Aftermarket suspension making handling worse?

[SkullWorks]

The problem with suspension tuning is everyone tries to start at the wrong place, ride height, or fender gap.

The other problem is it isn't even fair to ask a company to make a coilover "kit" for a car and expect it to work out of the box, suspension is usually the easiest to install of all car mods, and takes the longest to dial in.

Aftermarket kits, usually flat out suck, since a proper suspension setup would be fixed valving, but no one wants to (or understands) revalving shocks it's easier for your average Tom **** or Harry, to have an adjuster knob, but most AFTERMARKET companies have very poor control of the orifice alignment and shim stack tolerance, you are not going to even have shocks at all four corners that respond the same, couple that with spring rates dictated by the lowest common denominator (yo I slammed my sh!t yo) and the requirement to keep him off the bump stops, and you have a damper that isn't even effective for the given spring rate, which is too high for your non caged street car anyway....


sadly the best suspension solution for 240sx's has proven to be factory replacement bilsteins or Koni dampers with adjustable perches, who ever's top hats, and springs to match the car's weight,

I can't wait to see how much our average forum member over lowers this chassis, I think My 240sx track car is almost at stock height just because the toe/camber curves work best before you destroy, the factory geometry,


ok I'm just gonna stop typing now...sorry

[SkullWorks]

Originally Posted by Kimsey47

So, say you just want to get the car lowered an inch to make it "appear" better with larger wheels... Just get lowering springs with a similar rate as the stock? I don't want to make things worse to get a look I want, but I want the look! HAHA

thanked for honesty,

[Kimsey47]

Originally Posted by SkullWorks

thanked for honesty,

Thank you for thanking me while thinking of my honesty!

Yeah, don't want to slam it or ruin the dynamics of the car by trying to close some wheel gap by a small margin. I guess I'll just stay stock 4-evar!

[wcbjr]

Aftermarket...

[Calum]

Originally Posted by Kimsey47

So, say you just want to get the car lowered an inch to make it "appear" better with larger wheels... Just get lowering springs with a similar rate as the stock? I don't want to make things worse to get a look I want, but I want the look! HAHA

With this car you'll want to go to a slightly higher rate in the front to offset the higher roll center from lowering. But, after seeing RCE's car on their lowering springs designed to work with the stock dampers, AFAIK, they should fit you're goals we'll.

[RaceR]

Originally Posted by wcbjr

Aftermarket...

whoops.. Thank you! Skullworks also tried to improve my English I see.
Its my second language (bad excusse). I have edited my posts but the thread headline will not change properly. Is it not possible to fix that??

Originally Posted by Kimsey47

So, say you just want to get the car lowered an inch to make it "appear" better with larger wheels... Just get lowering springs with a similar rate as the stock? I don't want to make things worse to get a look I want, but I want the look! HAHA

Good question. I would like to hear what other people have to say on this as well. But here is my 2 cents..
If you are on a budget and just going to lower the car a little, like 0,8-1 inch I would not bother with cheap coilovers. Buy some lowering springs like you mentioned.
Pekingduck have a thread here.His car is on Eibach Springs -pro kit. Lowered one inch.
Another thread on the springs

Here is the thread for RCE springs.
Here is the post with most of the relevant info.
Their rates are:
250 lbs/in front
250 lbs/in rear

According to what I have read here somewhere.
Front OEM rates for BRZ is the same F/R.
Stock rates for FR-S is about 10% softer in front.
If anyone know the excact stock rates, and have a good source, please post.

[vividracing]

Originally Posted by Draco-REX

I think one problem is that most people see suspension modding like power modding. Getting more power from an engine is relatively simple. Bolt on an intake and exhaust and you get more power. If it's a turbo, get a tune and you get even more power. Piece of cake. The only trade off is reliability and mileage. And as long as the engine doesn't blow in the next year or so, it's considered "reliable" so that's not much of a trade-off.

Suspension tuning on the other hand is MUCH more complex, which is one reason why I enjoy it more than power modding. There is so much to take into consideration when you change one part that if you're not careful you'll make the car worse. Those drivers that have slammed cars on coilovers which bounce across the road have some of the worst handling cars out there, but they think they have the best.

I wish I could make my own parts, but that's just not possible. So to add to the challenge of properly tuning a suspension, part selection becomes part of the equasion. Springs from company X are not the same as springs from company Y. And just because a bunch of people say that $1000 set of Coilover Zs are good, it doesn't mean they actually are.

And then as a cherry on top, ALL of this has to be put into a frame of context based on what kind of driving the car is going to be doing. An AutoX suspension is not ideal for Track Days. A Track Day suspension is not ideal for a Canyon Carver. etc.. Where should you draw the line between geometry and CG height? Does your application call for roll stiffness to come from the springs or sway bars? Questions like this need to be asked when tuning a suspension.

I love it.

Add in the fact that the majority of people don't want to spend more than $1000 on coilovers, and that's basically the problem.

On a slightly related note... Don't push the limits of your new car with a new suspension setup until you're 100% used to it. I learned that the hard way with my S13.

[Dimman]

Originally Posted by Calum

With this car you'll want to go to a slightly higher rate in the front to offset the higher roll center from lowering. But, after seeing RCE's car on their lowering springs designed to work with the stock dampers, AFAIK, they should fit you're goals we'll.

Pretty sure on a MacStrut the RC will come down through the compression stroke. Roll couple (distance from RC to CoG) may increase depending on how much they change relative to each other. Ie if the geometry change drops the RC more than the physical drop lowers the CoG, the car will not resist roll as well as it did before.

[Calum]

Originally Posted by Dimman

Pretty sure on a MacStrut the RC will come down through the compression stroke. Roll couple (distance from RC to CoG) may increase depending on how much they change relative to each other. Ie if the geometry change drops the RC more than the physical drop lowers the CoG, the car will not resist roll as well as it did before.

[Gardus@Supersprint]

I think I'll fit a KW Var 3 or Bilstein PSS9 kit on my car. The KW Clubsport is too stiff for daily use. Ohlins are too expensive, and I trust only 1st grade german stuff on suspensions.

I'm going to tune it starting from the specification the factory suggest relatively to the customer use.
They do a very good development job and it's very sad that most people just slam their cars or have them tune that by a mechanic with no experience in coilovers setup.

One of the important thing is to adjust the height on a set of scales in the most driven configuration (in my case driver only and half a tank).

The good think about an adjustable coilover setup is that, if you know what you're doing, you can adjust them depending on tyres and weather.
I plan to fit some R888s or Neovas for the good weather seasons (included trackdays) so the suspension setup needs to be stiffer than stock to avoid excessive roll and pitch BUT if I'm going to to fit lighter wheels the compression and rebound values won't need bee too extreme as the wheel/tyre package movement is easier to control.

But I also plan to fit some 16" with winter tyres, and the car will need to be higher and softer with those.

Also dampers need to be renewed often (20-30k miles) if heavy used.

[konichiwaa-B]

I just picked up my FRS the day after Memorial Day, and I'm very happy with it, but I would like to lower it at least 1" all around. I'm satisfied with the way it handles and how stiff the suspensions is. I just don't get why Toyota didn't close the gap on the wheel wells like BMW and Audi do. So although I hate to mess with a good thing, I'd like a little lower ride height. I am thinking the Eibach pro-kit springs will give me the ride height I'm looking for without changing the handling characteristics for the worse.

[ultra]

Most people don't know jack about suspension tuning. Some of us are lucky to know a little more than jack due to experience but even that is not the same thing as knowing how to properly set up a car for a given situation.

Suspension setup is really only understood by a hadful of people, usually with substantial experience in competitive motorsports.

I'm not trying to imply that most people are idiots or anything - the simple fact when it comes to suspension tuning is that the more complex your setup is, the more variables there are to play with. Unless you have the tools to do a bunch of data logging as well as the skills to understand those logs it's completely subjective.

As much as I like to fiddle with stuff in the end I have to defer to people with much more experience than I have in order to do things right, which is why I appreciate vendors who are happy to don ample R&D on their products and share the rationale behind their findings.

For example, playing with alignments is one thing. When you add ride height into that equation you need to suddenly consider a whole bunch of other factors such as geometry.

When you add coil overs into the equation you need to add damping rates to the pile ofnthings to consider and when double adjustable coil overs and custom spring rates come into the picture you need to consider shock dynes, bump settings, rebound setting AND sping rates, geometry and alignment.

Then add adjustable sway bars to the mix. Oh, and of course the effects of the upgraded rubber and different wheel offsets you've probably added by now...if not R compound rubber.

Just adding sway bars, better rubber an an alignment is enough to keep me busy for awhile.

When I've had double adjustable KW V3s and r comps and adjustable top hats on my Evo it took me a ton of time and research to get that all sorted out. At least I had a Racelogic Performance Box to benchmark lap times and G forces with, plus he data logging software, but even then I had doubts and called in Robi Fuller to do my setup.

I ended up pretty close to his setup by pure luck.

And even then, that was a track setup. The car wa great on smooth roads but when adding poor surfaces to the equation it wasn't so hot.

people who aimlessly bolt on parts are probably not going to end up with very good results if they haven't done a good amount of research or bought from a vendor who openly shares theor R&D findings and can confidently respond to individual setup questions, as opposed to a vendor who hides behind a brand name.

Bottom line - we ought to value those vendors around here who are open and honest with their findings and are willing to field questions. I don't trust anyone who claims to have a great product or setup just because they claim it's wonderful and 'worked for them' without being able to provide details and/or data.

[ultra]

I should add - my preferred method is to look at what other folks are doing who are successful in AutoX or Time attack and go from there, doing my own testing.

I'm a copycat and proud of it. The trick is knowing who to take setups from and who to ignore.

Having said that, I'm planning on running my 86GT stock for awhile until I feel that I've fully mastered it before I go around messing with it.

Suspension setup fetishism can be a heck of a money pit.

[7thgear]

Originally Posted by ultra

I should add - my preferred method is to look at what other folks are doing who are successful in AutoX or Time attack and go from there, doing my own testing.

I'm a copycat and proud of it. The trick is knowing who to take setups from and who to ignore.

Having said that, I'm planning on running my 86GT stock for awhile until I feel that I've fully mastered it before I go around messing with it.

Suspension setup fetishism can be a heck of a money pit.

the thing to worry about are the people who know jack about tuning but happen to be good drivers

i know a couple of people that have dumped big money into their car and have perfromed very well at events, but when i start talking to them about their setup they just blink. They bought off the shelf parts and had a mechanic put them on, end of story.

it's quite bizzare, but such is life.