I apologize in advance if the mods would prefer this in a different section. Considered popping it into 92-99, but it'* not a "problem" or "issue" exactly. Or the performance section, but I'm really just after some clarification. The 92 Olds 88 I just picked up has the FE1 suspension and no ELC. I'm building my parts list for the suspension based off the FE1 to FE2 post in Techinfo. I've got a question about the springs. I've encountered a few posts mentioning that the FE2 relied on the ELC setup to assist the springs in the rear. Will the springs listed in the suspension upgrade thread cause the rear to sag w/o ELC? Seems the choices in the Moog lineup are either the ones listed or constant rate replacements. Also, 2 front progressive rate springs are listed in the Moog lineup (CC656 & CC65. The 658'* are listed in the write-up, but listed for SSEi/LSS (supercharged, basically) based on application. I note car in the write-up is NA (CC656 application). I take it the 658'* were used based on them being the higher rate spring? My head hurts from trying to sort the "multiple spring rates" for each RPO concept. I just want the Float-a-Matic FE1 gone. This is the last part of list I'm doubting.

Do not attemnpt FE2 without ELC. It'* a calculated part of the equation. Do not use a constant-rate spring.

Do not 'over-spring' the front. If anything, you need more in the back (slightly) than the factory setup provides.

You want all 4 springs, both swaybars, and the ELC system/struts. Or a simple air strut manual replacement.

FE2 does not rely on ELC, That'* only if you're pulling parts from an ELC car. Non ELC got different springs...

Maybe I'll just refer to whatever this will becomes as "upgraded" instead of FE2. None of the parts stores I've checked online (rockauto/autozone/advance/napa/o'reilly) even mention ELC in the spring description, only in regards to struts. I've looked using both the Olds and a 93 Bonneville for the vehicle & the list is the same on springs. Maybe I'll email FM & see if I can just get the spring rates. The only thing sourced anywhere but the parts store will be the 32mm/21mm stabilizer bars (and center link stuff). so this won't be a matter of "get it all from the same car". Still irritated by the whole ELC thing. If it'* just to maintain a level ride height, I'd think it only came into play with the vehicle loaded or the springs sagging from wear to the point the rear drooped. Bah, the spring selection on the 7 was just a matter of HD or standard suspension . More research tonight I guess.

Grrr..."Federal-Mogul is not able to answer consumer inquiries directly." Guess that idea went out the window. Time to see if the brain-trust at O'reilly can get me an answer. Not holding my breath.

Well, I found the following for TRW on Advance Auto'* site...

CC656 (NA Front): INSIDE DIA.= 6.34 in.: BAR DIA.= 0.625 in.: FREE HEIGHT= 14.69 in.: SPRING RATE= 136 Lbs./In.: LOAD= 441 Lbs.: LOAD HEIGHT= 11 in.: END 1= PIG TAIL: END 2= TANGENTIAL

CC658 (SC Front): iNSIDE DIA.= 6.34 in.: BAR DIA.= 0.625 in.: FREE HEIGHT= 15 in.: SPRING RATE= 136 Lbs./In.: LOAD= 519 Lbs.: LOAD HEIGHT= 11 in.: END 1= PIG TAIL: END 2= TANGENTIAL

CC653 (Rear): INSIDE DIA.= 4.25 in.: BAR DIA.= 0.64 in.: FREE HEIGHT= 13.66 in.: SPRING RATE= 400 Lbs./In.: LOAD= 1230 Lbs.: LOAD HEIGHT= 10 in.: END 1= SQUARE: END 2= SQUARE

CS5711 (Rear, "Regular Duty" not progressive rate): INSIDE DIA.= 4.25 in.; BAR DIA.= 0.578 in.; FREE HEIGHT= 14.69 in.; SPRING RATE= 201 Lbs./In.; LOAD= 943 Lbs.; LOAD HEIGHT= 10 in.; END 1= SQUARE; END 2= SQUARE

I noticed while looking that the part #'* for various brands are similar. McQuay-Norris, for example, is FCS656V for CC656 & RCS653V for CC653. Moog PN'* are identical to TRW. I thought Moog/TRW were the same company, but don't see TRW listed under Federal-Mogul'* brands at their website. Autozone'* Duralast part #'* mimic McQuay-Norris, but have only a 1 yr warranty instead of Lifetime. Now I won't just flat-out assume spring rates are identical between brands, but I find the part # similarity potentially telling. Off for more forum searching regarding spring rates, lol.

So there is such thing as non-ELC FE2 suspension? Guess I'm way behind the learning curve on springs/struts

I just spent the last couple hours reading every thread brought up with "spring rate" for a search. A lot of what I read just confused me more. Mainly coming back to the ELC stuff being required or not. But since I'm not doing FE2 (no ELC & not adding it) I'll just continue to refer to my "upgrade". Here'* the thing that strikes me with the rear springs: no matter the brand, the choices are the 653 variable rate or the 5711 constant rate!

I'm leaning toward doing my "upgrade" as follows:
Front: CC656 springs & 32mm bar
Rear: CC653 springs & 21mm bar
Poly end-link bushings, replace all others if needed upon inspection
KYB GR-2 all the way around
Possible move from 205/70/15 to 215/65/15

My reasoning for the 656 up front instead of the 658 in the article is trying to achieve a potentially more neutral balance (less understeer). The tires on the beast right now are 6-7 year old Douglas Touring. Full tread depth with maybe 10k miles on them, but scary in the wet under braking. Both passenger side tires appear to be dry rotted also. Seriously looking at Yoko AVID TRZ'* as replacement. They look to have a very nice bang for the buck factor and get rid of the nasty single ply sidewall Douglas turds. Can't really go very aggressive with the tires as this will be my inclement weather car & I'll have to retain some snow ability. Could go with dedicated summer/winter sets, but the 7 will fulfill my "banzai run" needs. As the Olds was free & I sold 2 of my "crap" cars, I figure I can toss around $1k at it & still be even.

Any input here would be appreciated.

I'm thinking that the CC653'* will not be the way to go. The CC 653'* are designed to work with the ELC, so they will not work properly without it. I was told of a CC 655 from the suspension shop I deal with that fits and does not rely on the ELC, but I have not done any research on that part number, so I don't know how accurate it is.

The CC655 are listed for.86-88 BUICK FULL SIZE (LESABRE) OLDS (DELTA 88 ).
INSIDE DIA.= 4.187 in.: BAR DIA.= 0.656 in.: FREE HEIGHT= 13.84 in.: SPRING RATE= 355 Lbs./In.: LOAD= 895 Lbs.: LOAD HEIGHT= 11 in.: END 1= SQUARE: END 2= SQUARE

Load height is 1" higher, than the 653 or 5711. So I'm now wondering why the 653 & 5711 both have the same load height. I'm also wondering why if the 653 is the ELC application, nothing anywhere on the 4 parts sites I've checked mention ELC in regards to springs. Only "regular duty" or "Hef-T-Coils" in TRW lingo. Thinking through this in my head and assuming the 5711 is a non-ELC application, why would the 653 have the same load height? I'd assume slightly lower load height for an ELC type application if the ELC was contributing to the load height of an unloaded vehicle. Otherwise I come back to the ELC setup being used to keep the car level under load. Do vehicles with ELC & newish springs droop in the rear with no air added to the struts? As I don't have the system, I can't check this. Did F41 have ELC or rely solely on springs to set heigh in the rear? Trying to find ryhme or reason with the ELC stuff. If the 653 are ELC dependent, that means the 5711 become the only option.

I was wondering this the other day myself. Posted this and here is what I got:

http://www.bonnevilleclub.com/forum/...ic.php?t=78066