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Discussion Starter · #1 ·
Going to be purchasing a set of Riaction coil overs and would like to know what everyone's opinions are on the most ideal setup for our cars.

I own a 97 vr4 being built to ~600hp range. Car will be used for spirited street use and the occasional track use. Mainly I want the car to handle extremely well and be able to effectively transfer power while still be able to enjoy driving on the weekends. I do not mind stiffening the ride a bit but within reason. I am leaning towards a 10k F/R ON SWIFT SPRINGS question is: being on swift springs would it be beneficial to go to an 8 F/R set up. or a completely different set up.

I would like to hear from people who have swift springs set ups, but everyone is welcome to throw in their experiences. Coil overs are not my expertise so feel free to chime in. Thanks
 

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I have HKS Hipermax IV GT rated at 8kg/mm front, 6kg/mm rear. These are almost perfect for me, and honestly the best coilovers I have ever purchased. Dampening has not been adjusted, and left at factory settings.

To give reference, if I recall based on my research.. Original OEM spring rates are 5kg/mm front, and 2kg/mm rears.

Performance wise, I am lowered about 2.25" all around. It plants on the ground firmly without much body roll (I also have a PRM front strut bar). I am able to take most clover leaf hair pins at 60-65MPH, but that's as hard as I'll push it for a public road. The tightest apex I hit was about 35 degrees with a sharp corner and I pushed it to about 40MPH on that without any skidding or loss of traction.

For cruising and general driving, it is not entirely stiff - but not like driving a boat/clouds with the original suspension. A great medium in between. I would describe it as "firm." Going over bumps, ridges, etc is very comfortable - still has a small jolt.. But not as bad as the cheapo coilovers that people use with crazy spring rates like 16Kg/mm fronts and 12Kg/mm rears as an example.

At stock horsepower with bolt ons (filter, downpipe, test pipe, catback), the weight shifts to the back and plants the rear "moderately", I have a small amount of chassis lift on the front, but all 4 wheels are still planted on the asphalt.

I hope this helps.
 

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Discussion Starter · #3 ·
I have HKS Hipermax IV GT rated at 8kg/mm front, 6kg/mm rear. These are almost perfect for me, and honestly the best coilovers I have ever purchased. Dampening has not been adjusted, and left at factory settings.

To give reference, if I recall based on my research.. Original OEM spring rates are 5kg/mm front, and 2kg/mm rears.

Performance wise, I am lowered about 2.25" all around. It plants on the ground firmly without much body roll (I also have a PRM front strut bar). I am able to take most clover leaf hair pins at 60-65MPH, but that's as hard as I'll push it for a public road. The tightest apex I hit was about 35 degrees with a sharp corner and I pushed it to about 40MPH on that without any skidding or loss of traction.

For cruising and general driving, it is not entirely stiff - but not like driving a boat/clouds with the original suspension. A great medium in between. I would describe it as "firm." Going over bumps, ridges, etc is very comfortable - still has a small jolt.. But not as bad as the cheapo coilovers that people use with crazy spring rates like 16Kg/mm fronts and 12Kg/mm rears as an example.

At stock horsepower with bolt ons (filter, downpipe, test pipe, catback), the weight shifts to the back and plants the rear "moderately", I have a small amount of chassis lift on the front, but all 4 wheels are still planted on the asphalt.

I hope this helps.
Those are nice coilovers, I actually had my eyes on them for a bit. that's great info man appreciate it. Is it best to have the rear a lower rate then the front? somebody on here had a nice write up about BC coilovers being optimal at 10 F/R. was thinking id mimic that setup on the riaction coilovers.
 

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Those are nice coilovers, I actually had my eyes on them for a bit. that's great info man appreciate it. Is it best to have the rear a lower rate then the front? somebody on here had a nice write up about BC coilovers being optimal at 10 F/R. was thinking id mimic that setup on the riaction coilovers.
Now I'm not a professional racer or engineer by any means.. But based on my research it depends on your application..

  • Ideally you want to match weight distribution with spring rate.
  • A stiffer front spring rate, will induce more understeer
  • A stiffer rear spring rate, will induce oversteer
  • Stiffer spring rates will reduce traction, but in return, have improved body roll and stability characteristics
  • Less stiff springs will encourage traction, but increase body/chassis roll.

Now with that side, it entirely depends on your application as you can mix and match to your needs. One coilover spring rate cannot do it all.

If you take a look at how weight distribution works under load, the force will always transfer to the rear of the vehicle.
When the load is transferred to the rear, (note point 5 in the list) it'll put as much force as it can to the ground.

This is just my rough idea, of momentum and physics of racing, etc. In my case, I primarily drag race.

There is a lot of art when it comes to fine tuning suspension.. In most cases, if you're not doing anything too serious, I wouldn't consider getting too technical with advanced spring rate combinations and dampening.
 
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Now I'm not a professional racer or engineer by any means.. But based on my research it depends on your application..

  • Ideally you want to match weight distribution with spring rate.
  • A stiffer front spring rate, will induce more understeer
  • A stiffer rear spring rate, will induce oversteer
  • Stiffer spring rates will reduce traction, but in return, have improved body roll and stability characteristics
  • Less stiff springs will encourage traction, but increase body/chassis roll.

Now with that side, it entirely depends on your application as you can mix and match to your needs. One coilover spring rate cannot do it all.

If you take a look at how weight distribution works under load, the force will always transfer to the rear of the vehicle.
When the load is transferred to the rear, (note point 5 in the list) it'll put as much force as it can to the ground.

This is just my rough idea, of momentum and physics of racing, etc. In my case, I primarily drag race.

There is a lot of art when it comes to fine tuning suspension.. In most cases, if you're not doing anything too serious, I wouldn't consider getting too technical with advanced spring rate combinations and dampening.
hey man sounds like you know a lot more then me when it comes to this lol. What you stated above definitely makes sense. Our cars are already pretty close to an even weight distribution i believe 58/42. with most modifications/deletes I've done + battery relocation to trunk id say I'm closer to the 50/50 I think what I will be trying is a 10 F/R and do fine tuning to my liking with the dampening settings and I think that should do the trick
 

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hey man sounds like you know a lot more then me when it comes to this lol. What you stated above definitely makes sense. Our cars are already pretty close to an even weight distribution i believe 58/42. with most modifications/deletes I've done + battery relocation to trunk id say I'm closer to the 50/50 I think what I will be trying is a 10 F/R and do fine tuning to my liking with the dampening settings and I think that should do the trick
Honestly, some things are only trial and error.. As it's all just a mathematical/scientific hypothesis until someone actually "tests" the suspension settings out. I would say shoot for it, and if your manufacture allows you to buy springs separately you can always mix and match at that point.

With modifications and deletes for weight distribution, I would recommend getting onto a 4 wheel scale and seeing what the exact weight numbers are before making the assumption.

In addition, with weight distribution, the interesting fact is that our platform is actually real-wheel biased with our AWD system. IIRC, it's either 45/55 or 40/60. (Note: I experienced this first hand by stupidly taking my car out when it was snowing with soft summer tyres... Yeah, no bueno. On a stand-still the rear end instantly lost traction from 0-5mph and I was already fish tailing. Luckily I made it home in once piece lol.)

With that said, you do have to take into consideration of all things done to the vehicle such as spring rate (incl. lower/upper strut bars and sway bars), drivetrain, weight distribution, etc.. To fully maximize weight transfer, traction, etc.,

Some things to note:

A spring rate that is 10Kg/mm is 10Kg/mm, there is no way to change this fact. If I am correct, the purpose of this is to determine how your chassis sits, how far your suspension will travel before bottoming/topping out, and also where you want the weight transfer occurs.

Damping will adjust how fast the shocks will compress (squeeze), and rebound (release). It'll be the determining essentially how fast the "bumping/jumping" factor is, and how long it lasts. What I mean by this is.. Energy has to go somewhere, and it needs to dissipate. Soft shocks will continue to allow energy and momentum to travel, where as it's the opposite for stiff shocks... With that said.. you can imagine you'll want to strike a goal in mind. Comfort, weight transfer, traction, etc,.. One damping setting can't do it all.

Too soft a shocks, something is going to bounce like crazy over bumps or weight transfer, and remove traction. Too stiff of shocks won't compress, and anything you go over will skip your tyres like crazy.. It'll also mitigate weight transfer, so traction can be lost as well.
 
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That is essentially the suspension and theory behind the physics of it. With all that said, I'm not a professional racer or engineer like I mentioned earlier, I just do my diligence and eventually want to go semi-pro in drag, time attack, or W2W .. I race about a few times out of the year, so I haven't had the actual use of fine tuning suspension. In most cases, grab a set of coilovers you'd like to try (always highly recommend reading spring rates at the minimum) and 7/10 of most cases, you're good to go right out of the box.

Biggest thing to note however, once you step away from stock suspension, you will never get the comfort back no matter what you do unless you swap out to like 3kg/mm springs. Coilovers will always ride more harsh than the OEM setup.
 

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That is essentially the suspension and theory behind the physics of it. With all that said, I'm not a professional racer or engineer like I mentioned earlier, I just do my diligence and eventually want to go semi-pro in drag, time attack, or W2W .. I race about a few times out of the year, so I haven't had the actual use of fine tuning suspension. In most cases, grab a set of coilovers you'd like to try (always highly recommend reading spring rates at the minimum) and 7/10 of most cases, you're good to go right out of the box.

Biggest thing to note however, once you step away from stock suspension, you will never get the comfort back no matter what you do unless you swap out to like 3kg/mm springs. Coilovers will always ride more harsh than the OEM setup.
absolutely, that's some great information appreciate you sharing. I am not concerned about losing comfortably in my suspension as long as its bearable of course. Trying to draw a fine line between comfort and race mode is a challenge and all depends on the cars set up and what your build is intended for. I'm pretty confident in the setup I plan to go with. I will be sure to post a review once it is all finalized
 

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absolutely, that's some great information appreciate you sharing. I am not concerned about losing comfortably in my suspension as long as its bearable of course. Trying to draw a fine line between comfort and race mode is a challenge and all depends on the cars set up and what your build is intended for. I'm pretty confident in the setup I plan to go with. I will be sure to post a review once it is all finalized
No problem! I'm glad I could help. All the information is out there in the world, but sometimes it's a little overwhelming on where to find the information/digest it. I would love to help as much as I can.

Shoot for the stars, and let us know how the setup goes. The only way to know, is to find out for yourself.
 
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hey man sounds like you know a lot more then me when it comes to this lol. What you stated above definitely makes sense. Our cars are already pretty close to an even weight distribution i believe 58/42. with most modifications/deletes I've done + battery relocation to trunk id say I'm closer to the 50/50 I think what I will be trying is a 10 F/R and do fine tuning to my liking with the dampening settings and I think that should do the trick
These cars are front-heavy, and getting anywhere closer to "50/50" F/R will require substantial reduction and placement... guarantee that you are nowhere close. If you meant cross weights, then that is another story and way more easily attainable with some work and planning.

Lots of points have already been mentioned. Weigh it, adjust, drive it, assess, and change springs and/or adjust additionally as it becomes necessary. Discussing right now is kind of moot without actual feedback or data much like anything else, period. This is even more true if your car is not even done yet and may undergo different plans.

-sent from my Galaxy Note 9
 
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