# BC, D2, Ksport, XYZ, coilovers any one use them yet?



## taverncustoms (Feb 18, 2011)

there seem to be alot more coilover avalible for the TT quattro not these seam to be quality brands has any one used them yet? 
BC, D2, Ksport, XYZ, 

http://ksportusa.com/products/coilovers/

http://www.d2racing.com/coilovers/rs-series/

http://www.xyzcoilovers.com/

http://www.bcracing-na.com/


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## TheDeckMan (Sep 26, 2004)

I would not want to be in the first wave. I would stick to name brands even if used was only in the budget.


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## paullee (Feb 3, 2008)

Bought the Ksport Kontrol Pro coilovers when I got the TT 5 years ago. If I had a do-over, I'd go with something else. The design of the front was rather non-specific to the TT and I had to get creative with securing the brake lines during install. It also did not go as low as I wanted to and the ride overall is a little harsh, even with the front on its softest setting.


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## taverncustoms (Feb 18, 2011)

I'm more interested in the adaptability of the XYZ and BC coil overs they use strut body hight adjustment so you can adjust spring preload sepreate from ride hight. this will alow a fine tuning of the spring rate, the V3's don't even have that option. i think i will be buying a set of bc or xyz


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## taverncustoms (Feb 18, 2011)

think I've narrowed it down to BC they have a larger Motorsport following.


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## TheDeckMan (Sep 26, 2004)

If you don't dyno the shocks screwing with the dampening is worthless.


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## ejg3855 (Sep 23, 2004)

*FV-QR*

Call up [email protected] Get a set of ISC's I think he might still be running his intro pricing.


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## taverncustoms (Feb 18, 2011)

I decided on these, because: great reviews, superior adjustments, motorsport breed, larger shock piston, and last but not least price.


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## Marcus_Aurelius (Mar 1, 2012)

Spring rates?


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## TheDeckMan (Sep 26, 2004)

taverncustoms said:


> I decided on these, because: great reviews, superior adjustments, motorsport breed, larger shock piston, and last but not least price.


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## taverncustoms (Feb 18, 2011)

Marcus_Aurelius said:


> Spring rates?


they do offer custom spring rates. but they come with:

copied from the website:

Spring Rate - kg/mm
front 62-170-7 
Rear 62-47-125-11-S

I would also like to note these coil overs have Adjustable pre-load for the spring, like a superbike suspension . so you can pre-load the spring for your particular application. instead of the un-sprung weight of the car providing the pre-load. also because height is adjusted at the strut body you don't loose shock travel by lowering the car.


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## taverncustoms (Feb 18, 2011)

DeckManDubs said:


> Motorsport breed :sly: Superior adjustments has me wondering however. Because other than a few on here, like Max and myself and a couple others, adjustability is only useful if you can test the results. Butt dyno does not apply here. Lap times are even just a crude way of testing.
> 
> 
> 
> ...


I plan to use a Iphone G force meter to dial these in. gonna be allot of driving in a circle at Auto X speeds. may not be the best way but that's what I got.


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## Marcus_Aurelius (Mar 1, 2012)

taverncustoms said:


> they do offer custom spring rates. but they come with:
> 
> copied from the website:
> 
> ...


Adjustable spring preload don't mean much if anything at all (especially when the ride height with the coilover is independent of the spring and done by screwing the strut into the housing). Ideally, you don't want to preload a coilover spring at all, and that's why there's a market for tender springs (take the slop at full droop but allow to dial an ideal zero preload). The "custom" spring rate is only a 2k bump in any direction, it can help if the balance is off, but 2k doesn't do much in terms of substantial customization (luckily, the spring rate ratio front/rear is on point with these). 


My observation:

- They are the "better" one out the line up you had posted. At least their spring rates seems to be somewhat mindful of the platform's motion ratio (a big plus vs the other coilovers with completely butchered spring ratio). 7k/11K gives you and absolute rate of 392lbs/616lbs springs front to rear. Taking the bars out of the equation for simplicity, and pluging the calculated motion ratios (.95/.65), you'll have an effective rate of 372lbs/400lbs at the wheels with these coilovers. Not bad at all for a budget coilover! 

- They only offer a 2k spring bump in any direction just like most generic coilovers. This tells me that they are not too confident about their valving. They also seem not offer revalve which would have been great if they did (then it would give a true choice of spring selection). 

- Without individual dyno plots for each coil, having adjustment is a curse. Noah mentioned it before and I can not stress this enough. First of all, you don't know how unmatched the set is (the given is that they're not going to fully match). Secondly, the adjusters are going to have a linear ramp but the valving curves most likely have some digression (most modern shocks do a various degree) and compression/rebound curves and possible crosstalk is unknown. 

- The welded piece that houses the adjuster on the rear shocks takes a good chunk of travel away. Knowing how limited our compression travel is in the back, you're advised to not run the car low in the back. Also, ishave as much as you can from the rear bump stop to try to make up for the loss travel.

- The hardware looks pretty solid.


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## Marcus_Aurelius (Mar 1, 2012)

taverncustoms said:


> I plan to use a Iphone G force meter to dial these in. gonna be allot of driving in a circle at Auto X speeds. may not be the best way but that's what I got.


Futile exercise if you ask me, the only way to set them is to dyno. Without knowing what each adjustment does to what on each individual coil, it's impossible to dial properly. Steady state grip (measuring lateral G in a skidpad) tells you nothing about the important stuff you want to dial in (mainly transition characteristics as well as bumb/undulation absorption). :beer:


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## taverncustoms (Feb 18, 2011)

Marcus_Aurelius said:


> Adjustable spring preload don't mean much if anything at all (especially when the ride height with the coilover is independent of the spring and done by screwing the strut into the housing). Ideally, you don't want to preload a coilover spring at all, and that's why there's a market for tender springs (take the slop at full droop but allow to dial an ideal zero preload). The "custom" spring rate is only a 2k bump in any direction, it can help if the balance is off, but 2k doesn't do much in terms of substantial customization (luckily, the spring rate ratio front/rear is on point with these).
> 
> 
> My observation:
> ...


not bad for


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## Marcus_Aurelius (Mar 1, 2012)

taverncustoms said:


> not bad for


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## 20v master (May 7, 2009)

taverncustoms said:


> not bad for


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## taverncustoms (Feb 18, 2011)

20v master said:


> You keep saying "


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## 20v master (May 7, 2009)

taverncustoms said:


> I respect max's opinion, However IMO I have a sportbike and even though its a completely different animal, spring preload will really help balance the vehicle F-R & L-R, I like the adjustabillity i think in the long run its going to be beneficial to me. and having the height adjustment in the shock body instead of the spring perch allows you to have longer suspension travel even when lowered. on most TT coils like the H&R's on my DD the lower you go the less shock travel you get.
> 
> there are deals out there for these you just have to look MSRP is 1200.00


You still didn't answer the question. How much less than $1K? And preload doesn't help you on balance and isn't really needed unless you plan on doing some rally baja action. Yes, compromised travel is a bad thing, but why do you think you need so much travel when going low? Full travel once fully lowered could be viewed as a bad thing on the opposite end of the spectrum. Addressing the lack of travel would apply to the rear more than the fronts anyways, and the rear isn't where the deciding feature is located in the first place.


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## taverncustoms (Feb 18, 2011)

20v master said:


> You still didn't answer the question. How much less than $1K? And preload doesn't help you on balance and isn't really needed unless you plan on doing some rally baja action. Yes, compromised travel is a bad thing, but why do you think you need so much travel when going low? Full travel once fully lowered could be viewed as a bad thing on the opposite end of the spectrum. Addressing the lack of travel would apply to the rear more than the fronts anyways, and the rear isn't where the deciding feature is located in the first place.


here is a good article on preload for you: http://www.auto-ware.com/setup/wtdstxwt.htm

and im not trying to sell these. these sell from "make offer" to 1299.00 the lowest listed price is 995.00 OBO 

and the rear shocks are adjustable just like the fronts. and allow you to preload the spring on the rear arm.


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## taverncustoms (Feb 18, 2011)

once you understand preload you will be able to set static sag and that will "Balance" the car. a properly set up suspension should have the same sag at all 4 corners with the driver and full race weight. you should be able to remove & install the sway bar bolt with no tension on the bar (with the driver in the car.) this would be nearly impossible to do on a custom ordered spring. because if you adjust ride height to get a proper-ish static sag the un-sprung height would be different L-R so in situations like cresting a hill at speed or a slalom the car will have an undesirable roll toward the lower side.

And to add on top of all that a perch adjusted coil especially if lowered can become overextended in a zero G situation. yes jumping. if your cresting a hill fast enough for both spring to become unloaded they will become free floating not my idea of a good time. this would not happen in a turn because of the sway bar.


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## taverncustoms (Feb 18, 2011)

While lurking through the internet I found this thread VERY interesting.

http://www.lxforums.com/board/f140/awd-bc-coilover-install-uas-air-bags-218118/

Air bags on a set of BC coilovers would in theory give you a race capable air ride system. because the spring perch is separate from ride height all you would need is a plate for the bag. no welding required. and you can increase bag pressure at full length for insreased spring rate hmm interesting. air bagged auto X car. you could use a fiber air tank for light weight and a single compressor. or just use a small nitrogen tank.

I dont think it would be as good as springs though.


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