
Posts: 3,003
Likes: 89
From: Indy IN
The C6Z shocks are a bit stiffer and in relation to your springs the car will be a bit more overdamped and a bit more harsh. The Bilstein sport shocks in the front have almost exactly the same damping as the C5Z shocks, and are probably a good solid upgrade and a better match for your springs. It depends on what you are looking for. The base suspension is pretty flacid, and a set of bars and shocks will sharpen it up a lot. You still have pretty soft springs, and if you want the next step in handling above the stiffer bars and shocks you need something on the order of a Z06 spring set.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
So, you're not going to be "tucking" the tires with QA1 coilovers.
I sold them after taking the pic. Many people say a picture is worth 1000 words but that one cost me about $75...
I was just looking through thread again for another question and noticed the QA1 reference the first time so I figured it'd be a good idea to throw the picture and description here considering that this is a referenced thread for lowering.
Peter
Last edited by lionelhutz; Apr 10, 2011 at 12:13 PM.
Thread Starter
Safety Car
Joined: Jun 2009
Posts: 4,738
Likes: 15
From: OC Calif
St. Jude Donor '10
A little late but here's a pic of a rear QA1 coilover bottomed out. I disconneced the stock spring and installed the coilover with no spring and put the weight of the car on the bump stop. That is a 305/30/19 PS2 which is something like 0.25" smaller in diameter than the stock C5 rubber.
So, you're not going to be "tucking" the tires with QA1 coilovers.
I sold them after taking the pic. Many people say a picture is worth 1000 words but that one cost me about $75...
I was just looking through thread again for another question and noticed the QA1 reference the first time so I figured it'd be a good idea to throw the picture and description here considering that this is a referenced thread for lowering.
Peter
So, you're not going to be "tucking" the tires with QA1 coilovers.
I sold them after taking the pic. Many people say a picture is worth 1000 words but that one cost me about $75...
I was just looking through thread again for another question and noticed the QA1 reference the first time so I figured it'd be a good idea to throw the picture and description here considering that this is a referenced thread for lowering.
Peter
I've found that the differences in the Base suspension vs. a C5Z suspension (being the leaf spring) will help with the travel of the shock not bottoming out as easily. I switched out to C5Z and it holds nice, both cornering (with the Bilstein Sports and C6Z51 sways) and a 1.25" drop.
Perfect lowering for me has been 1.25" both front and rear. Gives a nice profile as the space between the fender and tire is constant all the way around (front and back space equals the top gap) has a nice look and a decent street ride, even on crappy freeways.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
The QA1's have around 1" less compression travel then the C6Z06 shocks I am running which let my wheels go right up until they just touch the fender.
The QA1's are fixed length. Others like Pfadt and LG are adjustable in length so at least in theory these could allow more travel than any C5 replacement shock would.
Peter
The QA1's are fixed length. Others like Pfadt and LG are adjustable in length so at least in theory these could allow more travel than any C5 replacement shock would.
Peter
Thread Starter
Safety Car
Joined: Jun 2009
Posts: 4,738
Likes: 15
From: OC Calif
St. Jude Donor '10
The QA1's have around 1" less compression travel then the C6Z06 shocks I am running which let my wheels go right up until they just touch the fender.
The QA1's are fixed length. Others like Pfadt and LG are adjustable in length so at least in theory these could allow more travel than any C5 replacement shock would.
Peter
The QA1's are fixed length. Others like Pfadt and LG are adjustable in length so at least in theory these could allow more travel than any C5 replacement shock would.
Peter
I'd like to see someone measure up a C6Z shock as I did in the first post, to see the overall length of the body with plunger off car, then fully compressed.
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Michael S. Palmer
Safety Car
Joined: Dec 2009
Posts: 3,724
Likes: 9
Our parts are absolutely not the same as LG or QA1, or anyone else for that matter. Our Newest single adjustable suspension solution is a completely proprietary design by Pfadt Race Engineering, with more features packed into it than any other single adjustable coilover on the market.
In the end, there really is only SO much you can lower these cars. Once you've packaged a coilover with enough shock travel to satisfy a wide range of ride heights, your next point of contact is wheel to fender, and without aftermarket fenders there isn't much you can do about this.
In the end, there really is only SO much you can lower these cars. Once you've packaged a coilover with enough shock travel to satisfy a wide range of ride heights, your next point of contact is wheel to fender, and without aftermarket fenders there isn't much you can do about this.
Pro
Joined: Jul 2010
Posts: 698
Likes: 2
From: Memphis TN
St. Jude Donor '11-'12-'13-'14-'15-'16-'17
cutting the bushings...
Once again the forum is there to help.
Pros, Racers etc. won't get much out of this. Neither will anyone running Coilovers.
Those of you that have or are contemplating lowering beyond stock bolts (including cutting the front bushings, removing the front bolt, swapping the rear bolts for aftermarket) might find some of this interesting.
LOWERING THE REAR:
Myth: “aftermarket (7”) bolts are needed to lower beyond the stock bolts” and “you need to leave 3 or 4 threads showing on stock or aftermarket bolts”
Truth: You can get more out of your stock bolts if you want to. Besides being able to loosen the bolt, widening the gap between A-arm and Spring (which lowers the car), there is a 3-ribbed bushing on the top and bottom of the bolts. If you cut one of the 3 ribs on both bushings (never cut the one that goes into the A arm or spring-it’s obvious when you see it), you can get another ½” of lowering out of your stock bolts.
The 7” bolts make you miss some critical adjustments. You will be jumping from the maximum lowering you can get out of the stock bolts to a 2” drop. Using 6” bolts allows you to graduate from the Stock Bolt Maximum to just below maximum, and then getting up to 1.5” drop if you max the 6” bolt out. You can also cut the bushings as mentioned earlier, and get it back if you find it’s too low, using the 6” bolt. It’s all simple math.
Myth: you can always raise your car by just re-tightening the bolts
Truth: Not if they are too long (typical 7” is too long for stock shocks as we learned above). Carriage bolts, which is what is used in this application, are not all-threaded bolts, you run out of threads.
After you set your bolts, with the threads even on both sides, drop the car and go for a spin, the suspension will settle. It’s NOT abnormal for one side to need more threads shown than the other to get it the same on both sides. If you take your car in to get aligned and corner balanced, they may set your car slightly off height from one side to another. But, from a ‘looks’ category, you will be climbing under there a few times. You will find that ¼” of thread difference can raise or lower the car MUCH more than the ¼”. Plan on ONE thread equals 3/16” change in height. I tightened my bolts down ¼” and the car came up 5/8”.
I hope this helps......
Those of you that have or are contemplating lowering beyond stock bolts (including cutting the front bushings, removing the front bolt, swapping the rear bolts for aftermarket) might find some of this interesting.
LOWERING THE REAR:
Myth: “aftermarket (7”) bolts are needed to lower beyond the stock bolts” and “you need to leave 3 or 4 threads showing on stock or aftermarket bolts”
Truth: You can get more out of your stock bolts if you want to. Besides being able to loosen the bolt, widening the gap between A-arm and Spring (which lowers the car), there is a 3-ribbed bushing on the top and bottom of the bolts. If you cut one of the 3 ribs on both bushings (never cut the one that goes into the A arm or spring-it’s obvious when you see it), you can get another ½” of lowering out of your stock bolts.
The 7” bolts make you miss some critical adjustments. You will be jumping from the maximum lowering you can get out of the stock bolts to a 2” drop. Using 6” bolts allows you to graduate from the Stock Bolt Maximum to just below maximum, and then getting up to 1.5” drop if you max the 6” bolt out. You can also cut the bushings as mentioned earlier, and get it back if you find it’s too low, using the 6” bolt. It’s all simple math.
Myth: you can always raise your car by just re-tightening the bolts
Truth: Not if they are too long (typical 7” is too long for stock shocks as we learned above). Carriage bolts, which is what is used in this application, are not all-threaded bolts, you run out of threads.
After you set your bolts, with the threads even on both sides, drop the car and go for a spin, the suspension will settle. It’s NOT abnormal for one side to need more threads shown than the other to get it the same on both sides. If you take your car in to get aligned and corner balanced, they may set your car slightly off height from one side to another. But, from a ‘looks’ category, you will be climbing under there a few times. You will find that ¼” of thread difference can raise or lower the car MUCH more than the ¼”. Plan on ONE thread equals 3/16” change in height. I tightened my bolts down ¼” and the car came up 5/8”.
I hope this helps......
Race Director
Joined: Dec 2000
Posts: 17,786
Likes: 5
From: Florida
This has been a good thread to read for building knowledge on the effect of lowering and finding the right shock absorber. But I need a question answered and thought this thread would be the most appropriate place.
My '02 Z06 is bone stock (54K daily driven miles) and I just bought new C6Z shocks as the stockers are starting to feel a little sloppy after those miles. I have read that the C6Z shock will actually cause the car to rise a little. Can anyone tell me what the net ride height effect will be with adjusting down the stock front/rear bolts to their max with the C6Z shocks?
I'm not a big fan of the stock wheel well gap on my Z, but I've lived with it for 4 years now and if I can keep it the same or improve it slightly without bottoming out the new shocks, then great. And if I have to cut down bushings, then so be it. But I'd like to know what I can expect before I start going to beyond-stock extremes.
Thank you in advance for sharing your own experiences.
-Dean
My '02 Z06 is bone stock (54K daily driven miles) and I just bought new C6Z shocks as the stockers are starting to feel a little sloppy after those miles. I have read that the C6Z shock will actually cause the car to rise a little. Can anyone tell me what the net ride height effect will be with adjusting down the stock front/rear bolts to their max with the C6Z shocks?
I'm not a big fan of the stock wheel well gap on my Z, but I've lived with it for 4 years now and if I can keep it the same or improve it slightly without bottoming out the new shocks, then great. And if I have to cut down bushings, then so be it. But I'd like to know what I can expect before I start going to beyond-stock extremes.
Thank you in advance for sharing your own experiences.
-Dean
Pro
Joined: Sep 2011
Posts: 531
Likes: 1
From: Tampa Fl
I have followed every step of this thread in order to lower my 03z. the rear turned out fine, but when i changed to do the fronts i couldnt get the bolt to move.
I first jacked up the front right and then proceeded to take the weight off of the spring with a second jack. once the weight was off the rubber stop on the bottom i then tried to rotate the bolt, using a 10mm closed end, counter clockwise(lower car). I was unable to make the bolt turn. I then applied wd40, waited, then tried again. nothing i tried worked to turn the bold.........
Any thoughts?
I first jacked up the front right and then proceeded to take the weight off of the spring with a second jack. once the weight was off the rubber stop on the bottom i then tried to rotate the bolt, using a 10mm closed end, counter clockwise(lower car). I was unable to make the bolt turn. I then applied wd40, waited, then tried again. nothing i tried worked to turn the bold.........
Any thoughts?
Pro
Joined: Jul 2010
Posts: 698
Likes: 2
From: Memphis TN
St. Jude Donor '11-'12-'13-'14-'15-'16-'17
You're almost there...
Believe it or not, you're almost there. You need to make sure the pressure from the leaf spring is relieved. With the car elevated you will need to use a jack and a wood block to push up on the bottom of the leaf spring. At that point you will see a gap appear between the lower control arm and the rubber bushing of the lowering bolt. Eventhough you have damaged the head of the bolt, you should be able to get it to turn.
Try that or something like that.
Be safe...
Try that or something like that.
Be safe...
I have followed every step of this thread in order to lower my 03z. the rear turned out fine, but when i changed to do the fronts i couldnt get the bolt to move.
I first jacked up the front right and then proceeded to take the weight off of the spring with a second jack. once the weight was off the rubber stop on the bottom i then tried to rotate the bolt, using a 10mm closed end, counter clockwise(lower car). I was unable to make the bolt turn. I then applied wd40, waited, then tried again. nothing i tried worked to turn the bold.........
Any thoughts?
I first jacked up the front right and then proceeded to take the weight off of the spring with a second jack. once the weight was off the rubber stop on the bottom i then tried to rotate the bolt, using a 10mm closed end, counter clockwise(lower car). I was unable to make the bolt turn. I then applied wd40, waited, then tried again. nothing i tried worked to turn the bold.........
Any thoughts?
Race Director
Joined: Dec 2000
Posts: 17,786
Likes: 5
From: Florida
Melting Slicks
Joined: Jun 2010
Posts: 2,809
Likes: 3
From: Yorktown Virginia
Melting Slicks
Joined: Mar 2013
Posts: 3,311
Likes: 386
From: Toronto Ontario
this seems to be the best and most informative thread regarding the suspension after lowering your car beyond stock specs
I bumped this so more people can chime in with more up to date info and see if they can help
I am at the point now I want to lower my car but I don't want to ruin the ride like I did on my last FRC
I bumped this so more people can chime in with more up to date info and see if they can help
I am at the point now I want to lower my car but I don't want to ruin the ride like I did on my last FRC
