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Discussion Starter · #1 ·
Hey all - now my tune is settled, looking to add the X73 suspension! Before I walk into it, want to get everyone's opinion on the alignment specs I should go for and what the OEM ones are from factory.

Thanks!
 

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I've got -1.5deg F and -1.9 deg R, with, IIRC, 1/16 toe in the rear. with no wear issues. Zero toe in F.
Neutral handling, no wandering on Interstates and on twistees it turns right now.
 
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Those are good numbers from Mike. Doesn't matter what the factory spec is cause their settings will tend to make the car understeer for safety reasons. This is what works at about -1.5 in front and -2.0 in the rear for camber, with toe at 0.0 front and 10-12 minutes in for the rear. Many call this a "sports alignment" which gives the car great balance for more aggressive driving. Good for the street and the track.
 

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I'm also curious about factory X73 alignment specs. My car feels neutral now, and actually tend to get a bit of oversteer first, which is odd, since understeer is supposed to kick in first. But I have crappy F1s though. And front tires have a wider patch than they should for 235s, according to TireRack specs; maybe that's why.
 

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Those are good numbers from Mike. Doesn't matter what the factory spec is cause their settings will tend to make the car understeer for safety reasons. This is what works at about -1.5 in front and -2.0 in the rear for camber, with toe at 0.0 front and 10-12 minutes in for the rear. Many call this a "sports alignment" which gives the car great balance for more aggressive driving. Good for the street and the track.
Hi lovetoturn - where did you get this numbers from?
 

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Discussion Starter · #7 ·
I've got -1.5deg F and -1.9 deg R, with, IIRC, 1/16 toe in the rear. with no wear issues. Zero toe in F.
Neutral handling, no wandering on Interstates and on twistees it turns right now.
Those are good numbers from Mike. Doesn't matter what the factory spec is cause their settings will tend to make the car understeer for safety reasons. This is what works at about -1.5 in front and -2.0 in the rear for camber, with toe at 0.0 front and 10-12 minutes in for the rear. Many call this a "sports alignment" which gives the car great balance for more aggressive driving. Good for the street and the track.
Hey guys, should I get the alignment done with the spacers on or off?
 

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Discussion Starter · #9 ·
Guys, what is your CASTER setting? slightly forward? Let me know when you get a second.

I've got -1.5deg F and -1.9 deg R, with, IIRC, 1/16 toe in the rear. with no wear issues. Zero toe in F.
Neutral handling, no wandering on Interstates and on twistees it turns right now.
Those are good numbers from Mike. Doesn't matter what the factory spec is cause their settings will tend to make the car understeer for safety reasons. This is what works at about -1.5 in front and -2.0 in the rear for camber, with toe at 0.0 front and 10-12 minutes in for the rear. Many call this a "sports alignment" which gives the car great balance for more aggressive driving. Good for the street and the track.
 

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My caster is 8.8 and 8.95 degrees which is rite on the limit for the left and slightly over on the right side, but I have 13 mm of shim in the front LCAs which causes it to increase. This is fine for the track and weekend driving without any problems.


As per my alignment sheet the X73 specs are as follows where: (' =degrees) and (" = minutes)


Front: CAMBER @ -1'05" to -0'35" TOE @ -02" to -04" Caster @ 7'50" to 8'50"
Rear: CAMBER @ -2'05" to -1'35" TOE @ +03" to +13"


The front camber is too low and needs to be raised to be about (.5 degrees or 30") less than the rear and not the factory 1 degree. Porsche put that in to make the car safely understeer at the limit but an experienced driver can run the numbers that we have been talking about here.
 

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As per my alignment sheet the X73 specs are as follows where: (' =degrees) and (" = minutes)
Front: CAMBER @ -1'05" to -0'35" TOE @ -02" to -04" Caster @ 7'50" to 8'50"
Rear: CAMBER @ -2'05" to -1'35" TOE @ +03" to +13"
I'd like to see a Porsche document, just to be sure. Besides, those alignment specs should be listed like this: -0.70 +/- 0.35, -1.70 +/- 0.35, etc., with the middle number always the target. And yes, the front seems too conservative. Also worth knowing would be what are the alignment limits of the stock X73 suspension, but doubt even Porsche documentation would show that.
 

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That makes sense now. Struts don't have adjustable caster, and even though Porsche doesn't say our cars have struts all around, that's exactly what they have. Thx.
Exactly. And OEM GT3 LCA's only allow minimal caster adjustment (eccentric hole or middle hole, so either a lot of caster or near stock), but many track folks run solid thrust bushings which are fully adjustable via a sliding puck. Hence the very high caster on my car.
 

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It won't matter.
In theory it shouldn’t for some adjustments, but it does. The geometry is dynamic. Motorsports alignments are also done with hot tire pressure.

Here are my settings. I have the LCA and toe arms from Tarrett, and JRZ RS1 touring suspension.




Sent from my iPhone using Tapatalk
 

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My shop uses a different alignment machine with the following print out. Says X73 on it. Usually with X73 the max front camber is about -1.75 and I saw -2.25 in the rear after the springs were installed. A very aggressive alignment and the car handles great with RE-71Rs.

Text Font Receipt Document Paper
 

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Hey guys, not familiar reading these reports, anyone care to weigh in regarding the alignment specs I just got? Car is a 2014 981 BS w/ X73. First alignment since I got the car with 1200 miles on the clock, now has about 10k. Put new Pilot Sport 4S all around.

Thanks

 

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Santos, either that shop doesn't know what is doing, or you have suspension damage on your car. The front camber is basically zero on one wheel, and over 1 degree on the other; totally unacceptable. Didn't they tell you??? In addition, those specs don't sound right for any Porsche. Only 0.20º of base camber is for a freaking Buick, not a sports car. Manufacturers prefer understeer, but I don't see how you can have decent handling with anything less than at least half a degree, but more like 0.75 at the very least for an S. Take the car to a reputable shop with Porsche experience, in case you have suspension issues. Good luck.
 

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Santos, either that shop doesn't know what is doing, or you have suspension damage on your car. The front camber is basically zero on one wheel, and over 1 degree on the other; totally unacceptable. Didn't they tell you??? In addition, those specs don't sound right for any Porsche. Only 0.20º of base camber is for a freaking Buick, not a sports car. Manufacturers prefer understeer, but I don't see how you can have decent handling with anything less than at least half a degree, but more like 0.75 at the very least for an S. Take the car to a reputable shop with Porsche experience, in case you have suspension issues. Good luck.
Wow. I did find it odd that it seemed like it wasn’t even left to right and a lot of numbers in the red, but didn’t realize it was that bad. There isn’t any sign of damage to the suspension or wheels, that I am sure of. But this alignment is from my Porsche dealership in Los Angeles, if they aren’t qualified I’m not sure who is.
 

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Who ever did that alignment is incompetent. Like ELP_JC said the camber on the front is a joke. It was off by a mile and they basically left it that way. I also agree that the target numbers are just wrong. I would take it back to them with some copies of this and other threads and make them do it again to get it right. I would go back with a half tank of gas and have them do it with you in the car. It should take no more than 30 minutes to get this accomplished. You want the specs I listed in post #4.

I have the best mechanic in the region who specializes in motorsports, and this is where he would put it for you to take full advantage of the X73 suspension. If the tires wear a little to fast on the inside, back out a little camber in each the front and rear. Try to keep about .3 to .5 more negative camber in the rear to maintain good balance in the car.

If you want to get all of the suspension goodies and go overboard, then you can eventually shoot for something more like what I have now in post #16. This would only be for a modified car and an experienced driver who tracks the vehicle. The specs from post #16 are not for a daily driver street car.
 
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