Lowering/Raising the rear.... threads vs height question
Thread Starter
Race Director
Joined: Oct 1999
Posts: 17,710
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From: Phila PA, Bonita Springs FL
Lowering/Raising the rear.... threads vs height question
Wondering if there is any perscribed rule of thumb for threads in relation to height?
Like 4 threads=1" ??
Anyone know?
I need to raise the lowered rear slightly, because with the addition of 19" rims, it seems I'm getting some slight fender rub, that wasn't present with my former 18" rims.
I can easily do it, just don't have the time for trial & error.
I'd like to raise by 1/2"-3/4".
With my 18" rims/tires, I could put 2 fingers between the top of the tire & the fender. With these 19" ones, 2 won't fit. I'd like be able to fit 3. That should be enough clearance not to rub if I glide over a bump, but still retain the lowered look.
Like 4 threads=1" ??
Anyone know?
I need to raise the lowered rear slightly, because with the addition of 19" rims, it seems I'm getting some slight fender rub, that wasn't present with my former 18" rims.
I can easily do it, just don't have the time for trial & error.
I'd like to raise by 1/2"-3/4".
With my 18" rims/tires, I could put 2 fingers between the top of the tire & the fender. With these 19" ones, 2 won't fit. I'd like be able to fit 3. That should be enough clearance not to rub if I glide over a bump, but still retain the lowered look.
Team Owner
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Re: Lowering/Raising the rear.... threads vs height question (indypace78)
I don't think there is any correlation between the number of threads and the height. :nonod: I think you need to adjust and measure.....not what you wanted to hear, I know. :chevy
Burning Brakes
Joined: Nov 2001
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From: Statesboro Ga
Re: Lowering/Raising the rear.... threads vs height question (indypace78)
When I was posting questions about lowering mine and was wondering the same issue, someone mentioned something like 1 turn = 5/64". Sorry, I threw out the printed out post after getting done, so I'm not absolutely sure, but I'm pretty sure about remembering this.
But, it was also pretty much a consensus that each Vette may react differently, especially when you factor in the settling that just naturally occurs over the week or two after lowering.
But, it was also pretty much a consensus that each Vette may react differently, especially when you factor in the settling that just naturally occurs over the week or two after lowering.
Thread Starter
Race Director
Joined: Oct 1999
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From: Phila PA, Bonita Springs FL
Re: Lowering/Raising the rear.... threads vs height question (GLF)
After just doing it, it looks like 5-6 threads = 5/8-3/4".
My rear lowered ride heigh was about 27 1/4 ".
Turned about 5 threads, now both sides measure about 28".
Can't really fit 3 full fingers inbetween the top of the tire & the fender, but 2 definitely goes in with space left.
Just went out for a 20 mile ride, lets the suspension settle down.
Still looks good, in porportion now, as before, it looked like the rear was slammed in relation to the front, no rubbing over bumps, rides nice!
I'm a happy camper now! :yesnod: :lol: :hurray:
Feels good when you do something yourself & it works out! :lol: :smash:
So I guess the moral of the story is if you have lowered your car, and move up tp 19" rims & tires in the rear, (from 18's), you might have to bump the rear up slightly.
Also, I originally lowered my car by just turning the stock bolts & leaving 2 threads showing.
Didn't use longer bolts, didn't cut any bushings..
[Modified by indypace78, 7:27 PM 8/2/2003]
My rear lowered ride heigh was about 27 1/4 ".
Turned about 5 threads, now both sides measure about 28".
Can't really fit 3 full fingers inbetween the top of the tire & the fender, but 2 definitely goes in with space left.
Just went out for a 20 mile ride, lets the suspension settle down.
Still looks good, in porportion now, as before, it looked like the rear was slammed in relation to the front, no rubbing over bumps, rides nice!
I'm a happy camper now! :yesnod: :lol: :hurray:
Feels good when you do something yourself & it works out! :lol: :smash:
So I guess the moral of the story is if you have lowered your car, and move up tp 19" rims & tires in the rear, (from 18's), you might have to bump the rear up slightly.
Also, I originally lowered my car by just turning the stock bolts & leaving 2 threads showing.
Didn't use longer bolts, didn't cut any bushings..
[Modified by indypace78, 7:27 PM 8/2/2003]
Melting Slicks
Joined: Nov 2000
Posts: 2,333
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From: USA
Re: Lowering/Raising the rear.... threads vs height question (indypace78)
Indy,
The rear bolts have about 14 threads per inch. It would seem that a 1/2" drop would take about 7 threads but in my experience the car drops (changes) more than the ratio of threads.
You also have to consider how much fuel is in the tank.
And, that by raising one side you also raise the other side somewhat.
In your case I think I would raise both sides 5 threads (turns) and check from there after driving.
I can loosen/tighten my rear bolts in about 5 minutes.(3 minutes to find the proper wrenches) You do not need to jack the car up, just slide under and adjust.
Dave
The rear bolts have about 14 threads per inch. It would seem that a 1/2" drop would take about 7 threads but in my experience the car drops (changes) more than the ratio of threads.
You also have to consider how much fuel is in the tank.
And, that by raising one side you also raise the other side somewhat.
In your case I think I would raise both sides 5 threads (turns) and check from there after driving.
I can loosen/tighten my rear bolts in about 5 minutes.(3 minutes to find the proper wrenches) You do not need to jack the car up, just slide under and adjust.
Dave
Melting Slicks
Joined: Nov 2000
Posts: 2,333
Likes: 32
From: USA
Re: Lowering/Raising the rear.... threads vs height question (BQuicksilver)
As a rough rule, 5 turns is 0.5 inch.
Since he is working on both rear corners though, raising one side 5 threads will raise the other side a little. Then when he raises the second side it will raise the first side a little. :confused:
He should come up with 1/2" to 3/4".
Dave
Racer
Joined: Jun 2003
Posts: 385
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From: West Lafayette Indiana
Re: Lowering/Raising the rear.... threads vs height question (corvette dave)
You don't have to do any math.
In the Helms service manual is clearly states that 1 turn is equal to 2mm.
:chevy:
In the Helms service manual is clearly states that 1 turn is equal to 2mm.
:chevy:
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