Stiffer rear sway on 996 GT-3?
10-07-2012, 02:47 PM
#16
Hey was talking with a knowledgeable guy today about the understeer in the 6-GT3 .He suggested going to a stiffer rear sway bar..I have recently installed The Goldcrest Front splitter and increased rake to the rear both of which have helped.
Has anyone gone to a stiffer rear sway and what's the verdict.It certainly seems like it would help but I would think fixing the end that isn't 't working right might be better.I am running the Motion Control double remotes and springs are 850F 1000R Thanks in advance HOM
Has anyone gone to a stiffer rear sway and what's the verdict.It certainly seems like it would help but I would think fixing the end that isn't 't working right might be better.I am running the Motion Control double remotes and springs are 850F 1000R Thanks in advance HOM
Good summary and discussion of setup changes here to reduce/increase understreet/oversteer
here: https://rennlist.com/forums/997-gt2-...eer-101-a.html
High speed corner exit balance I'd think aero balance as mentioned.
10-07-2012, 02:58 PM
#17
Racer
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Agree with everything Andy says.
I have a bit of the same issue, but "a push is always better than over-rotation" according to drivers a lot better than me, and I agree. You can always lift a touch to help keep it on track.
I feel it at the exit of high speed corners (T2 Mosport), and have to nail the line, or adjust it a bit to get a good track out.
Last year, my first in the GT3, I thought that the car pushed 'a lot', but now not so much. The rad was already tilted and had the top bumper openings, but I only closed the bottom vents this year. The car now feels a bit more planted at top speeds, but it could be in my head, as I get more comfy.
Early in the year, I tried the 8 degree shims for a few laps, and felt that the car pushed a bit more, so went back to the 4's.
I am surprised that your bars are full soft all around, typo? Counter-intuitively, my bars are full stiff in front, and one from stiff in back => loose is fast. The setup was done by a GT3/Cup-only, race shop.
I assume that you meant stiffer rear setting, as opposed to replacing the bar itself since you are at full soft currently and could simply adjust.
Maybe all we need is wider rubber in the front...
I have a bit of the same issue, but "a push is always better than over-rotation" according to drivers a lot better than me, and I agree. You can always lift a touch to help keep it on track.
I feel it at the exit of high speed corners (T2 Mosport), and have to nail the line, or adjust it a bit to get a good track out.
Last year, my first in the GT3, I thought that the car pushed 'a lot', but now not so much. The rad was already tilted and had the top bumper openings, but I only closed the bottom vents this year. The car now feels a bit more planted at top speeds, but it could be in my head, as I get more comfy.
Early in the year, I tried the 8 degree shims for a few laps, and felt that the car pushed a bit more, so went back to the 4's.
I am surprised that your bars are full soft all around, typo? Counter-intuitively, my bars are full stiff in front, and one from stiff in back => loose is fast. The setup was done by a GT3/Cup-only, race shop.
I assume that you meant stiffer rear setting, as opposed to replacing the bar itself since you are at full soft currently and could simply adjust.
Maybe all we need is wider rubber in the front...
Francois,
Just checked my bar setups, and I'm full stiff on front and 1 off full soft on the rear (hole 2 out of 4). I thought we had the same set up, but maybe we have different rear bars since I broke mine last year. Anyways, virtually no push in low or high speed corners, so set up is almost perfect for my driving. Don't disagree re more rubber though, front and rear.
Steve
10-07-2012, 10:55 PM
#19
Nordschleife Master
We all need more wing, and Steve, I now understand why you got the cup wing.
A pro drove my car at Road Atlanta last week. We were flat coming down T12 (similar to T4 Mosport, but leading to the front straight), and the back end broke loose at the bottom. He kept it on the track, and a few seconds later turned to me calmly and said "needs a little more wing, hahaha". So now I get it.
HOM, I understand your comment about why anyone would need more wing, but you want to make sure that the big lump stays back there.
In your comments, you talk about adding "clicks", I assume that you mean moving the drop link bolt in one direction or the other...? Otherwise, we are not talking about the same thing.
Steve, I just checked to be sure, and yes, I am one hole from full stiff in the back. This is the second hole when counting from the body of the bar. Or if you prefer, the third hole from the tip.
I find my car very well balanced, and no longer feel that it pushes (I must have learned to manage the weight transfer better), unless I am really cooking it at the exit of a fast turn... but that could be because I apexed too early...?
A pro drove my car at Road Atlanta last week. We were flat coming down T12 (similar to T4 Mosport, but leading to the front straight), and the back end broke loose at the bottom. He kept it on the track, and a few seconds later turned to me calmly and said "needs a little more wing, hahaha". So now I get it.
HOM, I understand your comment about why anyone would need more wing, but you want to make sure that the big lump stays back there.
In your comments, you talk about adding "clicks", I assume that you mean moving the drop link bolt in one direction or the other...? Otherwise, we are not talking about the same thing.
Steve, I just checked to be sure, and yes, I am one hole from full stiff in the back. This is the second hole when counting from the body of the bar. Or if you prefer, the third hole from the tip.
I find my car very well balanced, and no longer feel that it pushes (I must have learned to manage the weight transfer better), unless I am really cooking it at the exit of a fast turn... but that could be because I apexed too early...?
10-08-2012, 07:54 AM
#20
Rennlist Member
Thread Starter
Everyone thanks for such great ideas!does anyone know the relationship between aero and sway bar?I understand that the sways only do their work in turns so when they start to function they ,I assume,would be interacting with aero but how do you tune them together?
I often hear comments from other 6-GT3 drivers (with large rear aero)about how planted the rear is .I run extensively at VIR the section where I get the high speed push is the up hill Esses .My best section times through there always comes when the front is biting best never feel that the car is loose there at all.With the current set up I have the sways full soft F&R and actually am also towards the soft side on the MCS remotes.The car rotates beautifully when asked but the only time it feels "loose"is slower speed corner exit.Should I try increasing settings on the remotes commensurate with increasing sway stiffness?TIA HOM
I often hear comments from other 6-GT3 drivers (with large rear aero)about how planted the rear is .I run extensively at VIR the section where I get the high speed push is the up hill Esses .My best section times through there always comes when the front is biting best never feel that the car is loose there at all.With the current set up I have the sways full soft F&R and actually am also towards the soft side on the MCS remotes.The car rotates beautifully when asked but the only time it feels "loose"is slower speed corner exit.Should I try increasing settings on the remotes commensurate with increasing sway stiffness?TIA HOM
10-08-2012, 07:11 PM
#21
HOM, I'm relatively new to suspension setup as I put in JRZ adjustables this past winter. The approach I've taken was setting the sways at full stiff front and full soft rear to start. Then I concentrated on the shock settings. First to dial out drama during braking, then corner balance. I started that process by starting at the mid settings both bump/compression and rebound. Refer to the link I posted earlier for specific shock adjustements for these situations. Once I got comfortable with the shocks I then started making changes to the sways. I was getting way too much push in turns like 5a at VIR, so I increase stiffness in the rear to one off full stiff. That made a huge difference. Now the car feels like it can just carve through turns like that and is very stable through the uphill esses there. Since then I've only been making one adjustment depending on which type of track I'm at. If I'm at a track like NJMP I add more rear sway stiffness and If I'm at a track like the Glen I soften up the rear bar to dampen the weight shift in the rear through T3.
Hope this helps.
Hope this helps.
10-09-2012, 01:35 AM
#22
Nordschleife Master
These cars are all about the weight transfer.
Good luck.
10-09-2012, 01:59 AM
#23
Rennlist Member
The point of downforce is keep car planted on all 4 corners ie aero. Any other suspension modifications/alignment is personal preference. Guys who like understeer and guys who like oversteer have similar laptimes(but Im biased -oversteer is faster but understeer is predictable lap after lap). Pick your poison. But if goofball decides to put toe out on rear on a rear engine rwd layout time to change goofball. Mike
