SO ive been learning more and more about suspensions and setting them up and this and that and I have a question...won't more aggressive sway bars render wheel camber adjustments less effective? My thinking behind this is that adding negative camber to produce more grip in the corner requires that the car be able to 'roll' onto the full surface of the tire through weight transfer aka body roll. Sway bars are designed to minimize body lean/roll. So if I had a setup with negative camber in the front for more grip, then added an aggressive front sway bar, could I possibly be doing more harm (in terms of grip) than good? Im referring to a McStrut design. THanks in advance!
You won't add enough wheel rate with a sway bar to negate roll. It's not an issue.
I read that handling is all about getting the tires to grip the road the most. Negative camber does that more in corners than sway bars, so it theoretically means it's more important.
What mazdeuce said.
Also, I think you overestimate the amount of camber gain built into most suspension (especially Mac Struts). The reason we put static negative camber (i.e. when the car is at rest), is because most suspensions don't have enough camber gain when it starts to lean. For example, you start with -3 deg camber but once in a corner the effective camber can become 0 or even become positive. This is done because the suspension has to deal with other things than just cornering. While you want your wheel to gain camber in compression when cornering, you want to keep as straight as possible for traction when braking or for tire wear when fully loaded with passengers and junk. So it becomes a big compromise.
If you were talking about springs you'd be correct, but as others have said sway bars have little effect on how much body roll the car will eventually settle into a corner with. When I added a front sway bar to my car which originally didn't have one, with hard springs, it cut down body roll by maybe 1deg. Sway bars have a bigger effect on turn-in and handling balance.
On this same model car with the soft stock springs, both models with the rear bar only and models with front & rear bars will settle right onto their bumpstops on the outside wheels in a hard turn.
Also to expand on the macstrut issue, macstruts have a small "butterzone" where they have a decent camber curve, and once the suspension moves out of it the camber will start moving the wrong way. To get your suspension into this zone the line from the LCA pivot to the ball joint should be sloping down somewhat from the body when the suspension is at rest (so that the camber will become more negative on compression and positive on extension - ideally the line should be level when you hit the bumpstop).
Unfortunately, on a lot of macstrut cars, from the factory this line is level or even sloping up, so you'll never get your suspension travel into the "butterzone" without heavy modifications (like drop spindles + coilovers that let you jack up the strut length to compensate) or a suspension lift!
ncjay
Dork
4/14/15 8:37 a.m.
Sway bars are not aggressive. Sway bars are either stiffer or softer.
Also, it is entirely possible to put too stiff of a front bar on a car, especially a MacPherson strut car, to the point where it does not weight transfer and there is no dynamic camber gain. "too stiff" also depends on what you're doing. If you're road racing on wide open courses, you probably want the added stability and are willing to forgo the improved weight transfer. For Autocross on the other hand it might be more advantageous to disconnect your front bar.
ok thanks the quick responses...so what ive gleaned from this is that there aren't any common or readily available sway bars for most cars that would render the advantages of camber adjustment ineffective. The body will roll either way.
BY the way my car is an acura rsx type s
So my next question then is for HPDE and eventually open track days and time trial events, what is the ideal setup? From what ive gleaned off of this forum and other places my attention needs to be focused on SEAT TIME +
1. Good damper adjustable Coilovers (already have those)
2. Suspension bushings (to reduce play and to channel energy back into the suspension)
3. Tires
4. Sway bars/aero to fine tune
am I right?
wbjones
MegaDork
4/14/15 10:53 a.m.
from what I've read about the RSX-S is that Honda screwed up the suspension (compared to the Integra) so badly that race teams like Real Time finally gave up on them
that said … the STF guys that are making them work … sorta… are basically eliminating the rear suspension … i.e. to the tune of 1000+# rear springs and huge rear bars
and + 10000000 for the seat time … even as "bad" as the RSX suspension is, you can still have a ball on the track with it … but to get it to rotate (i.e. lessen the understear) it seems that you'll need to really up the rear stiffness
oh …and a LSD .. the car has enough power to spin the unloaded front tire on corner exit just about any time … or so I've read
In reply to wbjones:
im with you on the LSD...however im skeptical about the numbing of the rear suspension. For autocross (reffering to your STF remark) im sure that would be fine to get it to rotate, but for HPDE and track days only im thinking that would work again me and might even be catastrophic. I think ill just play with camber and seat time until I decide I need more. I would almost rather run a front wind splitter to increase front end grip than take any grip away from the rear...ive pretty much given up on autocross lol
I would suggest against giving up autocross because it's one of the cheapest ways to compete in motorsports, even if you're not that good. I would also bump tires into the second most important part of your car behind the driver.
Another reason camber improves the grip is from tire deflection. Even if you have no suspension (like a go kart), camber can help. Think of it like a pencil eraser. Put the eraser end on the table straight up and down. Now push the pencil sideways. Notice how the eraser flexes and the flat bottom of it is no longer contacting the table. Add "camber" to the pencil and do the same test. As you push, the "contact patch" flexes and puts the most rubber on the table.
The secret is to have static camber, dynamic camber, sidewall compliance, and body roll all set up to work together. Increasing the bar's stiffness will likely reduce the amount of camber needed since body roll will decrease, but going too stiff can just make that axle lose lateral traction.
What I'm saying is; body roll is not the only reason for adding camber, but you are right; reducing body roll would reduce the need for additional static camber. Stiffer or shorter sidewalls tend to need less camber since there is less deflection of the sidewall. My e30 had 215/60-15s on it. I used about 1.5 degrees of camber in the front. I threw some 17s on it that I found on CL (forget the tire size, but same overall diameter, and 215mm) and it understeered badly... and it was downright freaky in the rain.
In reply to Mr_Clutch42:
Not to mention that it's a good way to test your car for HPDE/TT...
I've just started autocrossing and I'm not "that good" either (surprise, eh?) but something that became immediately obvious is that a lot of autocross experience will translate to the track, especially the apart about having to be on it at all times, being smooth and finding the right lines.
INITIALDC5 wrote:
In reply to wbjones:
im with you on the LSD...however im skeptical about the numbing of the rear suspension. For autocross (reffering to your STF remark) im sure that would be fine to get it to rotate, but for HPDE and track days only im thinking that would work again me and might even be catastrophic. I think ill just play with camber and seat time until I decide I need more. I would almost rather run a front wind splitter to increase front end grip than take any grip away from the rear...ive pretty much given up on autocross lol
ok … RealTime gave up on it because (so I've read) they couldn't fix the rear end
BoxheadTim wrote:
In reply to Mr_Clutch42:
Not to mention that it's a good way to test your car for HPDE/TT...
I've just started autocrossing and I'm not "that good" either (surprise, eh?) but something that became immediately obvious is that a lot of autocross experience will translate to the track, especially the apart about having to be on it at all times, being smooth and finding the right lines.
while not everyone is the same, I found that autocross taught me a lot about how to handle my car when things started to go "oops" … with much less danger / damage … a lot of that knowledge translated very well to the track
an early track day, I got the car sideways (dumb move on my part) and was able to drive out of it … the instructor asked if I shouldn't be in the intermediate group … and I told him it was from a-x … he said something to the effect … ahhh .. now I understand
Im just so hesitant to mess with Sway Bars. If anything I will fit the TYpe R rear swaybar from Japan (that goes on the DC5 Type R, its a tad bit thicker and noticeably better overall and a popular upgrade for people with this car)
besides that I think the key is suspension set up and seat time like you guys have said
Also, many autocrossers have said to not spend money on performance parts until you know exactly what your car, and driving style needs. If you're guessing (or/and hesitant) about which parts you need, you're not a fast enough driver yet.
Excuse me while I bogart this link from the other autocross thread
http://youtu.be/BIhJdjNC1KE
That is measurable proof of seat time paying off. Look at the time dropped off of that ONE element! Imagine that time difference spread over a 40 second course with a dozen elements! And not a dime was spent in that video
Well there was some much needed repair work that had to be done to my car before i even get home to track it. My front LCA bushings were cracked.ill be replacing those with Energy Suspension pieces. My front sway bar endlinks were popping, so i bought replacement units from Hardrace. Im going to go with the type r sway bar in the rear so i ordered the hardrace endlinks for the rear bar as well. The knockoff poorly designed coilovers i used to have i replaced with quality BC Racing units. And lastly i will get rid of the hard heavy chinese rubber tires i have and im looking at some star specs or rivals or comp 2s....i think that this is a reasonable launching point. When i get back to the states ill be taking her to the suspension shop for camber adjustments
I'd look at the new Bridgestone's … the RE71R … so far, this early in the season of new tires, they seem to be the E36 M3s
they're what I and one of my competitors are on .. and the other 2 in the class are just waiting until more are available …
both she and I are beating the other 2 by as much as 3 and 4 sec. on 50 - 60 sec. courses … and we all were usually with in a sec of each other last yr on our Toyo's
amg_rx7
SuperDork
4/14/15 10:26 p.m.
INITIALDC5 wrote:
So my next question then is for HPDE and eventually open track days and time trial events, what is the ideal setup? From what ive gleaned off of this forum and other places my attention needs to be focused on SEAT TIME +
1. Good damper adjustable Coilovers (already have those)
2. Suspension bushings (to reduce play and to channel energy back into the suspension)
3. Tires
4. Sway bars/aero to fine tune
am I right?
"Ideal" is going to vary depending on your skill level. For HPDE and eventually open track days, I'd say that most important thing is:
Seat time with a GOOD instructor in a GOOD organization so that you can learn skill and technique and be safe from someone that actually knows. It takes a lot longer to learn on your own and if you are given poor advice.
Read a couple of BOOKS, not forums, on performance driving. Amazon has many.
As far as the car goes:
Phase 1 - between 0 and 5 or 10 track days:
1. Maintenance is up to date, you've read a book or two and aren't a complete idiot.
2. Good brakes, shocks and suspension overall are in good working condition. Stock bushings are more than fine if they are in good condition.
3. Good tires. Even if they are all seasons.
Just get out there, have fun and learn.
Phase 2 - you don't necessarily need to do this to get on track but it does help make the car more fun to drive on track. If you haven't done it yet, start thinking about this after your first couple of track days once you figure out whether you like it and want to continue.
4. Improved shocks and spring setup w/ a good performance oriented alignment. This helps better control body movements and weight transfer making the car feel more stable - especially on initial turn-in and braking.
5. Track oriented tires
6. Fix any inherent flaws in the car's suspension geometry.
Phase 3
7. Better brakes, track oriented pads
8. More instruction. There's always something to learn if you can find a good teacher.
Whether you NEED more camber or bigger sway bars only comes from experience. You have to understand the problem you are trying to solve in order to make the right decision on that. You'll only be presented with the problem or thing you want to resolve after being on track and gaining experience.
It's good that you are reading up but for set up find something middle of the road that will be easy on the tires. Also leave the car on the soft side, the typical new driver thing to do is make the car uber stiff which tends to make it skaty....the response may feel immediate but the car won't build as much grip.
With that said none of it really matters becuase for your first track event you won't be near the limit of the car. What typically happens is the instructor drives two laps at 4/10ths and laps faster than the student.
The reality is once you start steering with the pedals you may very well change the set up. My underpowered wonder is set up in a manner that if you haven't mastered ultra fine trail braking, don't have your brain set on attack attack attack and do not nail the exact turn in speed you'll be slow. The car is easy to drive but getting the last bit requires that balance of ferocity and finesse, think the old gunslinger adage "take your time in a hurry". This is basically true of all cars and learning that balance takes time.
Again just get a base set up, you may find like me you prefer a car biased toward oversteer or find it less taxing and more consistent to have the slightest bit of understeer. It's common for two fast drivers to have polar opposite set ups.
The one thing you can do now, if you are driving overseas, is learn to be really smooth squeezing the brakes on and then slowly easing them off as you turn in. This is the toughest thing to learn and pays the most dividends and you can actually practice on the street at completely legal speeds.
Tom