[will.c]

This is not another "what coils should I get" thread. Rather I just need some of the members' input on what the differences are between these coils, each of which seeming to have its own "custom" or proprietary valving of the Koni shocks.

TC Kline True Match S/A: $1700~1850 + camber plates
http://www.tcklineracing.com/index.c...&Calculate=Yes
http://store.vacmotorsports.com/tc-k...tem-p2349.aspx

Ground Control Street/School or Street/Touring S/A: $1700~1850 incl. camber plates
http://www.ground-control-store.com/.../II=809/CA=172
http://www.ground-control-store.com/.../II=843/CA=172

HPA Koni Coilover Kit w/ Swift Springs S/A: $2300 incl. camber plates
http://www.hpashop.com/product.sc?pr...categoryId=236

As for my needs: track-worthiness 90%; daily drivability 10%; zero or minimal lowering; much stiffer than stock sport sus.

Thanks a lot.

Edit - due to my lack of knowledge, this may have turned into another "what coils to get" thread. I apologize in advance for your discomfort, and appreciate any input.

[StarReaver]

I would like to know this as well. I'm leaning towards TC Kline SAs, since I'm running them on my M Coupe, but an E90 is a completely different animal.

[akotten]

I have the TC Kline S/A with vorshlag camber plates. I just ordered an M3 strut brace so I can start playing with rebound settings some more. So far, I like them quite a bit. Only had one day at the track, but initial impressions were good. Good improvement for sure.

[nitehawk]

Originally Posted by akotten

I have the TC Kline S/A with vorshlag camber plates. I just ordered an M3 strut brace so I can start playing with rebound settings some more. So far, I like them quite a bit. Only had one day at the track, but initial impressions were good. Good improvement for sure.

What spring rates did you go with? How much camber are you running on the streets?

[akotten]

Originally Posted by nitehawk

What spring rates did you go with? How much camber are you running on the streets?

I believe its a Swift 392# up front and TCK 600# in the rear. IIRC, the alignment sheet said ~-0.5-0.6 camber when the plates are least aggressive. I usually put them at full camber for the track though.

[will.c]

I see that TCKR is the popular choice so far. How much stiffer are they compared to sport suspension? Your cars don't look like they're gonna tip over at the track?

On the other hand, how are they on the streets if you turn them down to fully soft?

[cvc 22349a]

If the GC c/o kit still includes the M3 rear camber arms, then they're the best value. GC probably has the best campber plates too.

[StarReaver]

OP, if you're planning to track 90% of the time, have you considered TCK D/As? You can adjust compression ratios in addition to rebound settings, so you can really fine tune the car to whatever track you're visiting. Additionally, if you plan to compete in stock-configuration competition classes, they can build setups that are rule-compliant. The trade off is that they are more expensive, however.

Or just go with Moton Clubsports. Proper race coils. Not for street use, however.

[will.c]

Originally Posted by cvc 22349a

If the GC c/o kit still includes the M3 rear camber arms, then they're the best value. GC probably has the best campber plates too.

The kit that includes M3 rear camber arms are about 250 more. What would be the benefit of this conversion btw, other than more availability of "proper" race coilovers?

I def agree best value either way. I just hope their kit's Eibach springs are somewhat comparable to the TCKR or Swift springs.

[will.c]

Originally Posted by StarReaver

OP, if you're planning to track 90% of the time, have you considered TCK D/As? You can adjust compression ratios in addition to rebound settings, so you can really fine tune the car to whatever track you're visiting. Additionally, if you plan to compete in stock-configuration competition classes, they can build setups that are rule-compliant. The trade off is that they are more expensive, however.

Or just go with Moton Clubsports. Proper race coils. Not for street use, however.

I track about 5% of the time but my mind is focused on track performance 90% of the time I drive

I def considered the DA "Smart Design." They are about 30-40% more in cost. Dp you think this is justifiable for DA over SA?

No hardcore racing yet, I've had about 10 track days so far, and I'm coming to a point where my car rolls and dives sooo much that I believe my soft suspension is the limiting factor. I just wanna make it pretty tight.

[StarReaver]

Originally Posted by wonho

I track about 5% of the time but my mind is focused on track performance 90% of the time I drive

I def considered the DA "Smart Design." They are about 30-40% more in cost. Dp you think this is justifiable for DA over SA?

No hardcore racing yet, I've had about 10 track days so far, and I'm coming to a point where my car rolls and dives sooo much that I believe my soft suspension is the limiting factor. I just wanna make it pretty tight.

Ah, I understand. The SAs are MORE THAN capable of handling full-on track days, for novice and experienced track rats alike. You will definitely see improvement in your lap times and overall feel of the car. It all boils down to this:

• Do attend more than 1 track day a month?

• Do you see apexes, cones, and chicanes in your sleep?

• Do your friends call you Senna?

• Is 1 or 2 milliseconds an eternity to you?

If you answered 'yes' to any of these questions, go for the DAs. If not, you will be perfectly happy with the SAs.

[turugara]

I've driven on both the TCK DA and now on my AST 5200's. I will have to say that in terms of control and feel, the AST 5200's win hands down every time. Furthermore... I will say that also in terms of comfort, either on soft or hard while daily driving, the AST also win hands down.

If your thinking of spending the coin, you may want to consider a REAL track car damper such as the JRZ RS1's or RS-Pro. You just have so much better customer support, dampening control, etc etc everything that you want for a track car or a street car. Just overall better.

They are more pricey... but once you get past 2k, what's 3k =)

Check out Charles's review of his JRZ's.
http://www.e90post.com/forums/showthread.php?t=712517

[turugara]

Oh Wonho. The answer to "Which coilover to get" is simple

August track event you'll have access to an e92 with...

1. My AST 5200's
2. Charle's JRZ's
3. Rob's JIC Cross
4. AST 4100's

and there are probably a few that I'd forgotten. Wait till then. Test drive the coilover on the cars as oppose to intertubes speculation.

Then decide.

[CJ421]

Originally Posted by turugara

They are more pricey... but once you get past 2k, what's 3k =)

Yeah - get a ride in our cars ... then double your budget and you'll be golden. Actually, I think the JIC's would be pretty close to what you want to spend.

Do you have an LSD yet? What tires are you running?

[will.c]

Originally Posted by StarReaver

• Do attend more than 1 track day a month?

• Do you see apexes, cones, and chicanes in your sleep?

Yes to these two at least

Originally Posted by turugara

Oh Wonho. The answer to "Which coilover to get" is simple

August track event you'll have access to an e92 with...

1. My AST 5200's
2. Charle's JRZ's
3. Rob's JIC Cross
4. AST 4100's

and there are probably a few that I'd forgotten. Wait till then. Test drive the coilover on the cars as oppose to intertubes speculation.

Then decide.

Aww.. you guys are so nice. Appreciate such generous offer. In return I shall remind you how soft stock suspension is by scraping front corners while trail braking... esp on right hand turns since I'm 250lb haha

On a serious note, so ASTs are that much better than TCKs huh...

Originally Posted by CJ421

Yeah - get a ride in our cars ... then double your budget and you'll be golden. Actually, I think the JIC's would be pretty close to what you want to spend.

Do you have an LSD yet? What tires are you running?

I choked a little when I saw the pricing for the JRZs. I think I might have to settle with second tier. I'll save up some more until next month I guess.

No LSD nor planning on. Cost is not justified IMO. I just won't try to drift.

I like my star specs a LOT. They are worn, though, and I might not even last through the 3 days at NJMP.


Thanks for the responses guys!

[E90335iflyer]

I am in the market for a set of coil overs for my DD. I know mono tubes are the bomb and I have them on my other two toys, but I am not about to spend that kind of money on my DD.

The Ohlins and AST 4100 looks to be in the same price range and will certainly yield better performance. Although I don't mind trying the Koni based single coil over for a change for under $2K!

[Doyle]

Originally Posted by turugara

I've driven on both the TCK DA and now on my AST 5200's. I will have to say that in terms of control and feel, the AST 5200's win hands down every time. Furthermore... I will say that also in terms of comfort, either on soft or hard while daily driving, the AST also win hands down.

If your thinking of spending the coin, you may want to consider a REAL track car damper such as the JRZ RS1's or RS-Pro. You just have so much better customer support, dampening control, etc etc everything that you want for a track car or a street car. Just overall better.

They are more pricey... but once you get past 2k, what's 3k =)

Check out Charles's review of his JRZ's.
http://www.e90post.com/forums/showthread.php?t=712517

Ha! It's only money...just wait for the gov't to print more!

On a serious note, HPA has the 5200's for ~$1.5k more than TCK DAs. I have no doubt that they are better.

I'm still convinced that TCK offers the best bang for the buck.

OP: Hit up Harold@HPA. He sells all of the products mentioned in this thread and will have the best advice on these forums. It's up to you to determine where the price gets a little steep. For me, when I start looking at 50% $$ of a Spec e30 in just suspension for my DD, I draw the line, lol.

[turugara]

I will say that VAC or GC know what the hell they are doing with suspension and would probably be the best bet for your money if your going to go with below 2k coilover. Talk to me and Charles in person and I'll let you know what I mean by that or PM me.

[TC Kline Racing]

Originally Posted by E90335iflyer

I am in the market for a set of coil overs for my DD. I know mono tubes are the bomb and I have them on my other two toys, but I am not about to spend that kind of money on my DD.

The Ohlins and AST 4100 looks to be in the same price range and will certainly yield better performance. Although I don't mind trying the Koni based single coil over for a change for under $2K!

I am curious to know why so many people feel that mono-tube shocks are "the bomb" vs. twin tube?

[turugara]

Originally Posted by TC Kline Racing

I am curious to know why so many people feel that mono-tube shocks are "the bomb" vs. twin tube?

First off, I don't have industry experience and only know what I read online. To answer your question, mono-tube shocks are not necessarily "the bomb" vs twin tube.

But the reason it is believed so is because the common literature online compares traditional twin tube dampers to traditional mono-tube dampers as oppose to comparing modern twin tube dampers produced for motorsport applications which are drastically different than traditional twin tube dampers. The difference is that the gas chamber and the chamber between the floating gas piston and the foot valve are located circumferentially around the damper body.



Damper (c) is a regular monotube damper and damper (b) is a traditional twin tube damper. Damper (a) is a through rod monotube damper. Through rod dampers can be either of the twin tube or monotube variety. The main benefit of them is that the gas chamber is not necessary to compensate for the voume changes caused by rod insertion. However, they generally still have a small gas chamber to compensate for the volume changes caused by temperature variations and damper compliance.

A modern twin tube damper uses the circumferential tube as an external passage for the damper fluid. This passage connects the rebound and compression chambers. The majority of these dampers have solid pistons without and orifices or valves. These pistons instead of moving through the fluid, force the the fluid through the external passage.

The major differences is that the gas chamber pressure in the monotube damper always acts on the compression chamber. In the twin tube damper the gas chamber acts on different sides of the piston. This allows twin tube dampers to run much lower gas pressure without the risk of rebound chamber cavitation. The lower gas pressure decreases the stress on the damper and rod seal and reduces the gas spring effect on the damper. The other major difference is that in the twin tube damper there is much more fluid flow.

In fact, the higher pressures necessary in the monotube dampers to prevent cavitation also puts more stress on the damper and the seals. This can lead to more hysteresis from the fluid compressibility and damper compliance. Since the piston and rod seals are required to withstand higher internal pressures they often have more friction.

So the long answer is no. Monotube is not the final word in suspension. However for all intents and purposes in comparing traditional twin tube as the BMW OEM vs monotube aftermarket dampers such as JRZ, Moton, Ohlins, monotube tend to be better.

Information derived from the Thesis submitted by Christopher Meissen titled "Development and Validation of a physical model for a modern twin tube damper"
http://jagger.me.berkeley.edu/~cmeis...risMeissen.pdf

[nitehawk]

Originally Posted by turugara

I've driven on both the TCK DA and now on my AST 5200's. I will have to say that in terms of control and feel, the AST 5200's win hands down every time. Furthermore... I will say that also in terms of comfort, either on soft or hard while daily driving, the AST also win hands down.

Hmm, I would like some enlightment on this. From what I've read, monotube dampers are harsh at low speeds. The breakaway friction is alot higher than a twin tube design, so little suspension movement occurs and is not a good trait for street use. Twin tubes are not as responsive at initial shaft movements, meaning they are better at soaking up bumps.

Having both style dampers, you did not experience this?

EDIT: Just saw your post above, but I'm wondering strictly from a street comfort point of view...

[turugara]

Originally Posted by nitehawk

Hmm, I would like some enlightment on this. From what I've read, monotube dampers are harsh at low speeds. The breakaway friction is alot higher than a twin tube design, so little suspension movement occurs and is not a good trait for street use. Twin tubes are not as responsive at initial shaft movements, meaning they are better at soaking up bumps.

Having both style dampers, you did not experience this?

I think those specific differences are a generalization of the twin tube vs mono-tube dampers. My AST 5200's have a huge range of adjustability and on soft settings (with the same 400f/800r swift springs), it felt more comfy than the twin tubes. Whether this is attributed to the design of the monotubes with the external reservoir, I don't know.