E90Post
 


N54Tuning.com
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > Suspension | Brakes | Chassis > Swift springs, AST coilovers, M3 bits... first take



Reply
 
Thread Tools Search this Thread
      05-01-2011, 11:24 PM   #1
sappersix
Private
1
Rep
74
Posts

 
Drives: '07 E90 335i
Join Date: Dec 2009
Location: Bay Area, CA

iTrader: (0)

Swift springs, AST coilovers, M3 bits... first take

I had Swift springs (400/800), AST 4100s and M3 front control arms and tension arms installed last week.

First, M3 controls arms/tension arms. Great upgrade. Like some of the other folks who have done this, this is an immediate pay back in terms of steering feel and positive turn-in. Definitely worth it.

Second, Swift/AST combo. All I can say is I can't wait to get this setup out to the track. I've tracked my stock E90 before and had loads of fun. However, after these add-ons, the car feels more planted, more solid, and very sure-footed. Granted, I haven't really hit it hard on the streets (and I still want everything to settle before pounding it), but the first indications are great. I had the car lowered just a bit.

Just want to say thank you to Harold at HP Autowerks for being super responsive and helping me think through what I wanted/needed in terms of suspension upgrades.

Also, want to say thank you to the team at Sonic Motorsports in Mountain View, CA. They did a bang up job on installation and alignment. Feels great!

So...
Done --> PROcede v5, M3 front suspension, Swift springs, AST coilovers
On order --> Vishnu DCI, Vishnu PWM meth kit, Quaife LSD
Deciding --> which FMIC?
Debating --> should I do DPs?

Darn it... this is getting expensive!
__________________
'07 E90 335i | 6MT | ZSP | ZPP | Alpine White | Terra Dakota Leather | Aluminum Trim
Procede | PWM Meth | Vishnu DCI | AST4100 | Swift Springs | Quaife LSD | M3 suspension
Appreciate 0
      05-02-2011, 12:01 AM   #2
skinrock
Agent Smith
skinrock's Avatar
46
Rep
2,860
Posts

 
Drives: 2013 Fusion AWD
Join Date: Jan 2011
Location: The Matrix

iTrader: (9)

Garage List
2007 335i  [3.45]
Quote:
Originally Posted by sappersix View Post
Darn it... this is getting expensive!
Tell me about it. I have suspension on the way and plan on taking it to SonicMS. I also have an LSD sitting here, going to have MPT install it.
Appreciate 0
      05-04-2011, 08:06 PM   #3
subieworx
Lieutenant
7
Rep
403
Posts

 
Drives: 07 335
Join Date: Jun 2010
Location: Ohio

iTrader: (1)

It' a very nice combo. Mine were a little bouncy in the rear, but I got that taken care of. Love them now.
Appreciate 0
      05-04-2011, 10:47 PM   #4
sappersix
Private
1
Rep
74
Posts

 
Drives: '07 E90 335i
Join Date: Dec 2009
Location: Bay Area, CA

iTrader: (0)

Quote:
Originally Posted by subieworx View Post
It' a very nice combo. Mine were a little bouncy in the rear, but I got that taken care of. Love them now.
After a few days of driving, I'm noticing a bit of bounce on the rear too. Everything is currently set at six clicks off soft. What settings did you end up at for street?

I assume at at the track, I should dial all the way to the firmest setting?
__________________
'07 E90 335i | 6MT | ZSP | ZPP | Alpine White | Terra Dakota Leather | Aluminum Trim
Procede | PWM Meth | Vishnu DCI | AST4100 | Swift Springs | Quaife LSD | M3 suspension
Appreciate 0
      05-05-2011, 10:17 PM   #5
f00dstamps
Private First Class
United_States
2
Rep
125
Posts

 
Drives: 2010 BMW 335d
Join Date: Feb 2011
Location: US

iTrader: (0)

Send a message via Skype™ to f00dstamps
Harold also helped me with a set of AST 4100's with the Swift 400/800 springs. The car is very confident in turns and handles bumps well. The floating feeling of the stock suspension is no longer there.

I started with the settings at full soft and am continually adjusting them. Right now, I'm 7 clicks from soft on the front and 3 clicks from soft on the rear. The front feels good but I may stiffen up the rear as I continue to drive it. I also have some wheels on the way which would eliminate the RFT's and probably give me a much better ride. I will probably end up raising the rear a big once the new wheels are mounted.
Appreciate 0
      05-05-2011, 10:46 PM   #6
specE30Dude
New Member
specE30Dude's Avatar
0
Rep
19
Posts

 
Drives: 335d
Join Date: Mar 2010
Location: Oakton, VA

iTrader: (0)

I installed these on my 335d but went with 450/800. I don't have much to compare this to but I have expressed to harold that the back seems too bouncy and unstable. I have my ASTs at 1 click from stiff in the rear and still getting a bouncy feeling. For ex: if I drive over a speed bump, the car will compress, rebound then settle, unlike the front that compresses then rebounds to the original stance. I have been delaying a more lengthy write up as I have been meaning to take this to a local shop who is very experienced with suspensions on these cars. The front feels fine but I'm considering going down to 700s in the rear?? Will right a more detailed write up in coming weeks.

Does anyone have a detailed write up on the physics of how the right set up should work, feel and handle? Any feedback, thoughts or opinions are appreciated.
Appreciate 0
      05-05-2011, 10:58 PM   #7
f00dstamps
Private First Class
United_States
2
Rep
125
Posts

 
Drives: 2010 BMW 335d
Join Date: Feb 2011
Location: US

iTrader: (0)

Send a message via Skype™ to f00dstamps
Quote:
Originally Posted by specE30Dude View Post
I installed these on my 335d but went with 450/800. I don't have much to compare this to but I have expressed to harold that the back seems too bouncy and unstable. I have my ASTs at 1 click from stiff in the rear and still getting a bouncy feeling. For ex: if I drive over a speed bump, the car will compress, rebound then settle, unlike the front that compresses then rebounds to the original stance. I have been delaying a more lengthy write up as I have been meaning to take this to a local shop who is very experienced with suspensions on these cars. The front feels fine but I'm considering going down to 700s in the rear?? Will right a more detailed write up in coming weeks.

Does anyone have a detailed write up on the physics of how the right set up should work, feel and handle? Any feedback, thoughts or opinions are appreciated.
I also don't have much to compare this to besides my 335d's stock non-sport suspension and my old S2000 lowered with eibach pro-kit springs. There is no comparison to my stock suspension. It feels very planted on the highway and 30mph 90 degree turns even when the intersection has bumps. My opinion is that I would not categorize this suspension as unstable. In fact, it feels more stable than my S2000 was due to the squirrelly nature of the car. Unfortunately, I no longer have that car so I cannot compare them back to back.

I'm pretty low in the back right now so I'm not sure if that has any effect on the bounciness. I expect that I will probably end up stiffening up the back. I am tuning the suspension one click each day during my route to and from work so that I'm travelling the same road for comparison. I'll share what my final settings end up being. Please keep me updated on the feedback that the local shop gives you.

Thanks.
Appreciate 0
      05-05-2011, 11:03 PM   #8
cvc 22349a
Colonel
cvc 22349a's Avatar
United_States
27
Rep
2,266
Posts

 
Drives: 335i
Join Date: Sep 2007
Location: SF Bay

iTrader: (8)

Did you guys with stiff rear springs that are feeling bouncing upgrade your rear subframe bushings to M3?
__________________
2007 E90 335i, TiAg, 6AT, ZPP, ZSP, ZCW, 6FL, HD
Quaife lsd, ETS fmic, GIAC s/w, Dinan intake/exhaust/oc, KW/M3 susp, Apex Arc 8, Mich PSS
Appreciate 0
      05-05-2011, 11:16 PM   #9
MrTerryliu
Brigadier General
MrTerryliu's Avatar
United_States
48
Rep
3,215
Posts

 
Drives: 335i
Join Date: Feb 2008
Location: bay area

iTrader: (6)

Send a message via AIM to MrTerryliu
how much did sonicms charge you. if u feel uncomfortable posting here u can pm me.
Appreciate 0
      05-05-2011, 11:19 PM   #10
f00dstamps
Private First Class
United_States
2
Rep
125
Posts

 
Drives: 2010 BMW 335d
Join Date: Feb 2011
Location: US

iTrader: (0)

Send a message via Skype™ to f00dstamps
I did not upgrade my rear subframe bushings. I'm only on click 3 of 12 on the rear and the bounciness of the rear is not bad. I'm hoping that I can eliminate it with the adjustments that I have left.

Quote:
Originally Posted by cvc 22349a View Post
Did you guys with stiff rear springs that are feeling bouncing upgrade your rear subframe bushings to M3?
Appreciate 0
      05-06-2011, 08:35 AM   #11
madmaxhk
Private
2
Rep
66
Posts

 
Drives: BMW 135i 08
Join Date: Nov 2010
Location: Hong Kong

iTrader: (2)

Quote:
Originally Posted by subieworx View Post
It' a very nice combo. Mine were a little bouncy in the rear, but I got that taken care of. Love them now.
I have AST 4100, 400/800 installed on my 135i. I also have the m3 subframe bushing and m3 front and rear sway bar and Quaife LSD installed. The rear end seems to not be stable, every time when I step on the throttle, the rear just sunk a bit then robound back to the normal. Front is 3 clicks from full stiff and rear is 1 click from full stiff
I've sent a pair of rear dampers to AST for revalving to be at least 50% stiffer than before 5 weeks ago. I'm still waiting for AST to finish the revalve, but still not ETA yet. I'm considering to get the 900lb springs as well. Anway I'll let you guys know once I have my dampers back.

Last edited by madmaxhk; 05-06-2011 at 08:48 AM.
Appreciate 0
      05-06-2011, 10:10 AM   #12
sappersix
Private
1
Rep
74
Posts

 
Drives: '07 E90 335i
Join Date: Dec 2009
Location: Bay Area, CA

iTrader: (0)

Quote:
Originally Posted by specE30Dude View Post
I installed these on my 335d but went with 450/800. I don't have much to compare this to but I have expressed to harold that the back seems too bouncy and unstable. I have my ASTs at 1 click from stiff in the rear and still getting a bouncy feeling. For ex: if I drive over a speed bump, the car will compress, rebound then settle, unlike the front that compresses then rebounds to the original stance.
I certainly would not describe the back as unstable. In fact, to me, the car is MUCH more stable than stock ZSP with the Swift/AST combo. It's level through turns, absorbs bumps in a turn and stays planted, increasing confidence.

However, I do agree with specE30Dude's description of the front to back difference. In fact, that's exactly the feeling I have. Front compresses, rebounds, done. Rear compresses, rebounds and takes a bit to get back to equilibrium.

I have only been driving these for a week. I haven't started playing with the adjustments yet (mostly because the adjustment extenders have been on backorder from Harold and I'm too lazy to peel back the trunk liner).

I'll start playing around with the adjusters as I can. Like a previous poster, I'm hoping that by increasing the rebound dampening I can deaden some of the bounce without getting too wooden in the rear. Plus, I have a follow-up appointment with Sonic to do a final alignment after everything settles, so maybe they'll have some ideas too if it still feels weird to me.

All this being said, I haven't taken this setup out to the track yet and that's where I really want to see how she does...

I'll post any updates. And I'm certainly interested in hearing what others' experiences are.
__________________
'07 E90 335i | 6MT | ZSP | ZPP | Alpine White | Terra Dakota Leather | Aluminum Trim
Procede | PWM Meth | Vishnu DCI | AST4100 | Swift Springs | Quaife LSD | M3 suspension
Appreciate 0
      05-06-2011, 10:18 AM   #13
The HACK
Garland Operator 7G
The HACK's Avatar
41
Rep
3,482
Posts

 
Drives: 2006 MZ4C, 2013 Veloster Turbo
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day

iTrader: (1)

Increase the rear rebound.
__________________
Quote:
No way I'd ever take my BMW to the track.
Quote:
Then why do you have $3,000 worth of suspension mods on your car?
Quote:
...
-Overheard at the last B****rfest.
Appreciate 0
      05-06-2011, 10:31 AM   #14
UltraRacer13
Wannabe Track Rat
UltraRacer13's Avatar
British Virgin Islands
19
Rep
911
Posts

 
Drives: 08 335xi e92 MT
Join Date: Mar 2010
Location: Texas

iTrader: (1)

i was running 2 on front and rear. I agree that maybe I need to go up on the back, maybe 3 or 4. For the track, Brian Hanchey from AST suggested I go 6 front/rear and that worked very well as a place to start. I think in the future I may go 5 front/ 8 rear. I also have 400/800. I have been waiting for this thread, I love these coils and am curious what setup others are running to get them dialed in.

FWIW, I haven't adjusted them since the track and can say 6/6 is too stiff for the road. Only feels good hauling on the highway.
__________________

XI | COBB | AST | Vorshlag | PFC | STETT | StopTech | Apex | DCI
Appreciate 0
      05-06-2011, 10:40 AM   #15
f00dstamps
Private First Class
United_States
2
Rep
125
Posts

 
Drives: 2010 BMW 335d
Join Date: Feb 2011
Location: US

iTrader: (0)

Send a message via Skype™ to f00dstamps
[quote=sappersix;9539769]I have only been driving these for a week. I haven't started playing with the adjustments yet (mostly because the adjustment extenders have been on backorder from Harold and I'm too lazy to peel back the trunk liner).QUOTE]

I've been driving with my trunk liner out until I finish my adjustments.
Appreciate 0
      05-06-2011, 11:55 AM   #16
HP Autosport
BimmerPost Supporting Vendor
United_States
418
Rep
11,443
Posts


 
Drives: F80 M3
Join Date: Mar 2007
Location: Santa Barbara, Brembo, GIAC, Koni, Ohlins, Performance Friction, Quaife, Stoptech, Vorshlag

iTrader: (29)

Some of the bounce you guys are feeling are in the oem lower damper saddle, it's all rubber, the upper rebound and compression cushions are of a soft rubber foam material doesn't help the situation either. The deflections in these components aren't being controlled by the dampers at all.

Many choose to upgrade to the M3 rear lower camber links, that will take care most of the bounce. Then there is the M3 rear subframe bushings, but at 7 hours or so labor many will choose not to do it.
Appreciate 0
      05-06-2011, 09:40 PM   #17
specE30Dude
New Member
specE30Dude's Avatar
0
Rep
19
Posts

 
Drives: 335d
Join Date: Mar 2010
Location: Oakton, VA

iTrader: (0)

Quote:
Originally Posted by HP Autowerks View Post
Some of the bounce you guys are feeling are in the oem lower damper saddle, it's all rubber, the upper rebound and compression cushions are of a soft rubber foam material doesn't help the situation either. The deflections in these components aren't being controlled by the dampers at all.

Many choose to upgrade to the M3 rear lower camber links, that will take care most of the bounce. Then there is the M3 rear subframe bushings, but at 7 hours or so labor many will choose not to do it.
I was thinking along the same lines today as I was pondering would it could be. I have not had time to visit a local shop (RRT - AST has listed on their site as East Coast vendor). I will try to visit within the next 1-2 weeks, and will post their feedback too. I still believe that that the dampers need to be re-valved to handle the stiffer springs but I'm thinking my described ride experience is being defined by some of the following:

1) Stiffer springs are amplifying the softness of the rear subframe bushings, thus making it noticeable in the rear. Harold pointed this out too.

2) Stock trailing arm bushing is being overstressed and beyond geometric happiness with the car being lowered causing slight bump steer. This is what may be giving me the feeling of slightly unstable. However, the rear is not incredible low at 13 1/8 from center of hub cap. I do need to raise the front as it's currently at 11 12/16ths. I chopped the rear bump stop in half so there is plenty about 2" of damper travel - I would think this is enough. Any measurements by others would be nice to compare too!

Harold - You pointed this out too..Can you please expand on this with your wisdom? I found this older post from you implying what is likely to address the described: http://www.e90post.com/forums/showthread.php?t=246614

3) Crappy RFT's! I assume this may be slightly increasing he spring rate given its poor stiff ride. I have new Michelin Super Sports waiting to go on a set of Advan RS's so this too may help. I suspect I will have the wheels by the end of this month so I'll have to wait still several more weeks for a final assessment.

Any thoughts are appreciated. Sooner or later, I will have this to my liking and I'll be sure to share the results.
Appreciate 0
      05-08-2011, 08:37 PM   #18
specE30Dude
New Member
specE30Dude's Avatar
0
Rep
19
Posts

 
Drives: 335d
Join Date: Mar 2010
Location: Oakton, VA

iTrader: (0)

In case anyone was curious what the current height described by my last post looks like, I've attached a photo that was taken today. I hope to have the new wheels/tires by the end of the month and will post more then.

Also, additional feedback from a drive this weekend through some great twisties up to the top of the Shenandoah Mtns. The suspension felt VERY good and planted going in and coming out of the turns under heavy breaking driving at 95% of what the tires would allow. Clearly, a huge improvement from stock. With that said, the road was recently paved and no bumps whatsoever.

After the new tires/wheels are installed and ride height is adjusted a bit more (slightly higher), I will provide more feedback.
Attached Images
 
Appreciate 0
      05-09-2011, 12:14 AM   #19
HP Autosport
BimmerPost Supporting Vendor
United_States
418
Rep
11,443
Posts


 
Drives: F80 M3
Join Date: Mar 2007
Location: Santa Barbara, Brembo, GIAC, Koni, Ohlins, Performance Friction, Quaife, Stoptech, Vorshlag

iTrader: (29)

Quote:
Originally Posted by specE30Dude View Post

Harold - You pointed this out too..Can you please expand on this with your wisdom? I found this older post from you implying what is likely to address the described: http://www.e90post.com/forums/showthread.php?t=246614
Are you referring to the benefits of the M3 rear lower camber links? Or the oem 135/335i camber link with excessive deflection not being control by the rear dampers.
Appreciate 0
      05-11-2011, 06:41 PM   #20
specE30Dude
New Member
specE30Dude's Avatar
0
Rep
19
Posts

 
Drives: 335d
Join Date: Mar 2010
Location: Oakton, VA

iTrader: (0)

Quote:
Originally Posted by HP Autowerks View Post
Are you referring to the benefits of the M3 rear lower camber links? Or the oem 135/335i camber link with excessive deflection not being control by the rear dampers.
It would be nice to hear your explanation of both but the topic was more around the cause of the slight bouncy feel in the rear.
Appreciate 0
      05-12-2011, 01:51 AM   #21
Orb
Lieutenant Colonel
No_Country
37
Rep
1,747
Posts

 
Drives: 335
Join Date: Jun 2006
Location: Canada

iTrader: (1)

Quote:
Originally Posted by specE30Dude View Post
I was thinking along the same lines today as I was pondering would it could be. I have not had time to visit a local shop (RRT - AST has listed on their site as East Coast vendor). I will try to visit within the next 1-2 weeks, and will post their feedback too. I still believe that that the dampers need to be re-valved to handle the stiffer springs but I'm thinking my described ride experience is being defined by some of the following:

1) Stiffer springs are amplifying the softness of the rear subframe bushings, thus making it noticeable in the rear. Harold pointed this out too.

2) Stock trailing arm bushing is being overstressed and beyond geometric happiness with the car being lowered causing slight bump steer. This is what may be giving me the feeling of slightly unstable. However, the rear is not incredible low at 13 1/8 from center of hub cap. I do need to raise the front as it's currently at 11 12/16ths. I chopped the rear bump stop in half so there is plenty about 2" of damper travel - I would think this is enough. Any measurements by others would be nice to compare too!

Harold - You pointed this out too..Can you please expand on this with your wisdom? I found this older post from you implying what is likely to address the described: http://www.e90post.com/forums/showthread.php?t=246614

3) Crappy RFT's! I assume this may be slightly increasing he spring rate given its poor stiff ride. I have new Michelin Super Sports waiting to go on a set of Advan RS's so this too may help. I suspect I will have the wheels by the end of this month so I'll have to wait still several more weeks for a final assessment.

Any thoughts are appreciated. Sooner or later, I will have this to my liking and I'll be sure to share the results.
It will not be possible to correct any instability with the rear suspension when you increase the spring rate or added a stiffer sway bar (it is not going to get any better not matter what!!!!). The explanation is simple….think about how load is transfer to one member at time and you see that the reaction forces at the sub frame will take a chunk of the load and not the spring. I think I was the first to discover this back over 3 years ago…remembering TC Kline was thinking I was nuts running a spring over 500 lb/in on the rear. Tuning the suspension was a complete failure until I upgraded the sub frame bushing and front tension strut. As for upgrading the valving, it should not be necessary considering the motion ratio and your current suspension frequency. The dampener only cares about frequency not spring rate. The dog tracking or side to side motion is due to the OEM rear toe links and front tension struts. You not are going to get a real smooth ride with mono tube dampener with washer stacking valve system. Discrete compression valving for high low speed is a bear minimum. If you dropped the car more than 0.8” then you might as well forget tuning or raise the car back up. The car should be dropped evenly front and rear. Bump stop length should be about 45-50 mm for the rear and 30-35 mm in the front with the softest possible material. The isolator on the rear dampener are not huge issue but changing the bottom ones to M3 setup does help correct over and under shoot in transient conditions.

Orb
Appreciate 0
      05-13-2011, 09:51 AM   #22
sappersix
Private
1
Rep
74
Posts

 
Drives: '07 E90 335i
Join Date: Dec 2009
Location: Bay Area, CA

iTrader: (0)

Orb, thanks for weighing in. I had been avoiding the subframe because of labor cost, but maybe I'll need to do it. I'll give myself a bit more drive time on the new setup before making more changes.

BTW, I just ordered my Bentley shop manual. Could a mechanically minded, but weekend warrior mechanic do an R/R of sub-frame bushings?
__________________
'07 E90 335i | 6MT | ZSP | ZPP | Alpine White | Terra Dakota Leather | Aluminum Trim
Procede | PWM Meth | Vishnu DCI | AST4100 | Swift Springs | Quaife LSD | M3 suspension
Appreciate 0
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 03:43 PM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST