C5 Tech Corvette Tech/Performance: LS1 Corvette Technical Info, Internal Engine, External Engine, Tech Topics, Basic Tech, Maintenance, How to Remove & Replace
Sponsored by:
Sponsored by:

Lowering: short simple question

Thread Tools
 
Search this Thread
 
Old Apr 18, 2011 | 11:25 PM
  #1  
sothpaw2's Avatar
sothpaw2
Thread Starter
Safety Car
15 Year Member
 
Joined: Sep 2002
Posts: 4,030
Likes: 6
From: Maryland
Default Lowering: short simple question

I've read up on this and have been adjusting my car's ride height on the stock bolts.

Short question: On the rear, to lower, you turn the bolt CC, making the space between the A-arm and spring longer correct? :o

I'm making small adjustments now so it's hard to be sure...

Thanks

Andy
Reply
Old Apr 19, 2011 | 12:43 AM
  #2  
joeflyer's Avatar
joeflyer
Drifting
25 Year Member
Conversation Starter
All Eyes On Me
Liked
 
Joined: Dec 1999
Posts: 1,679
Likes: 23
From: Newark CA
Default

Correct. Longer bolt length equals lower ride height. This is reverse of the front suspension.
Reply
Old Apr 19, 2011 | 01:45 AM
  #3  
striper's Avatar
striper
Le Mans Master
15 Year Member
 
Joined: May 2005
Posts: 6,366
Likes: 249
From: Fort Lauderdale, Florida
Default

Just undo the rear bolts until there are almost no threads left. Tighten the front bolts until you can't tighten any more. Actually, I would first remove the front bolts and cut the rubber bushings in half and then reinstall and tighten. That's how my car is done.
Reply
Old Apr 19, 2011 | 08:22 AM
  #4  
Solofast's Avatar
Solofast
Melting Slicks
20 Year Member
Conversation Starter
All Eyes On Me
Top Answer: 1
 
Joined: Aug 2004
Posts: 3,003
Likes: 89
From: Indy IN
Default

Originally Posted by striper
Just undo the rear bolts until there are almost no threads left. Tighten the front bolts until you can't tighten any more. Actually, I would first remove the front bolts and cut the rubber bushings in half and then reinstall and tighten. That's how my car is done.
Actually if you do this the way striper recommends your car will handle like a pig, ride rougher than an ox cart and in a few months you will be back at the alignment shop because it is wandering all over the road.

Look in the sticky at how to do it right. If you lower it too much in the back the rear shocks will bottom out and that will not only screw up your handling, it will ruin your alignment. You should expect the rear screws to be different. If you adjust them to be the same the corner weights will be off and the car will oversteer turning left and push turning right. There's a right way to do it and a wrong way, and you will just make more work for yourself if you screw it up.

Here is a link to the right way to do it.

http://forums.corvetteforum.com/1576940245-post106.html
Reply
Old Apr 19, 2011 | 08:48 AM
  #5  
helga203's Avatar
helga203
Le Mans Master
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2010
Posts: 6,002
Likes: 722
Default best way

Sorry. Simplest way to lower, put a 600lbs guy on the top of your car.:craz y:

Last edited by helga203; Apr 19, 2011 at 09:10 AM.
Reply
Old Apr 19, 2011 | 12:34 PM
  #6  
sothpaw2's Avatar
sothpaw2
Thread Starter
Safety Car
15 Year Member
 
Joined: Sep 2002
Posts: 4,030
Likes: 6
From: Maryland
Default

Originally Posted by Solofast
Look in the sticky at how to do it right. If you lower it too much in the back the rear shocks will bottom out and that will not only screw up your handling, it will ruin your alignment. You should expect the rear screws to be different. If you adjust them to be the same the corner weights will be off and the car will oversteer turning left and push turning right. There's a right way to do it and a wrong way, and you will just make more work for yourself if you screw it up.

Here is a link to the right way to do it.

http://forums.corvetteforum.com/1576940245-post106.html
That's interesting about the rear bolts being different left vs right. My right side is maybe .125" higher. Even the RF is a little higher than the LF. I'll have to get it on scales some time...what should the 4 corner weights be...equal?

BTW--I did lower the fronts a tiny bit from where the shop had them and now both screws are 1-2 thread from bottomed out. The height as measured on the rail at the front jack point is about 4.875". At least for my 2002 unit, I don't see the front going much lower on unmodified stock bolts.
Reply
Old Apr 19, 2011 | 04:16 PM
  #7  
Solofast's Avatar
Solofast
Melting Slicks
20 Year Member
Conversation Starter
All Eyes On Me
Top Answer: 1
 
Joined: Aug 2004
Posts: 3,003
Likes: 89
From: Indy IN
Default

Originally Posted by sothpaw2
That's interesting about the rear bolts being different left vs right. My right side is maybe .125" higher. Even the RF is a little higher than the LF. I'll have to get it on scales some time...what should the 4 corner weights be...equal?

BTW--I did lower the fronts a tiny bit from where the shop had them and now both screws are 1-2 thread from bottomed out. The height as measured on the rail at the front jack point is about 4.875". At least for my 2002 unit, I don't see the front going much lower on unmodified stock bolts.
The bolts are't different, the chassis is bent. They all are cause that's the way the tooling was made. When you get the car cornerweighted the rear screws will be different by about two or three turns. It's not a big deal, but if you lower the car so that the bolts are even your corner weights will be off by a good bit.

What you want to do when you are corner weighting the car is get it so that the percentages of weight from front to rear on each side are the same. That is, if you have 52% front and 48% rear on the left side you get the same percentages on the other side. That way the car corners the same going left or right. When doing the corner weighting, simply compare cross weights (sum of LF and RR) to (sum of RF and LR). When they are equal you are properly balanced. Note that the left side will be a little heavier than the right, but that's because of your weight (you should put weight in the seat to simulate the driver) and the weight of other stuff in the car like the steering wheel make the left side heavier.
Reply
Old Apr 19, 2011 | 06:19 PM
  #8  
seoulbrooks's Avatar
seoulbrooks
Instructor
 
Joined: Oct 2010
Posts: 240
Likes: 2
From: Yangpyeong Gyeonggi-Do
Default

Previous owner just maxed out on the stock bolts. Vette was all over the road and beat me to death. I know its a sports car but ones body can only handle so many bone shakes. When they put it up on the rack the rear shocks were bottomed out and the front had very little play. They adjusted the height back to within OEM specs and did a new alignment. Was I pleasently shocked on the ride home, lt was like I had a new vehicle. Handles much better and ride quality is now comfortable.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-1

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-2

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-3

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-4

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-5

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-6

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-7

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-8

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-9

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
Old Apr 19, 2011 | 09:26 PM
  #9  
sothpaw2's Avatar
sothpaw2
Thread Starter
Safety Car
15 Year Member
 
Joined: Sep 2002
Posts: 4,030
Likes: 6
From: Maryland
Default

Originally Posted by Solofast
The bolts are't different, the chassis is bent. They all are cause that's the way the tooling was made. When you get the car cornerweighted the rear screws will be different by about two or three turns. It's not a big deal, but if you lower the car so that the bolts are even your corner weights will be off by a good bit.

What you want to do when you are corner weighting the car is get it so that the percentages of weight from front to rear on each side are the same. That is, if you have 52% front and 48% rear on the left side you get the same percentages on the other side. That way the car corners the same going left or right. When doing the corner weighting, simply compare cross weights (sum of LF and RR) to (sum of RF and LR). When they are equal you are properly balanced. Note that the left side will be a little heavier than the right, but that's because of your weight (you should put weight in the seat to simulate the driver) and the weight of other stuff in the car like the steering wheel make the left side heavier.
Good info.--I wouldn't have guessed a difference in chassis left to right.
As measured at the jacking points on the frame rails, is 1/8" about the same as 2-3 threads of the bolt????
Reply
Old Apr 19, 2011 | 10:21 PM
  #10  
Solofast's Avatar
Solofast
Melting Slicks
20 Year Member
Conversation Starter
All Eyes On Me
Top Answer: 1
 
Joined: Aug 2004
Posts: 3,003
Likes: 89
From: Indy IN
Default

Originally Posted by sothpaw2
Good info.--I wouldn't have guessed a difference in chassis left to right.
As measured at the jacking points on the frame rails, is 1/8" about the same as 2-3 threads of the bolt????
Don't know how much shows up at the jacking points. LG motorsports has had a bunch of C5's on their surface plate and measured them prior to setting them up for the track. They said all of them were pretty much the same and in one thread on the Road Race and autocross page they noted how much it was. They said it was in the kickup on the passenger side.

And OBTW, most of the rear subframes are actually offset to the left of the car about 1/4 of an inch too. To get a proper alignment if you are tracking the car you will need to grind the hole in the frame that the rear subframe pin sticks into by about 1/4 of an inch. Otherwise you end up with about -1 degree of negative camber on passenger side and -2 degrees on the left. If you move the subframe you can get it centered properly and get -1.5 degrees on both sides.

Last edited by Solofast; Apr 19, 2011 at 10:24 PM.
Reply
Old Apr 20, 2011 | 04:07 PM
  #11  
leadfoot4's Avatar
leadfoot4
Team Owner
25 Year Member
Active Streak: 60 Days
Active Streak: 90 Days
Community Builder
 
Joined: May 2001
Posts: 87,320
Likes: 1,585
From: Western NY
Default

FWIW, I'll suggest this....With your car on as flat a surface as possible, use the lower a-arm pivot bolts, both front and rear, as your measuring points. Equalize these measurements side to side, with a little front downward rake, for aerodynamic stability.
Reply
Old Apr 20, 2011 | 04:41 PM
  #12  
sothpaw2's Avatar
sothpaw2
Thread Starter
Safety Car
15 Year Member
 
Joined: Sep 2002
Posts: 4,030
Likes: 6
From: Maryland
Default

Not a bad idea about the A-arm bolts...do you have a pic of them though? I'll have to open her up and also the shop manual. This reminds me though that I could also look up the official way to measure ride height here and at least derive what to measure left & right.

The frame rail at the jacking ponts is really easy to measure from so very convenient. Right now I have :

LF, RF: 4.79", 4.65"
LR, RR: 5.03", 5.06"

I would think since the car is symmetrical in the rear that if you measure from the rails the rear should be fairly even. I'm not super happy about the front but both bolts are about 1 thd from bottoming out. From what I've read, lots of folks set the car up this way (front almost bottom out, rear add some rake).
Reply
Old May 8, 2011 | 04:01 PM
  #13  
Jason's Avatar
Jason
Team Owner
10 Year Member
 
Joined: Jun 1999
Posts: 71,447
Likes: 6
From: Miami bound
CI 4-5-6-7 Veteran
Default

Don't forget to add your weight to the driver's seat.
Reply

Get notified of new replies

To Lowering: short simple question





All times are GMT -4. The time now is 07:51 AM.

story-0
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-1
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-2
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-3
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-4
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-5
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-6
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-7
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-8
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-9
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE