Damper settings/suspension geometry

[Flyboygsxr]

When I get home from Afghanistan I will be installing all of the mods I have ordered while I was out here...Here is a list of the mods:

18 X 9.5 & 18 X 10.5 ENKEI PFO1'S
TOYO R888'S 275 FRONT AND 295 REAR
EIBACH SPORTLINE SPRINGS
STEEDA BILLET LOWER CONTROL ARMS
STEEDA ADJ. PANHARD BAR
STEEDA UPPER STRUT MOUNT KIT CAMBER/CASTER PLATE
STEEDA LOWER TRAILING ARM RELOCATION BRACKET
STEEDA HEAVY DUTY UPPER CHASSIS MOUNT
BUMPSTEER KIT
CAMBER ADJUSTMENT BOLTS
COMPETITION UPPER 3RD LINK W/RO (ADJ. UPPER CONTROL ARM)
5.0 LOGO BILLET OIL SEPARATOR

I have had the car on the track in stock form and it was very balanced. I never had to worry about snap oversteer. I am concerned that with the stiffer sportlines the car will be more prone to oversteer. I was curious if anyone had the same setup and if so what damper settings they found worked the best on the track with the sportlines. Are the stock dampers capable of handling the stiffer springs or do I need to go with something else? Also, the steeda LCA relocation brackets say they need to welded in. Can I get away with just bolting them on or should I weld? As for readjusting the pinion angle, I have no experience with this so feedback and how-to from those who have already done this would be appreciated. The bumpsteer kit...is this really necessary or have I wasted my money? Lastly, with these mods have I ruined the suspension geometry and will I have a hard time getting the suspension geometry correct so the car is balanced? I also plan on running -2.0 degrees of camber initially with the camber plates so do I even need to install the camber bolts or is this overkill? If there is anything else I have failed to mention please feel free to chime in. Thanks again guys.

Adam (Flyboy)

 

[cloud9]

With your staggered wheel setup you shouldn't have a problem with oversteer. If you do just soften the rear dampers one or two settings. You can just bolt the LCA relocation brackets, you do not need to weld them. Steeda's installation instructions have recommended settings for your upper control arm to set the correct pinion angle. As far as the camber bolts, it depends on how much those springs lower the front end. Factory camber is approximately -0.9 degrees, but after you lower it there will be increased negative camber. I guess you could wait on installing the bolts until you install the springs and see where you land.

 

[LindsayEOD]

I talked with TJ, I think, from Steeda and he said that their relo brackets HAD to be welded in. That's the main reason I didn't go with them. It's a really nice list of mods Adam. Make sure you post up pics of your progress.

 

[cloud9]

I talked with TJ, I think, from Steeda and he said that their relo brackets HAD to be welded in. That's the main reason I didn't go with them. It's a really nice list of mods Adam. Make sure you post up pics of your progress.

Interesting. The FRPP brackets can be bolted.

 

[LindsayEOD]

Interesting. The FRPP brackets can be bolted.

Yep. The BMR, Whiteline, and FRPP can all be bolted. I'm sure there are more, those are just the ones I looked at.

 

[Grant 302]

If you do lower the car this much, I think you would need to add the following too:
Better struts/shocks.
Lowering Ball Joints like Steeda X-11
Softer bump stops
Yes, I think you need the bumpsteer kit to go this low.

Regarding the cars balance...odds are you need an adjustable sway bar...not sure if that would be front or rear or both.

The steeda brackets must be welded.

My opinion is that it doesn't make sense to go that low on the rear. At 1" lower on with the P springs, I already don't like how little travel I have before I'm sitting on the (trimmed) bumpstops. If I were looking to go that low, I'd probably go with coilovers.

For the camber, if you want to run at -2 degrees, I doubt you would need both bolts and plates. You might be about there just by lowering the front that much. Just a guess, but I think it would land between -1.8 and -2.2.

 

[Sesshomurai]

I have similar setup. Running sportlines as well. All advice so far is spot on.

I will say this. When I went to a front stiffer sway bar and squared R compound tires (275's), I had some oversteer conditions (because of the added grip) that caused the TC/SC system to engage at high speed. Please don't forget to disable your traction and stability control completely or the stock ABS/ECM settings will think the car is going unstable (higher G's), when in fact, its not.
Otherwise, you will find slot-car like handling. Its great.

 

[Flyboygsxr]

If you do lower the car this much, I think you would need to add the following too:
Better struts/shocks.
Lowering Ball Joints like Steeda X-11
Softer bump stops
Yes, I think you need the bumpsteer kit to go this low.

Regarding the cars balance...odds are you need an adjustable sway bar...not sure if that would be front or rear or both.

The steeda brackets must be welded.

My opinion is that it doesn't make sense to go that low on the rear. At 1" lower on with the P springs, I already don't like how little travel I have before I'm sitting on the (trimmed) bumpstops. If I were looking to go that low, I'd probably go with coilovers.

For the camber, if you want to run at -2 degrees, I doubt you would need both bolts and plates. You might be about there just by lowering the front that much. Just a guess, but I think it would land between -1.8 and -2.2.

The Eibach Sportlines come with new shorter bump stops so I shouldn't have to do any trimming. I looked at the X-11 ball joint on Steeda's website. If anyone has used this product before and give feedback on it that would be nice. The springs will lower the front about 1.5" so I wasn't sure if these would be necessary or not? Seems like they would be a pretty easy install considering I'll already have the front end apart. I agree that I don't think I'll need the adjustable camber bolts with the camber plates and the car being lowered. Thanks for the reply

 

[Flyboygsxr]

I have similar setup. Running sportlines as well. All advice so far is spot on.

I will say this. When I went to a front stiffer sway bar and squared R compound tires (275's), I had some oversteer conditions (because of the added grip) that caused the TC/SC system to engage at high speed. Please don't forget to disable your traction and stability control completely or the stock ABS/ECM settings will think the car is going unstable (higher G's), when in fact, its not.
Otherwise, you will find slot-car like handling. Its great.

Can you tell me what other mods you have done to your car besides the sportlines? Did the sportlines upset the balance of the car or make the ride too harsh for the track? I want the car to be more firm than stock but I don't want the car to be upset too easily when going over bumps or rough spots on the track. I am curious if you have gone with new ball joints to correct the suspension geometry. Here is an interesting article from steeda regarding suspension geometry and the need for the extended ball joints when you have a lowered car:

http://www.steedablog.com/2010/05/steeda-balljoints-what-your-lowered-stang-needs/

Not the exact ball joints I was looking at but interesting.

 

[Sesshomurai]

I looked at the X-11 ball joint on Steeda's website. If anyone has used this product before and give feedback on it that would be nice. The springs will lower the front about 1.5" so I wasn't sure if these would be necessary or not? Seems like they would be a pretty easy install considering I'll already have the front end apart. I agree that I don't think I'll need the adjustable camber bolts with the camber plates and the car being lowered. Thanks for the reply

I'm having the Steeda bumpsteer and ball joints installed tomorrow. Will let you know.

 

[Flyboygsxr]

I'm having the Steeda bumpsteer and ball joints installed tomorrow. Will let you know.

Great, I look forward to hearing your feedback. Have you had the car on the track without the extended ball joints and bumpsteer kit?

 

[Sesshomurai]

Great, I look forward to hearing your feedback. Have you had the car on the track without the extended ball joints and bumpsteer kit?

Yes. Many times. The mods I've made (in this area) during the track season improved the handling dramatically.
I expect the bumpsteer and ball joints to (among other things) correct the slight oversteer condition (on uneven curved stretch of road) that is confusing the traction control system at very high speeds - even though i disable it.

 

[VTBoss302]

Yes. Many times. The mods I've made (in this area) during the track season improved the handling dramatically.
I expect the bumpsteer and ball joints to (among other things) correct the slight oversteer condition (on uneven curved stretch of road) that is confusing the traction control system at very high speeds - even though i disable it.

IIRC, the FR ABS module should completely disable the AdvanceTrac.

 

[cp85gt]

I am also looking to try the Eibach Sportlines along with a set of Koni Sports. Does anyone have an update on using extended balljoints? After reading over the Vorshlag 2011 GT build on another forum, it does not appear that they have tried these, although it was a long thread and I could have missed it. I am wondering if the extended balljoints are more useful for a street car build that will use lower rate springs, as compared to the higher rates found in an adjustable coilover, to provide more wheel rate without compromising ride quality. Also, I have read some feedback stating either breakage or premature wear.

 

[Sesshomurai]

I am also looking to try the Eibach Sportlines along with a set of Koni Sports. Does anyone have an update on using extended balljoints? After reading over the Vorshlag 2011 GT build on another forum, it does not appear that they have tried these, although it was a long thread and I could have missed it. I am wondering if the extended balljoints are more useful for a street car build that will use lower rate springs, as compared to the higher rates found in an adjustable coilover, to provide more wheel rate without compromising ride quality. Also, I have read some feedback stating either breakage or premature wear.

I have the sportlines and recently added the steeda bumpsteer and ball joints, but haven't been on the track yet with the bumpsteer/balljoints yet. The sportlines drop the car quite a bit and reduces the center of gravity. Improves handling quite a bit IMO but other parts should accompany the drop (e.g. adj rear LCA's, bumpsteer, adj upper rear control arm). My next suspension leap will be to ohlins dampers front/rear. the springs are just for now.

PS. I run front dampers at 5, rears at 4, but with my lowered and square wheel/tire setup I might change the rear to 5 as well.

 

[cp85gt]

So you still have the original tokiko's with the sportlines and you have tracked the car with r comps? I would think that the tokiko's would be a bit underdamped for all but regular street driving. I'm wondering with just an upgrade to a Michelin PSS would the Koni sports be a must do upgrade with the sportlines. I'm curious to hear how the tokiko's have done for you at the track. With the extended balljoints I've heard that you can feel the difference just with around town driving. Do you have any initial driving impressions?

 

[Sesshomurai]

So you still have the original tokiko's with the sportlines and you have tracked the car with r comps? I would think that the tokiko's would be a bit underdamped for all but regular street driving. I'm wondering with just an upgrade to a Michelin PSS would the Koni sports be a must do upgrade with the sportlines. I'm curious to hear how the tokiko's have done for you at the track. With the extended balljoints I've heard that you can feel the difference just with around town driving. Do you have any initial driving impressions?

Yes, the stock dampers are underdamped for serious track use. A double adj damper setup is minimum for that IMO.

But with all the suspension improvements I've made (and there are many), the car is very precise now with no noticeable tail wag on braking, noise dive, understeer, body roll, etc.

BUT, the stock dampers do get upset a bit on regulation (candy striped) taller curbing (for me) unless you are going in a straight line. I surmise this is due to the lack of a rebound damper setting coupled with my tighter chassis (rollbar, sway bars, etc) -- so for now, I stay away from high speed articulated curb usage (outside curbs are simply out of the question). YMMV.

 

[cp85gt]

Are you saying that since the tokiko's adjust both compression and rebound at the same time that your car becomes disproportionately unsettled with an abrupt suspension change like running up on a curb?

 

[Sesshomurai]

Are you saying that since the tokiko's adjust both compression and rebound at the same time that your car becomes disproportionately unsettled with an abrupt suspension change like running up on a curb?

My car does under certain circumstances. What I want to do is experiment with slightly lower compression and higher rebound settings. My thought is that when taking a curb at high speed I want the damper to absorb most of that shock by compressing more slowly but rebound quickly to get the tire back on the ground for the next sharp turn. Mainly I use the rising esses at VIR (120+mph left/right/left/right) as my standard for performance in this area. Still sorta new at this though.

 

[zzyzx]

Here's what I consider to be a helpful example of how different parameters affect geometry for a strut based suspension:

http://zzyzxmotorsports.com/library/strut-tech-20070918.pdf

I'll simply add that irrespective of your target camber of -2.0, you should set your top camber plate to full negative (inboard). That will likely yield something > -2.0 in your case, so the bolts are not necessary. In fact, I'd advise against them unless you have an explicit need.

If you have any questions about the link I posted, let me know. Though at this point I take the concepts in there for granted, I realize that they are still in the "black art" realm for many.