Lowering
- Thread starter gabe_13corolla
- Start date
Nothing wrong with cutting coil springs, as long as it's done correctly, as with anything. Automotive engineers like Herb Adams has been cutting coil springs for years with stellar results. Stock springs have already settled and so cutting stock springs can actually be better than using aftermarket springs that haven't settled yet.
I wouldn't argue with an established engineer, but it's not something I'd feel comfortable driving. Technically speaking, both cut springs and lowing springs aren't that great for your struts. It's like driving around heavily weighted all the time and will just wear them out quicker. To solve that problem, you gotta drop some coin on the whole coil-over set up. But as for going cheap, I'd trust buying springs "made for" lowing over "if you do it right" cutting stockers.
It works. It's proven. It's safe. It costs much less than donating our hard earned money to aftermarket spring companies, who by the way cut their own springs. 
I've seen coil-over spring equipped cars driving down the road and they look like a bouncing skateboard. Besides, a Corolla is an economy car and for the massive amount of money that would be needed to upgrade all the components of an economy car just to make it competent in the first place, well might as well buy a real high performance car to start with and avoid the hassle and big expense of modifying an economy car.
I've seen coil-over spring equipped cars driving down the road and they look like a bouncing skateboard. Besides, a Corolla is an economy car and for the massive amount of money that would be needed to upgrade all the components of an economy car just to make it competent in the first place, well might as well buy a real high performance car to start with and avoid the hassle and big expense of modifying an economy car.
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But cutting springs is doing it right and in fact it's superior than donating hard earned cash to aftermarket spring companies, who also cut their springs.
The suspension engineer Herb Adams who developed the Pontiac Trans AM WS-6 high performance suspension package recommends cutting springs as opposed to buying new springs. He raced his Pontiac Fire AM in the 24 Hours of Daytona race and did very well with cut coil springs.
Take a look at the pictures of his race cars. Hot stuff! - http://www.google.com/search?q=Herb...5N5LTkQekoYDABA&ved=0CCwQsAQ&biw=1024&bih=635
Here is some information on how to properly cut coil springs from Herb Adams suspension engineering book, "Chassis Engineering" -
http://books.google.com/books?id=rY2ujnNrhf0C&pg=PA34&lpg=PA34&dq=Herb+Adams,+cutting+springs&source=bl&ots=HfQBfazM8t&sig=GOq_8E9aY8bQcQvQs2E7pOUryXw&hl=en&sa=X&ei=C7qvUsDaFYTtkQfjjYDYBA&ved=0CDMQ6AEwAQ#v=onepage&q=Herb%20Adams%2C%20cutting%20springs&f=false
The suspension engineer Herb Adams who developed the Pontiac Trans AM WS-6 high performance suspension package recommends cutting springs as opposed to buying new springs. He raced his Pontiac Fire AM in the 24 Hours of Daytona race and did very well with cut coil springs.
Take a look at the pictures of his race cars. Hot stuff! - http://www.google.com/search?q=Herb...5N5LTkQekoYDABA&ved=0CCwQsAQ&biw=1024&bih=635
Here is some information on how to properly cut coil springs from Herb Adams suspension engineering book, "Chassis Engineering" -
http://books.google.com/books?id=rY2ujnNrhf0C&pg=PA34&lpg=PA34&dq=Herb+Adams,+cutting+springs&source=bl&ots=HfQBfazM8t&sig=GOq_8E9aY8bQcQvQs2E7pOUryXw&hl=en&sa=X&ei=C7qvUsDaFYTtkQfjjYDYBA&ved=0CDMQ6AEwAQ#v=onepage&q=Herb%20Adams%2C%20cutting%20springs&f=false
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Yes older, more experienced and knowledgeable suspension engineers like Herb Adams do know their stuff. They've been there and done that, as the saying goes. Herb Adams didn't win races on theories but on documented facts. He's a chassis expert.
From his book, "Chassis Engineering" on lowering a vehicle, page 33 - http://books.google.com/books?id=rY2ujnNrhf0C&pg=PA34&lpg=PA34&dq=Herb+Adams,+cutting+springs&source=bl&ots=HfQBfazM8t&sig=GOq_8E9aY8bQcQvQs2E7pOUryXw&hl=en&sa=X&ei=C7qvUsDaFYTtkQfjjYDYBA&ved=0CDMQ6AEwAQ#v=onepage&q=Herb%20Adams%2C%20cutting%20springs&f=false
"Lowering - Before you invest in springs to lower your car, you should be aware that your chances of success are much better if you simply cut your existing springs. All springs take a certain amount of permanent set after they are installed. (Note that new cars sitting in a showroom are higher than the same models with only a few thousand miles on them). This change in ride height is caused by the inevitable loss in load that any new spring experiences. If you put new springs on your car, they will settle as much as an inch in the first few months. Obviously, if your car was the correct height when you installed the new springs, it will be too low after a few months.
This is why I recommend you cut your existing springs and save the cost of new springs. The results will almost certainly be better. Your car's existing springs have already taken a permanent set, so you know where they will end up. If you want to lower your car, you can cut your existing springs to achieve the ride height you want with one operation.
Springs don't wear out, so you can save the cost of new springs if you trim your existing ones. We have found that most coil springs should be cut 1/2 coil to lower the car and still keep adequate ride height. If your springs have sagged, you don't even have to cut them because the car is already at a lower ride height".
Then on page 35 there are step by step instructions on how to correctly cut coil springs.
On variable rate springs, page 31 - "Variable Rate Springs - A study of the optimum springs rates for a car eventually come to the conclusion that the best spring rate is a variable one. We would like to have a soft spring rate to absorb the road irregularities and then have a high spring rate to absorb the larger bumps. Springs are available that are made with a variable rate. You can identify these coil springs by noticing that the spacing between the coils is different from one to the other. The design concept of these springs is correct, but in practice they don't work too well. Since car springs only operate in a limited percentage of their travel, the amount of change in rate is usually pretty small. Jounce bumpers provide this same variable rate feature with more consistency".
-- B.F.Goodrich T/A Certified Tire Specialist.
Herb Adams didn't win races on theories but on documented facts. He's a chassis expert. From his book, "Chassis Engineering" on lowering a vehicle, page 33 - http://books.google.com/books?id=rY2ujnNrhf0C&pg=PA34&lpg=PA34&dq=Herb+Adams,+cutting+springs&source=bl&ots=HfQBfazM8t&sig=GOq_8E9aY8bQcQvQs2E7pOUryXw&hl=en&sa=X&ei=C7qvUsDaFYTtkQfjjYDYBA&ved=0CDMQ6AEwAQ#v=onepage&q=Herb%20Adams%2C%20cutting%20springs&f=false
"Lowering - Before you invest in springs to lower your car, you should be aware that your chances of success are much better if you simply cut your existing springs. All springs take a certain amount of permanent set after they are installed. (Note that new cars sitting in a showroom are higher than the same models with only a few thousand miles on them). This change in ride height is caused by the inevitable loss in load that any new spring experiences. If you put new springs on your car, they will settle as much as an inch in the first few months. Obviously, if your car was the correct height when you installed the new springs, it will be too low after a few months.
This is why I recommend you cut your existing springs and save the cost of new springs. The results will almost certainly be better. Your car's existing springs have already taken a permanent set, so you know where they will end up. If you want to lower your car, you can cut your existing springs to achieve the ride height you want with one operation.
Springs don't wear out, so you can save the cost of new springs if you trim your existing ones. We have found that most coil springs should be cut 1/2 coil to lower the car and still keep adequate ride height. If your springs have sagged, you don't even have to cut them because the car is already at a lower ride height".
Then on page 35 there are step by step instructions on how to correctly cut coil springs.
On variable rate springs, page 31 - "Variable Rate Springs - A study of the optimum springs rates for a car eventually come to the conclusion that the best spring rate is a variable one. We would like to have a soft spring rate to absorb the road irregularities and then have a high spring rate to absorb the larger bumps. Springs are available that are made with a variable rate. You can identify these coil springs by noticing that the spacing between the coils is different from one to the other. The design concept of these springs is correct, but in practice they don't work too well. Since car springs only operate in a limited percentage of their travel, the amount of change in rate is usually pretty small. Jounce bumpers provide this same variable rate feature with more consistency".
-- B.F.Goodrich T/A Certified Tire Specialist.
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Hey everyone new to this Forum i just got my 14 Corolla last Saturday i need to lower i hate the big gap, but i dont know how much i should cut the springs i dont want to much because i will be getting 18" TSW rims and i dont want the rubbing. I dont want to drop it more than 1" how much coil should i cut !?
Scott. Cutting springs works if you only plan on dropping a little. Anything over an inch (depends on the car of course), and you risk bottoming out the suspension which will cause severe chassis damage. Lowering springs require stiffer rates.
Yes, Eibach and other companies cut springs from one larger one, but they have the stiffer rates that 1. Keep suspension from bottoming out, and 2. Allow the car to perform in corners better because roll is minimized.
Racing today is far different from racing in the 70s. Most cars handled horribly then. Most performance cars today also use progressive springs, and you never cut those under any circumstances.
Yes, Eibach and other companies cut springs from one larger one, but they have the stiffer rates that 1. Keep suspension from bottoming out, and 2. Allow the car to perform in corners better because roll is minimized.
Racing today is far different from racing in the 70s. Most cars handled horribly then. Most performance cars today also use progressive springs, and you never cut those under any circumstances.
Impac, personally I never cut springs, but at an inch you should be okay (just keep in mind that if you load the car with passengers that you are more susceptible to bottom out and damage the chassis).
Easiest way to get your proper cut length would be to remove the front tires and get the car on jackstands, then use two hydraulic jacks (with a sheet of rubber to protect your control arm), and lift both control arms until you are off the jackstands (make sure you do this near the ball joint).
Measure the spring length at this position. Then measure the spring length when it is removed from the strut.
(spring length free * inches to lower) / (spring length under load) = distance to cut from free spring length
Easiest way to get your proper cut length would be to remove the front tires and get the car on jackstands, then use two hydraulic jacks (with a sheet of rubber to protect your control arm), and lift both control arms until you are off the jackstands (make sure you do this near the ball joint).
Measure the spring length at this position. Then measure the spring length when it is removed from the strut.
(spring length free * inches to lower) / (spring length under load) = distance to cut from free spring length
Scott, anti-sway bars don't stop nose-dive under hard braking, and they don't allow for minimum suspension travel (which protects the chassis). They also don't protect you from road imperfections in a corner. You still need stiffer springs.
Look up the spring rates of a stock car and compare it to the rate used for the same car that was track duty built. You're going to see a huge different.
Either the car is tuned for comfort but the suspension is too soft for racing, or the suspension is rough but excellent for racing. Some people have a different piece of the grey area that they prefer. I like hard suspension because I love cornering hard.
My '82 Mustang GT had $2,000 in suspension. It rode rough but that car did not want to let go of the road, even at 130+ m.p.h.
You could hold the brakes at threshold without locking the rears from a road imperfection because the car barely dived.
I've raced cars before, trust what I say.
Look up the spring rates of a stock car and compare it to the rate used for the same car that was track duty built. You're going to see a huge different.
Either the car is tuned for comfort but the suspension is too soft for racing, or the suspension is rough but excellent for racing. Some people have a different piece of the grey area that they prefer. I like hard suspension because I love cornering hard.
My '82 Mustang GT had $2,000 in suspension. It rode rough but that car did not want to let go of the road, even at 130+ m.p.h.
You could hold the brakes at threshold without locking the rears from a road imperfection because the car barely dived.
I've raced cars before, trust what I say.
Donabed_Kopolan - I've raced cars before too, for years. I'm not some wet-behind-the-ears kid. I've been in the automotive repair, maintenance and synthetic oil industry for over 30 years with automotive qualifications out the ying-yang.
A street car doesn't have to worry about nose-dive under braking as the stock springs are more than up to the job. Remember, the original poster here is talking about a street car, not a race car. A Toyota Corolla couldn't do 130 mph with a hurricane tailwind. Stiffer springs are not beneficial and will detract from both handling and ride quality. Bigger anti-sway bars will improve handling without reducing ride quality. It's interesting to note that NASCAR great Jeff Gordon has won Championships using the concept of softer springs with bigger anti-sway bars.
Overly stiff springs on a street car cause the tire/wheel assembly to bounce in the air when driving over uneven or bumpy road surfaces, instead of following the contour of the road. When a tire is in the air and not in contact with the road, that is not desirable for handling at all of course.
As the highly regarded suspension engineer Herb Adams points out, the 1985 Corvette had significantly softer coil springs than the 1984 model, (after many complaints from 1984 Corvette owners), with no loss in handling.
Herb Adams took an early 80's Mustang and improved its handling from only .75 g's to .92 g's without even touching the stock springs. This handling grip rivals the best cars in the world.
A street car doesn't have to worry about nose-dive under braking as the stock springs are more than up to the job. Remember, the original poster here is talking about a street car, not a race car. A Toyota Corolla couldn't do 130 mph with a hurricane tailwind. Stiffer springs are not beneficial and will detract from both handling and ride quality. Bigger anti-sway bars will improve handling without reducing ride quality. It's interesting to note that NASCAR great Jeff Gordon has won Championships using the concept of softer springs with bigger anti-sway bars.
Overly stiff springs on a street car cause the tire/wheel assembly to bounce in the air when driving over uneven or bumpy road surfaces, instead of following the contour of the road. When a tire is in the air and not in contact with the road, that is not desirable for handling at all of course.
As the highly regarded suspension engineer Herb Adams points out, the 1985 Corvette had significantly softer coil springs than the 1984 model, (after many complaints from 1984 Corvette owners), with no loss in handling.
Herb Adams took an early 80's Mustang and improved its handling from only .75 g's to .92 g's without even touching the stock springs. This handling grip rivals the best cars in the world.
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