Spring Test Roundup: BMR, MOOG, and GM
01-23-2012, 09:34 PM
#1
Install Director
Thread Starter
iTrader: (3)
Join Date: Nov 2001
Posts: 1,002
Likes: 0
Received 0 Likes
on
0 Posts
Spring Test Roundup: BMR, MOOG, and GM How serious are you about your suspension? Chances are you are in the category of people where it does not matter when you start talking little details. Nothing wrong with that. But there is a group of people where these little details start to matter. Where you want to know nuances that seem trivial to normal people. If you are one of those people, keep reading.
Different brand springs for 1997 - 2002 GM F-Bodies were purchased and tested to observe the exact spring rates. The springs used in the test were 2011 BMR Suspension rear and front springs, Moog rear springs, and GM Stock rear springs.
Read full tech article with results, photographs, and charts. Yes, we have a chart!
Here is the chart to make this a true InstallUniversity.com post.
Different brand springs for 1997 - 2002 GM F-Bodies were purchased and tested to observe the exact spring rates. The springs used in the test were 2011 BMR Suspension rear and front springs, Moog rear springs, and GM Stock rear springs.
Read full tech article with results, photographs, and charts. Yes, we have a chart!
Here is the chart to make this a true InstallUniversity.com post.
Last edited by wizkid; 01-28-2012 at 07:42 AM.
01-24-2012, 08:12 AM
#3
Install Director
Thread Starter
iTrader: (3)
Join Date: Nov 2001
Posts: 1,002
Likes: 0
Received 0 Likes
on
0 Posts
The rear spring for a stock camaro is linear. The BMR springs are dual rate.
This is meant to be just a reporting results type of article. A specific static height and crush height was needed so we were using and testing different springs to get the correct one. It was thought that if the MOOG springs were the advertised height and spring rate they would work, at least on paper.
When we measured their height we found that one spring was 0.5" shorter than the other. We also found the spring rating unacceptably low which would cause the car to sit lower than needed and squat more than the acceptable amount for this application.
Hypercoil springs were tested and I am adding those to the chart and article now. Strano's were not tested because our budget is only so big and no one volunteered up a set.
This is meant to be just a reporting results type of article. A specific static height and crush height was needed so we were using and testing different springs to get the correct one. It was thought that if the MOOG springs were the advertised height and spring rate they would work, at least on paper.
When we measured their height we found that one spring was 0.5" shorter than the other. We also found the spring rating unacceptably low which would cause the car to sit lower than needed and squat more than the acceptable amount for this application.
Hypercoil springs were tested and I am adding those to the chart and article now. Strano's were not tested because our budget is only so big and no one volunteered up a set.
Last edited by wizkid; 01-24-2012 at 09:00 AM.
Trending Topics
01-24-2012, 05:06 PM
#9
TECH Senior Member
01-24-2012, 08:41 PM
#11
Launching!
Join Date: Jun 2008
Location: Maine
Posts: 254
Likes: 0
Received 0 Likes
on
0 Posts
Very nice info, any chance you're going to test more springs?
Interesting thought on the progressive springs, it looks like when they are on the car they will actually not be in the progressive range much.
IIRC in the rear each corner weighs around 750lbs. Since rear spring rates are 1:1 with wheel rate (axle straight up and down that is), the springs would be compressed a little over 5.5" at ride height if I'm correct. Which is basically out of the progressive range.
So I'm thinking the springs are progressive just so they don't fall out when the car is jacked up, or if the car catches some air time lol.
*edit*
I didn't account for the unsprung weight (axle, brakes, wheels, tires, control arms, etc). Say all that was 300lbs, corner weight the spring would see is like around 600lbs. So that's a little under 4.75" spring compression at ride height. That brings it closer to the real progressive range.
Interesting thought on the progressive springs, it looks like when they are on the car they will actually not be in the progressive range much.
IIRC in the rear each corner weighs around 750lbs. Since rear spring rates are 1:1 with wheel rate (axle straight up and down that is), the springs would be compressed a little over 5.5" at ride height if I'm correct. Which is basically out of the progressive range.
So I'm thinking the springs are progressive just so they don't fall out when the car is jacked up, or if the car catches some air time lol.
*edit*
I didn't account for the unsprung weight (axle, brakes, wheels, tires, control arms, etc). Say all that was 300lbs, corner weight the spring would see is like around 600lbs. So that's a little under 4.75" spring compression at ride height. That brings it closer to the real progressive range.
Last edited by David_viny; 02-11-2012 at 05:06 AM.
01-25-2012, 10:02 PM
#13
Install Director
Thread Starter
iTrader: (3)
Join Date: Nov 2001
Posts: 1,002
Likes: 0
Received 0 Likes
on
0 Posts
A few more thoughts:
Send the springs or $$$ and spring tests are free. ;-)
Springs all application specific.
Yes, most if not all lowering springs for the F-Body are dual rate. The softer part coil binds or compresses. Then the final rate applies. In BMR's case their final rare is very close to 160 lb/in. Like Davud said above, the weight of the car takes the softer part of the spring out if the equation in this case.
I'll get a measurement on the uncompressed spring heights if I can remember.
Send the springs or $$$ and spring tests are free. ;-)
Springs all application specific.
Yes, most if not all lowering springs for the F-Body are dual rate. The softer part coil binds or compresses. Then the final rate applies. In BMR's case their final rare is very close to 160 lb/in. Like Davud said above, the weight of the car takes the softer part of the spring out if the equation in this case.
I'll get a measurement on the uncompressed spring heights if I can remember.
01-28-2012, 12:18 AM
#15
A few more thoughts:
Send the springs or $$$ and spring tests are free. ;-)
Springs all application specific.
Yes, most if not all lowering springs for the F-Body are dual rate. The softer part coil binds or compresses. Then the final rate applies. In BMR's case their final rare is very close to 160 lb/in. Like Davud said above, the weight of the car takes the softer part of the spring out if the equation in this case.
I'll get a measurement on the uncompressed spring heights if I can remember.
Send the springs or $$$ and spring tests are free. ;-)
Springs all application specific.
Yes, most if not all lowering springs for the F-Body are dual rate. The softer part coil binds or compresses. Then the final rate applies. In BMR's case their final rare is very close to 160 lb/in. Like Davud said above, the weight of the car takes the softer part of the spring out if the equation in this case.
I'll get a measurement on the uncompressed spring heights if I can remember.
01-28-2012, 01:10 AM
#16
I have a full set of Strano springs..
I will meet you in Chattanooga if you will come there.. Of course I need them back. LOL
I can meet you next weekend.
If you want to set something up, PM me.
BTW, if you aren't paying attention to the "trivial" details, you aren't modding your car right.
I will meet you in Chattanooga if you will come there.. Of course I need them back. LOL
I can meet you next weekend.
If you want to set something up, PM me.
BTW, if you aren't paying attention to the "trivial" details, you aren't modding your car right.
01-28-2012, 06:23 AM
#18
Install Director
Thread Starter
iTrader: (3)
Join Date: Nov 2001
Posts: 1,002
Likes: 0
Received 0 Likes
on
0 Posts
http://www.installuniversity.com/ls1...t-roundup.html
Let me check my schedule. I could send you a ups call tag. But first I need to get the schedule cleared for testing. I have the lab at my work and can weigh them anytime. And I'll gladly ship them back.
Btw, my work is in Lenoir City/West Knoxville. I'll pm you by Monday.
