how much bar is to much bar? Options

[ottox914]

I 'll first describe how the '14 is set up, then what I'm thinking and why, then you guys take it from there: Front: 21mm front T bars, 19mm weltmeister sway bar, set about 1/4 in from full soft, koni oil (911) sport adjustables in shortened housings, usually run at 1/2 turn in from full soft. Allignment as much neg as I can get, which is about 1 1/2 per side, 1/8 total toe out, caster at high end of factory specs. Back: Koni gas sports, (914), run full soft, 175# springs, threaded adjusters, no rear sway bar, no toe and no neg camber. Koni competition bump stops all the way around. Stock 15 x 5.5 rims w/Azenis, going to kuhmo or hoosier for next season, on either factory rims or 6.0 panasports. Rack spacers up front. Lowered to about 2-2.5" of travel for front struts before hitting the bump stops, back end lowered to corner balance to 49/51 diagonals. Open diff. 2.0 motor, soon to be kitcarlson'd, kerry hunter header w/supertrapp, "custom" (home-made) cold air kit, basically a K & N mounted on some pvc on top of the throttle body that sits right under the engine lid mesh w/the rain tray out.

I like the way it handles, in specific, the throttle lift oversteer at higher speeds to rotate around a cone. The car will be DSP for next season. Don't like the body roll. I think from seeing photos there is too much.

Plan of attack? I have always thought getting spring rates right was the first step, then sort the F/R balance with the sway bars, and fine tune at the track with shocks and air pressures, in that order. Here's what I'm thinking- go to the 23mm front sway bar, adjustable drop links to make sure there is no pre-load, add the (?) 18mm rear adjustable bar. Increase both bars a similar amount to try to retain the front/rear balance, and hopefully lose some body roll in the deal. Maybe go back to the 150# springs sitting in the garage.

Use is auto x, no lapping or road course stuff. (yet)

So, how about it? Anyone been there/done that? Most of the folks I've talked to locally stay away from a rear bar. I like the F/R balance the car currently has, and know how to fine tune it w/shocks/tire pressures for the conditions of the day. When I have tried to tighten up on the front bar, it just seems to become a pushing machine, and with the shocks set other than noted, it rides like a dump truck. Just gotta get rid of some roll, or just get used to it. waddya all think?

[Joe Bob]

Unless you have an LSD or gobs of power I would not use a rear bar for AX or on a tight course.

In the past, I tightened the front bar until it "pushed" and then backed off a full turn.

[Joseph Mills]

Here's what I'm thinking- go to the 23mm front sway bar, adjustable drop links to make sure there is no pre-load, add the (?) 18mm rear adjustable bar.  Increase both bars a similar amount to try to retain the front/rear balance, and hopefully lose some body roll in the deal.  Maybe go back to the 150# springs sitting in the garage.  

When I have tried to tighten up on the front bar, it just seems to become a pushing machine,

You've got some odd settings going on. (IMG:style_emoticons/default/unsure.gif)

Going to a bigger 23mm swaybar and to smaller 150# springs sounds like a recipe for extreme understeer (even counting the added rearbar).

When I went to a larger 22mm bar I had to go from 180 up to 250# springs to eliminate the push and get it to "rotate" again.

As you mention yourself, when you tighten up the front, it becomes a pushing machine.

[SirAndy]

do you have a roll-cage or bar?

if not, you'll always have body-roll, regardeless of your setup as the body itself twists around the center ...

i have a 22mm front bar and 180lbs springs in the back and virtually no roll whatsoever, thanks to the full cage.

(IMG:style_emoticons/default/wink.gif) Andy

[Bleyseng]

As Joseph says, go to a 23mm sway bar and also heavier rear springs like #200 non progressive ones. Then play with the settings on the shocks to set the car up. If the front is really tight (heavy T bars and sway) and the rear is pretty soft you can lift the front tire right off the ground (not good) because the rear will squat (roll). Balance is real important.
Go to 5 lugs and get some 7x15 cookies (cheap) to go with the Kuhmos (205's) and get some traction.

Geoff

[Joseph Mills]

Looking at your settings again, I think it might be worth your while to look over these "basic" suspension guidlines for our cars. I think Dave Darling collected this info as a basis to start from. I hope this file doesn't weird out when I copy it.

***********************************************
Alignment suggestions:
1. Front caster either stock (6 deg) or max you can get and have both wheels even. Street tires, stock suspension, reasonable driving:
-0.5 deg camber front
-1.0 deg camber rear
~1/16 inch toe-in front and rear.

2. Street tires, stock suspension, fairly aggressive driving or some autoX:
-1.0 deg camber front
-1.5 deg camber rear
~1/16 inch toe-in front and rear; possibly ~1/32" toe-OUT in front for a car biased more for autoX.

3. I wouldn't go much past this setup for any car with street tires.
Sticky tires, 140# springs/stock torsions/19mm front sway bar, autoX with some street:
-1.5 deg camber F
-2.0 deg camber R
~1/16 inch toe-OUT front
~1/16 inch toe-IN rear

4. Sticky tires, 220# springs/21mm torsions/22mm front sway bar, track w/some autoX:
-2.0 deg camber F
-3.0 deg camber R
~1/16 inch toe-OUT front
~1/16 inch toe-IN rear


Note that these are all very much "general recommendations". Everything from exact choice of suspension components, to exact tires, to pavement, to driving style all affects the setup!! So these might be a half-decent place to start from, but to find the "right" place you really must test and tune.
*************************************************

I think you would fall into the #4 category.

At Absolutely No Cost To You as a Forum Subscriber (IMG:style_emoticons/default/biggrin.gif)
I would suggest the following:

I would increase the stiffness to your present front bar (to eliminate lean), add some negative camber to the rear (better contact patch for traction), and go to stiffer springs (200-230#), in the rear to keep the car from pushing (and will also help eliminate lean).

You should be able to eliminate the unwanted lean you mentioned, but still maintain your car's balance that leans towards oversteer - for only the cost of rear springs.

well, plus the cost of your forum dues. (IMG:style_emoticons/default/biggrin.gif)

[Joseph Mills]

Go to 5 lugs and get some 7x15 cookies (cheap) to go with the Kuhmos (205's) and get some traction.
Geoff

(IMG:style_emoticons/default/agree.gif)

Good point.

All together, we have taken at least 7 seconds off your next AX! (IMG:style_emoticons/default/biggrin.gif)

(IMG:style_emoticons/default/beer.gif)

[Bleyseng]

yup! then go have some fun!


Geoff

[ottox914]

Thanks for the replies- some more info on the car and thoughts- Jospeh222- what did you find odd about the set up? As for going back to the 150's w/a rear bar, I didn't want to over-stiffen the back of the car, but from what has showed up in the thread, sounds like it might be hard to get too stiff w/the springs- this is a little worry for me, as I'd like a somewhat compliant ride to and from the events, which are usually 2+ hrs each way away from me. Why is it that everyone just goes bigger and bigger on the spring rates, and few go w/rear bars? What about that magic word, "balance"?

I think I've got the front bar nearly as stiff as I dare w/out more push. I do have a factory rear bar kicking around the parts bin I call a garage- how about that w/the 150's or 175's on the back, and just tighten up on the 19mm front, rather than spend $$$ on the 23? Reasonable or not?

As for chassis stiffness, I've added the Brad Mayeur rocker kits to both sides, and while there is no roll cage, its pretty impressive to jack it up and see no door gap changes, and this was a solid car to start with, no rust-o-ration project. A friend has the autopower full cage in his car, would it make THAT much of a difference?

I have a library of 914 articles, as many of us do, and refer back to a copy of "autocross" magazine, from about 1991, (currently grassroots motorsports) that porfiles David and Ellen Ferguson's 914-6, FP class, 2nd at the Nats that yr. Their set up at the time was 21mm T bars, 22mm sway up front, and in back an 18mm sway with 165 springs. Do you think this worked for them as they had- 1) more power, and 2) true slicks, not DOT tires.

Here in the middle of nowhere WI the driving season is pretty much over, but that means the wrenching season is just starting up... keep the ideas flowing. What setups are each of you using ?

[Dave-O]

Go to 5 lugs and get some 7x15 cookies (cheap) to go with the Kuhmos (205's) and get some traction.

Yeah! do this and then sell me your old stuff cheap!

Here in the middle of nowhere WI the driving season is pretty much over, but that means the wrenching season is just starting up

I hear ya, i've got a long project list too. But this darn school thing keeps getting in the way (IMG:style_emoticons/default/headbang.gif)

Keep it up!

David

[ottox914]

Hey, Dave-o, are you AKA David H., and did you leave the valley fair event early? If so, come to the club meeting tomorrow night- I am meeting Rob M. there, (red 914) to talk parts swaps, set ups, at 6pm, official club meeting starts 7:30pm.

[Dave-O]

Hey, Dave-o, are you AKA David H

I sure am! If all goes well i'll be there. My phone is 612-669-4314 if anything comes up just give me a call.

Thread hijack over...proceed with the great advise... (IMG:style_emoticons/default/aktion035.gif)

David

[Dave-O]

p.s. At Davanni’s Pizza on Riverside right?

[ChrisFoley]

You don't need a cage to stiffen the chassis, especially a bolt-in one.
The concern about a rear anti-sway bar is due to the common problem of the inside wheel spinning when powering out of corners. Since you have the rear bar, I say put it on and stiffen the front bar to match. If you don't like it you can disconnect the rear bar anytime.
Actually a Weltmeister adjustable rear bar can be set up softer than the factory rear bar which may limit some body roll without causing as much loss of traction on the inside tire.
With stickier tires you should be able to tolerate more rear stiffness with less tendency to spin the inside tire.

[Trekkor]

ok...me again.

31mm front bar 2/3 towards soft.
stock torsion bars
150# rear springs
stock rear bar
Koni yellow adj's all around ( front firm, soft rear)
Engman's weld-in chassis stiff kit in the inner longs.

Perfect

Very streetable and perfect rotation.

KT

[Joseph Mills]

Jospeh222- what did you find odd about the set up?

I do have a factory rear bar kicking around the parts bin I call a garage- how about that w/the 150's or 175's on the back, and just tighten up on the 19mm front, rather than spend $$$ on the 23?  Reasonable or not?  

What setups are each of you using ?

Odd? Aw, no big deal. These are just suggestions. But here is what you have:

Extreme neg camber F with no camber R.
Extreme toe-out F with no toe-in R.
I just think you can obtain more grip overall by changing that setup.

Did you read my post? I suggested you NOT go to a 23mm - here's what I said a few posts back: "I would increase the stiffness to your present front bar (to eliminate lean), add some negative camber to the rear (better contact patch for traction), and go to stiffer springs (200-230#), in the rear to keep the car from pushing (and will also help eliminate lean)"

Remember, in your first post you are the one who said: "Here's what I'm thinking- go to the 23mm front sway bar..."

Everytime these suspension threads start, they get confusing. (IMG:style_emoticons/default/biggrin.gif)

As Chris suggested, try out your R bar - and IF you like it, then install some heavier springs and remove the bar. Your car will stay flat AND have less spin.

Here is where I have arrived at thru good advice from this forum, plus some trial and error - good thing there is a market for almost new R springs. (IMG:style_emoticons/default/biggrin.gif)

Caster: equalized at 7
Camber F: 1.4
Camber R: 2.0
Toe F: 1/16"out
Toe R: 1/16"in
Ride height: w/Victoracers is 4.25" at doughnut
911 Torsion bar: 19mm
Welmeister bar: 22mm full soft
Turbo tie rods
Springs R: 250#
Koni adjustables F: full soft R: half hard
Weltmiester chassis stiffening kit +
7 & 8" fuchs with 205 & 215 kumhos

With this setup, and my driving style, my car rotates nicely at low to moderate speeds. Sudden input into the steering, and the rearend just folows around like a puppy dog. (IMG:style_emoticons/default/biggrin.gif)

But at high speeds, throttle lift will kick the rear out. Which can be eliminated by tightening up the F bar.

Sounds like you plan on doing some experimenting. Let us know what happens.


(IMG:style_emoticons/default/beer.gif)

[bob91403]

Would progressive springs solve his drive to, and then autoX concern?

[J P Stein]

I've learned some stuff about suspension for AX in the last few years..... mostly by finding out "oops, that didn't work" and as you go faster stuff that you thought worked just fine no longer cuts it.

Mostly I've been playing catch up with grippier tires.....hay, you start going faster (seat time helps too) revealing handling quirks that you didn't know you had (IMG:style_emoticons/default/confused24.gif)

One of the few "fer sures": If you're set at full soft on your front AR bar & you're still pushing, you've got a problem. (Unless you have one end or the other breaking loose consistently, you ain't going fast enuff.)

The "no rear AR bar to keep the back inside wheel on the ground" ditty works till it don't no more. Mines on the ground but leaves a long black streak around some corners.If your have more tire than power, this won't be a problem tho.....or you ain't going fast enuff.

An aside: I drove Jim Chamber's car at the last AX. Seemed well balanced on the first run as I was feeling it out.
Pushing it some an the next run revealed a oops. He has a rear AR bar. In a sweeper, power on....nice drift....picked up the inside rear tiar...speed fell off, got lotso grip, dipsy doodle readjustment of line....lost momentum....prolly lost a second right there. Now he has a challenge.

So..... I what to do with my problem?

Get an L$D?....ouch! Being a CSBO sux.
.
Stiffer rear springs.....this I will try a set of 275s & 300s one of em' ought to be about right....I can always stiffen the front AR bar iff'n it goes loose.

More tiar....sure, why not. I can go to monster meats in my class....getting fender over em' is gonna keep that down a bit tho.

BTW, Bob, progressive springs will really screw up an AX car's handling....if you're going fast enuff. (IMG:style_emoticons/default/biggrin.gif)

BTW II, what's happening with the ALL 914 AX?
March sux for me. I won't time to set a handle on my new set-up. I'd hate to come down there & stink up the joint. (IMG:style_emoticons/default/laugh.gif)

[bob91403]

I've got a set of 165 progressives on my street car. I like the way it feels, but I don't have much to compare it with. It was either that, or a set of 140s. Do you think I made the wrong choice? Exactly how would it screw up the handling?

[J P Stein]

I've got a set of 165 progressives on my street car. I like the way it feels, but I don't have much to compare it with. It was either that, or a set of 140s. Do you think I made the wrong choice? Exactly how would it screw up the handling?

You'll note I said handling of an AX car. They're fine for the street.

When a car leans into a turn the springs compress. As long as
this compression is uniform the handling is predictable. If the spring rate changes (slow in, fast out) in mid corner things can get dicey.....one could go from mild oversteer to severe oversteer, for instance. An AX is a good place to have this happen (IMG:style_emoticons/default/biggrin.gif) but it'll kill your time.