Who has upgraded their ZHP suspension?

[SonOfWMB]

I want to upgrade my stock ZHP suspension with 110k miles on it. What have people upgraded their suspension to, and how do you like it? I'm interested in performance, not looks.

[jvr826]

I have TC Kline single adjustable dampers, 500# springs up front, 600# in the rear, camber plates, sway bars. Absolutely love it! I run an aggressive alignment, soften up the dampers a bit for street driving, firm them up for autox and track days. It's low and has a nice rake to it.

Not for the comfort crowd.

[danewilson77]

Happy with the FK silverline X's....

[pyreguy]

Love my H&R Sports. I would recommend doing some shocks with as many miles as your stock shocks have on them though.


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[mimalmo]

KW V2 coilovers. Absolutely blows away the stock setup.

[bullfrogs_M3]

Running Function & Form V2 coilovers with UUC Swaybars. I love the F2 coils. I am able to adjust down the entire strut body without shortening the strut piston length. So right now I am slammed/sitting at 24" from ground to top of wheel well all the way around the car and it rides as smooth as a brand new stock setup.

[danewilson77]

I would most likely go with V2's next...but I have also heard very good things about Ground Control.

Droid + Tapatalk = FTW!

[Marcus-SanDiego]

I've never had ground control coilovers. I have had KWv2 before, though. They're outstanding. They've got my endorsement.

[SonOfWMB]

Interesting. Most seem happy with coilovers. I'm leary of a too-harsh ride in a daily-driver (my wife doesn't like even the stock sport suspension). I have never heard of Function and Form (F2 Autolife) before. I'll also look into the FK Silverline.

Anybody else?

[Marcus-SanDiego]

Actually, I have found the KW coilovers to be pretty comfortable for every day driving. I was really surprised. They're adjustable, and I guess I found a nice happy medium.

[bullfrogs_M3]

Interesting. Most seem happy with coilovers. I'm leary of a too-harsh ride in a daily-driver (my wife doesn't like even the stock sport suspension). I have never heard of Function and Form (F2 Autolife) before. I'll also look into the FK Silverline.

Anybody else?

I looked into all the coilovers on the market today and had to decide between ST V1 (same build product as KW V1 and the ST's actually made by KW) and the F2. I chose the F2's for their ability to raise and lower the strut body while still attached to the car and leave the strut piston at its full capability. With other coilovers if you lower your car, your actually lowering your spring and strut piston down into the strut body. The F2's did it the other way around so you can still keep your full dampening with the full range of the strut. The springs on the F2's are actually Eibach springs so they are pretty solid.

I don't think anyone here will lie to you. Coilovers are a significant investment at around $1K+ for a solid set. This is one area where you don't want to skimp on the product or features. Do as much research on the products you might get (KW, FK, ST) and contact the vendors to ask them questions. If you do autocross like in your pick you are definitely gonna need to look at the second version of each of those so you can fully leverage your daily driving AND you auto-x

[bcleaver]

As far as ride quality, most single adjustable shocks will have the ability to get pretty close to stock comfort. They can be adjusted for a more firm ride, but bearable. From my past experience most of the really noticeable ride quality deterioration comes when you start increasing spring rates.

If you're more serious about performance and less about ride quality, or just looks I would make sure to check out AST-usa

[SonOfWMB]

... I chose the F2's for their ability to raise and lower the strut body while still attached to the car and leave the strut piston at its full capability. ...

... Coilovers are a significant investment at around $1K+ for a solid set. ...

That makes sense about the strut body. I figure if I'm going to make the investment in time and money, I should get something I'll enjoy for the next 100,000 miles :). I don't want to make a mistake and buy the wrong thing just to save $200.

[spencers]

I'd kill for some AST 4100's...

[jvr826]

Spring rate plays a huge part in it, since that is not adjustable. You need to figure out what you want to achieve in the handling department. I chose 500/600 because I wanted to dial out understeer and reduce body roll. Tho my shocks are adjustable, I can't go full soft for comfort and still have the car handle like a BMW. What happens is the weight rolls off the stiff spring and onto a soft shock and the transition isn't smooth = sloppy handling. So there's a balance between the dampers and springs you need to reach. This is why springs and shocks are purchased as a matched set.

A friend of mine has an M3 with PSS9s on it and it's very livable on the street and pretty capable at the track and autocross too. It's much more comfy than mine on the street.

Adjustable height suspension, aka coilover, allows you to really dial things in. For one you'll get your car corner weight balanced for perfect weight distribution. This is something you cannot do with just a set of springs like H&R or the like... you get what the manufacturer thinks is best for the average E46.

[Johnmadd]

http://www.ground-control-store.com/products/description.php/II=124/CA=251

[SonOfWMB]

http://www.ground-control-store.com/products/description.php/II=124/CA=251

Given that my stock shocks are pretty worn out, I think I need new shocks as well. Have you used these?

What are the pros and cons of progressive springs vs linear springs?

[Johnmadd]

Don't know, but it is a reputable company and CHEAP.

[bcleaver]

Don't know, but it is a reputable company and CHEAP.

Given that it's just a set of springs with height adjusters it's not really that 'cheap'. True coilover packages consist of that as well as 4 struts.

[mimalmo]

For one you'll get your car corner weight balanced for perfect weight distribution. This is something you cannot do with just a set of springs like H&R or the like... you get what the manufacturer thinks is best for the average E46.


Worth quoting. If you invest in coilovers but don't spend the money to get your car corner balanced, you're missing out on the full potential of your setup.

[danewilson77]

Worth quoting. If you invest in coilovers but don't spend the money to get your car corner balanced, you're missing out on the full potential of your setup.

What if it's a DD? Would you notice the effects of CB?

[mimalmo]

Absolutely.

[danewilson77]

Absolutely.

Copy.....need to find a place then I guess. Thanks Eli....

[pyreguy]

I had KW V2's on the way and Eli at Autobahn South all lined up to do the CB for my GTI a few days before it was destroyed. Luckily I didn't have to eat the coilovers. That setup would have been excellent.

My car had low miles when I put the springs on. I left the stock shocks on. That way I could take my time to scope out the coilovers I wanna run. I figure when my shocks need to be replaced, I will be ready to step up. And corner balancing is a must.


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[jvr826]

Worth quoting. If you invest in coilovers but don't spend the money to get your car corner balanced, you're missing out on the full potential of your setup.

I'll share my experience on this. Long story short, I had mine all setup with one set of springs, corner balanced and aligned. Decided I needed stiffer springs, so swapped it all out and set the corners at the same exact height they were with the less-stiff springs, alignment the same too. Car felt "hunched over" until I had the CB done again. Moral of the story, you cannot guess at this.

The speed shop who did the CB and initial alignment charges just 2 hours of labor. CB can be time consuming, so set the ride height where you want it and they'll fine tune for you from there. They did mine with me sitting in the driver seat. In absence of you, they can put equivalent ballast in your place.

[bullfrogs_M3]

Who does CB'ing? Will my alignment guy be able to handle something like this?

[mimalmo]

That's exactly what they did with mine. Once the ride height was where I wanted it (gave it two weeks to settle), I brought it to Orr Autosport and they asked me my weight so they could get it correct with me in the car by using ballast. IIRC, I paid $150 or $200.

The rear of my car would not plant itself under strong acceleration out of corners, it felt a little weird. Now after being corner balanced, it's predictable and smooth.

[mimalmo]

Who does CB'ing? Will my alignment guy be able to handle something like this?

You will probably need to call around. Try EVOMS.

[SonOfWMB]

Prior to corner balancing, did you just set the ride height by measuring from the ground and adjusting until equal on all corners?

[mimalmo]

Never use the ground as a measurement point. Even the most skilled mason will tell you that it's nearly impossible to have perfectly level concrete across a large area.

Use the center of the wheel hub (roundel) to the fender instead.

[danewilson77]

When I measure my ride height....I measure from the end link bracket on the shock tube to the spring perch.

Droid + Tapatalk = FTW!

[jvr826]

Use the center of the wheel hub (roundel) to the fender instead.

Yup. Not my car, but illustrates technique...

http://www.bimmerfest.com/forums/attachment.php?attachmentid=101231&d=1174101670

[SonOfWMB]

I learn something new every day.

[bcleaver]

Yup. Not my car, but illustrates technique...

http://www.bimmerfest.com/forums/attachment.php?attachmentid=101231&d=1174101670

Yup, this