Rat Rod Nation - A place for motorheads
Rat Rod Nation builds => Rat Rod Tech Tips => Topic started by: Grumpyoldman on September 15, 2011, 10:29:56 AM
-
"Can we cut coil springs to lower a vehicle?"
"The design of the end of the spring determines if it can be safely cut. If it has the right end, it is OK to cut it."
Coil springs have 3 basic type of ends - Tangential End, Square End & Pigtail End.
Click the link below to find out more:
http://www.eatonsprings.com/cuttingcoilsprings.html
-
if you cut a coil spring, the sprint rate (K) actually increases, so be aware of that. Don't ask me the math involved.. that wasa 25 years ago in engineering skool. Haha
-
I have lowered the front of a couple of different vehicles over the years. Both I only lowered about 2". It is a low buck method. It does make your ride a little rougher. One method I cut coils and it turned out pretty good. The other I had an early 90's S-10 I wanted to lower the front 2". I first made sure I parked on level concrete and placed blocks under the frame and left about 2" between the blocks and frame. Then I picked the same area on both coils and heated a 3" to 4" length of the coil and let the truck settle onto the blocks. Left it sit on the blocks till the next day. That turned out good also. I know this is not the correct way to lower a vehicle but it works and doesn't cost anything but a little labor.
-
I have lowered the front of a couple of different vehicles over the years. Both I only lowered about 2". It is a low buck method. It does make your ride a little rougher. One method I cut coils and it turned out pretty good. The other I had an early 90's S-10 I wanted to lower the front 2". I first made sure I parked on level concrete and placed blocks under the frame and left about 2" between the blocks and frame. Then I picked the same area on both coils and heated a 3" to 4" length of the coil and let the truck settle onto the blocks. Left it sit on the blocks till the next day. That turned out good also. I know this is not the correct way to lower a vehicle but it works and doesn't cost anything but a little labor.
This is what I imagine when I hear.... "heat the springs to lower"
(http://i103.photobucket.com/albums/m125/justacog/Icons/08252007001.jpg)
Just saying.....
Cheers
RustyNCA
-
That is what you heard but it sure didn't look that bad. Looks like someone heated it in just one small spot. Plus I sure would not have heated it right in the middle. I wouldn't even consider using one that looked like that. Looks like it could come out.
-
Heating coil springs is dangerous! It removes the heat treatment, removes the hardness and causes stress between the anealed (heated) part and the original tempered part. That stress causes fractures in the metal that can lead to catastrophy!
It's not too hard to do some simple math to determine how much of the spring needs to be cut to attain the desired ride height. I use a simple ratio using installed height (weighted), compared to number of coils, related to the distance between the ball joint, control arm pivot and center of the coil. If the center of the coil is closer to the pivot, then it takes less cut to get results, if it is closer to the ball joint, then it takes more cut to get results.
If the installed height is 10" and the spring has 10 coils (just to make it easier to think about) then a reduction of 2" would be about 1 coil (give or take depending on spring centerline).
I dropped a Jag sedan 2" by cutting 3/4 coil and dropped my Corvair 3" by cutting almost 2 coils by using the above method. I got pretty close to my desired results by doing the math in my head.
-
That is what you heard but it sure didn't look that bad. Looks like someone heated it in just one small spot. Plus I sure would not have heated it right in the middle. I wouldn't even consider using one that looked like that. Looks like it could come out.
SUICIDE....
-
Heating coil springs is dangerous! It removes the heat treatment, removes the hardness and causes stress between the anealed (heated) part and the original tempered part. That stress causes fractures in the metal that can lead to catastrophy!
It's not too hard to do some simple math to determine how much of the spring needs to be cut to attain the desired ride height. I use a simple ratio using installed height (weighted), compared to number of coils, related to the distance between the ball joint, control arm pivot and center of the coil. If the center of the coil is closer to the pivot, then it takes less cut to get results, if it is closer to the ball joint, then it takes more cut to get results.
If the installed height is 10" and the spring has 10 coils (just to make it easier to think about) then a reduction of 2" would be about 1 coil (give or take depending on spring centerline).
I dropped a Jag sedan 2" by cutting 3/4 coil and dropped my Corvair 3" by cutting almost 2 coils by using the above method. I got pretty close to my desired results by doing the math in my head.
Not saying it is or isn't dangerous but I did this on an S-10 and put around 80,000 miles and neither failed. Like the above I wouldn,t drive it around the block. I had found it in one of the hot rod mags back in the 60's.
-
Heating coil springs is dangerous! It removes the heat treatment, removes the hardness and causes stress between the anealed (heated) part and the original tempered part. That stress causes fractures in the metal that can lead to catastrophy!
It's not too hard to do some simple math to determine how much of the spring needs to be cut to attain the desired ride height. I use a simple ratio using installed height (weighted), compared to number of coils, related to the distance between the ball joint, control arm pivot and center of the coil. If the center of the coil is closer to the pivot, then it takes less cut to get results, if it is closer to the ball joint, then it takes more cut to get results.
If the installed height is 10" and the spring has 10 coils (just to make it easier to think about) then a reduction of 2" would be about 1 coil (give or take depending on spring centerline).
I dropped a Jag sedan 2" by cutting 3/4 coil and dropped my Corvair 3" by cutting almost 2 coils by using the above method. I got pretty close to my desired results by doing the math in my head.
Not saying it is or isn't dangerous but I did this on an S-10 and put around 80,000 miles and neither failed. Like the above I wouldn,t drive it around the block. I had found it in one of the hot rod mags back in the 60's.
I understand, but some folks play Russian Roulette and get lucky as well. I'm glad you didn't have an accident.
-
EWWWW heating bad cutting good
-
Man I sure am glad I didn't kill myself. Just really don't know how I survived it all. :)
I guess I shouldn't use those ole tricks hot rodders used years ago.
-
LOL