[karr1008]

Originally Posted by waktasz

So do I want these or the RCE Tarmac2 coilovers?!? Decisions decisions.

Alreay planning my suspension for next season

I hear you. Same here.

[ButtDyno]

The Tarmac2s don't come with camber plates, right?

If you do 8610's, WRX struts and GC's with GC plates in the front and Grp N's in the rear, you'd be looking at like $1400-$1500. If you add the housings instead of doing the strut hacking that's another $600. So my guess is that this route is cheaper. The GC plates are excellent, and you can get a fairly stupid amount of camber out of them

It depends, I think, on whether you want double adjustable shocks (I didn't; I have enough knobs to turn) - and if you do, do you want to buy the 8611's or the KW-valved RCE's. The 8611's are $289 a shock IIRC, so that would add about $500 to your GC/Koni setup.

IIRC both the SA Konis and the KW/RCE's are happy with the same springrates. For me, being able to rebuild the shocks at one of three different places is a nice advantage for the Konis. The customer support should be excellent on both sides.

john

[waktasz]

I'm not sure I'd know wtf to do with double adjustable shocks...but it's nice . Are Konis, and KW shocks about the same quality wise though?

I'm starting to regreat my Zeals, although they autocross awesome, I'm only autocrossing 10 minutes a month or less :/ and want something with smoother valving.

[ButtDyno]

They're both reputable companies that make good products, AFAIK.

For me the tiebreakers were cost, rebuild-ability (there are 3 shops that do Konis), and not needing double adjustability. I felt like I didn't give much up going the route I went

john

[waktasz]

It's about a tie for me, as I sold my stock struts to a local autocross bum for $50! I did forget about needing the plates for the RCE t2's though.

Do you have your setup installed yet? Did I skip over your review earlier in this thread or what?

[ButtDyno]

No, it's still being written

It's going to be long...

[waktasz]

How do I subscribe to threads that will be created in the future?

[ButtDyno]

I'll put a link in here.

[MTR]

Originally Posted by ButtDyno

The Tarmac2s don't come with camber plates, right?

If you do 8610's, WRX struts and GC's with GC plates in the front and Grp N's in the rear, you'd be looking at like $1400-$1500. If you add the housings instead of doing the strut hacking that's another $600. So my guess is that this route is cheaper. The GC plates are excellent, and you can get a fairly stupid amount of camber out of them

It depends, I think, on whether you want double adjustable shocks (I didn't; I have enough knobs to turn) - and if you do, do you want to buy the 8611's or the KW-valved RCE's. The 8611's are $289 a shock IIRC, so that would add about $500 to your GC/Koni setup.

IIRC both the SA Konis and the KW/RCE's are happy with the same springrates. For me, being able to rebuild the shocks at one of three different places is a nice advantage for the Konis. The customer support should be excellent on both sides.

john

I'm unfamiliar with the strut hacking of the WRX strut. Are you just modifying the housing removing the stock strut and putting in the Koni? Is this the same for the STi struts? Saving $600 for housings sounds appealing.

[stretch]

I'm partially done my installation, but the lightning and thunder (which I had been working through) just opened up into a downpour. I do all my modifications in the middle of a parking lot, so lightning and rain stop me. (Hey, I don't mind getting wet, but my tools do!) So far, I've got one strut on.

My notes so far:

First off, I really hate reviews where people say nothing but great things about a product. That's crap. Everything with suspension design is a compromise and therefore has a pro and a con. Expect me to tell it like it is.

The assembly with springs but without camber plates is 13lbs, as measured on a bathroom scale (accurate to 0.25lbs). I measured my weight, then my weight + two coilovers, and divided the difference. Hopefully that'll be accurate.

This setup will not interfere with wide tires; the bottom plate is above the tread of the tire (just barely).

My 9" springs look progressive but aren't. This is really cool. Two coils are closer together than the others, but the coils barrel out a bit. Eibach makes these springs custom for Ground Control, and here's why GC asked for that: so in the event of a coil bind, they don't bang as loudly. Neat stuff.

The brake line doesn't mount properly- it's just a little too far away and stretches the brake line a bit. We're talking tiny, tiny amounts, but there just isn't enough tolerance in the brake line. I immediately called Mark and am the second person (out of 20+ sets sold) to report this. Mark hasn't been able to find a stock strut that didn't mirror their own design perfectly, so he's paying for me to ship my struts to him. Something is off by the slightest of amounts. Regardless, I really like how GC is handling this, paying for me to ship them my struts. So yes, this is a problem, but it likely won't be for a single other customer.

The strut top is non-standard. It's one, long threaded top. The stock pieces has a wider, non-threaded part (over which a tophat and washer fit) and a threaded part for the nut. The entire top of the Koni strut is an in-between diameter, probably intended to match the lower, larger diameter of the stock strut top but just a smidge to narrow. I cut out a piece of aluminum flashing (very thin) and wrapped it around the thread for a very tight fit, so no big deal. Still, not ideal. I'm not sure if the loose fit would have been a problem, but I like things tight. We're talking about the diameter being off by about a millimeter, a very small amount. I suspect Ground Control's camber/caster plates would accommodate this design better.

Unfortunately, the Whiteline plates I purchased require a strut design similar to stock, so I'm stuck on Group-N tops. Consequently, I have a set for sale.

The GC struts are 5/8 to 3/4 of an inch shorter than stock. I way over-estimated how short they would be. Therefore, these struts absolutely require GC's camber plates (which add bump travel) to lower the car any meaningful amount. I asked Mark about this, and he says the GC camber plates trade nearly an inch of droop travel for bump travel. That's a huge amount. For those looking to run stiff springs and a low ride height, definately buy these and ditch your existing plates. I would not recommend lowering the car more than half an inch without them, as I believe suspension travel is too valuable. I'm going for a stockish setup (moderate spring rates, minor drop) and thus deliberately didn't buy lowering camber plates but may reconsider.

I read a few dozen threads on the BMW forums, and they recommend Koni / Ground Control coilovers overwhelmingly over Bilstein PSS9's. Very interesting. Everyone loves Ground Control's valving- they even stock several different valvings for same model BMWs. I wonder if that's why Mark asked me, when ordering, if my vehicle was a track car or a daily driver?

Anyway, that's it for now. It's stopped raining.

[AnorexicSTI]

Originally Posted by stretch

1. The assembly with springs but without camber plates is 13lbs, as measured on a bathroom scale (accurate to 0.25lbs). I measured my weight, then my weight + two coilovers, and divided the difference. Hopefully that'll be accurate.

2. My 9" springs look progressive but aren't. This is really cool. Two coils are closer together than the others, but the coils barrel out a bit. Eibach makes these springs custom for Ground Control, and here's why GC asked for that: so in the event of a coil bind, they don't bang as loudly. Neat stuff.

3. The brake line doesn't mount properly- it's just a little too far away and stretches the brake line a bit. We're talking tiny, tiny amounts, but there just isn't enough tolerance in the brake line. I immediately called Mark and am the second person (out of 20+ sets sold) to report this. Mark hasn't been able to find a stock strut that didn't mirror their own design perfectly, so he's paying for me to ship my struts to him. Something is off by the slightest of amounts. Regardless, I really like how GC is handling this, paying for me to ship them my struts. So yes, this is a problem, but it likely won't be for a single other customer.

1. I like your weighing methodoligy . We're going to get along. Now, by any chance can you weigh the stock setup so we know how much we're saving over stock?
2. Any reason why you chose 9" springs over say 7 or 8" springs? I used 6" springs in the past to save weight... I know u have to choose a spring length that will take into consideration max load until bind... 6" was for an 1800 lb Honda... I'm thinking I will need 8" this time.
3. With aftermarket lines, the line can move within the bracket... I suspect this problem is only with stock rubber lines.

[AnorexicSTI]

Originally Posted by stretch

1. The strut top is non-standard. It's one, long threaded top. The stock pieces has a wider, non-threaded part (over which a tophat and washer fit) and a threaded part for the nut. The entire top of the Koni strut is an in-between diameter, probably intended to match the lower, larger diameter of the stock strut top but just a smidge to narrow. I cut out a piece of aluminum flashing (very thin) and wrapped it around the thread for a very tight fit, so no big deal. Still, not ideal. I'm not sure if the loose fit would have been a problem, but I like things tight. We're talking about the diameter being off by about a millimeter, a very small amount. I suspect Ground Control's camber/caster plates would accommodate this design better.

2. Unfortunately, the Whiteline plates I purchased require a strut design similar to stock, so I'm stuck on Group-N tops. Consequently, I have a set for sale.

3. The GC struts are 5/8 to 3/4 of an inch shorter than stock. I way over-estimated how short they would be. Therefore, these struts absolutely require GC's camber plates (which add bump travel) to lower the car any meaningful amount. I asked Mark about this, and he says the GC camber plates trade nearly an inch of droop travel for bump travel. That's a huge amount. For those looking to run stiff springs and a low ride height, definately buy these and ditch your existing plates. I would not recommend lowering the car more than half an inch without them, as I believe suspension travel is too valuable. I'm going for a stockish setup (moderate spring rates, minor drop) and thus deliberately didn't buy lowering camber plates but may reconsider.

1. What is aluminum flashing?
2. Why won't the WL camber plates work specifically? Will RCE lowering plates work?
3. What do u mean by TRADE an inch of droop travel for bump travel? Does that mean that droop travel is 1" less than stock but bump travel is 1" more than stock?

I guess RCE lowering plates are now on my radar again...

[lackskill]

Originally Posted by AnorexicSTI

1. What is aluminum flashing?
2. Why won't the WL camber plates work specifically? Will RCE lowering plates work?
3. What do u mean by TRADE an inch of droop travel for bump travel? Does that mean that droop travel is 1" less than stock but bump travel is 1" more than stock?

I guess RCE lowering plates are now on my radar again...

1. Think thin aluminum sheet like material.
3. I think by trading an inch of droop travel he means that there is 1" less droop travel and 1" more bump travel on the GC setup. It is not a comparison to stock.
2. I have no idea.

Threw off the order for fun

[Rootus]

I am really looking forward to what you think of these after you get them installed, especially after you've put a few miles on them. Someone I know (who I trust ... somewhat ) said that GC's have a reputation for being annoying on the street due to noise. I like the price, but if anything I'd like to reduce the amount of popping/squeaking/groaning I get out of the suspension, not increase it . Between the worn endlinks and clunking strut, my suspension sounds like it's going to fall apart...

[stretch]

So, I went out and finished installing the coilovers. I haven't driven the car yet, shame on me. I need to realign the tires first though, and I ran out of time. (I do my own toe alignments using nhluhr's method.)

I will say this: Ground Control definitely drilled out the strut housing mounting holes such that you gain a lot of camber by installing them. My front tires look about like the rears now, and I only have the OE camber bolt! What a nice touch.

Originally Posted by AnorexicSTI

1. I like your weighing methodoligy . We're going to get along. Now, by any chance can you weigh the stock setup so we know how much we're saving over stock?

I tried, but couldn't get the stock springs back on (for an apples-to-apples comparison) without using a spring compressor. That would've taken more time that I had today- remind me again later.

2. Any reason why you chose 9" springs over say 7 or 8" springs? I used 6" springs in the past to save weight... I know u have to choose a spring length that will take into consideration max load until bind... 6" was for an 1800 lb Honda... I'm thinking I will need 8" this time.

The 9" spring gives me just over 5.5" of travel. The 8" springs close to this, too, since it has one less coil wind and double-ground ends. I wouldn't use anything shorter than an 8" spring, but for you, that's probably what you want.

3. With aftermarket lines, the line can move within the bracket... I suspect this problem is only with stock rubber lines.

I'm going to fabricate a quick and dirty aluminum spacer (think 1.5" aluminum strip with two holes in it) to make the brake line work. No big deal. But you're right, it's probably time I just went to steel lines anyway.

1. What is aluminum flashing?

Paper think aluminum used for water proofing roofs and windows, installed under siding or shingles. It comes 10+ feet rolls at Home Depot.

2. Why won't the WL camber plates work specifically? Will RCE lowering plates work?

Whiteline has a proprietary nut that must be used to hold the strut on. It's threaded for a stock strut, but the Koni strut is larger. That's really the only problem, so I expect other plates would still work. I think Whiteline is the only company to do this- and it is a clever design, just not the most compatible one.

3. What do u mean by TRADE an inch of droop travel for bump travel? Does that mean that droop travel is 1" less than stock but bump travel is 1" more than stock?

Damn you, I know a long response is coming to that question. I'll have to make a suspension travel calculator for you or something. Anyway, here goes...

Most Impreza front struts seem to have 5 to 6 inches of travel. That travel must be divided up into bump and rebound- basically whatever is above or below your ride height. Any time you adjust the ride height of your coilovers via the lower spring perch, you're simply trading bump for droop or vice-versa. Lowering springs on the stock shocks have a similar effect of trading bump travel for droop.

If you raise your ride height via the spring perch (or install firmer springs), you gain bump travel but lose droop. If you lower your ride height via the spring perch (or install softer springs), you gain droop but lose bump travel. Lowering springs for the stock struts lower the car by being very progressive- perhaps only 150lb/in until ride height. If they weren't progressive, the springs would either be too short or they'd raise the car.

However, you can also change your ride height without touching the spring perch. This is what RCE's famous "lowering" camber plates do- they raise the top mounting point to accomplish this. But let's say you want to maintain your ride height after installing RCE's plates- you'd have to do what? Adjust the lower spring perch on your coilovers upwards, which causes you to trade droop travel for bump travel. That's what I meant in my earlier post. Most of the time, this is a very good trade.

Let's assume the wet weight of an STI (not yours!) is 3450lbs. 58% of that (percent of weight on front of car) would be about 2000lbs. Divide that by two and you have 1000lbs on each front tire. Subtract 100lbs for unsprung weight, and you have 900lbs left on the spring. Subtract another 50lbs because the gas pressure in the strut supports about that much. You're left with 850lbs for each front spring to support.

Knowing that, you can figure out how much droop travel can use. Note that this is the absolute peak amount you could use; having a sway bar installed means typically you need even less. In my case, I'm running 315lb/in springs. So, my springs will completely load or unload in 2.7 inches. With firmer 425lb/in springs, my springs would completely load or unload in 2 inches. See where I'm going with this? In the case of 425lb/in springs, having more than two inches of droop travel is useless.

So, what happens if the strut has 3 inches of droop travel but the spring unloads in 2 inches? You have completely wasted suspension travel. This is, unfortunately, what most popular coilovers do. You can see this in their use of a helper spring to hold the spring in place when it becomes completely unloaded. If I switched to 425lb/in springs at my current ride height, I'd have that problem too. I'd really love it if people would measure and report this data when they install their coilovers, but no one seems to. I suspect many very popular coilovers do not have sufficient bump travel at the ride heights they're being used at.

Anyway, what if you can recycle that wasted droop travel into bump travel? This is what Ground Control's camber plates do. They raise the top strut mount an inch, and you compensate for that by raising your spring perch too. Since the Koni struts have about 5.5 inches of travel, and only two inches of that need be droop (on 425lb/in springs), you can have the remaining 3.5 inches of travel for bump. That's a massive amount.

Remember, though, that perfect suspension travel setup only happens at one ride height. According to Mark, that happens at a 14.5" ride height on roughly 380lb/in springs. If you lower your car further, you're still sacrificing bump travel for wasted, useless droop. However, this isn't always a bad thing- with 3.5" in reserve, you could probably safely lose an inch of that (by lowering the car another inch).

The lowest winning autocrossers are said to use a quite low 13.5" ride height. I'm just estimating here, but with stock tops and GC coilovers, you'll have ~1.5" of bump travel (half inch into the bump stops) remaining while at that ride height. With GC plates, you'll have ~2.5" of bump travel remaining, half an inch off the bump stops. That's a pretty huge, important difference.

Currently, I'm running 315lb/in springs with the full 2.7 inches of droop I need to allow the springs to completely unload. I'm at roughly the stock ride height. I have about 3/4" before hitting the 2" long, soft bump stops, not bad. If I got the lowering camber plates, I'd have to run firmer springs or an inch lower ride height in order to avoid having to preloading my springs. I'd probably preload the springs a 1/4 inch (~80lbs) and lower the car 3/4 of an inch, that'd be perfect. Preloading springs can cause artificial wheel lift when entering or exiting turns and is bad. However, a minor amount of preload is not a problem if running sway bars since the odds of that corner ever needing to fully unload are reduced.

There is such a thing as too much bump travel, too. This occurs if your tire hits the fender! (Shrink your tire diameter if this happens.)

Hopefully this all makes sense.

The best solution to the suspension travel problem is to buy an adjustable length strut, like what Zzyzx sells. Notice how the entire strut body is threaded on those. Rather than fooling with various-height strut tops, you can just shorten a Zzyzx strut and accomplish the same thing. It's a much better solution that is sadly only commonly seen on cheap throw-away Japanese coilovers, done so they can reuse one model strut on several cars.

I guess RCE lowering plates are now on my radar again...

RCE lowering plates would trade 3/8" of travel instead of GC's inch. I'm guessing- if indeed the GC plates add an inch of travel and you want to run firm springs on Ground Control / Koni struts- that the Ground Control plates would be far better suited for your purposes. That added inch of travel is key. I'm curious if RCE Tarmac II's or Bilstein PSS9 coilovers would benefit as much from the added bump travel, too.

Originally Posted by Rootus

Someone I know (who I trust ... somewhat ) said that GC's have a reputation for being annoying on the street due to noise.

I can't stand suspension noise- a suspension is, by design, supposed to be smooth and fluid. So, you'll hear it from me if there's noise. I think Ground Control has a bad rep from many people who, against the advice of Ground Control, install short, stiff springs on their stock struts. They end up with a bouncy ride and a spring that becomes unseated every time they catapult off of a bump.

The nice thing about Ground Control is that you get a totally custom suspension. The bad thing about Ground Control is that they allow stupid people to pick it out themselves. If they advise against something, there's probably a reason!

Whew, this felt like a long post even for me.