Lowering Springs Making Handling Worse?
 

Hi guys,

I'm considering getting Eibach Pro-kit or Sportline lowering springs for my car. It's claimed to have a 1" and 1.4" drop, respectively, in case you didn't know.

I was wondering if getting a car lowered that low or with springs in general would have any negative impact on the handling and if it does, how else do I have to change to correct it.

I don't mind if it has no impact on handling whatsoever but I DO NOT want worse handling.

Don't get the sportline unless you're going to get upgraded shocks as well, the drop is too much for stock length shocks.

So just dropping it 1" is fine? That's what I was planning to do anyway. I wanted to get rid of some of the wheel gap and get a different-than-stock look without scraping on every little thing.

1" is fine on stock struts?

Just buy RCE Yellows. They are 250 lbs/in and perfectly matched to the OEM struts, putting them in the 65% critically damped sweet spot. RCE did their homework on a shock dyno with these and focused their efforts on handling instead of looks. A modest 20mm (.8 inches) drop and new bump stops are included. You'll notice more responsive, neutral handling with a sportier ride quality. Great for the street and track.

I'm selling mine pre-assembled with Whiteline Com-C top mounts here: http://www.ft86club.com/forums/showthread.php?t=70288

I'm not a track warrior like some of these other guys. I have gone to a few autoX's, but nothing to talk about. With that said, I have Sportlines. I am on cheap rubber (225/245) for now. I can't say that they have made handling worse. In fact I prefer my Sportlines over stock. They both have almost the same comfort levels, but the drive is a little bit flatter now. They are stiffer than stock to compensate for the change in height. If I have anything useful to say, it would be that my "factory spec" alignment is what's letting me down at the moment. It will wear your shocks out faster though. How much? No idea.

But that's just my opinion.

The car only has about 2.5" of bump travel stock, so taking up 1.5" of that with lowering means running MUCH higher spring rates, or bottoming out too much for good handling (unless where you're driving is glass smooth with no bumps).

For street driving and the odd auto x in a smooth parking lot you won't notice it, but on a less than brand new track you'll DEFINITELY notice it.

Thanks for the suggestion I'll consider these as well.

I don't mind running a higher spring rate, it can't be THAT much worse compared to stock right?

I forgot to mention that both Eibach kits come with shorter bump stops. But still, from what I have learned, going to the edges of shock travel isn't too good.

To run a 1.5" drop on stock shocks without bottoming out, you need way more spring rate than the shocks are happy with. That'll lead to a bouncy ride, and prematurely blown shocks.

Lots of people, including myself, run sportlines with no problems. It's a bit firmer than stock yes - you'll notice it most on bigger bumps like speedbumps and big potholes. Smaller bumps don't really seem much different than stock. I put better rubber on my car and had alignment done with camber bolts, so I can't how handling is affected by just adding springs, but I can tell you the car corners MUCH better than stock now. Don't let the "sky is falling" crew sway you - btw it's not 1.5" drop, and really not even the 1.4" drop Eibach claims, it's more like 1.2", not much more than the prokits etc. And I love the looks!

Exactly. The drop is perfect. Car looks and handles really well. I've pretty much driven the car at the limit around twisty roads and at autocross and haven't had issues.

I do want to install better springs/orshocks/orcoilovers for the future, but I think sportlines are just fine for now.


*UPDATE* This was two years ago. I thought I knew what I was talking about. The springs are just alright, definitely will need Koni Yellows because the ride gets really bad on OEM shocks.
I've been running my Ohlins R&T coilovers for the past year and it's night and day.

Pro Kit: More modest drop, better ride quality, and better chance your stock shocks wont blow.
Sportline: Extra .4" drop, worse ride quality, more of a chance your stock shocks will blow.

Reasons why I went Pro Kit:
- I live in NJ and DD my BRZ so snow/ice is an issue.
- I have a front lip and don't want to break it.
- I didn't want to buy new shocks at the moment. This isn't just for the fact that my stock shocks could blow with Sportlines..I care more about the ride quality.
- I drive 45 miles each way to work and have to keep camber in a stock-like spec for good tire wear.

I'm happy with the Pro Kit, it rides close to stock but definitely a bit harsher--the gf does complain at times. But it gets rid of the fender gap at a minimal sacrifice to ride quality. I will buy a set of coilovers next summer or if my stock shocks blow, whichever comes first.

Here's Pro Kit on 18"s wrapped in 225/40 tires.
https://dl.dropboxusercontent.com/u/...606_105229.jpg

You're missing my point. Will the car work fine on public roads, yes. Is the drop too much for the spring rate and shock travel to work well on a track, also yes. Look at quantitative results (lap times, corner speeds, etc) to see if it actually corners better. An inch of bump travel will be taken up by cornering forces easily, which leaves no bump travel for actual bumps. Any slight bump in a corner (again, on a track... not public roads) is going to upset the chassis in a big way.

You're way wrong if you think you haven't hit the bumpstops at all. The stock (and Eibach) bumpstops are very progressive and designed to be part of the spring rate. On stock suspension there is only like 5mm of bump travel before you touch the bumpstop, which means that with a person in the car you're already touching them. You may not have fully bottomed out, but you're most definitely engaging the bump stops every single time you drive the car.

Here's my car with swift sport springs (1" drop) mid corner in a fairly high g corner, notice how little clearance there is between my bumper and the track on the loaded side. With the tires I'm running (Dunlop ZII's), I really need more spring rate to preserve bump travel with only a 1" drop. If you're not running stick tires on a track, then it's a different story.

https://scontent-a-ord.xx.fbcdn.net/...75917611_n.jpg

[QUOTE=wparsons;1861007]You're missing my point. Will the car work fine on public roads, yes. Is the drop too much for the spring rate and shock travel to work well on a track, also yes. Look at quantitative results (lap times, corner speeds, etc) to see if it actually corners better. An inch of bump travel will be taken up by cornering forces easily, which leaves no bump travel for actual bumps. Any slight bump in a corner (again, on a track... not public roads) is going to upset the chassis in a big way.



You're way wrong if you think you haven't hit the bumpstops at all. The stock (and Eibach) bumpstops are very progressive and designed to be part of the spring rate. On stock suspension there is only like 5mm of bump travel before you touch the bumpstop, which means that with a person in the car you're already touching them. You may not have fully bottomed out, but you're most definitely engaging the bump stops every single time you drive the car.


Here's my car with swift sport springs (1" drop) mid corner in a fairly high g corner, notice how little clearance there is between my bumper and the track on the loaded side. With the tires I'm running (Dunlop ZII's), I really need more spring rate to preserve bump travel with only a 1" drop. If you're not running stick tires on a track, then it's a different story.

https://scontent-a-ord.xx.fbcdn.net/...75917611_n.jpg

No I think I do get your point, I'm just trying to dispel the myths about sportline springs, they work very well:

1) Sportlines won't 'blow' your dampers. It's possible they will shorten damper life yes, but you can probably say that about any lowering springs. As I mentioned before, real life drop between pro-kit, swift, etc and sportlines is not as big as you think.

2) You make the point, with sticky tires and stock suspension, track drivers at the limit are touching bump stops anyway. Yes if the track is rough the shorter springs will probably not comply with the tarmac as well, again this is probably true to a point with any lowering spring, sportlines will be a little worse.

3) Given a good driver who is an experienced track driver, will sportlines be worse than stock all other things equal? Maybe, probably depends a lot on the track. Again one might be able to make the same case about swifts or pro-kits.

4) Comfort level? This is a performance car, pull up your skirt! (just kidding!) The stock car is fairly stiff. Any lowering spring will be stiffer, are the sportline springs stiff? Yes. Do they bother me? Only when I hit tall speed bumps or deep potholes - in reality that bothered me on stock springs, just more so now that I am on the sportlines :) I don't scrape on anything (although I don't have a low front lip).

Lot's of myth out there - sportline springs won't 'blow' your dampers. sportline springs won't *ruin* handling (nor will any other lowering spring). Possible less than ideal in certain situations with rough roads, but nothing that really affects my driving or enjoyment of the car at all (and I live in the north where plows tear up the roads).

My point is, I spend maybe 300 hours a year in my car. If I'm LUCKY, maybe 3 of those hours will be lapping on a track this year, probably will be less than that. So that's 1% where I'd be worried about extracting the ultimate amount of performance, the other 99% of the time I'm enjoying my car on the streets. It handles brilliantly and looks fantastic with the setup I have - for the non-track-junkie (who really should be running on good coilovers tuned for this car) things like tires and a good performance alignment are a bigger concern rather than comparing swift springs (or other) to sportlines.

You're crossing up posts about different things... I'm not claiming sportlines do any of what you're defending.

For a 1.5" drop on sticky tires on a track, you need MUCH higher spring rates, which will blow the stock shocks in a hurry.

The sportlines are a good spring for anyone not tracking that wants that much of a drop, but they're too soft for the amount of drop for tracking with sticky tires. Their spring rate will definitely not hurt stock shocks. But, if you're tracking with sticky tires they're definitely not ideal. For your usage, I'm sure they work great.

[quote=bfrank1972;1861257]By that logic, why would you ever get rid of the stock suspension? You actually paid someone money for springs that give you worse ride quality and handling, void any kind of suspension warranty you had left, AND will inevitably force you to buy new dampers long before you would have to otherwise? Even though you DRIVE your car for significantly more time than you stare at the gap between the fender and the wheel every year? Really??

[quote=xxBrun0xx;1861464]Hmmm. I'm not sure I 100% follow you and your interpretation of my 'logic', let me break it down for you:

1) Many people (track oriented people too) decide to keep the stock suspension because it just works.

2) Honestly, I paid someone for spring that would get the look I wanted. Couldn't stand the wheel gap (and the stock wheel offset/width). I'm sure many will agree - a big reason why we bought our 86's is that it is a beautiful car, I'm just putting the finishing touches on the look. Oh by the way I have 'heavy' 18" rims too, and the car still handles amazingly well.

3) With the springs, it handles amazingly well. Maybe with the stock springs and the same tires I have, it would handle even better? I doubt I could tell much of a difference 99% of the time I'm driving. I'm not the one saying sportline springs are worse for my handling - quite the contrary, the way it handles now feels much better than when it was stock. Springs + tires + alignment, I don't care which is responsible. The car looks and handles the way I want.

4) 99% of the time I'm driving, I wouldn't feel like I'm driving a 4x4 around. I like driving a nice looking car, for me to see and other to see. If I want to become a track fanatic, I will probably go to a professional who will put quality coilovers on my car, with a good track alignment, track tires, maybe corner balance the thing. I have driven plenty of track and autoX events in my life, but I'm not going to obsess over suspension mechanics that mean something to race drivers but not much to daily drivers. The car feels great!

5) Again, why would I have to buy more dampers? By that time (many miles down the road) I'll probably be on coilovers anyway. Even if I DO spend for dampers, it'll be an upgrade. Don't really care too much about preserving OEM equipment. And wait, where are all these 'failed' OEM dampers anyway. Proof to back all this worrying?

Hope this clears things up. I'm VERY happy with my setup. I'm quite comfortable driving it daily. My dampers are just fine. It corners on rails. My car is not ruined. The sky is not falling.

My message, to all the folks who like the way sportline springs look, if you are a daily driver and not track addicted, they work very well. Don't believe all the sportline naysayers, a large % of them have probably never even had them on their car.

Not happy enough to stick with them, I guess.

Well no one is questioning that good coilovers are superior in every way to springs on stock dampers. There's always something better ;)

Any special informations on the RCE yellows? Seem unavailable/unknown in Germany.
Here you can order Eibach ProKit via Toyota dealership, not the sportline.
Other available springs via tuning shops are H&R, Weitec...

RCE Yellow springs are:
20mm drop front and rear
4.6 kg/mm front and rear
include replacement bumpstops front and rear

They are a great spring set that improves handling and rides well. Not a huge drop, but that's part of why they work so well.

We are a smaller american shop and our springs are produced here. We have had a few customers in Germany over the years and can ship there. We unfortunately do not have a reseller in Europe at the moment.

- Andy

With regards to Eibach Sportlines...I don't know if I'd say they ruin handling, but if handling and ride comfort is your main goal, I would just choose something else. If you must have the bigger drop, then go for it.

- Andy

:thanks:

I couldn't have said it better. This get's overlooked so often when considering springs for better handling.

My car with RCE Yellows and 245 Bridgestone RE-11A's getting loaded mid-corner on different tracks:

http://i.imgur.com/4CySEaq.jpg

http://i.imgur.com/r5CJP4S.jpg

This is with stiffer RCE sway bars installed as well. It's pretty much slammed on the bump stops on the loaded side. There's a good reason why RCE chose a mild drop and it's evidenced perfectly in these pics and this discussion. The preservation of bump travel is imperative for better handling.

Great insight, thanks! I guess I don't really know what it feels like to have better suspension.
In that case, I'll definitely be putting on better springs before my trackday later this year. But for the street right now, they function just fine.

But maybe people should? A good spring/damper combo is better than budget coilovers. Also, coilovers need to be rebuilt on a regular basis if you live in an area that's heavily salted during the winter and are typically very expensive. That being said, I agree that springs and dampers that are designed to work together will be better than a mismatched setup.

What tires are you running? How much track experience do you have?

On stock tires and a first track day, you'll be fine on sportlines.

Great, because like I said, I've taken the car countless times to twisty roads in the area and have attacked them quite aggressively. The car handled similar to as it did stock.. (But unknown to me till your comment, I guess I have been loading my bumpstops all the way now... yikes). :iono:

I'll be getting new tires before the trackday as mine are kaput right now (Stock tires up front, and RE760's in the rear), and I have had my eye on Pilot SuperSports.
I've been to the track twice with my old RX8, which handled similarly to this car, and I've been autocrossing with this car once after having installed the springs, shorter bumpstops, camber arms, and camber bolts. (I'm running -1.5 degrees all around).
I'm in no way a novice when it comes to driving my car, and wasn't really concerned about my spring selection having a negative impact on my cars handling until........well this thread basically.

Hah, don't worry. That's one reason for my prior 'rants' - these other threads, while validly targeted to the track performance crowd, can cause some hysteria :-D

Bump stops are part of your suspension design, and not just an emergency stop. Yes their ultimate function is to stop the suspension from traveling too far on the stock dampers, but they also have a load curve just like springs. It's steeper but it's not a hard stop - if you're cornering on a smooth road you probably won't even notice. If you are on a bumpy road/track, you may notice it as loss of traction, maybe 'squirreliness'.

Also as mentioned before, you need to be cornering hard enough, on a good enough surface, with good enough tires, to really be loading your suspension that much. Happens all the time to people on a track running max performance tires, might happen with the MPSS, will definitely happen sooner on a sportline equipped car vs a car with stock springs or longer travel coilovers, but it's not going to be disastrous! Might even be a little fun ;)

Go have fun, hit the track, see how it goes, and you'll find out soon enough if you need to upgrade.

Any stock one would be partially loading the bumpstops as well, that itself isn't a bad thing. What I was talking about was fully compressing the bump stop from cornering forces alone and having zero travel left for any bumps.

With PSS on a less than perfectly smooth track I would imagine you'll notice a couple times that you could use more travel (and/or spring rate), but it won't be disastrous, just possibly less than ideal.

I have the pro kit and really like it (and spacers, 25 mm rear and 20 mm fronts). Pro Kit is perfect for DD and will settle to 1" drop. It's not bouncy or harsh. IMO... just perfect height and drive. It's similar to the TRD springs. BUT always get an alignment soon after lowering it.

I've had the pro kit for over a year now and to be honest I don't really like them. I'm slowly getting closer and closer to buying something different. Not sure what yet but that's why I'm here :D. I have a 70 mile round trip to work and the streets here are terrible and the same goes for the freeway. Lane changes while my cars bouncing all over the place doesn't exactly inspire confidence either. Every morning I watch my headlights constantly bounce up and down and that's the same thing I see on cheap pos hondas. I feel like I'm one of those guys now. But that's just me.

I have a similar problem with my prokit Pandle, I do like a slight increase in firmness, but I can't even keep a cup of coffee in the cup holder and make it down the street without it spilling all over the place. And this is in a disposable cup with the small sip hole in it. This is my battle every morning when I start my commute to work. I'm itching for a nice ($1000 or less lol) set of coilovers.

I have to disagree. I notice the lack of travel and damping much more on the street than on the track. Street driving is more likely to give you the sharp impacts that result in a harsh ride than you'll get on even a bumpy track. I've tracked at Sebring, which is a converted WWII bomber field, a number of times and the car gets more upset by potholes than any of the weird seams at the track. At Homestead-Miami, which is immaculately surfaced, Sportlines work great.

Again, it comes down to what tires you have, how much track experience, etc. Ask good drivers with sticky tires, and you'll get the same answer every time.

How many of those weird seams are mid corner, especially in high G corners? All along I've been talking about the lack of travel and spring rate when looking at how loaded the suspension gets mid corner, not when traveling straight hitting bumps.

All, lowering springs are a compromise relative to the stock dampers. By definition they will not improve the overall handling. The lower they are , the greater the compromise.

I've used lowering springs on a couple of previous cars and in both cases it was clear that the car was under damped; on the street and on the track.

However, each person has their own tolerance for these things, so, I doubt there is a definitive answer.

I obviously would not recommend just lowering springs. Get matching dampers from a reputable source.


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Anybody actually tested the stock springs with better tires and better dampers and compared the lap times to lowered coilovers?

Better yet, anybody actually tested stock springs with uprated roll bars, better dampers and better tires?

I'm betting the benefit of lowered, stiffer springs is pretty marginal.

On the road I know which would be quicker.

I haven't seen any hard data on our cars, it would be a good test, but it would be a lot of work, not sure if anybody is willing to put in the time.

You know - I'm pretty sure you're right, lower/stiffer springs (all of them) probably compromise actual handling of the car a bit. I doubt it's by a huge amount - possibly meaningful for a professional (or very advanced amateur) driver.

The thing is, the lower/stiffer springs make my car *feel* sportier, even though deep down I know they're really not. But in my years of driving cars, I've found that I like spending my money/effort on fun-to-drive factor (mostly on public roads), rather than what gets me the best numbers around a track. I can't fault the track guys for going for the last tenth at the track, but I think mods that make the car *FEEL more fun don't get enough credit :)

FWIW, I have the Swift Spec-R springs on stock struts until I save up for SRCs and track the car about once a month. I had a couple more experienced people drive the car (Including @CSG_Mike) and both of them agreed that with a set of LCAs and some camber plates to maximize camber in the front and rear (Running as much as I can without LCAs and the Whiteline camber bolts atm), the car would handle very well for a car w/o coilovers. Of course, no springs will stack up to a good coilover (for that matter no budget coilover will stack up to a good coilover either), but for some one of novice to intermediate level, they will perform fine. They also have very competitive price tag. I picked mine up for $325.

EDIT: Also, they only lower the car about 1.0".

What if you add in Bilsteins with a spring such as RCE? Or at that point should you go to a a height adjustable coilover?

I asked RCE that question. The Tarmac springs plus Bilstein B8s come to about 1250 on FT-86SF. RCE Tarmac Zero coilovers are 1700 with the same spring rate. So what's the benefit of the extra 450?

The coils have height adjustability and the dampers are perfectly matched to the springs, whereas the spring/strut combo is fixed height and the off-the-shelf damper rates, while very good, aren't an exact match. Also, the coilovers have stainless steel construction, and I don't think the struts do. Neither come with top hats, so that would be an extra expense.

I think for myself, my suspension adventure will be yellows/OEM struts > add top hats > change to Tarmac Zeros, as I grow as a driver.