I searched and found some good info on rear sway bars but nothing that quite answers my questions.

About the car and current setup:

2000 Civic Si
STS Class
Springs - 550f / 750r
Camber - 2.2f / 1.6r
Toe - 0 all around
Stock swaybars
Tires - Azenis Sports (the new 615's)
Koni Sports (race valved and shortened)
Loose nut behind the wheel - 6.5 years autocrossing, currently Novice Chief at SASCA (San Antonio Sports Car Association)

I want the car to rotate more and am considering a rear bar. I got some good advice in this thread:

https://honda-tech.com/zerothread?id=1209321

But I have a couple new questions.

I have to decide between 2 things to do:

1) Disconnect the monster front OEM sway bar.
The good - get rid of some of the understeer and also keep it from trying to lift the inside front tire under accelleration.
The bad - Would the car loose some transition? What other problems would I incounter?

2) Add adjustable rear bar.
This is where my concerns arrise. My car leans very little in the turns (see pics below) and I'm wondering if the rear bar would even be effective. I'm rather new at this suspension tuning thing and I'm learning as I go so please forgive my ignorance. Doesn't a car need to lean a lot for the rear bar to work?





Thanks in advance!

K

 

I'd try a rear bar and more front spring.

A lot more front spring.

EDIT: Everyone is gonna disagree with what I'm about to say, but swap your springs front to rear

waits patiently for solo-x's response.....

 

I'd suggest more rear bar and perhaps more front spring too. Are you having any inside wheelspin problems?

Christian

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Xian &raquo;</TD></TR><TR><TD CLASS="quote">I'd suggest more rear bar and perhaps more front spring too. Are you having any inside wheelspin problems?

Christian</TD></TR></TABLE>

No wheelspin problems. In fact yesterday's course had a very sharp 1st gear 180' and I had no problem putting the power down. Im very confused as to what the higher front rates will do for me. Shouldn't a rear bias add oversteer therefore by adding front rate I add understeer? Again, forgive my ignorance in this....

 

It's pretty common to run a big rear bar; somewhere around 22mm is common. I have the Comptech 22mm adjustable sway/tie combo. It's a bit expensive but very nice stuff.

If you disconnect the front bar, you'll increase body roll, so you'll probably want to go up in spring rate. If you do that, swapping the springs like Carlos suggested might not be a bad idea, but you'd probably want to combine that with a bigger rear bar.

What tire pressures are you running currently? 36 psi front (from the other thread) seems a bit low. 38-40 is about ideal for the Azenis RT215. If running lower pressures in the rear doesn't do the trick, you can try higher (45+) in the rear.

Another thing to try is reducing rear camber.

Here's another recent thread that has some good info: https://honda-tech.com/zerothread?id=1313274

 

What are your rear shock adjustments? Have you tried running the rears up pretty high to see what effect it has? Shock adjustments cost nothing.

A rear bar is an option to make the car rotate more. So it adding some toe but you don't want to get too drastic if this is your daily driver. You could also try removing the front sway bar link on one side of the car just to alter the balance and see what you think. Maybe it wouldn't be the final fix but it will tell you if your sway bar balance end to end is having much effect. As mentioned, you will possibly sacrifice some transitional response in slaloms but you never know until you try. Plus doing this is free too. I don't think I would look into replacing the front springs yet, especially if the car is a daily driver. If you run a lot more spring, you will have less relaince on that front sway bar.

But first I would tweak with the parts that you have and see where that points you. Having a rear bar on these cars would not be much of a surprise though.

 

Lee, I've been playing with the adjustments and found that yes, near stiffest rear has been best but it's nowhere near enough to give me the rotation I'm used to.

 

Thanks for all the help guys.....

Going by what I have gotten here I will try disconnecting the front bar for the next event and see what I think.

As long as the only thing I should worry about in this is a loss of transition then I feel comfortable doing it. I just have images of the car diving wildly in the turns and being out of control.

Only one way to find out though right?

K

 

For autocross purposes, I absolutely *hate* the way a FWD car with no front bar handles.

The bottom line is that you have to figure out what works for you.

But I would really consider just swapping your springs front to rear before you try running with the front bar disconnected. It's free.......

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by carl_aka_carlos &raquo;</TD></TR><TR><TD CLASS="quote">For autocross purposes, I absolutely *hate* the way a FWD car with no front bar handles.</TD></TR></TABLE>

Just curious, what don't you like about the way it handles without a front bar?

 

the more i play around with this stuff the more i've discovered that for the most part it doesn't really matter. we got good results this weekend out of an EF with spring rates that were out of this world, the stiff ones on the "wrong end" too boot and just stock swaybars front and back.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Blue Si #72 &raquo;</TD></TR><TR><TD CLASS="quote">Just curious, what don't you like about the way it handles without a front bar?</TD></TR></TABLE>

i was speaking with the alien on a somewhat similar topic and the idea of disconnecting the front bar came up. his response was "if you do it you'll be hating life". no front bar = dead slow transient response

 

to the op, if you really want to free the car up, get rid of that rear camber. it's doing nothing for you but cause headaches. use the washer trick to shim it down to less then -.75* and you'll have all the mid corner rotation you need. added benefit is that you won't need to worry about a crazy toe alignment that will make the car a bear to drive day to day. of course, with 750 rear springs and race valved shocks, this thing isn't riding all to comfortably anyhow. i really enjoyed my 700/550, 24mm front bar/23mm rear bar setup with the camber change i mentioned above. a similar setup for your car would not only ride better but be easier to drive as well.

 

Add a little toe-out in the front, less camber in the read (maybe 1.0).

I would add a bigger sway bar in the rear, keep your front sway bar and swap your front and rear springs. The front need to be stiff to keep your tire flat on the road but the roll stifness should be more in the back to keep good traction in exit!

The rear spring rate does not realy need high IMO. Just a big sway bar to help weight transfert in the front.

 

I have a '99 Si and a larger rear sway bar helped a lot. I currently use a Mugen 24mm bar with a Beaks kit, but if I could go back in time I'd buy a Comptech 22mm adjustable bar. Changing tire pressure and adjustable shocks (currently using Koni Yellows with a Skunk 2 coilover kit) also help quite a bit for setting up my suspension for different courses.

 

3) As Nate suggested, take some more camber out of the back, you'll be amazed at what an improvement in rotation it will bring.

 

My vote is to try less rear camber too...something to do while you shop for a good deal on a sway bar.

 

Plenty of National-level STS events have been won by a car with lots of rear negative camber and a relatively soft front.

Lots of different ways to achieve the same result, you have to do what gets you to the finish as quick as possible.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jzr &raquo;</TD></TR><TR><TD CLASS="quote">Plenty of National-level STS events have been won by a car with lots of rear negative camber and a relatively soft front.

Lots of different ways to achieve the same result, you have to do what gets you to the finish as quick as possible. </TD></TR></TABLE>

well, my setup suggestions are for those of us that are mere mortals and get weak kneed at the sight of drivers like ken, kevin, andy, corey, billy, jason, chris, jrz, etc. a relatively soft front and lots of rear camber is too hard to drive fast for me. i need a setup that doesn't require as much talent to keep the end with the clear lights pointed forward.

i'm right there with you on the last comment. chang has been trying some VERY non-traditional stuff. things that both daddio and hollis commented on as "that won't work", "don't know why that's working so well", and "i wouldn't try that in topeka". it seems to work for him. like i said, i just don't think it matters as much as our multi-page dissertations seem to indicate.

nate

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo-x &raquo;</TD></TR><TR><TD CLASS="quote">to the op, if you really want to free the car up, get rid of that rear camber. it's doing nothing for you but cause headaches. use the washer trick to shim it down to less then -.75* and you'll have all the mid corner rotation you need. added benefit is that you won't need to worry about a crazy toe alignment that will make the car a bear to drive day to day. of course, with 750 rear springs and race valved shocks, this thing isn't riding all to comfortably anyhow. i really enjoyed my 700/550, 24mm front bar/23mm rear bar setup with the camber change i mentioned above. a similar setup for your car would not only ride better but be easier to drive as well.</TD></TR></TABLE>

ot,but what is the car weight at race trim?

 

Awww Nate, I think you give some of those guys (me at least) too much credit. IMO the extra negative camber and a bit of toe-in in the rear makes the car more forgiving, but that's with our setup. I will say though that we've gone stiffer up front this year (although proportionally we've gone even stiffer in the rear) and that our doing so was partially due to things I've seen here.

Lastly, there's one thing that everyone's forgetting here: tire contingency. Be aware that if you run Nate's suggested negative camber in the rear, you might wear off the part of the sidewall that says "Kumho", and only get paid half!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shakedown94 &raquo;</TD></TR><TR><TD CLASS="quote">ot,but what is the car weight at race trim?</TD></TR></TABLE>

i assume you were interested in my car's race weight. i was at 2230lbs last year, without driver.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jzr &raquo;</TD></TR><TR><TD CLASS="quote">Lastly, there's one thing that everyone's forgetting here: tire contingency. Be aware that if you run Nate's suggested negative camber in the rear, you might wear off the part of the sidewall that says "Kumho", and only get paid half! </TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo-x &raquo;</TD></TR><TR><TD CLASS="quote">

i assume you were interested in my car's race weight. i was at 2230lbs last year, without driver.

</TD></TR></TABLE>
yep, thanks
mine is at 1990 now in ep
now on race tires and need to up spring rate as running out of front travel now.
wanted to go to 650 with no front bar.
just looking at the difference in weight to try and see if 650 will be enough with no bar and 2" of wheel travel before upper arm hits the tower

 

UPDATE


This sunday I ran my first event without the front bar and it was quite surprising!

First off the car has so much front grip (relatively speaking of course, it is a fwd after all) and I can get on the gas a lot sooner than before. Also, there was very little loss of transition in the slaloms. In fact I was able to take the slalom much faster than my competitors in my class. Yes, the car leans a bit more but not enough to make any real difference to handling. For the first time since I put on the SSPS Konis I feel like the car is doing what I want it to.


Mission successful!!!!

 

Do you have any idea what your shock travels were before and after? It's quite possible that you were too stiff and not getting enough travel to handle properly. The only way to know this is to see your shock travels. This is made even more possible by the fact that the more body roll made it work. Body roll is a good thing! (to a point)