Suspension Tips, for those who want to lower this car.

[WWEVOX]

Thanks guys, this thread has helped me out a lot in figuring out what I'm going to do.

[soconfoozed]

Originally Posted by samsam5886

To me it's not about the wheel gap... it's about the wheel being concentric with the fender! And the FR-S/BRZ does that quite well, so IMO the FR-S/BRZ isn't too high at all. The ride height is perfect. In fact, lowering the car will ruin the already concentric wheel/fender look from the side. Who else agrees with me on this? There's no need to worry about scraping your car either as a bonus! And besides, the car's center of gravity is already low enough.

I wanted to chime in beyond thanks and say that as a purely aesthetic matter, this is where my eyes go as well. When something is out of round or non-concentric, it sticks out like a sore thumb. I've never understood the preoccupation with "wheel gap." "Wheel-doesn't-look-like-it-belongs" is way more obnoxious.

[Racecomp Engineering]

Excellent post Moto! Tire choice is the first question I ask when discussing suspension options with a client as it dictates how firm we need the suspension to be.

Originally Posted by ill86

Imo, it's not that simple. At first glance I noticed the spring rates were increased both front and rear. The front has been stiffened and now match the rear. Stiffer front springs will generally create more understeer. This is why toyota designed it to have stiffer rear springs than front.. To oversteer.

It's all personal preference.. But I believe that until the end user makes his/her own educated decision, making blind recommendations is not good advice.

I am going to first try some Tein H-tech springs and go from there. They keep the oem f/r balance and increase spring rates slightly. More so they keep the front softer sprung.

One thing to keep in mind is that if you increase the front and rear spring rates by an equal X amount OR by the same ratio, the balance may change. Just keeping that same ratio doesn't mean the car will keep the same balance, and this is especially true when lowering a car with a Mac strut up front. Roll centers and dynamic alignment changes are not identical at both ends and change at different rates with lowering the car.

Our goal was max grip for a sporty street tire with good ride quality and a fast, fun, easy to drive neutral balance. We did try a few other configurations...

- andrew

[camelflage]

so it would seem that the general consensus is that lowering the car about an inch and a half while keeping the spring rates close to stock and the dampers softer rather than harder will allow you to bring the car down some while not destroying the inherent handling properties?

[Racecomp Engineering]

Originally Posted by camelflage

so it would seem that the general consensus is that lowering the car about an inch and a half while keeping the spring rates close to stock and the dampers softer rather than harder will allow you to bring the car down some while not destroying the inherent handling properties?

Doing that would be a disaster!

An inch and half drop with spring rates similar to stock is going to leave you with extremely little suspension travel and if the spring rates are close to stock it will use it up very quick. Bad news. Awful ride and handling.

With regards to the dampers, it's more complicated than just softer or harder.

- Andrew

[camelflage]

Originally Posted by Racecomp Engineering

Doing that would be a disaster!

An inch and half drop with spring rates similar to stock is going to leave you with extremely little suspension travel and if the spring rates are close to stock it will use it up very quick. Bad news. Awful ride and handling.

With regards to the dampers, it's more complicated than just softer or harder.

- Andrew

ok, thats what i was thinking, and why i wanted to ask because i knew i couldnt be understanding that right.

[camelflage]

Originally Posted by Moto-P

My advice is therefore, to purchase a proper set of higher grip tire if upgrading the suspension all at the same time, and to choose a spring rate that is mild and soft, so that the agility of the car is not lost due to unwilling suspension, that might be too stiff. Set your shocks very soft if it's adjustable and increase it only if you can drive it without much "push" or initial under-steer.

Originally Posted by Moto-P

Stock Tires + Stock Tires = pretty darn good.

Low+ Stiff+ Stock tire = bad, hard to rotate, easy to understeer (plow)

Soft + mid-height -20~30mm (or plenty of stroke built into coilver) + medium grip street tire = FUN, Fairly quick, easy to handle, and close to original setup.

Low+Stiff+Race tires = proper race car setup, but requires a lot of driving skills to make it go fast.

re-reading also helps. i was looking at that first quote and just reading "soft soft soft". but now that i look at the second quote more carefully i see where i was just confusing myself after reading everything and my initial understanding was fine.

i use the same setup on my is300, but it didnt handle anywhere near as well as the fr-s from the factory, so there wasnt much worry about making it worse.

[Matt Andrews]

Originally Posted by Moto-P

I'd also like to add that STICKY tires on STOCK suspension REALLY DID WELL at the race track...

How do you define really well? Sticky street tires overpower the stock suspension. The stock dampers are nice for sure. But they were designed to work with wooden wagon wheels for tires. In my experience, a Hankook RS3 had enough grip to make the stock suspension sway around like a top heavy boat and get into the bumpstops at the limit. What track did you test on and what tires did you test to get good results with the stock dampers?

Originally Posted by Moto-P

Full race suspension will almost guarantee you will have a really slow, unwilling car, if you are not a really seasoned driver, and riding on nothing but appropriate RACE compound track slicks.

Sorry to ask for definitions again, but how do you define "full race suspension"? Last weekend we tested AST 4150's at buttonwillow (see my blog in my sig for details if you want). Those dampers can be tuned for good street tires as well as slicks. Good dampers make the car easier to drive. Not harder. Even less experienced drivers would be faster on these than on the stock ones. And while we didn't test it, the car would have likely been significantly faster on these dampers with stock tires than on the stock set up. These are the same shocks that are going to be standard equipment in Grand Am's Continental Challenge next year. Definitely full race. I think maybe what you meant was "really cheap, really stiff dampers will be harder to drive and be slower"

I appreciate the education you are trying to provide people, but suspension tuning isn't a scary endeavor. Yes, you can do it wrong, and there is no replacement for quality when it comes to part selection. But while the stock setup is good, there are plenty of ways to improve upon it without being a "pro".

Goodluck to everyone on your setups!
Matt Andrews

[Arnie_1]

Originally Posted by Racecomp Engineering

Excellent post Moto! Tire choice is the first question I ask when discussing suspension options with a client as it dictates how firm we need the suspension to be.

One thing to keep in mind is that if you increase the front and rear spring rates by an equal X amount OR by the same ratio, the balance may change. Just keeping that same ratio doesn't mean the car will keep the same balance, and this is especially true when lowering a car with a Mac strut up front. Roll centers and dynamic alignment changes are not identical at both ends and change at different rates with lowering the car.


- andrew

Agree with Andrew here. First thing I always ask when someone asks for suspension suggestions is "What tires do you plan to use with the car?", quickly followed by (or even preceded by) "What do you plan to do with your car?"

For me there seem to be two basic directions for suspension setup out there: "Aesthetic" or "Performance". Oftentimes people's parts choices and setup are the result of wanting to achieve a "look" or aesthetic. Nothing wrong with that. But its important to keep in mind that what looks cool doesn't necessarily mean it will handle well nor, for the track oriented, improve your lap times. So what Moto has been trying to get across is that the typical tuning notion of "lower/stiffer" does not equal "faster" or better handling. Unfortunately, just because the car "handles like a go kart" doesn't mean it actually handles well. The "Performance" oriented folk set their car up for the best handling possible for their situation, the look of the car will be what it will be. Their ride height comes from properly analyzing the tire type, spring/swaybar rate, geometry compromise and suspension travel.

Warning Rant :

As an aside, an interesting dynamic I'm seeing on this board is the cynism and mistrust many have with vendor input or claims. I guess its bad experience from other boards. I can understand that, because in the end, they all "just" want to sell you something. There are however, a few vendors out there who are enthusiasts first and foremost and I think people will see that over time through the quality of their posts and the kind of neutral information that benefits this growing community. From my experience with them on the Subaru and Evo boards, Race Comp Engineering is one of those vendors. Am I an employee? Nah, but I do like their proper approach to the development of parts. I don't think I've actually ever bought anything from them. For example, they don't just pick a random amount of lowering like "I think 30mm will look dope on this car". Performance is always utmost on their minds. They take the time to properly dyno test the dampers to see what they are capable of, measure the stroke, map out the geometry of the car and THEN consider what spring rate and amount of lowering will actually improve the handling of the car. And they are totally transparent in the development of these parts. You just need to search their threads on NASIOC to see how they went about developing their Bilstein setup for the current WRX. What we get as consumers are parts that work well FIRST, they MAY happen to look good.

The kind of lowering spring offerings is honestly something I'm surprised at living in Germany. Its ironic but here the "lower/wider" crowd really drives the aftermarket rather than the "peformance" crowd. Pretty much all lowering springs are minimum 30mm and often times 50mm recommend for stock dampers! And these are from reputable manufacturers like Eibach and H&R. You'd think they'd know better here. I just shake my head and wonder, have they even measured the stroke on the car's damper? 50mm easily sits most car's on their bumpstops. And then the spring rate is not much stiffer than stock (to maintain stock comfort levels). I just sit in disbelief sometimes.

Sorry for the rant! Back to the topic at hand.

[ultra]

This is a great discussion happening.

In my case I'm somewhat knowledgable about suspension setup (no pro) and my needs are a blend of looks, comfort and serious performance on a budget (yeah, unattainable holy grail, I know) so I'm finding this information very useful. Very grateful to everyone who has taken time to contribute.

Side note: The level of intensity here is nothing compared to Miata.net or the SCCA boards which is GOOD! Considering that this is a young board with a diverse audience revolving around a new car I think we're doing fine here.

The main points that I'm taking away from is thread are that:

1. You need to consider your needs carefully before proceeding in a particular direction.

2. You need to face the reality that you'll have to compromise as each approach will have definite pros and cons.

3. It takes a combination of discussion and experience to gain good knowledge about exactly what the pros and cons of certain approaches are.

4. In the end you need to make up your own mind.

Neither 1. or 2. are exactly rocket science but they're both VERY easy to forget no matter how experienced you are!

The better you do at 1,2 and 3 the less likely you are to end up being broke and unhappy once you reach 4.

[samsam5886]

Originally Posted by soconfoozed

I wanted to chime in beyond thanks and say that as a purely aesthetic matter, this is where my eyes go as well. When something is out of round or non-concentric, it sticks out like a sore thumb. I've never understood the preoccupation with "wheel gap." "Wheel-doesn't-look-like-it-belongs" is way more obnoxious.

:happy0180:

[wheelhaus]

Originally Posted by Matt Andrews

I appreciate the education you are trying to provide people, but suspension tuning isn't a scary endeavor. Yes, you can do it wrong, and there is no replacement for quality when it comes to part selection. But while the stock setup is good, there are plenty of ways to improve upon it without being a "pro".
Matt Andrews

Valid point, but unfortunately much of the aftermarket is geared toward "buy this it's better!" where many consumers assume that something will automatically make an improvement because it worked on a previous car, they saw an ad, want to be unique, or their friend said so. Matt is dead on that basic suspension tuning isn't a black art, but the underlying maths can be quite mysterious for those of us who aren't suspension engineers... It is pretty easy for a novice to "tune" a car into poorer handling without knowing it, simply because the experience and knowledge isn't there yet. Knowing who to trust is key. No matter what the goal, we need to understand what it is we're trying to improve upon, and what else is affected before going about purchasing parts. Just because the car came from the factory with (fill-in-the-blank-OEM-part-here) doesn't automatically mean the part needs to be upgraded.

Too many people assume that a faster machine will make them a faster driver... It may change the experience, lap times may improve, but the best upgrade that can be made to ANY car is the driver.

[jadewbj]

After reading all of this I am still a little confused about if it is possible to lower the car enough to remove the ugly wheel gap with a set of coils without ruining the handling.

I will be upgrading to 18's and using Tein Flex.

[kidgogeta]

Jade I'm the same way, want to get rid of the ugly gap but also want to retain performance and improve it. Might want to go with 18s in the future with 235s all around. Or the work cr kai staggered set up.