KW V3 with Swift Spring Conversion -OR- AST 4100's + Swift?

ibo · 11-02-2011, 06:42 PM

Hey all,

I've been running KW V3's for my XI, and right now I'm considering upgrading the KW progressive springs to Swift linear springs. I read some reviews about the conversion and its definitely a worthwhile upgrade. However, since the AST 4100's have come out, I'm wondering if it's a better choice to swap to the AST's and sell my V3's.

Does anyone have comments about which system has the better damper for a street car? I'm not currently tracking my car, but I'd like to leave the option open for the future (original reason why I got the V3). Also, I'd opt for the 336/672 lb/in Swift springs for a softer ride on the rough roads of pothole-infested Boston.

I know the KW V3's are D/A and the AST 4100's are S/A, but I'm mainly after a performance oriented street ride, so whichever can achieve a smoother ride while retaining adequate performance is sufficient for my purposes.

I'd really appreciate it if anyone with experiences with either, or better yet, both, can chime in with comments/suggestions. Thanks in advance.

Doyle · 11-02-2011, 07:27 PM

Neither. TC Kline True Match coilovers. Cheaper than the AST's, but more expensive than the Swift conversion. I LOVE mine. They will work perfectly with those spring rates.

http://www.tcklineracing.com/webdocs...Details690.cfm

stratplaya06 · 11-03-2011, 10:30 AM

I have the swift conversion for my v3's on my car, along with KW camber plates going on in a couple weeks.

I have m3 subframe bushings, tension struts, guide rods and rear sway already installed.

I am hoping for a little more compliant ride (even KW street comforts use linear springs vs the progressives on the v1-3 line) as well as better handling. I will post back when the installation is done.

EDIT: I am using the exact spring rates you are as these were used on another member orionredwing's car and he really liked the ride. Harold said this would be the optimum spring rates for a mostly street driven car with occasional HPDE and track days.

ibo · 11-03-2011, 04:47 PM

Quote:

Originally Posted by Doyle

Neither. TC Kline True Match coilovers. Cheaper than the AST's, but more expensive than the Swift conversion. I LOVE mine. They will work perfectly with those spring rates.

http://www.tcklineracing.com/webdocs...Details690.cfm

Thanks for your suggestion, but do you care to elaborate on why you chose these over the 2 options I mentioned? Have you personally tried the others to decisively say this is a better option? Not trying to raise a storm, just looking for some fact-based opinions for my own peace of mind. Either way, this is definitely an option worth looking into as well.

Doyle · 11-03-2011, 06:09 PM

Here is a short reason why I chose the TC Klines:

http://www.e90post.com/forums/showpo...84&postcount=6

While I have not personally run either the KW's or the AST's, the shop that I use sells them and has put both of them on other customers' cars. They have had issues with poor valving, and sway bar tabs shearing off of the KW's. They heartily recommend the 5xxx series AST's but they have issues with the 4xxx AST's getting blown out, leaking, or not being able to handle higher rates in the rear (mainly when cornering and hitting a bump/pot hole). Also, I was sold when I found out the HPA time attack car uses TC Klines, not KW's or AST's.

YMMV and all that. Whatever you choose, enjoy them!

11-02-2011, 06:42 PM	#1
ibo Private First Class 19 Rep 190 Posts Drives: '09 BSM 335xi e90 LCI M-Sport Join Date: Jun 2009 Location: Norcal iTrader: (2)	KW V3 with Swift Spring Conversion -OR- AST 4100's + Swift? Hey all, I've been running KW V3's for my XI, and right now I'm considering upgrading the KW progressive springs to Swift linear springs. I read some reviews about the conversion and its definitely a worthwhile upgrade. However, since the AST 4100's have come out, I'm wondering if it's a better choice to swap to the AST's and sell my V3's. Does anyone have comments about which system has the better damper for a street car? I'm not currently tracking my car, but I'd like to leave the option open for the future (original reason why I got the V3). Also, I'd opt for the 336/672 lb/in Swift springs for a softer ride on the rough roads of pothole-infested Boston. I know the KW V3's are D/A and the AST 4100's are S/A, but I'm mainly after a performance oriented street ride, so whichever can achieve a smoother ride while retaining adequate performance is sufficient for my purposes. I'd really appreciate it if anyone with experiences with either, or better yet, both, can chime in with comments/suggestions. Thanks in advance. __________________ COBB Stage 2+ \| Alpina B3 TCU Flash \| ER FMIC & CP \| Tial Q \| Injen CAI \| VRSF DP \| BMS OCC \| KW V3 \| M3 Rear SFB / Sway Bar / Susp Bits / Strut Brace \| Megan Racing Toe Arms \| HPA Swaybar Endlinks \| Apex EC-7 \| Michelin PSS \| MH 75mm Stud Conv \| OEM Perf Grills and Diffuser \| Exotics Tuning Front Lip \| LUX H8 \| Luminics Krypton JDM Yellow \| LLumar 35%
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11-02-2011, 07:27 PM	#2
Doyle Hellafunctional 37 Rep 426 Posts Drives: 335xi Join Date: Nov 2010 Location: N/A iTrader: (2)	Neither. TC Kline True Match coilovers. Cheaper than the AST's, but more expensive than the Swift conversion. I LOVE mine. They will work perfectly with those spring rates. http://www.tcklineracing.com/webdocs...Details690.cfm
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11-03-2011, 10:30 AM	#3
stratplaya06 Captain 46 Rep 967 Posts Drives: 2008 E92 335xi-SOLD 5.0 Miata Join Date: May 2008 Location: Maryland iTrader: (10)	I have the swift conversion for my v3's on my car, along with KW camber plates going on in a couple weeks. I have m3 subframe bushings, tension struts, guide rods and rear sway already installed. I am hoping for a little more compliant ride (even KW street comforts use linear springs vs the progressives on the v1-3 line) as well as better handling. I will post back when the installation is done. EDIT: I am using the exact spring rates you are as these were used on another member orionredwing's car and he really liked the ride. Harold said this would be the optimum spring rates for a mostly street driven car with occasional HPDE and track days. __________________ \| PROcede Rev3 \| Vishnu Meth \| DCI \| BMW Perf. Exhaust \| AR Coated/Catless \| CP-E FMIC \| Quaife \|
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11-03-2011, 06:09 PM	#5
Doyle Hellafunctional 37 Rep 426 Posts Drives: 335xi Join Date: Nov 2010 Location: N/A iTrader: (2)	Here is a short reason why I chose the TC Klines: http://www.e90post.com/forums/showpo...84&postcount=6 While I have not personally run either the KW's or the AST's, the shop that I use sells them and has put both of them on other customers' cars. They have had issues with poor valving, and sway bar tabs shearing off of the KW's. They heartily recommend the 5xxx series AST's but they have issues with the 4xxx AST's getting blown out, leaking, or not being able to handle higher rates in the rear (mainly when cornering and hitting a bump/pot hole). Also, I was sold when I found out the HPA time attack car uses TC Klines, not KW's or AST's. YMMV and all that. Whatever you choose, enjoy them!
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