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Lowering the Air Splitter

I am working to lower my splitter in an effort to reduce some understeer I am experiencing in a high speed corner.

I have started the process of making 1/2" shims and am 90% there. I have digitized the shape needed so on a CNC router I can cut expanded PVC to the proper size. I have ordered longer turnbuckles from ARP, although the are silver and expensive at $95 per set. Just need to find some longer mounting bolts and I am good to go. Hoping to get the PVC cut next week. My thought with the 1/2" shim is that I can add layers, trying the one layer than adding another to get to 1" if need be. 1.5" seems like way too much and too risky if I do any 4 wheeling. Curious if anyone else has lowered theirs and what you have learned?? I might be able to cut shims for others if someone is interested. Once I get mine cut, I will take some pics of all the parts.
 
Keep us posted on your progress on this. Most, if not all, of the spacers I've seen have been 1" and that's the size it was suggested to me to use.
 

PeteInCT

#LS-378 - So many Porsche's, so little time....
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John - you may want to look at reducing under steer in other ways. Mine was the stock height and it took my bumper clear off by a simple 2 off. My 285's up front with 35mm offset have no under steer. Look to your suspension and tires for the answer... IMHO

-Petr
 
PeteInCT said:
John - you may want to look at reducing under steer in other ways. Mine was the stock height and it took my bumper clear off by a simple 2 off. My 285's up front with 35mm offset have no under steer. Look to your suspension and tires for the answer... IMHO

-Petr

Pete - What occurred to u keeps running through my mind, especially as did a 4 off last week. I am running the same tires as u. My wing is doing what it should and giving me great rear traction, and what was oversteer before the wing is now under steer at a higher speed. That is also why I am thinking to try lowering the wing by just a 1/2" to see if that helps, yet have more forgiveness when I am off roading.
 
I have a pic showing the result of PeteInCT's two-wheeled travels and can attempt to upload provided that's cool with PeteInCT

Some things are NSFW...
 
If you want to go faster you'll have to pay for it one way or another. I know of three people that have ripped off their front clips and all had the 2012 LS splitter. The WC splitter doesn't stick out as far and I doubt the LS splitter gains much by sticking out farther. When you replace those 2012 LS splitters I'd buy the WC version. Another ripped off his 2013 LS splitter, which doesn't stick out nearly as far as the 2012, but he was backing off his trailer and it got caught on the trailer.
 

PeteInCT

#LS-378 - So many Porsche's, so little time....
Moderator
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Connecticut
VTBoss302 said:
I have a pic showing the result of PeteInCT's two-wheeled travels and can attempt to upload provided that's cool with PeteInCT

Some things are NSFW...

OK with me
 
NFSBOSS said:
If you want to go faster you'll have to pay for it one way or another. I know of three people that have ripped off their front clips and all had the 2012 LS splitter. The WC splitter doesn't stick out as far and I doubt the LS splitter gains much by sticking out farther. When you replace those 2012 LS splitters I'd buy the WC version. Another ripped off his 2013 LS splitter, which doesn't stick out nearly as far as the 2012, but he was backing off his trailer and it got caught on the trailer.
So far so good and I've mowed my fair share of alfalfa with it ;)
 
Drew - Once I have one cut and know how that worked, I will try to figure out a cost to do more of them. I am making the shim in 2 pieces to get better sheet yield and it will also be easier to cut. Another plus is it will cost less to ship as the size is then less than 36" each.
 
LS110 said:
Just after the apex of T2 at BIR with full throttle at about 115 to 125.

Have you tried adding some front rebound? It would be beneficial to do that as well as reduce the rear bump if you have double adjustable shocks. Also if you have too much toe out you might lose some grip in long sweepers from tire scrub. Not to say the spacers and additional downforce won't help, but often times there is more than one way to skin a cat. If you can set up the suspension right with less downforce, once you add more it will be that much better. Have you taken into account the stiffer spring rates that may be needed up front with additional downforce?
 
That is a good point about adjusting the suspension to counter the understeer. I have SVT adjustable dampers so I can play around with this some, although I do not have coil overs.

I also have 3.1 degrees of negative camber, and no toe adjustment. If I understand this correctly, given T2 is a right hand turn, the camber should be working in my favor as to the arc the tire will want to take due to the camber.
 
LS110 said:
That is a good point about adjusting the suspension to counter the understeer. I have SVT adjustable dampers so I can play around with this some, although I do not have coil overs.

I also have 3.1 degrees of negative camber, and no toe adjustment. If I understand this correctly, given T2 is a right hand turn, the camber should be working in my favor as to the arc the tire will want to take due to the camber.

Have you been taking temperature and pressure readings in the middle of your session? Its hard to know exactly what the car is doing in a particular turn without real time telemetry, but lets say that the inside tire is fully loading in the turn gaining almost all 3 degrees of positive camber so it is completely flat. The outside tire is going to gain even more negative and the inside edge is going to get really hot. You could be losing grip completely on the outside tire and that causes it to push a little. If thats the case, some stiffer springs or stiffer roll bar settings would help so that the car doesn't load up the inside tire quite so much. This may just be enough to have the outside tire not gain so much negative camber and the temps to be more even across the tire. It would be helpful to see some pics of the car in turn 2 to see just what your suspension is doing.

In any case, adding more front rebound should help. Making the car unload slower at track out would keep the car on the inside tire with more grip for longer.

Some other things you can do to combat understeer is lower the front tire pressure and raise the rear. Just by a little, maybe half a psi if possible.
 

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