[wutangben]

Ok, id like to hear what everyone has to say about sway bars.

I am ordering a set of suspension techniques sway bars for my prelude. A lot of people say you should only change the rear, so that you have more oversteer (or oversteer to cancel out all the understeer that we have). ive heard autocrossers say its the only way to go. ive heard some people argue that it will give you unwanted, snap-oversteer, and i've heard people say that it definately wont. I've heard other people say that if they sell the set then you should install both because they were meant to work together.

So, heres where i stand. when i get the kit, im going to install the rear and see how i like it. chances are, i will definately like it, but how will i know if its going to be better with the front installed as well? if i only install the rear, im going to sell the front one on ebay to help me cover the cost (which will be nice) but im still not sure what exactly i should do.

what do you guys think? post a vote too.

 

[James ITR]

I think that it all comes down to the type of driver you are. If you are pretty much one with your car and familiar on how it performs, then see what you need from there. You might be the type of driver who likes rear rotation. I really havent heard of anyone experiencing snap-oversteer with a larger bar. It also depends on the size you get. Auto-x without it first, then with the bar. From there, if you feel as if its too much oversteer, try using a larger front sway bar.

 

[wutangben]

I think that it all comes down to the type of driver you are. If you are pretty much one with your car and familiar on how it performs, then see what you need from there. You might be the type of driver who likes rear rotation. I really havent heard of anyone experiencing snap-oversteer with a larger bar. It also depends on the size you get. Auto-x without it first, then with the bar. From there, if you feel as if its too much oversteer, try using a larger front sway bar.

ive autocrossed before without the sway bars, so i guess ill install the rear, and if i dont think it has too much oversteer, ill just sell the front bar. sounds like a plan....?

 

[PseudoRealityX]

Like everyone is saying, you need to figure it out for yourself. My personal setup will have a ST front sway bar and a CMS rear one, to give a bit more oversteer and better turn-in than the ST combo.

 

[CivicSiRacer]

Personally I would do both bars so that you get less roll into corners and then dial in tire pressure to give you neutral or more oversteer. I hate snap oversteer

 

[wutangben]

what exactly is snap oversteer?

and PseudoRealityX: if you plan to buy the s/t front, maybe ill sell you mine when i get it...

let me know.

peace

 

[ITR#231]

what exactly is snap oversteer?

I'm not sure if this is even a real term, since "oversteer" has a broad enough definition to include gradual and rapid loss of rear traction. I would assume that it's being used here to describe a rapid loss of rear traction that puts you ass-backwards before you begin to feel the spin. Close enough?

As for the suspension setup, don't let the swaybars influence your driving technique. The sway bars do more than just determine understeer/oversteer. In fact, their contribution to the handling characteristics of the car is nothing more than an aritifact of their original purpose. If you want to keep the car rotating properly, you can vary tire pressures, tire sizes, camber, toe, damper settings, technique, etc., as needed. If I were you, I would use both bars to keep the greatest contact patch of tire on the ground with minimal body roll, and adjust the other things I mentioned as necessary to rotate the car (tire pressure and technique being my two top choices).

 

[PseudoRealityX]

what exactly is snap oversteer?

and PseudoRealityX: if you plan to buy the s/t front, maybe ill sell you mine when i get it...

let me know.

peace

Hahaha, you need to take a look at the link in my sig. For whatever reason, i doubt your sway bar will fit on my car

 

[Poboy]

I'm not sure if this is even a real term, since "oversteer" has a broad enough definition to include gradual and rapid loss of rear traction. I would assume that it's being used here to describe a rapid loss of rear traction that puts you ass-backwards before you begin to feel the spin. Close enough?

If you want to keep the car rotating properly, you can vary tire pressures, tire sizes, camber, toe, damper settings, technique, etc., as needed. If I were you, I would use both bars to keep the greatest contact patch of tire on the ground with minimal body roll, and adjust the other things I mentioned as necessary to rotate the car (tire pressure and technique being my two top choices).

I would say snap oversteer is when you plow (understeer) right at the beginning and the back end 'snaps' around with "rapid loss of rear traction"

With the prelude, I think the car is adequately sway barred up front stock. There's little body roll up front so you don't need a new front bar. Since the car is pretty front heavy and the front bar does an adequate jobs with that, you get a lot of understeer. I definitely plan to get a rear bar for my car because it's a relatively easy way to lessen understeer, I don't have adjustable shocks (yet), I have so much understeer I adjust tire pressure solely to affect understeer and not grip (I run 48psi up front and less than 30 rear), and I'm not good enough yet for driving technique to correct understeer.

Of course for the moment I race stock because I have to improve myself alot before I can say 'it's the car'. Although I do blame lousy stock tires often.

 

[ITR#231]

), I have so much understeer I adjust tire pressure solely to affect understeer and not grip (I run 48psi up front and less than 30 rear)

48 front and less than 30 rear? What tires are those? Seems like you'd increase your understeer that way. When I need the car to rotate more, I'll bump the rear pressures up until it does. The fronts should be set with a pyrometer, or at least FEEL it. You have nearly a 20 lb difference in the wrong direction as far as I can tell.

 

[wutangben]

Hahaha, you need to take a look at the link in my sig. For whatever reason, i doubt your sway bar will fit on my car

lol, i forgot i wasnt in the prelude forum anymore

everyone else: thanks for the advice, keep it comin.

peace

 

[Poboy]

48 front and less than 30 rear? What tires are those? Seems like you'd increase your understeer that way. When I need the car to rotate more, I'll bump the rear pressures up until it does. The fronts should be set with a pyrometer, or at least FEEL it. You have nearly a 20 lb difference in the wrong direction as far as I can tell.

Tires are stock (did I mention crappy?) Potenza RE92's. At first I thought the same, that I would be increasing understeer, but it doesn't work out that way. 48 in front is what I need to stay off the sidewall. In the rear, the lower pressures increase roll, increasing slip angle faster, reaching limit of adhesion (and over) faster. It seems counter intuitive, but it works, somewhat.

 

[PseudoRealityX]

Tires are stock (did I mention crappy?) Potenza RE92's. At first I thought the same, that I would be increasing understeer, but it doesn't work out that way. 48 in front is what I need to stay off the sidewall. In the rear, the lower pressures increase roll, increasing slip angle faster, reaching limit of adhesion (and over) faster. It seems counter intuitive, but it works, somewhat.

ever think to dissconnect the front one until you get the bigger rear?

 

[ITR#231]

ever think to dissconnect the front one until you get the bigger rear?

I think the only way I would do that is if I had something bad happen during a day (like something broke) and I needed a quick fix. Otherwise, I'm still convinced that understeer is usually something that can be fixed with tire pressure and technique.

Poboy,

I understand what you're saying, and I might agree given that I have worked with tires that increase grip as you add more air (take the new Kumhos, for example). However, I would still try this...

Chalk the front tires to check for sidewall rollover and make a run to heat up the tires (work them hard to really bring them up to temp.). Then have someone check the tire temps RIGHT AWAY after you leave the course (measure outer, middle, inner...in between the tread). With lots of understeer and 48lbs in the front, there is a chance that you will find the middle temps higher. If so, bring them down until your tire heats up evenly. A good compromise is having the middle and the outside even, since camber will determine how they heat up too, so the middles might never keep up. Once you have the front tires set, don't worry about sidewally rollover. If the temps are good accross the whole tire, you are NOT rolling over too much.

Now go back to the rear, and set them 3-8 lbs lower than the fronts. You already understand that screwing up the rear pressures on purpose is an acceptable way to induce oversteer (sort of...not perfect but it works). However, I would suggest that you go UP, not down, to take traction away. Every tire has a point at which it is over or under inflated and it's traction drops off. Under inflated, they will squirm and be sloppy. Over inflated, they will just break away easy. Continue to increase the rear pressures until you are either rotating properly, or you get significantly higher temps generated in the MIDDLE compared to the outer and inner. After that, if you need more traction you can drop the pressures a tiny bit. If you're still understeering with perfect front traction and poor rear (ie, overinflated), we'll talk technique.

Crappy tires don't matter as compared to good tires as long as they're the same on all 4 corners. No matter how low your traction is, you can still make the front or the rear brake away first some way or another. The only difference between sticky tires and crappy tires is the ultimate grip they provide before they break away.

 

[shorthand]

OK, I'm posting a swaybar physics thread, separate from this one. Swaybars are a very misunderstood concept.

 

[wutangben]

OK, I'm posting a swaybar physics thread, separate from this one. Swaybars are a very misunderstood concept.

sweet.

 

[Poboy]

PseudorealityX, I have thought about disconnecting the front bar, but I don't want to increase roll up front. The prelude has around a 70/30 weight distribution front/rear. Also, I want to be able to drive it well stock before I change characterisitcs so I have a better understanding of what's happening

ITR #231,
I'll definitely try your instructions when I get the chance. Unfortunately, around here we get 3 runs, no practice before, no fun runs after. Courses are typically around 60 secs. Next event I'll look for someone with a pyrometer and see if I can try what you said.

I have to say, most people would say that there's a huge dfference between crappy tires and good tires (talking about street tires). Granted, I haven't driven a prelude other than mine, so I can't really say, but I'm anxious to find out (when I have the money for new rims)

 

[PseudoRealityX]

PseudorealityX, I have thought about disconnecting the front bar, but I don't want to increase roll up front. The prelude has around a 70/30 weight distribution front/rear. Also, I want to be able to drive it well stock before I change characterisitcs so I have a better understanding of what's happening

ITR #231,
I'll definitely try your instructions when I get the chance. Unfortunately, around here we get 3 runs, no practice before, no fun runs after. Courses are typically around 60 secs. Next event I'll look for someone with a pyrometer and see if I can try what you said.

I have to say, most people would say that there's a huge dfference between crappy tires and good tires (talking about street tires). Granted, I haven't driven a prelude other than mine, so I can't really say, but I'm anxious to find out (when I have the money for new rims)

Hmm, maybe something you can at least expiriment with later on, once your driving is where you want it. Its just something to play with, and i only got the thought from talking to Jason Minehart at the season opener of the ProSolo and National Tour events this year. He was I believe 6th last year at Nats in H-Stock, so im pretty trusting of whatever he says....within reason

His car is a bit better than 70-30 though, more about 62-38ish.

 

[shorthand]

70 - 30 F-R weight for a Prelude? That's a big problem!

Wow, getting that to handle will be a trick.

As for the tires, I only have four events under my belt, but the amount of extra handling to be had from tire inflations was quite a surprise at my last event.

I started out inflating to 45F/35R like I did at the warmer events. My first run, I was snap oversteering all over the place. It was rather harrowing when I suddenly was aimed straight at the wall of the little short oval track we had peppered with cones.

It took me until the last run to get it sorted out right, (right around 40F/35R), but on that run I found 2.5 seconds on a 60 second course. There was definitely more out there though.

Without a rear swaybar, I get the feeling that you won't get the Prelude to oversteer with any reasonable tire inflation, but on a warm day, I'd take the fronts to their highest rated pressure and then start the rears around 35 psi and play from there.

3-8 lbs may not be enough difference for a weight distrubtion like that. The chalk trick is great for making sure both sets of tires are developing maximum grip.

Happy hunting. By the way, are we talking about adjusting the front swaybar for a stock class or one of the more open classes?

By the way, the roll is a secondary concern. The double wishbones handle large body roll angles better than any other suspension geometry. If you want to run stock, I would recommend that you seriously consider disconnecting or shrinking your front swaybar. Its certainly something to play with.

If you want to run a different class, feel free to get a matching rear swaybar instead.

 

[Poboy]

PseudorealityX, I'll probably take off the front bar at some point just to see how it drives. If I was planning on staying stock, I'd be doing it sooner rather than later.

shorthand, I may be off on the weight dist. some, I got the number off a discussion on a web board. I do know that it's very front biased, so I consider the number a valid possibility. The prelude actually handles pretty darn good, it just understeers like crazy. I've chalked the tires a couple of events and found 48 up front just about right. I haven't got the rears set just right yet, that's gonna require some tinkering.
I'll eventually probably run STS or SP (if I get a Quaife), once I'm satisfied with my driving.