Originally Posted by lobuxracer

The Sachs units are probably just fine, but getting support for them is just about zero in the US, so most track junkies aren't going to run them.

Originally Posted by lobuxracer

Swift springs are popular. Hypercoil is the brand known for delivering the spring rate printed on the box. Anyone else you should test to be sure. Some, like Tein, are junk from the start and have no consistency or adherence to specification. The majority of the solutions in this thread will work fine for anyone looking to change the ride of their car. Only the Penske and Ohlins TTX ILXA are truly track performance oriented. The Sachs units are probably just fine, but getting support for them is just about zero in the US, so most track junkies aren't going to run them. Penske and Ohlins both have resources available to fully tune your set up regardless of the spring rates you choose.

Bonus for the BC Racing from Figs is they will put them on a shock dyno and be sure you have as matched a set as possible. None of the other low cost options sport this level of attention to detail. Also, adjustability in the vast majority of aftermarket shocks is useless and utterly inconsistent from unit to unit, again with the exception of Penske and Ohlins whose adjustments actually work and are reasonably consistent from unit to unit. Sad but true, you're going to pay for this.

Last but certainly not least - there is an ideal damping rate for the springs you choose and the application (street comfort, street performance, track performance). If you don't want to get spendy, decide what springs you want and have a competent suspension tuner set up your shocks to match your purpose. You'll be WAY ahead of the pack if you do this because most aftermarket suspension sales are for fashion, not measured performance.

Originally Posted by Jwconeil

Couldn't have worded it this well myself. Unless you buy the above, you don’t actually know what your getting or if it’s consistent. The numbers on the box have no real value. You can have two front corners with different spring rates and shock values. Both Figs and RR will consult with you on the phone about your goals and what you need to achieve them if you go with these suspension options. Unfortunately, the price of entry is high.

You can see this in cars on the track running good stuff versus cheaper stuff. Some stay level in corners, some lean hard, but they both allegedly have the same spring rates. That’s what sold me.

Originally Posted by Hardrvin

Until more recently, not enough credit was given to the importance of the damper, everyone focused on spring rates. Ride quality and handling are both largely influenced by the damping, and that’s the true science and where the cost comes into a coilover.

With that said, it’s a curve of diminishing returns for cost to performance improvement like about anything. But the high end parts are truly good stuff.

The buzz word, and rightfully so is digressive damping. “High” damping for low speed for body control during handling maneuvers, “lower” damping for high speed for bump compliance and ride comfort.

Originally Posted by lobuxracer

This isn't exactly recent news. I knew the difference between high speed and low speed damping when I was tuning mini sprints in the early 90's and it wasn't new then. The thing that is fairly recent is the ability to change the viscosity of the oil with magnetism allowing for very fine adjustment of damping rates and a variability unmatched by mechanical means. Still all of this is primitive compared to truly active suspensions, and I believe it is truly sad F1 banned active suspension systems. Had they allowed development of this technology, it would be common in every vehicle by now. Cars would lean into corners like motorcycles and suspension geometries would have been adapted to take advantage of this capability. But FIA said no, and now we're still using passive systems in 2020...

Originally Posted by Slowlane

Thanks for sharing and great insight guys.
I have a late 2011 isf with the OEM Sacks shocks, travelled 76,000km (47,000 miles), car is very tight and unmodified.

I've ordered HKS Hipermax IV GT and SuperPro Control Arm Bush Kit SPF3491-90K, not planning on lowering it much and just leave it as is out of the box.

I use the car mainly for very spirited driving through the hills with lots of cornering, some over quite bumpy roads and the odd track day.

Just reading through all of this, do you think I'll be going backwards in performance and comfort?

Originally Posted by lobuxracer

The measure is simple if you are not competing. Do you like it better? If you do, all is well. If you are competing, then everything changes.

Originally Posted by Slowlane

Haven't received parts yet, not competing but want to improve handling performance and in particular the "feel" of the car and make it more communicative as l find it a little numb and disconnected.

Originally Posted by lobuxracer

Feel is total BS if you want measurable performance improvement.

I had a very intense conversation with an IRL suspension engineer some time ago flying in 1st class. "So, do you set up the car to make it feel better?" "No, I set up the car to be faster, it's the driver's job to deliver, and if he can't deliver, he's not going to be driving for us."

So given this it was pretty clear to me that feel means nothing if performance against a goal is what you seek. Your chassis tuner couldn't care less about how you feel the car handles.

Originally Posted by Slowlane

So you prefer a car that tells you nothing whats going underneath and feels disconnected?
Then its Interesting why Porsche GT cars have an incredible amount of connection with car and driver.

Maybe feel is the wrong choice of word.

Originally Posted by lobuxracer

When did Porsche win their first constructor's title in F1 or Champ cars, or IRL?

Originally Posted by ISFpowered

Good list. Thank you for taking the time to make this for us. I personally have Penske coilovers and have zero issues with them and I made the jump from stock 08 suspension to BC coilovers (huge downgrade from stock in my opinion) then sold those to buy Penske coilovers from RR and never looked back. I will say that once going to a high tier coilover it will set the bar really high from now on and you will not accept anything else after that. Im curious to try the ohlins TTX coilovers and weekend how they compare with Penske coilovers.

Originally Posted by Jwconeil

One of my closest friends threw some springs and spacers on his mustang, and he loves it. It feels more connected to him since he is feeling more from the car. The stanced look adds a big placebo. He fancies himself a great driver, and his car a driving machine.

I personally think the few hundred he spent probably reduced his cars capability, but it met his desired goals. I on the other hand, am saving for Penskes based solely on performance. I’m not chasing feel, I’m chasing pure function, and I want to make my car compete with my brother’s planned C6 Z06 build.

If your goal is a more connected feel alone, then mid-grade, or even cheap coils, will probably deliver it. Less suspension travel, and even poorly tuned suspension harmonics, will deliver all kinds of “feel” you didn’t “feel” before. The biggest measure of coils on this forum is how they ride, or “feel.” There is nothing wrong with that if that’s what you want.

If your after performance and function, then the conversation changes very quickly, and words like harmonics and geometry become king. The price off entry also changes. It’s very important to differentiate the feeling of performance, and performance. The placebo effect is so powerful that it has actually cured symptoms, and is measured in all drug studies. Google “nocebo” effect if you really want to know how powerful a “feeling” can be.

Originally Posted by Slowlane

Thanks for chiming in, no I dont want just the feel, I need the car to be more planted and balanced in fast corners. Not competing but get together with a lot of freinds on weekend blasts through the mountains..
I hope I dont regret the HKS on my 2011 isf on oem Sachs shocks.
I went through this a long time ago with a 996 turbo, put on new PSS10 bilsteins and the car handled worse at any settings.