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Thread: DRC to Koni swap

  1. #1
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    DRC to Koni swap

    After reading the post on this swap ... twice, I see the question was asked, but don't think answered … which is … how to cut a grove into the koni replacements.

    Last fall I swapped out the DRC for the koni’s. Kept the original springs but replaced all top bushings. I set the rears on the lowest perch and have had zero problems with rubbing on the axle (so far at least).

    The end result of the swap (in my case) is that even after driving a couple thousand clicks my front is still sitting a good ½ to ¾ inch higher than the rear (based on gap between tire and fender). Although this makes the car pretty much perfectl,y level I would prefer to have the original rake. So, either I raise the rear to the middle perch or lower the front.

    So, would appreciate input regarding: 1) cutting the groove and 2). (for those that have the experience) will cutting the groove ½ to ¾ below the existing groove lower the front end by same. Has anyone experienced any problems by lowering the front by this amount?

    Thanks, in advance, to all who take the time to provide input / advice.

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    Registered User Bigglezworth's Avatar
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    Quote Originally Posted by Roots View Post
    After reading the post on this swap ... twice, I see the question was asked, but don't think answered … which is … how to cut a grove into the koni replacements.

    Last fall I swapped out the DRC for the koni’s. Kept the original springs but replaced all top bushings. I set the rears on the lowest perch and have had zero problems with rubbing on the axle (so far at least).

    The end result of the swap (in my case) is that even after driving a couple thousand clicks my front is still sitting a good ½ to ¾ inch higher than the rear (based on gap between tire and fender). Although this makes the car pretty much perfectl,y level I would prefer to have the original rake. So, either I raise the rear to the middle perch or lower the front.

    So, would appreciate input regarding: 1) cutting the groove and 2). (for those that have the experience) will cutting the groove ½ to ¾ below the existing groove lower the front end by same. Has anyone experienced any problems by lowering the front by this amount?

    Thanks, in advance, to all who take the time to provide input / advice.
    Machine shop can provide this for you. I did it to my one set of Koni's here and I also did it to a set of OEM DRC dampers. On a side note, I wore grooves in to the rear spring perches where they rubbed on the axle shaft when set to the lowest setting. Important to note that the Koni kit is not sold as fitting the RS6, it's sold as an A6 kit. The OEM A6 axle shafts are smaller in diameter than the RS6 shafts and as such have improved clearance. Depending on your cornering characteristics and how much weight you have in the car while hitting dips and the likes, will depend if you will ever experience any rubbing.

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    Hey Bigglezworth ... thanks for the info. I'll triple check for rubbing, but a mute point now as I think I'm just going to raise the rear to the middle perch. Kind of liked the look from the lower perch (which is why I was considering lowering the front) but getting that 1/2" or so back won't hurt in the tire clearance category and should get me back (close at least) to the stock rake.

    Another question ... if I may ... given your experience. How did or do you find the ride to be after the swap. I ask because at times I wonder if there's not something wrong with one of the front struts ... as over sharp "edges" (like a sewer, or going in or out of an entrance or something) the suspension still "bottoms out" giving a pretty good bang. Now if it did this on both sides I'd say ok, maybe I should of thought about the springs a little harder ... but it definitely seems to be worse on one side as compared to the other. So I'm wondering, could it be that my shop didn't get the adjustment right (locked) in on that one side. Appreciate your thoughts / input...and Thanks!!!

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    I was battling the "clunk" from one of the front struts for a while after the swap - until I finally found out that the upper shock mount nut wasn't tightened all the way!
    However, if you're describing feel and not the sound - well, keep in mind the fact that you can only adjust the rebound on these, not compression.

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    Of course ... dah. So focused on a potential shock problem (I think because I replaced the upper mounts at the same time) that I didn't even stop to think maybe it's where the assembly bolts to the car that there could be problem. Will check those bolts for sure ... and Thx for the feedback, much appreciated

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    Registered User 4.2Crew's Avatar
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    Quote Originally Posted by Roots View Post
    ......I wonder if there's not something wrong with one of the front struts ... as over sharp "edges" (like a sewer, or going in or out of an entrance or something) the suspension still "bottoms out" giving a pretty good bang. Now if it did this on both sides I'd say ok, maybe I should of thought about the springs a little harder ... but it definitely seems to be worse on one side as compared to the other. So I'm wondering, could it be that my shop didn't get the adjustment right (locked) in on that one side.

    After about 60k miles on the Konis, I noticed a similar sharp clunk from the rear passenger strut area... After removing both rear struts and and testing the rebound and compression forces on an Instron machine (tensile tester), it was apparent the struts had different force-response profiles (rebound & compression)... I contacted Koni, they sent and billed me for 2 new rear struts. After confirming the pass-side strut had a bad "foot valve", they credited me for the 2 replacement rears.... Koni provides a lifetime warranty to the original purchaser----or at least they did in 2014. Good luck.
    2003 RS6 l SE Exhaust l Koni Yellow Sports w/stock springs l Lowered 1"F 1.25"R l EPL Tuned l 19 x 9.5 VMR V713 & 265 PSS's l 50% window tint l Protective film on entire hood, bumper and front quarter panels l

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    Registered User lswing's Avatar
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    Bringing this topic back up, see attached pic. Rear of the car has been a bit bouncy when strut rebounds to top. Looked under and you can see the perch rubbing on the axle too. Don't ever really hear it, and I don't think it's that bad, thoughts on it being a risk? Might just raise up one perch mark. Also, that strut bouncing on top of rebound, and ideas? Taking a look at bushings and connections. Front strut performance seems to be fine.

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    Registered User Bigglezworth's Avatar
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    Bounce is due to having shock rate cranked up and too stiff. I found I had to dial mine way down to get rid of the 'bounce' you describe. I noted the interference of the bottom perch with the axle in a thread some months back. This is specifically due to the fact that OEM S6/RS6 axle shafts are larger diameter than the A6 counterparts which is why the 'kit' isn't marketed for the S6/RS6 platform even through it bolts up....
    '02 S6 Avant Silver - Pokey | Carbon Black/Ebony RS6 w/ stuff - darn quick | '03 Daytona Grey/Ebony RS6 w/ more stuff - quicker yet | '91 NSX CDN issue with 6spd & BBSC - quicker yet and then some | '87 Buick GNX OEM clone w/ lots of stuff - quickest hands down

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    Registered User lswing's Avatar
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    Quote Originally Posted by Bigglezworth View Post
    Bounce is due to having shock rate cranked up and too stiff. I found I had to dial mine way down to get rid of the 'bounce' you describe. I noted the interference of the bottom perch with the axle in a thread some months back. This is specifically due to the fact that OEM S6/RS6 axle shafts are larger diameter than the A6 counterparts which is why the 'kit' isn't marketed for the S6/RS6 platform even through it bolts up....
    Thanks for the updated info Bigglez. From what I can remember the shock stiffness is one turn towards firm, and it's bit firmer than i need really, so maybe I'll try and turn it a few towards soft and see how it goes. Yep, noted that you had the same interference issue, was just posting to confirm mine was the same. I don't really ever hear it hitting/rubbing, must just be on bottom out during sporty driving. Can't see it leading to anything catastrophic though...
    Ace/Edge TC - Tozo Trans - MTM TCU - REVO/ME7 tune - Wagner IC's w/ Venair Hoses - Aux Radiator delete - Hotchkis Sways - Hawk HPS Pads - Koni Sport Struts - Scroll KO4 Turbos - Devil's Own WM - 421whp/452wtq on Mustang Dyno - http://www.audirssix.com

  10. #10
    Registered User Bigglezworth's Avatar
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    Quote Originally Posted by lswing View Post
    Can't see it leading to anything catastrophic though...
    It can and has.....

    http://www.rs6.com/showthread.php/26...ht=broken+axle
    '02 S6 Avant Silver - Pokey | Carbon Black/Ebony RS6 w/ stuff - darn quick | '03 Daytona Grey/Ebony RS6 w/ more stuff - quicker yet | '91 NSX CDN issue with 6spd & BBSC - quicker yet and then some | '87 Buick GNX OEM clone w/ lots of stuff - quickest hands down

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    Uh that's not due to "usual" rubbing, though - but rather because of improper perch/c-clip installation.

  12. #12
    Registered User Bigglezworth's Avatar
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    Quote Originally Posted by nubcake View Post
    Uh that's not due to "usual" rubbing, though - but rather because of improper perch/c-clip installation.
    You're no fun. haha

    Not 'usual' rubbing no.

    Yes improper C-clip install. Was noted as such quite some time back when another member had the same problem.

    http://www.rs6.com/showthread.php/32...ght=koni+perch
    '02 S6 Avant Silver - Pokey | Carbon Black/Ebony RS6 w/ stuff - darn quick | '03 Daytona Grey/Ebony RS6 w/ more stuff - quicker yet | '91 NSX CDN issue with 6spd & BBSC - quicker yet and then some | '87 Buick GNX OEM clone w/ lots of stuff - quickest hands down

  13. #13
    Registered User lswing's Avatar
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    All good stuff to keep an eye on, thanks fellas. Will probably raise up the rear to the next clip up to reduce/prevent the rubbing. The back sits a bit low anyhow compared to front, maybe just 1/8" or so.
    Ace/Edge TC - Tozo Trans - MTM TCU - REVO/ME7 tune - Wagner IC's w/ Venair Hoses - Aux Radiator delete - Hotchkis Sways - Hawk HPS Pads - Koni Sport Struts - Scroll KO4 Turbos - Devil's Own WM - 421whp/452wtq on Mustang Dyno - http://www.audirssix.com

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