Help characterize Eibach, Intrax, B&G, and Moog springs

[zak]

Purpose of this thread is to characterize these various springs to determine which might provide the best handling, and/or provide the best mix of street comfort and performance. Yes, the initial and final spring rates are all now known (I will be posting the results of load testing the front Moogs on a test machine), but I need data on the other springs in order to model and compare them. As further explanation, am trying to decide whether Intrax or Eibach will be going on the front of my car with the new struts I'm building, but this should help everyone. At issue is the relative amount of low rate, vs high rate portions of these different springs - a spring that transitions to high rate more quickly is what I'm after.

I just pulled out an uncut Eibach spring, and need the same data for Intrax and B&G.

EIBACH FRONT
Bottom/high rate coils*: 3.0
Transition coil ~ 1.0
Upper/low rate coils: 2.5
Wire diameter: 0.635 inch
Free height 14.2 inch

* includes the bottom tail of the spring, to be understood that the first half turn is on the perch and therefore inactive.

To help with this, take the spring and count the number of each of the coils to the nearest quarter turn. If the spring is on a strut indicate how much of the upper, low rate coil is touching or completely collapsed.

To determine where the tranistion coil begins, for the Eibach I was able to fit four fingers between the high rate coils. As soon as that was not possible (working upwards) I called this the start of the transition coil. The low rate coils were all about 3/4 of an inch apart, once the coils became evenly spaced again they counted as the low rate portion.

Please do not clutter up this thread with your opinion of how each of the springs makes your car look, how we should just all run coilovers, how you successfully cut 3 and a half coils off of spring X, how spring Y made your car feel like it handled better, etc. etc. Thanks for your help in finding out which of these springs can be used for maximum roll stiffness.

Any questions post here or PM. Thanks - zak

 

[zak]

MOOG FRONT (uncut)
Bottom/high rate coils*: 3.0
Transition coil ~ 1.0 to 1.5*
Upper/low rate coils: 2.5 to 3.0*
Wire diameter: 0.625 inch
Free height 17 inches (uncut)

*depending upon where you call the transion, a half coil could be low rate, or it could be transistion, for a total trnasiton plus low rate coil count of 4.0

 

[Phoenix]

Note that the MOOG coils are ATX only , they stop making the MTX ones. At least thats what they told me.

It was sitting way high when I installed them on my gutted MTX.

 

[K-Dawg]

Also, there's Gen 1 and Gen 2 Moog springs.

 

[zak]

The ones above were off an ATX application, will see if I can find a number on them. Most cut at least one full coil on these, will comment on that later. And the split in Moogs catalog runs more along the lines of Gen I vs Gen II IIRC, there never was a MTX spring application.

Anyone have front Intrax they can look at?

 

[zak]

Anyone have front Intrax they can look at?

pretty please . . . . .

 

[LOUDSHO92]

I have NO IDEA who would ever have that type of information or springs... :angelnot:

 

[inverse1216]

i have some intrax springs here how do you want me to measure these things the only thing i understand from the above info is free height. is the wire diameter just the thickness of the coil and the upper and lower rate the spacing between the coils? be glad to get you the info just let me know what im looking for

 

[zak]

inverse - thanks. Start counting the coils at the very bottom. You will probably be able to fit say 4 fingers in between each coil. as you work upward you will reach a point where that can not be done easily - that point is your "high rate" coil count to the nearest quarter turn.

Working from the top (closely spaced) coils you will note that you can only fit one finger in between. work your way down, counting the coils, until it starts to widen - mark that point with a marker or something. This is the low rate coil count.

The distance between those two points is the transition portion (in the middle) it will probably be 3/4's to 1 and a half turns.

Unless you have a caliper don't worry about the wire diameter it is almost certainly 5/8's.

Thanks again

 

[inverse1216]

zak,

ok on the front spring from the bottom i can go 3 coils and on the fourth i can only go 2. from the top i can only go 2 coils before i go from one finger to two. the distance in that "middle" i measured an 1 1/8. idk if im doing this right hope this gives you some insight. if there is anything else let me know.

 

[zak]

Thanks!

Here is your data in table form:

INTRAX FRONT
Bottom/high rate coils*: 3.0
Transition coil 1 1/8th
Upper/low rate coils: 2.0

Looks like Intrax have a shorter low rate range before they botton the low rate coils and transition to high rate. This could also account for their somewhat lower ride height compared to Eibach.

My Instron measurements of the front Moogs indicate they start out at 140 lb/inch, then transition to 180 lb/inch. By cutting a coil from the top, low rate portion that willy bump up the low rate portion to 150 or more (need to model that). So, a performance benefit over the 93-94 and newer 155 lb/inch front springs, but not over 200 lb/inch 89-93 MTX springs.

 

[zak]

Just some notes.

94 ATX FRONT code SCH
Total Coils - 6.0 turns (linear)
Free height 16 3/`6 inch
Wire diameter 0.60 inches
Ford stated spring rate: 155 lb/inch

 

[zak]

i have no idea who would ever have that type of information or springs... :angelnot:

b&g = ???

 

[LOUDSHO92]

b&g = ???

We have had the information posted for a while now: SHO Source

 

[zak]

You have posted the spring rates, yes. Per the thread above, I'm trying to characterize the low rate vs high rate spring travel amounts.

 

[SeanMc]

Eibach = t3h suck
Intrax = t3h w1n

 

[boogeyman]

any one have any input about the ride quality diffrence between the b&g s2`s and the intrax springs i want to lower my car a bit but dont want a crazy harsh ride cruising around

 

[LOUDSHO92]

any one have any input about the ride quality diffrence between the b&g s2`s and the intrax springs i want to lower my car a bit but dont want a crazy harsh ride cruising around

They are the same.