[YoungBlood]

Long story short, will Eibach Pro kit, be an improvement in handling over ZSP coils? I'm on all new Bilstein B4 shocks and struts, I don't plan to upgrade since these are new. I want a hair lower in the front than ZSP, but I'll gladly save the money if there's not a tangible handling improvement. Eibach's have almost identical springs rates to the ZSP kit, and most people only go .5 lower, if even that in the rear, so to me, on essentially stock dampers, I don't see how I'd get much of an improvement over oem. Who has gone to Eibach from ZSP, and was there an improvement to justify getting them? Other thing I'm considering is the Supreme Power lowering perch, since it'll bring the front where I want it, for $200 less than Eibach, and I'd get essentially identical ride height. Thoughts? Experience?

The reviews you're likely to get will be from those that changed springs and dampers at the same time. That won't help here given that, as you mentioned, the spring rates are pretty much the same and the upgraded dampers make the biggest/most noticeable difference out of those two parts anyway.

In this case, I would just trim the strut tab that sits on the lower knuckle and drop the whole assembly down a bit. That's a "free" solution and won't cause you to lose any suspension travel like the lowering perches will.

[YoungBlood]

Originally Posted by FCobra94

The reviews you're likely to get will be from those that changed springs and dampers at the same time. That won't help here given that, as you mentioned, the spring rates are pretty much the same and the upgraded dampers make the biggest/most noticeable difference out of those two parts anyway.

In this case, I would just trim the strut tab that sits on the lower knuckle and drop the whole assembly down a bit. That's a "free" solution and won't cause you to lose any suspension travel like the lowering perches will.

I was thinking about doing that! I was going to get under there and cycle the suspension to see if it would hit anything, with the strut sitting a bit lower. Have you done this?

No, I can't since I'm running "oversized" tires.

As long as you have a decent amount of space between the lower spring perch and top of the tire, you should be fine though. Spacers would also help, if you need them.

[YoungBlood]

Originally Posted by FCobra94

No, I can't since I'm running "oversized" tires.

As long as you have a decent amount of space between the lower spring perch and top of the tire, you should be fine though. Spacers would also help, if you need them.

gotcha! I am running 8.5 ET 23 up front, so I think it should clear without issue, but I'll double check. I'm actually on Tein springs right now, waiting on new bumpstops for my oem height to get in so I can go back to stock

Just curious; why are you stepping away from the Teins?

[YoungBlood]

They were much too low, especially with oem damping. I can smack my fender when turned, hitting a bump, not talking rubbing, but full on mashing the top of the tire into the fender. 1/4 longer bumpstops might save that from happening (pretty much stock sport ones, I have e36 m3's ones now), but then I'll be riding with 1/2 shock shaft showing before I contact the bumpstops, I have under an inch as it is. I also rub on my front bumper when turning up an incline. The rear spring rate being so much higher than stock (580 vs 440 or something like that) give me major bounce in the rear when accelerating, if there are any undulations in the road or bumps it gets kinda freaky actually, it hops, and then I get wheelspin since it unweights so hard, sort of a hop-spin hop-spin while wot unless it's a totally smooth road. It felt loose over stuff like that with oem sport, but at least it stayed it contact with the road.
I'm doing rear subframe bushings and hopefully that will combat that. The cornering at high speed was far better, but I was on blown struts without knowing it and sport springs with worn out bumpstops. I have e36 front stops right now, which are the perfect height for cruising, I only hit them hard on big dips, but turning I can hit my fender going into driveways etc, and autocrossing I had to leave early, since there was a dip coming into a corner that I kept hitting my fender coming into.

Long story short, if you wanna go low and keep it fairly comfy they're great. If you wanna improve highspeed corner handling, they're great. For canyon bombing, autocross, etc on stock dampers, I'm just way too under damped, and I'd rather pull em out, sell em, and run sport springs since I just got new dampers and shocks. Some Koni yellows, and these would probably be great, since more compression damping would likely keep you out of the fender 90% of the time, but still too low for my taste. I'm tucking the rear tires by about half an inch, and the front by about the same. If I was on stock height tires, that might also keep you out of the fender as well.

[YoungBlood]

Well, stuck my head under there to see how much clearance I have, it's not a whole lot. I can shave maybe 1/4 off that stop tab, and then I'll only clear by a few mm. Thinking about it though, any little bit helps the stock nose high stance. I also can for sure fit 15mm spacer if my ride height goes up that much (I'm dropped a solid 2") so going up 1.5" will leave tons of room for some 15mm spacers or even 18, which might let me go a solid 1/2 lower just off that. Not sure it's worth it when there are proven options like Eibach or SP perches

[Khy335i]

hey mate, I definitely felt a slight improvement in feel/handling, lowered before/after pic below, definitely down an inch or so:

Stock E92 335i with M Sports Package Springs (top) vs Eibach Pro Kit (bottom)

If you're buying for an handling "improvement", it might not be worth the $200. The objective of the springs are really for lowering your car. If you want handling, get some coilovers

I also fitted 15mm spacers in the rear and 12mm in the front without any problems on stock wheels and tyres (255/30R19 225/35R19)

Originally Posted by YoungBlood

Not sure it's worth it when there are proven options like Eibach or SP perches

Which version of the B4s do you have? Sport or base?

Either way, I'm not sure I'd trust either the Eibach springs or lowering perches when paired with a budge-minded damper like the B4 in the first place...they just aren't meant to go lower on; that's what B8s are for.

Come to think of it, if you're going as far as aggressive street driving and even auto-crossing, why didn't you go with B8s or yellows to begin with? You would have seen the highest performance advantage from those compared to any of the spring combinations you've already ran or are considering in the first place.

Also front vs rear spring rates cannot be compared simply by numerical figures alone; that's not how it works. Suspension design, wheel rate, motion ratio, etc. are all factors that you are not considering. For that reason, "major bounce" was a result of poor damping and worn/ineffective rubber bushings more than rear spring rate in your case. Sure, upgraded rear subframe bushings might have helped in your hop-spin scenario, but proper dampers, upgraded upper shock mounts, guide rods, etc. would likely have eliminated most all of it.

[YoungBlood]

Originally Posted by FCobra94

Which version of the B4s do you have? Sport or base?

Either way, I'm not sure I'd trust either the Eibach springs or lowering perches when paired with a budge-minded damper like the B4 in the first place...they just aren't meant to go lower on; that's what B8s are for.

Come to think of it, if you're going as far as aggressive street driving and even auto-crossing, why didn't you go with B8s or yellows to begin with? You would have seen the highest performance advantage from those compared to any of the spring combinations you've already ran or are considering in the first place.

Also front vs rear spring rates cannot be compared simply by numerical figures alone; that's not how it works. Suspension design, wheel rate, motion ratio, etc. are all factors that you are not considering. For that reason, "major bounce" was a result of poor damping and worn/ineffective rubber bushings more than rear spring rate in your case. Sure, upgraded rear subframe bushings might have helped in your hop-spin scenario, but proper dampers, upgraded upper shock mounts, guide rods, etc. would likely have eliminated most all of it.

I agree, I should've gotten Koni yellows or bilsteins in the first place. I'm running the sport specific version. I went for the B4's simply because I was being cheap, and it's definately biting me in the ass so my only solution, if want to keep my brand new dampers, is to go back to stock essentially. That at least will give me balanced handling. Not better handling, but balanced at least.

[YoungBlood]

So, I think I'm gonna shave a tiny bit off the stop tab (like 1/4 or so) and remove the rubber spring pad like the SP perches do, and pull the strut plate at the top out as well, read lots about it not being an issue on e9x chassis. all those small things should net me close to .5 inches total. Rear subframe bushings will be here this weekend as well. Bit of a bummer since it looks cool on the Tein springs but I want something I can drive without worrying about destroying my fenders or my tires on my fenders, or without taking flight over bumps. Lesson learned, cheaping out bites you in the ass

Removing the pad is probably a bad idea...not worth the ~1/16" you're likely to gain from it.

Just toss those dampers on CL and get something you'll actually be happy with yo.

[YoungBlood]

Originally Posted by FCobra94

Removing the pad is probably a bad idea...not worth the ~1/16" you're likely to gain from it.

Just toss those dampers on CL and get something you'll actually be happy with yo.

Either way, I want something that rides like, at least half an inch higher. I think I'm gonna just throw sport suspension back on, and save for a set of coilovers so I can just dial it in to what I actually want. This whole fiasco could've been avoided with coilovers. I'm currently just waiting on my new front bumpstops to get in, as well as my whiteline subframe inserts, and a set of 275/30/18 drag radials that I'm gonna stuff onto my 162's... This car is better in a straight line than a corner so I'm taking it to the strip! lol

[bin01123]

Originally Posted by Khy335i

hey mate, I definitely felt a slight improvement in feel/handling, lowered before/after pic below, definitely down an inch or so:

Stock E92 335i with M Sports Package Springs (top) vs Eibach Pro Kit (bottom)

If you're buying for an handling "improvement", it might not be worth the $200. The objective of the springs are really for lowering your car. If you want handling, get some coilovers

I also fitted 15mm spacers in the rear and 12mm in the front without any problems on stock wheels and tyres (255/30R19 225/35R19)

Attachment 1639901

Thanks for posting this in order to see the difference in height. I've got an M Sport and I'm happy with the height. Going to pass on springs and replace the oem struts with Bilstein B8s only. Thanks again.

[stevesingo]

Originally Posted by bin01123

Thanks for posting this in order to see the difference in height. I've got an M Sport and I'm happy with the height. Going to pass on springs and replace the oem struts with Bilstein B8s only. Thanks again.

You can use Eibach Pro springs for 6cyl diesel Touring to get a slight increase in stiffness without the ride height drop.

https://www.e90post.com/forums/showthread.php?t=1602649