[RUQWIKR]

Just FYI, for FE3, the springs and swaybars are different between SS Coupe and Convertibles.

[TheRealJA105]

Has anyone confirmed the FE4 rear bar is solid?
FE3 was 10.0 lbs and FEA was 10.2 lbs. A solid bar would be significantly heavier.

[RUQWIKR]

Originally Posted by TheRealJA105

Has anyone confirmed the FE4 rear bar is solid?
FE3 was 10.0 lbs and FEA was 10.2 lbs. A solid bar would be significantly heavier.

FE4 rear is solid with 27mm OD and ~17.75#.

[TheRealJA105]

Originally Posted by RUQWIKR

FE4 rear is solid with 27mm OD and ~17.75#.

Thank you for this! Assuming my measurements are close enough to accurate and using Puhn's Sway Bar Stiffness equations, the FEA rear bar on full stiff is the same rate as the FE4 rear bar and it is 7.5 lbs lighter.

[RUQWIKR]

Originally Posted by TheRealJA105

Thank you for this! Assuming my measurements are close enough to accurate and using Puhn's Sway Bar Stiffness equations, the FEA rear bar on full stiff is the same rate as the FE4 rear bar and it is 7.5 lbs lighter.

Nope - I was told by someone (I trust) who had them tested that the FE4 was about 20% stiffer than the FEA in the short / stiff hole. What wall thickness are you using? I've seen one cut open, and the FEA wall thickness was just above 4mm.

[TheRealJA105]

0.180" and you're telling me it's 0.157" so close enough isn't close enough in this case. However I would bet they are made from standard 8 BWG tubing so that would put it at 0.165". My calculations based off of my measurements and weights had me at 7 BWG tubing.
Actually now that i'm looking at all of this again, 3/4" Sch. 80 pipe is 1.05" OD with a wall thickness of 0.154" and that seems like the winner here.
I was also calculating under the assumption that the FE4 bar was dimensionally identical to the FE3 bar, but solid.

[glamcem]

Originally Posted by RUQWIKR

FE4 rear is solid with 27mm OD and ~17.75#.

Thanks. Finally some valid information on this.
How about the front bars? Do you think we can have some info on that as well.

(If the total weight difference is about 7 lbs I can live with that especially it seems pretty low and near the end of the car.)👍

[rotis]

In order from soft to firm, my notes for bars-

Front bars-
FEA - 1.04" x .156w
FE3 - 1.09" x .152w
FE4 - 1.18" x .157w
Strano - 1.25" x .188w (adjustable)
Hellwig - 1.25" x .250w (adjustable)

Rear bars-
FEA - 1" x .165w (adjustable)
FE3 - 1" x .165w
FE4 conv - 0.98" solid
FE4 coupe - 1.06" solid

As noted, the FE4 coupe rear bar is 27mm solid, the FE4 convertible rear bar is 25mm solid. (added to info above, converted to inches)

Edited to add more bars from my notes.

[RUQWIKR]

Originally Posted by TheRealJA105

0.180" and you're telling me it's 0.157" so close enough isn't close enough in this case. However I would bet they are made from standard 8 BWG tubing so that would put it at 0.165". My calculations based off of my measurements and weights had me at 7 BWG tubing.
Actually now that i'm looking at all of this again, 3/4" Sch. 80 pipe is 1.05" OD with a wall thickness of 0.154" and that seems like the winner here.
I was also calculating under the assumption that the FE4 bar was dimensionally identical to the FE3 bar, but solid.

Go with 0.165" as he said right about 4.15/4.2mm wall thickness on FEA rear.

[glamcem]

So it looks like rear ZLE (FEA) swaybars are stiffer than the SS 1LE(FE4) sway bars.

Edited: it looks like I misread and front FEAs are thinner (softer)

[waterman]

Good discussion.

Info and research appreciated gentlemen.

[TheRealJA105]

Originally Posted by rotis

In order from soft to firm, my notes for front bars say-

Front bars-
FEA - 1.04" x .156w
FE3 - 1.09" x .152w
FE4 - 1.18" x .157w

As noted, the FE4 coupe rear bar is 27mm solid, the FE4 convertible rear bar is 25mm solid.

Awesome, this thread finally turned into what I wanted it to. I went back and read my posts and I did have a bad attitude at the beginning, but I hated that no one knew the answers and just said FE4 bars/endthread.

Originally Posted by RUQWIKR

Go with 0.165" as he said right about 4.15/4.2mm wall thickness on FEA rear.

Thank you again. Not sure whether its metric tubing, SAE tubing,or standard pipe now????? If the FE4 rear is actually 27mm it must be metric bar stock.
I believe his actual testing more than my measurements and calculations. Do you have the actual test numbers?

Originally Posted by glamcem

So it looks like rear ZLE (FEA) swaybars are stiffer than the SS 1LE(FE4) sway bars.

Edited: it looks like I misread and front FEAs are thinner (softer)

Your edit is correct.
Both FEA Bars then FE4 front. All front bar length dimensions are the same.

[Mountain]

Originally Posted by rotis

In order from soft to firm, my notes for bars-

Front bars-
FEA - 1.04" x 0.156w
FE3 - 1.09" x 0.152w
FE4 - 1.18" x 0.157w
Strano - 1.25" x 0.188w (adjustable)
Hellwig - 1.25" x 0.250w (adjustable)
BMR - 1.25" X 0.188W (adjustable and none)

Rear bars-
FEA - 1" x 0.165w (adjustable)
FE3 - 1.02" x 0.165w
FE4 conv - 0.98" solid
FE4 coupe - 1.06" solid
BMR 1.25" x 0.188w (adjustable and none)

As noted, the FE4 coupe rear bar is 27mm solid, the FE4 convertible rear bar is 25mm solid. (added to info above, converted to inches)

Edited to add more bars from my notes.

Added BMR bars and spec I've seen on FE3 coupe

[TheRealJA105]

I think we are trying to get too precise with our diameter measurements and wall thicknesses. There is no way GM (and aftermarket) isn't sourcing standard materials for these. The hundredths of inches will definitely fall within mill tolerances. Still not sure if we should be looking at SAE or metric standard sizes though. The solid bars point to metric, hollow bars look like both.