Stock ride height or lower?

[old greg]

Originally Posted by serialk11r

could you explain a bit more how to lower a car while preserving suspension geometry characteristics?

You'd need to either move the inboard suspension mounts, or move the outboard points in relation to the wheel (either with a custom/aftermarket upright, or something like Whiteline's extended ball joint kits).

A drop spindle, like LSxJunkie mentioned, is usually just like a stock upright, except the spindle or wheel bearings are moved vertically upwards on the upright. In this way, the entire car (suspension and all) is lowered and the suspension geometry is mostly unchanged (Scrub radius and trail will change, unless they are accounted for).

[serialk11r]

Say you drop the car...0.5-1" with coilovers. Would that make a noticable difference in performance and wear? Or would drop spindles still be ideal?

With drop spindles, I don't see any issues with the front wheels, but doing that to the rear would move the drive shafts (is that what they're called?) a bit. Is this a problem at all?

[MrVito]

Originally Posted by LSxJunkie

For an inch drop, the change in geometry would be negligible for a street car. You won't need to run drop spindles. However, depending on the design, your set of coilovers may not allow you to set the ride height at only an inch drop. Manufacturers understand that people who run coilovers tend to want their cars to be low, so they run shorter bodies. To allow people to slam their cars while maintaining some semblance of shock stroke, sometimes the highest you can set them is 1.5" lower than stock. For such a mild drop, especially on a street car, I'd run shocks and springs instead of adjustable coilovers. They really are overkill on most cars.

Which brings up another point. If you're not going to go auto-x or HPDE, you really don't need coilovers. And if you're going to get them, remember that you may actually be HURTING your cars handling if you neglect to get your car corner balanced and aligned (so you get almost even contact at all four corners), set the preload (often overlooked), and then spend the time getting the dampers set right.

What you're concerned about is the half shafts. Don't be. The drop would barely move them, and they (this is true of all IRS cars) have CV joints to allow them to articulate with the movement of the suspension. And inch won't do anything to them.

I try to articulate everything you just said to most of the people I know that are just getting into cars. Something else that a lot of people don't consider is the spring perch placement on an adjustable coilover vs a stock style MacPherson strut. The spring perch on stock style MacPhersons locates the spring completely above the wheel and tire, leaving only the body of the damper behind the wheel/tire combo. Adjustable coilovers typically have the spring and perch situated much lower, which actually reduces the amount of wheel width/ tire width that can be fit within the wheel well.

Is it nice to be able to set the ride height exactly where you want it? Of course it is. Given the choice of adjustable coilovers or a quality spring with some nice Koni's though, I'll take the shock/spring combo every time. I know that I can get new shocks from the same manufacturer in a couple of years, but who knows if the company that made brand-x coilovers will still be around to rebuild them when the time comes. Now if it's a dedicated track car that you're trying to eke every last .01th of a second from, and have the knowledge/skills/patience to change the setup for every given track and track condition, then I'd say a fully adjustable coilover is a great idea.

On a slightly related note, I wonder how much quality camber plates will cost for this car?

[Racecomp Engineering]

One thing that bothers me is when people suggest that ALL coilovers are automatically better than ALL spring/strut set-ups for every possible user. That's simply not true.

Some springs do suck really bad. Some coilovers suck really bad too. Sometimes a coilover may not be the right choice for how you use the car.

We make springs, struts/shocks, and coilovers and there are times when we'll recommend one set-up over the other (even if it would be nice if everyone bought JRZ 4 way motorsport coilovers every time they called, that might not work well for 99.99% of people ). We'll have all of the above for this car, and swaybars, and camber plates, and some other nice things but we know that different set-ups will work for different people.

The point is do some research, go for some rides, and educate yourself on what makes one suspension better for your particular needs. Learn to understand the advertising gobbly gook and understand when one "feature" is really just cost saving measure or total BS. There are MANY poorly designed parts out there that are marketed well enough that people don't question if the part works or not. Maybe they should.

- Andrew

[Ryephile]

Originally Posted by Racecomp Engineering

The point is do some research, go for some rides, and educate yourself on what makes one suspension better for your particular needs. Learn to understand the advertising gobbly gook and understand when one "feature" is really just cost saving measure or total BS. There are MANY poorly designed parts out there that are marketed well enough that people don't question if the part works or not. Maybe they should.

- Andrew

[This is not directed at you Andrew, in fact it's an opportunity for you to be "the better Tuner"]

...and this is where the automotive aftermarket makes a shining arse of itself. It's significantly easier, cheaper, and more profitable to make well-marketed crap products than to make well-marketed quality products.

The main problem isn't that consumers are naive [a virtual given], it's that there are no standards to which aftermarket parts are held. There's no way for the consumer to differentiate between crap and quality other than spending obscene amounts of money on experience and testing. Most people don't have the time or education to be bothered with figuring out how to make their car "better". They trust the Tuner. When the tuner is barely more knowledgeable than the customer, it makes for a lose-lose situation where everyone is mad because crappy products were used.

My proposal? Full disclosure of how the aftermarket offering makes the car better and worse than stock.

Take for example KW coilovers. Their Suspension Techniques line takes V1 valving and builds it from cheaper components. This might be fine for someone on a tight budget in the arid southwest USA, but will be a failure waiting to happen in the Rust Belt. Furthermore, the valving and oil used in V2 and V3 dampers are significantly better than V1, making them more consistent and better overall performers. This is a case where money buys you quality, but as some of us know, this is rarely the case.

So, "doing research" rarely involves the internet, and usually involves simply buying everything and figuring out the one or two products that actually work. It would be helpful if the Tuner actually helped the customer instead of simply offering a wall of products with zero knowledge of them.

Food for thought.

[Racecomp Engineering]

Roger that....I agree.

We do plan to do our best to educate where we can and explain how things work, along with advantages and disadvantages. Having been in this line of work for 7 years now (add a lot more for Myles the owner) it used to bother me to see the reality of how the suspension tuner market operates....with most "suspension" companies having no clue what works and what doesn't and still managing to control the market simply through saturation and advertising. It bothered me when we unwittingly did some (really basic) R&D for some of them....and I don't mean that in a ****y egotistical sense because it was basic suspension 101 stuff. But being open and educating people is good for us and good for everyone.

Those that really care about function and improving handling is a niche market that we are happy to cater to. And a growing number of people are getting it. Makes me happy. Ha. I'll stop ranting.

- Andrew

[Dimman]

Originally Posted by serialk11r

Hey LSx, I'm curious about this and I seem to have a little trouble finding info on this...could you explain a bit more how to lower a car while preserving suspension geometry characteristics? From what I know it seems like most people either cut their springs (this messes up too many things to make me comfortable) or get coilovers that preserve the travel, but coilovers don't change the geometry.

I suppose suspensions have some flexibility to accomodate, for example, heavier loads, but the suspension can never behave as it was intended to if lowered like this.

The geometry has a bit to do with roll-centers. The assorted points and pivots in the suspension form a variety of intersections/centers that affect how the forces play on the car. And since the suspension moves, the centers move too. The engineers jobs seem to be minimizing how much they squirm around as the suspension cycles through its designed travel. Then there is also how the camber changes as it moves.

Umm, kind of realizing that I'm out of my league explaining this...

Any of the more knowledgeable suspension guys want to expand on Roll Centers and Camber Gain/Loss?

[MrVito]

If you REALLY want to learn about suspension, (not to mention metallurgy and other interesting automotive info) pick up "Engineer To Win" by Carrol Smith. He's written a number of technical books on the subject of race cars, but a lot of that information can be taken and applied to your toy car. I have to admit it's a heavy read, but I still refer back to that book on a regular basis.

[Ryephile]

Originally Posted by MrVito

... pick up "Engineer To Win" by Carrol Smith....

His whole series is great. Fundamental reading IMO.

Originally Posted by Racecomp Engineering

Roger that....I agree.

We do plan to do our best to educate where we can and explain how things work, along with advantages and disadvantages. ........

Those that really care about function and improving handling is a niche market that we are happy to cater to. And a growing number of people are getting it. Makes me happy. Ha. I'll stop ranting.

- Andrew

PM returned

We can do our best to intelligently inform consumers, but in the end, clearly communicating the expectations to the customer will result in a happy sale.

[Dimman]

Originally Posted by MrVito

If you REALLY want to learn about suspension, (not to mention metallurgy and other interesting automotive info) pick up "Engineer To Win" by Carrol Smith. He's written a number of technical books on the subject of race cars, but a lot of that information can be taken and applied to your toy car. I have to admit it's a heavy read, but I still refer back to that book on a regular basis.

I have 'Engineer to Win', but it isn't heavy on suspension. Some bits on how he changed his mind on Ackerman steering, and rising rate suspension through linkage changes on push/pull rod suspension. Plus "RADIUS EVERYTHING!" for the machinists.

Maybe 'Tune' or 'Prepare' has the more in-depth suspension stuff?

[serialk11r]

Thanks for the info everyone. I noticed that for a mild drop some people just use slightly shorter springs, but this obviously would affect the ride as you'd lose suspension travel and increase spring rate. So for a really mild drop is there not really any way to preserve stock suspension characteristics?

[Ryephile]

Originally Posted by serialk11r

Thanks for the info everyone. I noticed that for a mild drop some people just use slightly shorter springs, but this obviously would affect the ride as you'd lose suspension travel and increase spring rate. So for a really mild drop is there not really any way to preserve stock suspension characteristics?

Lowering springs don't always affect the ride in some circumstances, but generally speaking, they hurt the big picture of overall suspension tuning.


Here is an example:

Your stock car has 5" of stroke, including 1" of "bumpstop squish", with ride height centered, thus providing 2.5" rebound travel, 1.5" compression, and 1.0" of very high rate bumpstop squish. This kind of scenario is rather typical.

Then, you swap in 1" lowering springs. Now you have 3.5" rebound, 0.5" compression, and 1.0" of very high rate bumpstop squish. Any bump in the road larger than 0.5" will feel harsher than stock because you're engaging the bumpstops sooner and with more force. The car will also be more unpredictable in the corners, as you're likely leaning on the bumpstop. Hitting bumps in corners also becomes unsettling to the chassis, as you're likely squeezing the crap out the bumpstop and bending the sheet metal in the strut towers. The springs are doing almost no work now, because the bumpstop is holding up most of the car in the corners.

This is why having proper designed suspension is essential for a quality overall experience [good ride and good handling]. Good coilovers [i.e. not ones with a hundred "features" for only $699] retain total stroke, but center it at a lower ride height. You'll still have 5" of total stroke, 2.5" rebound, 1.5" compression, and 1.0" of very high rate bumpstop travel, but it's centered with the chassis sitting a certain amount lower than stock.

Cheers,
Ryan

[Racecomp Engineering]

That sums it up well. Lowering springs are ultimately a compromise that have to work within certain limits...the advantage being that they are cheaper and generally you don't have to worry about things like salt/snow. The lower you go, the more problems you have in terms of both suspension travel and suspension geometry. Coilovers generally fix the travel problem, but don't fall into the trap of thinking that dual height adjustable coilovers are the only way to go.

One thing we like to do with our RCE performance springs is stick with a mild drop AND include shorter bumpstops. Coupled with a solid increase in spring rate that the OEM shocks can handle, the result is pretty darn nice. For the GR chassis Impreza STI, we offer the RCE Black spring that has just a 5mm drop (essentially 0mm for the 2011 cars) AND includes shorter bumpstops for the front and rear. So you actually end up with more travel before the bumpstop. A very different feel than the typical lowering spring. A substantial reduction in roll/pitch/dive without riding the bumpstops like just about everything else out there. For those that require a drop for the look, we do offer the RCE Yellow springs with slightly more drop and still include shorter bumpstops.

We will probably offer RCE Black and RCE Yellow springs for the BRZ and FRS. Mild drop for Black and medium drop for Yellow, both with shorter bumpstops, both with nicely matched spring rates. Hopefully the OEM dampers can handle some rate, but if not, we'll try to offer custom valved Bilsteins as well.

If you're going to spend a lot of time at the track, coilovers will offer a significant advantage. We'll have some of those too.

- Andrew

[Dimman]

Pet peeve with coilover companies: The use of the words 'ways' for describing adjustment. If you only have one dial/clicker, you only have one 'way'. Each 'way' should be for each aspect that the adjuster controls. Double adjustables are two-way. The amount of detents on the adjuster is hardly relevant, but companies seem to like out-doing themselves by offering "30 WAY ADJUSTABLE SHOCKS!".

/rant