09-22-2020, 02:12 PM | #67 | |
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In reality, I'm sure it's not by much and the kit is tuned to perform best when within recommended height settings.
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09-22-2020, 03:29 PM | #68 |
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Spring stiffness does not change with preload. This article does a good job of explaining this.
http://www.superstreetonline.com/how...the%20opposite. |
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09-23-2020, 08:49 PM | #69 | |
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What I think happens when you raise the perch is the shock piston is extended further up along with the height of the top of the upper spring mount. The spring itself is not compressed any further. If it was, the car would not be raised when you move the spring perch up. |
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09-24-2020, 06:48 AM | #70 | |
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On partially threaded like the B16, you adjust the height by adjusting the preload on the spring. The higher the height setting, the more the spring is compressed. It's really as simple as that. There's a reason higher end coil overs have independent height adjustment from preload. To not have this issue. The spring has the same preload and thus same initial force no matter which height it is set to.
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09-24-2020, 10:16 AM | #71 |
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I think this FB post sums it up and is consistent with my experience.
This is my understanding. The total shock travel is made up of compression stroke (called "bump" stroke as the shock is compressed when you hit a bump) and rebound or extension stroke (called "droop" which happens when the shock is extended). The total suspension travel is droop+bump stroke. So, let's assume the car has 4" of total suspension travel when sitting on the ground and ride height is set such that the spring/shock can compress 2.5" before it hits and fully compresses the bump stops and can extend or rebound up 1.5" before it tops out and can no longer extend any further. When the car is sitting on the ground, assuming 50/50 weight distribution and 3600 lb car, on each corner of the suspension 900 lbs of force is being exerted. This compresses and preloads the spring. If you raise the spring perch by .5", you are basically pulling the shock piston up by .5", thus raising the car by .5". The distance between the top hat of the suspension and the spring perch does not change when you raise the perch. If this distance decrased, you would be adding preload to the spring. Instead, what happens is the car just goes up by .5" as the spring perch is raised .5". So with this adjustment, the compression stroke available increases from 2.5" to 3" but the rebound stroke available (how much the suspension can extend up before topping out) decreases from 1.5" to 1". You can see how much potential rebound stroke is available by observing what happens with the shock when you jack up the car. As you raise the body of the car, initially, the tire continues to sit on the floor as the suspension is being unweighted and extended. The bottom of the shock that's bolted to the hub of the rim/tire is static as the top of the shock is raised thereby pulling and extending the shock piston. Once you raise the body of the car several inches and the shock piston cannot extend any further (shock now topped out) the tire lifts off the ground. The amount that you were able to raise the car before the tire comes off the ground represents how much rebound or droop travel your shock can move before it is completely topped out. So, when you raise a car by moving the spring perch up by .5" in a single adjustable coilover, you are reducing the rebound stroke of the car by .5" (reduces upward movement stroke of the suspension from 1.5" to 1") while adding .5" bump stroke (the amount the suspension can compress before bottoming out increases from 2.5" to 3"). The explanation in the link above is consistent with my experience with the several single adjustable coilover set ups I've had in multiple cars. Whenever I raised the spring perch on these cars, the ride height goes up and the ride quality always noticeably improved because I was not adding any significant amt of preload to the spring and was, in fact increasing suspension travel for the compression stroke. I've had the exact same experience with my Blistein coilovers on my F80. It is presently set to the highest setting in front and fairly high in the rear and the car rides noticeably better than when it was set about 1/2 way down. |
09-24-2020, 02:07 PM | #72 | ||
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The only time moving the spring perch increases preload is if the car being set on the ground wouldn't compress the spring from where it is in droop.
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09-25-2020, 03:53 PM | #73 | |
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KW goes into detail regarding preload and ride height here as well, just scroll down a bit. http://blog-int.kwautomotive.net/in-...in-the-bmw-m4/ |
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10-05-2020, 01:29 PM | #74 | |
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I'm pretty sure im going with these after the review but would want them discounted. Let me know either PM or here. Thanks |
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10-05-2020, 01:52 PM | #75 | ||
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2017 F80 M3 ZCP / AA GESI DPs / Akrapovic Evo / BBS FI-R 19" / Bend Calibration ECUTEK Flex Fuel | Bilstein B16 DDC + CS EDC / BMC Filters / BMS OCC / CSF HE / ESS CP / Nitto NT555R2 / PD Crank Hub / SPL Suspension / Uniden R7 / Wagner Top Mount IC
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10-05-2020, 03:24 PM | #76 | |
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Also since this is referenced to you the OP, I dont have EDC on my car but I have to imagine the non EDC version of the coils should ride/feel the same as the Damptronic version? |
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10-05-2020, 03:26 PM | #77 | ||
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IND or extreme power house are good sources for Black Friday sales. I would follow all the vendors on Instagram so you know what codes to apply for Black Friday.
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2017 F80 M3 ZCP / AA GESI DPs / Akrapovic Evo / BBS FI-R 19" / Bend Calibration ECUTEK Flex Fuel | Bilstein B16 DDC + CS EDC / BMC Filters / BMS OCC / CSF HE / ESS CP / Nitto NT555R2 / PD Crank Hub / SPL Suspension / Uniden R7 / Wagner Top Mount IC
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10-28-2020, 04:01 AM | #79 |
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11-18-2020, 08:25 AM | #81 | |
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Ian Shea ishea@turnermotorsport.com Looking forward to getting them on! |
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11-19-2020, 11:08 AM | #82 | |
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11-25-2020, 12:00 PM | #83 |
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Have been reading all the posts with great interest and would like to pull trigger to take advantage of BF sales, if any occur. My only concern is that I live in Calif. and roads are not good. I have an '18 F80 zcp with EDC and 20" wheels and really don't want to ruin the ride for DD, it is already pretty firm on the 20's. I like idea of leveraging EDC so if/when track can go all out and use comfort on poor roads. I don't mind firm, but jarring when hitting poor sections of road not so much. I guess just looking for final feedback that I wont be ruining the ride. Would like lower stance and improved handing then I'm all in.
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11-25-2020, 12:57 PM | #84 | |
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I live in CA as well... I don’t have too many “jarring” impacts and I run 20’s. Firmer, oh yes, but I’m also lower than should be at the moment. Others have reported better comfort with the KW’s. |
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12-03-2020, 12:45 PM | #87 |
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My car is an 18 ZCP 6MT. This has been the progression so far and why:
Stock: Nice but a bit dull and way to high so I wanted it lowered. Nothing crazy I’m more about performance then stance. MP-HAS: Decided to go down this route as it lowered the car to where I wanted and it handled better. The catch here is the dampers. The rebound are way to slow and the car feels unsettled by road imperfections. Freeway ramps with expansion joints are a good example. If its this bad on the road it will x10 worse on a track. MS-HAS/CS Coding: Much better rebound damping in comfort. Sport and Sport+ introduce so much compression that the rebound cannot catch it quickly enough so the car pitches (front to read) over imperfections. The dampers just are not that great, no way around that. They are always behind and not offering enough damping and speed. Bilstein B16 Damptronic with adjustable H&R sway bars/SPL end links/camber plates/corner balance: (In theory at this time) After some research I’m aiming for a good compromise for a 10% track and 90% street driven car. I may do 4-8 track days a year and just want something that is fast enough but stable at ~85%. To me track prepped “focused” cars feels great on the street. Will probably install the monoball thrust arm bushings as well. Did not go with the KW as some they are soft and when looking at other platforms the Bilstein’s seem like the preferred choice of the track focused drivers and was also recommended by my installer that does a lot of work on German cars with a heavy track focus. I have installed coil overs on all most of my cars in the past but wanted to try the MP-HAS route as I still have two years of warranty left. All I can say is I tried. I am all ears for any suggestions and comments. Last edited by irunalot; 12-03-2020 at 03:25 PM.. Reason: Typing while in a meeting is a bad idea |
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12-03-2020, 05:16 PM | #88 |
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I almost went the b16 route but decided to go with a bit more comfort and did the B6 damptronic and Eibach's which are both on order. I have the 20" run flats ('18 zcp) and did not want anything appreciably more stiff as I live in Calif and roads suck, also wanted to keep the EDC as well. KW's v3's sat too low and KW damptronic a bit pricey. I guess we shall see.
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