1 (edited by alloriginaltone 2021-05-19 10:12 AM)

Topic: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

Our Volvo S60 rides a little too high - because it's totally stock - except for all the crap we pulled out of it.  So, we need to lower it.

You all know we gotta stay on a budget partly because we are trying to keep our kids in college (except when we fly them home to race) but also because those extra laps for cheaty looking smurf blue springs will completely destroy our plans for domination.

So...I would like to hear some experienced viewpoints on cutting springs to lower ride height.  It would be ultra-mega-extra awesome to hear from anyone who has lowered the ride height (and stiffened it) on a Volvo S60.

Here are some questions to get this party started:

1. Cut or not?  Seems like it's fairly popular among Lemons teams.
2. How much to cut?
3. Should we try and re-bend the end to sit in the spring perch better/flatter?
4. Extra-credit bonus:  Should we cut the S60 springs or go the even stiffer XC70 springs and cut those?

Thank you!

PS - No need to talk about torching the springs. Not going to do that.

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

My experience with cutting springs has been you just have to sneak up to it in small increments.  The sweet spot seems to end up around 1.25 to 1.75 turns but not always.  The problem is that you could cut 1 turn, it drops 1/8", cut another quarter off, drops another 1/8", cut another quarter and it drops 1".  Even though that first cut only dropped 1/8", you need to move to the other side and do that as well.  If you cut away on just one side, the rest of the car can artificially hold that corner up so keep switching from side to side.

Yes, I would go with the XC70 springs.  Actual race springs are a ton stiffer than the factory springs (like 4x or more) and even cut are stiff way below "real" race car stiffness.  Alternatively you can measure up the springs you have and look through the Moog universal spring chart to see if there is some other OEM spring that is the right size, shorter and stiffer.  https://www.moog-suspension-parts.com/u … prings.asp

Also alternatively if your springs are a common Late Model/roundie round racecar size (5" IIRC) you can find a huge selection of used springs on eBay in all kinds of sizes and spring rates.  And they are cheap.

1990 RX7 "Mazdarita"  1964 Sunbeam Imp (IOE 2013 Sears Pointless) 2002 Jaguar x-type (Winner C-Class 2021 Sears Pointless)
Gone bye-bye
1994 Jaguar XJ12 (Winner C-Class 2013 Sears Pointless)  1980 Rover SD1 (I Got Screwed 2014 Return of Lemonites)

3 (edited by AT-JeffT 2021-05-20 07:32 AM)

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

I don't have any first-hand experience with cutting springs but in theory, I don't believe it will lead you to quicker lap times.

Cutting the springs does two things (mostly), 1) lowers the center of gravity of the car and lowers the ride height.  2) Moves the roll center of the car lower.  These two things have opposite effects on the handling.  It may differ for every car, but I would imagine you would end up with a net neutral or net loss in lap times. 

The idea for changing to stiffer springs is to minimize weight transfer and keep weight more even across all the tires.  Lowering the center of gravity doesn't help all that much.  Moving the roll center lower and increasing the roll couple will mean the car will experience more roll/weight transfer. 

I would go for the stiffer springs.


EDIT: Seems like there is more to cutting springs that I first thought.  Thanks for those who weighed in.

4 (edited by chaase 2021-05-19 12:27 PM)

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

AT-JeffT wrote:

I don't have any first-hand experience with cutting springs but in theory, I don't believe it will lead you to quicker lap times.

Cutting the springs does two things (mostly), 1) lowers the center of gravity of the car and lowers the ride height.  2) Moves the roll center of the car lower.  These two things have opposite effects on the handling.  It may differ for every car, but I would imagine you would end up with a net neutral or net loss in lap times. 

The idea for changing to stiffer springs is to minimize weight transfer and keep weight more even across all the tires.  Lowering the center of gravity doesn't help all that much.  Moving the roll center lower and increasing the roll couple will mean the car will experience more roll/weight transfer. 

I would go for the stiffer springs.

Cutting the springs increases the spring rate of many springs. Here is an article I found on Eaton Spring website that goes into the math and why it works. Whether or not it will help their lap times is a different matter.

https://www.eatondetroitspring.com/cutt … culations/

1992 Saturn SL2 (retired) - Elmo's Revenge -  Class B winner, Heroic Fix winner x2
1969 Rover P6B 3500S(sold) - Super G-Rover - I.O.E Winner, Class C Winner
1996 Saturn SW2 - Elmo's Revenge (reborn!), Saturn SL1  Dazzleshipm Class C winner
1974 AMC Javelin - Oscar's Trash heap - IOE,”Organizer's Choice" and "I got Screwed" award winner

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

AT-JeffT wrote:

I don't have any first-hand experience with cutting springs but in theory, I don't believe it will lead you to quicker lap times.

Cutting the springs does two things (mostly), 1) lowers the center of gravity of the car and lowers the ride height.  2) Moves the roll center of the car lower.  These two things have opposite effects on the handling.  It may differ for every car, but I would imagine you would end up with a net neutral or net loss in lap times. 

The idea for changing to stiffer springs is to minimize weight transfer and keep weight more even across all the tires.  Lowering the center of gravity doesn't help all that much.  Moving the roll center lower and increasing the roll couple will mean the car will experience more roll/weight transfer. 

I would go for the stiffer springs.

I would disagree.  Every car we've had where I cut the springs with the resulting lowering (RX7, SD1, Imp, S-type) resulted in much improved handling, quicker lap times and lowered tire wear.  Something to also keep in mind that when you lower a macpherson strut car, you also gain negative camber.  Yes, you certainly can engineer a car to handle better at stock height (i.e. Eyesore) but the ability to do so is beyond the capability, knowledge and budget of most Lemons teams.  You also certainly don't want to go too low as you screw up the suspension geometry.  For what we are doing, cutting the springs on that Volvo will make it faster and likely have better tire wear.  Cutting the XC70 springs would probably be even better yet.

1990 RX7 "Mazdarita"  1964 Sunbeam Imp (IOE 2013 Sears Pointless) 2002 Jaguar x-type (Winner C-Class 2021 Sears Pointless)
Gone bye-bye
1994 Jaguar XJ12 (Winner C-Class 2013 Sears Pointless)  1980 Rover SD1 (I Got Screwed 2014 Return of Lemonites)

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

AT-JeffT wrote:

I don't have any first-hand experience with cutting springs but in theory, I don't believe it will lead you to quicker lap times.

Cutting the springs does two things (mostly), 1) lowers the center of gravity of the car and lowers the ride height.  2) Moves the roll center of the car lower.  These two things have opposite effects on the handling.  It may differ for every car, but I would imagine you would end up with a net neutral or net loss in lap times. 

The idea for changing to stiffer springs is to minimize weight transfer and keep weight more even across all the tires.  Lowering the center of gravity doesn't help all that much.  Moving the roll center lower and increasing the roll couple will mean the car will experience more roll/weight transfer. 

I would go for the stiffer springs.

You also missed the (very common) issue they are trying at least in part to correct...when you gut a luxury car for racing, you end up removing so much weight your static suspension sag is greatly reduced so you are not at factory ride height anymore.  Heck, even our Saturn SL2 gained more than inch in front and 3/4" in the rear from gutting and caging.

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

step one, remove isolators. check height, step 2 cut a little at a time. Rears are usually 1" = 1", fronts differ.

"get up and get your grandma outta here"

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

Can you use the springs and struts/shocks from the XC?  I would assume the shocks are matched to a stiffer spring.

Cut 1/2 coil at a time, make sure they are separated from the strut when you do it.  Sometimes you may need helper springs if you cut too much to keep the coils in their seats.

Team whatever_racecar #745 Volvo wagon

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

When ever I cut springs The spring  always had a "flat" end and not a "pigtail" end. After cutting  I always  heated the spring end.  I did this progressively by heating the spring about 3/4 of a turn from where I cut the spring. I would put pressure on the spring by pushing down on it as the spring was heated. As soon as the spring gave a bit I stopped and moved a bit closer to the cut end. IF done right you end up with a spring that resembles the look of an uncut spring. Doing this results is further lowering of the car so you have to be careful not to cut to much. As someone said 'sneak up" on it.

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

Such great info.  We will go with the XC70 springs...will cut to match the height of the S60 springs...and then cut additional from there to lower...could be a fair bit to lower since these are stiffer springs already.  So, as someone said....we'll sneak up on it.

For the helper springs....the inside diameter of these springs is large - about 5.5".  I like the helper spring idea...but I only see helper springs that are much smaller in diameter.  The ones I've seen would end up inside the existing spring and not provide any support to the bottom of the main spring.  If anyone has an idea for helper springs that are large enough, that would be appreciated.

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

alloriginaltone wrote:

Such great info.  We will go with the XC70 springs...will cut to match the height of the S60 springs...and then cut additional from there to lower...could be a fair bit to lower since these are stiffer springs already.  So, as someone said....we'll sneak up on it.

For the helper springs....the inside diameter of these springs is large - about 5.5".  I like the helper spring idea...but I only see helper springs that are much smaller in diameter.  The ones I've seen would end up inside the existing spring and not provide any support to the bottom of the main spring.  If anyone has an idea for helper springs that are large enough, that would be appreciated.

I guess the other way is to safety wire the bottom of the spring to the perch...

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

I'd be hesitant to add helper springs.  I can't see springs of differing dimensions providing combined linear results.  I've used big zip ties to secure the spring to the lower seat.  Just don't secure the top as well.

1990 RX7 "Mazdarita"  1964 Sunbeam Imp (IOE 2013 Sears Pointless) 2002 Jaguar x-type (Winner C-Class 2021 Sears Pointless)
Gone bye-bye
1994 Jaguar XJ12 (Winner C-Class 2013 Sears Pointless)  1980 Rover SD1 (I Got Screwed 2014 Return of Lemonites)

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

I've had success welding a little vertical strip of metal to the bottom spring perch to give me peace of mind that the spring will stay put after I've cut it.

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

Spank wrote:

I've had success welding a little vertical strip of metal to the bottom spring perch to give me peace of mind that the spring will stay put after I've cut it.

Very clever idea.

15 (edited by chaase 2021-05-23 06:09 AM)

Re: Cutting Springs-Fear and Loathing- or Real Solutions to Real Problems

Spank wrote:

I've had success welding a little vertical strip of metal to the bottom spring perch to give me peace of mind that the spring will stay put after I've cut it.

We did that for all of the Saturns where we cut the springs.

1992 Saturn SL2 (retired) - Elmo's Revenge -  Class B winner, Heroic Fix winner x2
1969 Rover P6B 3500S(sold) - Super G-Rover - I.O.E Winner, Class C Winner
1996 Saturn SW2 - Elmo's Revenge (reborn!), Saturn SL1  Dazzleshipm Class C winner
1974 AMC Javelin - Oscar's Trash heap - IOE,”Organizer's Choice" and "I got Screwed" award winner