I want to INCREASE my ride height

[Digitalwave]

Technically, there are several inches of "travel" when the spring and shocks are unloaded, i.e. when the car is jacked up. Of course you realize that the spring and shock are compressed when the car is lowered back down though. The 1" of travel Jay is refering to is the distance of shock travel you have left once the car has settled down and the weight has compressed the spring and shock. If you can shine a flashlight up into your wheel well when the car is on the ground you will see how little travel is available.

I'd have to say though, just ignore comments like asubimmer's, his grandpa owns Korman so sometimes that goes to his head I think.

Eibachs work for some people but compared to other available springs (namely H&R Sport, the closest alternative) they are a poor design. The spring rates on the Eibach Pro Kit are just barely stiffer than the stock rates. Given the sizable drop the springs provide (I'd say closer to 2", not 1.6" as they advertise), it is very similar to riding on chopped stock springs.

It's not that the build quality of the springs is poor, as Eibach is definately one of the best spring manufacturers out there, it is simply that the rates and the amount of drop on the Pro Kit springs leave something to be desired.

[Old'n'Slow]

Technically, there are several inches of "travel" when the spring and shocks are unloaded, i.e. when the car is jacked up. Of course you realize that the spring and shock are compressed when the car is lowered back down though. The 1" of travel Jay is refering to is the distance of shock travel you have left once the car has settled down and the weight has compressed the spring and shock. If you can shine a flashlight up into your wheel well when the car is on the ground you will see how little travel is available.

I'd have to say though, just ignore comments like asubimmer's, his grandpa owns Korman so sometimes that goes to his head I think.

Eibachs work for some people but compared to other available springs (namely H&R Sport, the closest alternative) they are a poor design. The spring rates on the Eibach Pro Kit are just barely stiffer than the stock rates. Given the sizable drop the springs provide (I'd say closer to 2", not 1.6" as they advertise), it is very similar to riding on chopped stock springs.

It's not that the build quality of the springs is poor, as Eibach is definately one of the best spring manufacturers out there, it is simply that the rates and the amount of drop on the Pro Kit springs leave something to be desired.

Thank you, Digitalwave, for an answer!

I do fully understand that the Eibach Pro-Kit spring rate is rather soft, especially for a somewhat aggressive lowering spring. Their site claims that you lose more ride quality from going plus 1 than from installing their springs, so it's not surprising that these aren't much stiffer than stock. Even fully loaded, I can't personally report any problems, but that may not be everyone else's experience...

I've had H&R OE Sports, and I further understand both from this forum and from speaking with someone at H&R familiar with e30s that the OEs and Sports have identical spring rates, just different amounts of lowering. I thought the OEs were a bit stiff at the time, but in hindsight, I think it was my shocks that were too stiff. Maybe I'll try the Sports w/ my Konis, or maybe IE Stage 3 for the lowering, but now we are getting into much stiffer springs...I suppose there's always the Cup Kit...

With the race-prepped 240Z I drove in the early 80's (showing my age!) we simply used the stiffest lowering springs we could obtain and ran our Konis at full soft. This all but eliminated roll, and maximized rear traction. Ride, however was barely streetable and most definitely not limo-like!:eeek:

Again, thanks for a well-thought-out response. :up:

[Digitalwave]

RE: other springs. I'd say the Cup Kit is somewhere between the Eibach Pro Kit and H&R Sports as far as stiffness goes. The IE3's are the stiffest of the bunch, but are still streetable (for most people).

Cheers for civil debate, rather than internet flames wars 8-)

[Mystikal]

Looks like I pissed off the old guy.

I didn't mean to offend you, I'm only stating fact. I will quote my own reply to a similar query a few months back:

Springs are made up of numbers, it's as simple as that. No black magic, no hidden features.

Now, Eibachs are significantly shorter than stock springs (usually 40-70% of the actual travel), and are not in any significant form stiffer. This makes them a horrible design, that only gets worse over time with their sagging.

I personally know that even a 300lb/in spring rate in the front (over twice the Eibach's) at the SAME ride height that the Eibachs provide is just enough. IE Stage III's or H&R Race's are 310lb/in, and are enough to lower a car that much. There is a reason H&R Sports don't lower a car to the extreme Eibach Pro-Kits do, it's because a car does NOT handle well at that height with that soft of a spring rate. Add that to the fact that H&R Sports are at 190lb/in (28% stiffer) yet make the car sit almost an inch higher shows just how far off Eibach engineers were when they designed the spring kit for our cars.

And Ground Control coilovers come with any rates you want. The lowest GC will sell you for the front is 300lb/in, which is over twice the rate of a Pro-Kit. Yeah, think about that one.

So...to sum it up:

o Pro-kit rates are almost identical to a stock E30 M3
o The springs make the car sit significantly lower
o These two points add up to excessive bottoming

o H&R Sport springs do not lower the car as much up front, and are 28% stiffer. Mathematically, this is a much more logical design.

And BTW, your point about where your Konis are set in relation to bottoming is not valid, you are adjusting the rebound. This has nothing to do with jounce.

[Old'n'Slow]

Looks like I pissed off the old guy.

Naw, man.

I just get frustrated when I get answers that don't make sense to me. That last post was awesome. Very helpful.

So if the Cup Kit springs aren't as stiff as the Sport springs(speaking now of H&R), how does the Cup Kit get away with being so low? Just wondering what H&R did to make that work.

I'm going to stick a set of Sports under my car in the next week or so and see how it feels. I like it low, but geez, 300# front springs from IE sound very "track" and not very "street" for the busted up, frost-heaved roads around here.

Again, thanks for your continued efforts at clarification. :)

[nando]

So if the Cup Kit springs aren't as stiff as the Sport springs(speaking now of H&R), how does the Cup Kit get away with being so low? Just wondering what H&R did to make that work.

I don't have any experience with the cup kit, but I'm going to go out on a limb and say the custom matched shocks/struts that come with the cup kit probably make a big difference.

[Digitalwave]

To be honest the more I think about it I think its the shocks that are softer on the Cup Kit setup. The Cup Kit is softer than the H&R Sport/Bilstein Sport combo and I think a big part of it is the harshness of the Bilsteins.

[Mystikal]

Naw, man.

I just get frustrated when I get answers that don't make sense to me. That last post was awesome. Very helpful.

So if the Cup Kit springs aren't as stiff as the Sport springs(speaking now of H&R), how does the Cup Kit get away with being so low? Just wondering what H&R did to make that work.

I'm going to stick a set of Sports under my car in the next week or so and see how it feels. I like it low, but geez, 300# front springs from IE sound very "track" and not very "street" for the busted up, frost-heaved roads around here.

Again, thanks for your continued efforts at clarification. :)

Cool. I know I came off arrogant earlier what without any evidence to back up my statement, but I'm just tired of posting it all the time. Maybe I'll just cliff notes it in my sig, hah!

Like TJ said, I'm pretty sure the Cup Kit has relatively high spring rates compared to Eibachs or similar, but the dampers are more like Konis (less bound dampening, much more comfortable than the stiff Bilsteins). Which brings me to my next point: Springs do not affect ride quality in nearly the same manner as dampers do. If two springs are both progressive (any non-coilover, really), even if one has twice the rate the ride really doesn't change very significanty. I've posted in the past that I've driven in two E30s with stock dampers, one with a Pro-Kit and one with Stage III's, and they felt damn near the same. The difference is the Stage III's won't bottom out, and will really help with roll control.

[Old'n'Slow]

I've posted in the past that I've driven in two E30s with stock dampers, one with a Pro-Kit and one with Stage III's, and they felt damn near the same. The difference is the Stage III's won't bottom out, and will really help with roll control.

So you're saying I shouldn't fear IE 3's much higher spring rate when compared to the Pro Kit, Sport or Cup Kit? I'm going to continue using my Konis. I'd prefer not to deal with the increased front camber, but I could always use the OE "crash mounts" that add half a degree or so of positive camber to each side.

What strikes me is reading somewhere about how the H&R Race springs, which the IEs were modeled after, were unstreetable for most normal mortals. I don't want a crashy sounding ride, but I suppose if I really hated them, I could find someone around here to buy them!

CliffsNotes? CliffsNotes?! You read all of that? :mrgreen:

[Mystikal]

Nope, you shouldn't fear it at all. Every experienced suspension engineer (whether they work for a spring or a damper producing company, and notice I said engineer and not PR guy) state that it is always the dampers that dictate ride quality, and not the springs. I've heard of 600lb/in front and 800lb/in rear A4s riding better than stock; dampers honestly do at least 90% of the work we feel as ride quality.

H&R does not recommend the Race springs for the street because of the extreme lowering, from what I understand. That said, I'm not convinced they'll make your car sit ANY lower than the Eibachs do, plus the car won't bounce as much as you leave driveways, crest speedbumps, etc.

[Old'n'Slow]

Nope, you shouldn't fear it at all. Every experienced suspension engineer (whether they work for a spring or a damper producing company, and notice I said engineer and not PR guy) state that it is always the dampers that dictate ride quality, and not the springs. I've heard of 600lb/in front and 800lb/in rear A4s riding better than stock; dampers honestly do at least 90% of the work we feel as ride quality.

H&R does not recommend the Race springs for the street because of the extreme lowering, from what I understand. That said, I'm not convinced they'll make your car sit ANY lower than the Eibachs do, plus the car won't bounce as much as you leave driveways, crest speedbumps, etc.

Thanks. This has been very informative. For now, I have a set of H&R Sports I'm gonna throw under there tomorrow. Until I have the time to weld in some IE toe and camber adjusters, I'm going to firm things up a bit, and not have my rear tires devoured by the over-spec-rear-toe-monster. IE3s in late spring when it's just a bit warmer. I'll be due for brake fluid then anyway...

Again....

THANKS!