Who has the stiffest rear adjustable sway bar?

[cannga]

OT -- Gotboost, Was at your "shop" with the wife's GX 470 today (30k service). Outstanding service from the service guys (I'm your spy on your "underlings." LOL ).

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[KA 997TT]

Originally Posted by cannga

Re. corner balance, a purist would argue that corner balance should be done only with adjustable drop link.
I have no direct experience but have read that the steps are:
1. Disconnect drop link
2. Corner balance
3. Connect drop link. The adjustable drop link allows this last step to be done without creating pre load on the suspension.

It's a little too complicated for me to explain why here but next time your car is up on the rack, tell the tuner to explain to you why you could create pre load on the sway without adjustable link.

I had the corner balance done with the sway bar links disconnected. the rears fit fine even though they are not adjustable. the fronts are adjustable and work well.

[KA 997TT]

Originally Posted by cannga

Hello KA many good points you are asking. I am glad, and thanks to Sharkwerks, the drop link has finally got the attention it deserves. As Neil has mentioned, most definitely an after market drop link will make the sway bar feels stiffer. By replacing the compliant rubber joint with an all metallic heim joint, the drop link will
a. Increase the effect of the sway bar
b. Increase the effect of any change you make to the sway bar settings

When I was doing my "web research" way back when, I could not find any report on the effect of drop link alone (without any other parameter change). So far, I've switched in/out twice. This is what I have found (emphasis: personal preference/opinion):

Pro's:
As expected, the car does lean less (change from my initial impression)
Makes the car feel less rubbery and bouncy
Makes car feel stiffer and more planted

Con's:
Increase road noise
Increase engine noise to cabin (weird, but true)
When you hit bumps, the car will make a solid noise and in general feel harsher on street driving.

For lack of better description, it's almost as if you are increasing the damping factor of the coil-over. I would run my tires a little lower (1 psi) with the solid drop link than without.
A couple of us in fact have found that with rear drop link set to full stiff on an after market sway (mine is GMG, the other person's is GT3's), the car is almost intolerable hard for street driving. I would be interested in others' impression on this.

Considering what it does, it is not a surprise that this drop link is used more often by people on GT3 forum (rennlist). IMHO, if you are taking this car to the track, it's a no brainer. For street driving, it's a matter of personal preference. I switch it in and out every 6 mos or so because although the drop link makes the car feel harsh, there is a very nice planted and aggressive sensation to the car with it. Cost of switching = $100, very cheap.

BTW, I believe the very first post I saw of drop link is by ERP (anyone corrects me as needed). I use Tarett as it's been around a very very long time and used by people on rennlist GT3 forum. RSS should be fine also.

It takes a while to go through your replies Can, i should charge you to post... J/K
Full of useful information, Thank you i will definitely be looking into all this. at the end of the day, I like a stiffer ride.
I currently have the rear to stiffest, the front to medium (I have the 20" wheels) so it is better and reduces wheel hop.
The springs are quite stiff and the dampeners do an excellent job. If you were to drive my car you would wonder why am I looking for better? It is a disease, I am always on a hunt for that just a little better. I am only interested in a tweaked street application to be honest with you. I will give the rear drop links a try and go from there.
From everyone's feedback, I have a very good idea of the direction to go on at this point.

[GotBoost?]

Originally Posted by cannga

OT -- Gotboost,
Was at your "shop" with the wife's GX 470 today (30k service). Outstanding service from the service guys (I'm your spy on your "underlings." LOL ).

Can,

Let me know ahead of time when you come by.

[KA 997TT]

Originally Posted by GotBoost?

Can,

Let me know ahead of time when you come by.

Off topic here,
I see a lot of users from the So CA area, how is it down there? I have two clients that have been asking me to move to SD. How is the economy and housing market? I would need to worry about a job or anything...

[vividracing]

The Agency Power rear bar is the largest diameter on the market. 3-way adjustable solid bar.

[KA 997TT]

Originally Posted by vividracing

The Agency Power rear bar is the largest diameter on the market. 3-way adjustable solid bar.

Do you want a cookie for this? I still am researching a better alternative. thanks for your input. Diameter does not mean stiffest. you can have a much smaller bar in diameter but the spring rate is greater. If you want to provide me with information on spring rate of your product VS. GMG or RSS or whomever that would be great as it will help me with my research.

[vividracing]

My post answers your topic. We made this rear bar the stiffest because of how we like to dial AWD cars with more oversteer. Most rear bars are 24mm where ours is 25. There is no "spring rate". If you search our blog at www.agency-power.com/blog, you can read the technical aspects there. No thanks on the cookie.

[KA 997TT]

you did not provide me with anything I need. But thank you again for the input.

[vividracing]

http://www.agency-power.com/blog/age...ear-sway-bars/

[cannga]

OT - Mike,
Thanks. I came late and it was a minor service so didn't want to bother you.
Surely I'll come calling when the Turbo charge kit I've just added crack the Lexus V8 block. LOL.

>>>>
It takes a while to go through your replies Can, i should charge you to post... J/K
>>>>>>

KA, somehow it seems like I am getting the bad end of the deal here.

Anyway, sway bar could be a frustrating topic. For one, no one publishes official specs, so consumers are left with speculations and rumors. Second, even if we do have the specs (torsion spring rate I think, not just thickness), I am not sure we know what to do with them.

Probably, the most helpful "specs" are provided by GMG: "The rear sport sway bars offers a torsional stiffness increase of 30,45 and 60% while the front front sway bar offers an increase of 15/25 and 35% over the factory bar." http://www.gmgracing.com/porsche_suspension.shtml
Since they are made by Eibach, I felt comfortable buying them, but really I have no idea how to define the "best" sway bar. Being "stiffest" to me does NOT mean being the best sway bar -- it depends on the setup and what you are looking for.

BTW, as you already know, the sway is there to a. increase lat. stiffness and b. adjust handling. If you want to just stiffen the car, I think the better route is to use higher spring rates.

[KA 997TT]

Originally Posted by cannga

OT - Mike,
Thanks. I came late and it was a minor service so didn't want to bother you.
Surely I'll come calling when the Turbo charge kit I've just added crack the Lexus V8 block. LOL.

>>>>
It takes a while to go through your replies Can, i should charge you to post... J/K
>>>>>>

KA, somehow it seems like I am getting the bad end of the deal here.

Anyway, sway bar could be a frustrating topic. For one, no one publishes official specs, so consumers are left with speculations and rumors. Second, even if we do have the specs (torsion spring rate I think, not just thickness), I am not sure we know what to do with them.

Probably, the most helpful "specs" are provided by GMG: "The rear sport sway bars offers a torsional stiffness increase of 30,45 and 60% while the front front sway bar offers an increase of 15/25 and 35% over the factory bar." http://www.gmgracing.com/porsche_suspension.shtml
Since they are made by Eibach, I felt comfortable buying them, but really I have no idea how to define the "best" sway bar. Being "stiffest" to me does NOT mean being the best sway bar -- it depends on the setup and what you are looking for.

BTW, as you already know, the sway is there to a. increase lat. stiffness and b. adjust handling. If you want to just stiffen the car, I think the better route is to use higher spring rates.

Do they have more than one application for the 997TT? I know I had the GMG's front and rears before. They were ok.

[vividracing]

I spoke with our engineer on the sway bars and this is what I was told. So hope this helps:

When comparing anti-sway bars of same configurations, both made of solid steel alloy, different diameter bars can be directly compared. Larger diameter bars have a higher bar (spring) rate. If the bars are wider, or have longer arms (moments) they cannot be directly compared. We measure in pounds-per-inch at the end link, just like a coil spring. The adjustment holes change the rate in a direct linear relationship as well. Sway bars are just torsion springs, but they effect the chassis much differently than a chassis spring.

Note that anti-sway bars are used for tuning both the roll rate and chassis balance (oversteer-understeer), and this is not just a "more-is-better" approach. The chassis setup (springs, shocks, bars, alignment, tire-wheel selection, etc.) is more important as a whole than any one element. Bars are for tuning! German cars are usually tuned light on sway bars, as much of their tuning philosophy is based on high-speed testing. Here, US enthusiasts appreciate lower speed cornering, as our "fast motoring" is much more limited. Tight corners at lower speeds are more fun (and faster) with less body roll, as the tire contact patch is larger and more stable.

[KA 997TT]

Originally Posted by vividracing

I spoke with our engineer on the sway bars and this is what I was told. So hope this helps:

When comparing anti-sway bars of same configurations, both made of solid steel alloy, different diameter bars can be directly compared. Larger diameter bars have a higher bar (spring) rate. If the bars are wider, or have longer arms (moments) they cannot be directly compared. We measure in pounds-per-inch at the end link, just like a coil spring. The adjustment holes change the rate in a direct linear relationship as well. Sway bars are just torsion springs, but they effect the chassis much differently than a chassis spring.

Note that anti-sway bars are used for tuning both the roll rate and chassis balance (oversteer-understeer), and this is not just a "more-is-better" approach. The chassis setup (springs, shocks, bars, alignment, tire-wheel selection, etc.) is more important as a whole than any one element. Bars are for tuning! German cars are usually tuned light on sway bars, as much of their tuning philosophy is based on high-speed testing. Here, US enthusiasts appreciate lower speed cornering, as our "fast motoring" is much more limited. Tight corners at lower speeds are more fun (and faster) with less body roll, as the tire contact patch is larger and more stable.

Dan,

Thank you for taking the time to explain... Since i was 13 I drove in Europe and places with no speed limit so i am very familiar with open road handling vs. taking corners fast and hide from the cops.
I do understand the dynamics of the vehicle and what it takes to tune the suspension by simply driving my car and feeling what is needed to tune or where should there be compensation. with the stiffer springs i have and the dampeners tuned in right at this time with the help of a few local folks and Moton, I am now getting to the Sway bar tuning and I have learned a few things from this thread on where to go next.
If you want my honest opinion on other and further explanation you may want me to email it to you and not share it here. To leave it at this, I thank you for the information as I do thank others on this post and I am sure I can call it a good experience and great feed back. now I move on to the next challenge...

[GotBoost?]

Originally Posted by KA 997TT

Off topic here,
I see a lot of users from the So CA area, how is it down there? I have two clients that have been asking me to move to SD. How is the economy and housing market? I would need to worry about a job or anything...

KA,

The economy is starting to recover IMO. I think there are some smooth sailing days ahead. I am the eternal optimistic you know. But seriously, I don't feel the economy here is as bad as the media portrays it to be.

As far as real estate goes, that varies by area. I have been buying some properties for investment purposes and I am finding that in certain areas, you can't give the houses away. On the flip side, there are parts of Orange County where the real estate market is pretty hot now. I've lost a few bidding wars already.

The San Diego market is doing ok. The real estate market in that area has been hit pretty severly. Now is probably a good time to buy there.

Make the move man. We have a small group of 6 speeed members here that can do some runs with ya!