Aerodynamics question
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From: Jersey City New Jersey
Aerodynamics question
I'm not sure if this is in my head or a reality but I recently lowered the rear end of my C6 on stock bolts so its only about half an inch lower than stock. I did not touch the front. At high speed the front end feels a bit ligthter than it did before. Am I crazy or is this happening? Should I lower the front to even it out? Or is this just in my head because lowering half an inch in the rear shouldn't make any real difference.
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From: Southampton NJ
Check this posting on how to set Z - Height.
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Race Director
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From: Southampton NJ
the rake wouldn't come into play at a 100mph, i had the same problem when lowered, even at lower speeds, got the alignment and its fine now, have been 165 straight as an arrow with skinnies and drag radials
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From: Jersey City New Jersey
I had an alignment done after it was lowered and it drives straight just feels a little less stable. Also it seems to be a little lower on the driver side could this be the problem?
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From: Southampton NJ
Safety Car
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From: Opelika Alabama
you and walt white must be smoking something, by dropping the rear he's pointed the nose up like the edge of a wing and is lifting the nose, the other guy talking about "wedge" is right these are not "lowering bolts" as alot of you engineers like to call them, they are "wedge bolts" just like in NASCAR and the Corvette is one of the few street cars that have them, they are for setting the front to rear "wedge" I love going for sprited drive's with the" lowering bolt cars" I always wonder why they all ways end up on the back of the group?
Drifting
Joined: Aug 2009
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From: South Fla
St. Jude Donor '10, '17-'18-'19
you and walt white must be smoking something, by dropping the rear he's pointed the nose up like the edge of a wing and is lifting the nose, the other guy talking about "wedge" is right these are not "lowering bolts" as alot of you engineers like to call them, they are "wedge bolts" just like in NASCAR and the Corvette is one of the few street cars that have them, they are for setting the front to rear "wedge" I love going for sprited drive's with the" lowering bolt cars" I always wonder why they all ways end up on the back of the group?
Instructor
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I you wanted to be 100% sure to maintain the factory balance while lowering, you would need 4 scales to measure before and after corner weight bias. You would still be left with a different static spring rate, but that is less of an issue.
Le Mans Master
Joined: Oct 2006
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From: Cumming, GA
To maintain the rake you should lower the front as well. Any reason why you would lower the rear and not the front? Based on what you posted it sounds like the car is level at park most likely.
But when on the gas the rear is going to squat making the front higher than the back now. If you lower the front too, once on the gas it will still squat the back BUT it will create a close to level height vs the front being higher. I lowered mine all around and cut the bushings. I still have rake from front to back.
But when on the gas the rear is going to squat making the front higher than the back now. If you lower the front too, once on the gas it will still squat the back BUT it will create a close to level height vs the front being higher. I lowered mine all around and cut the bushings. I still have rake from front to back.
CF Senior Member
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From: Tucson Arizona
There is a factory spec rake but most serious Corvette racers I know essentially level their car for track use eliminating the factory spec rake. Just turning the so-called 'lowering bolts' an equal number of turns is no guaranty your car will be setup properly. Actually, the setup may be off right from the factory (you don't know unless you check it first). Anytime you turn one of the 'lowering bolts' it affects the other corners of the car (the one diagonally the most). To some extent you can adjust the setup using the 'lowering bolts' but specific procedures should be followed, measurements taken, etc.
Le Mans Master
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From: Austin Texas
I'm not sure if this is in my head or a reality but I recently lowered the rear end of my C6 on stock bolts so its only about half an inch lower than stock. I did not touch the front. At high speed the front end feels a bit ligthter than it did before. Am I crazy or is this happening? Should I lower the front to even it out? Or is this just in my head because lowering half an inch in the rear shouldn't make any real difference.
2: you have decreased the rear roll center. This alter how much weight is transfered to the front and back tires in corners.
Pro
Joined: Dec 2007
Posts: 674
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From: Miami Beach FL
Personally I can't see myself modifying a car and and jerry rigging it. Put some pfadt coil-overs on the car and do it right. If it still feels light its because you are going 190mph and dont have a some cannards and a rear wing...
...yea, I said it... a wing.
But seriously the pfadts are worth every penny, it's night an day... and yes you may feel a little light past 190 and yes you may need a wing if you intend on sustaining and passing that speed while changing lanes vs bikes on the highway... If you got the vette for any other reason... return it and stick to the right lane... I hear Kia is making some nifty cars
...yea, I said it... a wing.
But seriously the pfadts are worth every penny, it's night an day... and yes you may feel a little light past 190 and yes you may need a wing if you intend on sustaining and passing that speed while changing lanes vs bikes on the highway... If you got the vette for any other reason... return it and stick to the right lane... I hear Kia is making some nifty cars
Last edited by xcessivex; Aug 27, 2009 at 01:49 AM.
Tech Contributor
Joined: May 2008
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From: Howell Michigan
St. Jude Donor '09-'10-'11
There is a factory spec rake but most serious Corvette racers I know essentially level their car for track use eliminating the factory spec rake. Just turning the so-called 'lowering bolts' an equal number of turns is no guaranty your car will be setup properly. Actually, the setup may be off right from the factory (you don't know unless you check it first). Anytime you turn one of the 'lowering bolts' it affects the other corners of the car (the one diagonally the most). To some extent you can adjust the setup using the 'lowering bolts' but specific procedures should be followed, measurements taken, etc.
Auto-x and road racing at a lower speed track might also benefit from leveling. But I believe that any high speed track with turns the car would benefit with maintaining rake to add down force. I guess my thought is this would allow for higher speeds in and out of turns.
A car used as a daily driver it probably doesn’t matter much and the factory setting might be the best all around choice.
If you are a speed demon and not really racing anyone but your personal ego then maintaining or adding more rake might be the better choice to keep the vehicle more stable, in that the added drag doesn’t matter. This might be the better choice for the original poster.
