Home Forums Tire , Wheel, Brake and Suspension Best Coilover Suspension for a Streetable Track car

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    • Shannon Whitehead
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    • TKO MOTORSPORTS TEAM
      Member
      Post count: 778

      Hello Aevus
      Really depends on what you want todo with your car and why you want or need to upgrade. If your a serious street/track junky then its worth the extra money and upgrade to custom built shocks for your application. If your just looking to have fun run of the mill less expensive stuff can get you by.
      You always want to keep it simple especially when it comes to shocks. Properly designed and engineered 2 way adjust shocks is all you really need.

    • Aevus
      Member
      Post count: 914

      Repeat Thread? Asked and Answered?

      One thread is about chassis, that one is about suspension. Overwhelming, JonB?

    • Aevus
      Member
      Post count: 914

      TKO MOTORSPORTS TEAM said:
      Hello Aevus
      Really depends on what you want todo with your car and why you want or need to upgrade. If your a serious street/track junky then its worth the extra money and upgrade to custom built shocks for your application. If your just looking to have fun run of the mill less expensive stuff can get you by.
      You always want to keep it simple especially when it comes to shocks. Properly designed and engineered 2 way adjust shocks is all you really need.

      Thanks for the input.

      I get most of my suspension info on suspensionsecrets website and it seems that 3 or 4 way dampers MIGHT solve my problem (stiff race set-up but streetable)

      https://suspensionsecrets.co.uk/damper/

      If a damper is 3 way adjustable then it allows the rebound to be adjusted and the high speed bump and the low speed bump to be adjusted. A track car needs to be very stiff to prevent the body from rolling on corner entry as much as possible if it has the grippy tyres and aero to match the set up like in most single seater categories. However, when the car encounters a sudden bump such as a kerb or a pothole in the track, it can make the car lift up in the air and lift the tyre off the ground due to the set up being so stiff. This is bad for grip as the tyre is not able to generate any grip in the air. One way to combat the sudden jolts is to soften the suspension to account for kerbs, however this means that the cornering capabilities are limited due to the increased body roll and mass transfer during cornering. This is where a 3 way damper becomes essential.

      But I have zero experience with such highly adjustable dampers, it might be overkill for my use…

      The other solution may be adjustable sway bars, so I get a planted mid corner feel while having something ”soft” on a straight line

    • TKO MOTORSPORTS TEAM
      Member
      Post count: 778

      Lots of good info out there and lots of bad info out there. Its very hard to weed through whats good and bad.

      There are a couple rules of thumb in motorsports world in general and shock world specifically

      1. Keep it simple. Dont think at your level you need to add complexity to go faster. Most of the time complexity ( unless you can support it) = slower
      2. Most 4-8 way adjustable shocks are absolutely useless for amateur road racing. Yes they are cool, and having cool looking knobs to turn is bad ass; But unless you are a full time race engineer looking for 2-3 tenths every weekend 4-8 way adjust is a great way to mind-F yourself and loose time on track.
      3. You cant have the best of both worlds. There is no such thing as great street /track shock suspension set up. You can have a GOOD street/track car suspension setup.

      Yes sway bars!. We have been over things just like this in tko tips and track tweaks
      If you have the option adjusting sway bars is almost always our first goto when trying to fix certain problems.

    • Aevus
      Member
      Post count: 914

      Yes sway bars!. We have been over things just like this in tko tips and track tweaks
      If you have the option adjusting sway bars is almost always our first goto when trying to fix certain problems.

      I had GT3 adjustable sway bars on the Porsche I just sold and loved it. Now, on my gen3 Viper I find the ACR (solid) bars I just installed a bit soft, especially rear. And not being able to adjust them makes it worst… But, hey, maybe there is a good reason not to make it too stiff! No traction control, lots of torque, etc… That’s why I was now focusing on the suspension.

    • Shannon Whitehead
      Keymaster
      Post count: 274799

      I replaced sway bars on my Gen IV and put MCS singles on the car and have been very happy with it for rallies, autoX, and track days. MCS are nicely adjustable too when wanting to load up the trunk for rallies and weekends out and about. Car still very drivable on a daily basis IMO. I have done sub-2m40s laps at CoTA with street tires on MCS and always felt confident in the corners. I am not a “track rat,” just casual, so what do I know?

      2-34.jpg

    • TKO MOTORSPORTS TEAM
      Member
      Post count: 778

      Aevus said:
      I had GT3 adjustable sway bars on the Porsche I just sold and loved it. Now, on my gen3 Viper I find the ACR (solid) bars I just installed a bit soft, especially rear. And not being able to adjust them makes it worst… But, hey, maybe there is a good reason not to make it too stiff! No traction control, lots of torque, etc… That's why I was now focusing on the suspension.

      Yes your absolutely right. Cars like vipers a little more compliance ( softer) is not a bad thing. Helps with driver fatigue increases consistency and you will have alot more fun on the track and better comfort on street.
      You might try working with the BC coil overs you have to get a better idea of where you want to go and where you feel improvement is possible. Possible you may even find that what you have now works for you and there is another area that needs improvement that maybe a better bang for the buck.

    • GTS Dean
      Member
      Post count: 1839

      IMO, the best way to make your suspension work is to free up the swaybar, wishbone and shock pivot points with aftermarket bushings and/or monoballs. This will provide very accurate control feedback and minimize deflections. You will also be able to feel each adjustment in your shocks. I already did monoball lower wishbones and rear shock clevis adapters when I installed my EMI Penske triples. They have just come into an entirely new level of responsiveness with the addition of urethane upper bushings, the IPSCO greasable sway bar bushings and TKO end links.

      Having the proper baseline shock valving and springs for your vehicle and driving style is extremely important. If you are going to spend the money on them, spend time talking to their application experts so they are set up with the most flexibility around a design target.

    • Aevus
      Member
      Post count: 914

      FrgMstr said:
      I replaced sway bars on my Gen IV and put MCS singles on the car and have been very happy with it for rallies, autoX, and track days. MCS are nicely adjustable too when wanting to load up the trunk for rallies and weekends out and about. Car still very drivable on a daily basis IMO. I have done sub-2m40s laps at CoTA with street tires on MCS and always felt confident in the corners. I am not a "track rat," just casual, so what do I know?

      2-35.jpg

      Your car is beautiful, love the color match, congrats

    • Aevus
      Member
      Post count: 914

      GTS Dean said:
      IMO, the best way to make your suspension work is to free up the swaybar, wishbone and shock pivot points with aftermarket bushings and/or monoballs. This will provide very accurate control feedback and minimize deflections. You will also be able to feel each adjustment in your shocks. I already did monoball lower wishbones and rear shock clevis adapters when I installed my EMI Penske triples. They have just come into an entirely new level of responsiveness with the addition of urethane upper bushings, the IPSCO greasable sway bar bushings and TKO end links.

      Having the proper baseline shock valving and springs for your vehicle and driving style is extremely important. If you are going to spend the money on them, spend time talking to their application experts so they are set up with the most flexibility around a design target.

      It makes sense. Will start with the TKO parts upgrade then I might get my rear dampers revalved with 16 or 18kg/mm springs.

      I prefer to make incremential upgrades, in order to understand better the effects of each.

      That being said, I’m still under the impression the chassis is (or will be, with all the upgrades done) the weakest link. I obviously shouldnt compare a Viper gen3 chassis with a carbon tub as I experienced with a Mclaren 720s, but still. A stiff chassis is something really enjoyable. Maybe I could start with an X brace over the engine similar as the gen5 ACR?

    • GTS Dean
      Member
      Post count: 1839

      I think that the Gen 3 cars – even with no fixed roof, were notably stiffer than the Gen 2 GTS in beaming and torsion. Published specs might show the numbers.

      IIRC, they had structural firewall castings made of magnesium. If you try to x-brace the front, you should investigate the Comp Coupe platform to see where/how they tied in; or if they are similar enough to copy or not.

    • Aevus
      Member
      Post count: 914
    • Aevus
      Member
      Post count: 914

      GTS Dean said:
      IMO, the best way to make your suspension work is to free up the swaybar, wishbone and shock pivot points with aftermarket bushings and/or monoballs. This will provide very accurate control feedback and minimize deflections. You will also be able to feel each adjustment in your shocks. I already did monoball lower wishbones and rear shock clevis adapters when I installed my EMI Penske triples. They have just come into an entirely new level of responsiveness with the addition of urethane upper bushings, the IPSCO greasable sway bar bushings and TKO end links.

      Having the proper baseline shock valving and springs for your vehicle and driving style is extremely important. If you are going to spend the money on them, spend time talking to their application experts so they are set up with the most flexibility around a design target.

      Dean, I’m curious: what spring rates do your run with your Penske triples?

      —-

      Few options for my gen3: BC racing, Moton, KW and Penske.

      So far I’m considering either BC racing singles w/Swift springs or Penske w/Hyperco springs.

      Swift are available only by 2kg increments (roughly 110lbs/in) which is not as convenient as the Hyperco (25lb/in ?)

      Would like 725-750lbs front and 925-950lbs rear (based on my experience with the BC racing I have now)

    • Aevus
      Member
      Post count: 914
    • TKO MOTORSPORTS TEAM
      Member
      Post count: 778

      Aevus said:
      also Cortex…

      https://cortexracing.com/product/ultimate-performance-jri-dodge-viper-coilover-shocks/

      If your choosing between Penske or BC…. Penske is a far better shock and spring package and a much better choice, BUT they arent cheap. Hyperco springs are the best springs available and the only springs we use. Penske shocks are one our competitors but we have to be honest and always respect well engineered products.

    • Aevus
      Member
      Post count: 914

      I’m ready to place an order for a whole new kit and will probably go with Hyperco springs but still undecided about spring rates…

      I have 672lbs Front and 784lbs Rear for now, with the dampers set at stiffest.
      I’m thinking 725lbs Front + 950lbs Rear since I’ll upgrade from BC racing singles to Penske double and TKO’s parts everywhere, which might help keeping the ride somewhat acceptable for the street.

      I don’t plan to add any aero, so maybe 950lbs is a bit overkill or will cause the car to feel unbalanced?
      Also, I see that stock Viper rates (including ACR) have 2:1 ratio or so: rear spring rate 2x what is in front… Is it only because of the aero or else?

    • Lawineer
      Member
      Post count: 1162

      I’m pretty happy with Tractive. They have the helper spring that you can really notice. Plus dynamic adjustment. Over 60mph (basically all the time on the track) , I’m pretty sure that helper spring is fully compressed with my aero.

      I’m with TKO. Dont get suckered into the gimmick of “11 way adjustable.”

      Shocks don’t even make as big a difference on lap times as you’d expect. At my home track in my C7, I was very consistent, lap after lap. My DSC shock controller overheated and went to full soft- which is really effing soft. we’re talking wallowing down the straight. I went from DSC on mag-ride to basically 4 blown shocks. I went half a second slower- if that. Now, I was a lot less consistent and it was a miserable experience, but considering I went from an awesome shock setup to about as bad as humanly possible, it’s not all that much. The differences between various brands won’t be 10% of the difference in what I lost.

      Also, please don’t make the mistake of “stiffer is better.” This is especially not true when you don’t have underbody aero as a concern. It would be a lot easier to put metal rods there with no spring or damper if stiffer was always better. Weight transfer (to a certain point) is your friend.

    • GTS Dean
      Member
      Post count: 1839

      Aevus said:
      Dean, I'm curious: what spring rates do your run with your Penske triples?

      —-

      Would like 725-750lbs front and 925-950lbs rear (based on my experience with the BC racing I have now)

      Long delayed answer:

      My shocks have Hyperco springs – 600# fronts, 800# rears that were supplied with my custom valved Penskes.

      Unless you are running a large splitter and a wing, be careful about going super stiff with spring choice. They will pound you on the road, especially if you have much concrete pavement around you.

      They may also require different valving to control the spring harmonics. This was a big problem with the Gen 2 ACRs that were equipped with the Dynamic shocks. The rear springs were 1100#/inch. I think the reasoning was that in SCCA T-1 the GT-2 wing was allowed and the factory wanted to make sure customers who ran under those rules could legally use all the downforce the wing could provide with OE suspension.

    • Aevus
      Member
      Post count: 914

      finally ordered 750/950lbs

    • Aevus
      Member
      Post count: 914

      IMG_8580.jpg

      Got my Penske double w/Hyperco springs, will get them installed next week along with that:

      https://tkomotorsports.com/product/viper-rear-lower-shock-mount-with-spherical-bearing/

      Can’t wait to see/feel the result!

    • Shannon Whitehead
      Keymaster
      Post count: 274799

      Baller.

      Random tip: my MCS shocks can be hard to install when the canisters are pressurized. You can release the pressure to help with this, but of course, you need to have the right equipment to refill them.

      Other than that, it should be a pretty easy install…the adjustable perches make all the difference since you don’t have to screw with spring compressors.

    • GTS Dean
      Member
      Post count: 1839

      You can gain some installation room by slightly loosening the lower wishbone bolts, reducing rubber bushing preload and letting them drop down a bit. Urethane bushings are less of a problem – and monoballs are no problem at all. I don’t think it applies to Aevus, but those still on rubber bushings are strongly advised to follow service manual torquing procedures. It makes a BIG difference.

    • Aevus
      Member
      Post count: 914

      Thanks for the tips, I will pass the info to my mechanics. As I undestand the canisters needs to be placed (attached?) in the trunk and on each sides of the engine bay?

    • Shannon Whitehead
      Keymaster
      Post count: 274799

      Aevus said:
      Thanks for the tips, I will pass the info to my mechanics. As I undestand the canisters needs to be placed (attached?) in the trunk and on each sides of the engine bay?

      I placed mine there for ease of access and servicing, but I’m not sure they have to be located there.

    • Shannon Whitehead
      Keymaster
      Post count: 274799

      I’m looking for an upgrade that would make a good difference from my actual BC racing w/upgraded Swift springs (12/14kg rate)

      Should I look for a 3 or 4-way adjustable coilovers?

      I’m looking for something stiff but streetable. The actual 12kg/mm front and 14kg/mm spring rate I have is pretty much the max I can tolerate, unless better quality coilovers keeps the car (a bit) comfy.

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