When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I'll be having a new set of tires installed in a few months on my 2013 Grand Sport.
At that time, I'd like to have the factory alignment modified to PFADT specs, which I understand is the way to go for best tire life.
This car is not raced straight line, or track. Just normal street driving.
As you can see, PFADT offers 6 different sets of alignment specs.
It would seem that I'd want the one indicated in the image below.
Since I know very little about wheel alignment specifications, I thought I glean some opinions from those who do.
Does the "Performance Street" offer the best specs for my needs, or should I consider something different?
First question; are you happy with your current tire wear?
Second; have you looked at the OEM alignment specs for your GS? I think you might be surprised to see that they are very close (like the same) as the Phadt specs you are looking at.
Now if you are seeing tire wear on the front inside edge, consider going with these specs. I have 47K on my GS using this set-up and all 4 tires are wearing perfectly flat. I don't track my car but I do enjoy a spirited drive on a crooked road every now and again.
I drive approx. 20% in heavy traffic, about 20% in moderate to light traffic, about 20% very light traffic open road around 45-50 mph, and about 40% highway driving at 65 to 75 mph.
Approx. 75% of my driving is "normal", no different than any other car.
About 25% is "spirited", occasionally the rear tires will break loose, but never smoke.
That's the best description I can give you, I hope that helps???
Originally Posted by hisvett
First question; are you happy with your current tire wear?
Second; have you looked at the OEM alignment specs for your GS? I think you might be surprised to see that they are very close (like the same) as the Phadt specs you are looking at.
Now if you are seeing tire wear on the front inside edge, consider going with these specs. I have 47K on my GS using this set-up and all 4 tires are wearing perfectly flat. I don't track my car but I do enjoy a spirited drive on a crooked road every now and again.
First question....the fronts are wearing evenly.
The rears are wearing noticeably more on the outside edges.
It looks like when the outside 4" to 5" of the rear tires are bald, the inside 5" will still have about 2/32" to 3/32" of tread.
Second,....no I have not looked at the O.E.M. specs, and yes I am surprised.
Why then does everyone talk about the PFADT Performance Street alignment, as though it was the Holy Grail of alignments, and provides for better wear?
[QUOTE=
First question....the fronts are wearing evenly.
The rears are wearing noticeably more on the outside edges.
It looks like when the outside 4" to 5" of the rear tires are bald, the inside 5" will still have about 2/32" to 3/32" of tread.
Second,....no I have not looked at the O.E.M. specs, and yes I am surprised.
Why then does everyone talk about the PFADT Performance Street alignment, as though it was the Holy Grail of alignments, and provides for better wear?
Again, thanks to all who've contributed advice.[/QUOTE]
It sounds like your front alignment is OK for the "Brand/Type" of tire and your driving habits. The rears wearing on the outside would tend to tell me that they are "Toe'd" in too much but only an alignment printout will tell you for sure.
As far as the "PFADT" following; I see it as a lack of education
For myself, after many years of playing with performance street and race cars, I have found for my GS and my EZ "Street" driving habits that a max of -.5 Camber works best on the fronts along with 1/16" toe in. I would also go with the Firestone "Lifetime" alignment; pay one price and take your car back every 6 months (if you like) for an adjustment.
It sounds like your front alignment is OK for the "Brand/Type" of tire and your driving habits. The rears wearing on the outside would tend to tell me that they are "Toe'd" in too much but only an alignment printout will tell you for sure.
As far as the "PFADT" following; I see it as a lack of education
For myself, after many years of playing with performance street and race cars, I have found for my GS and my EZ "Street" driving habits that a max of -.5 Camber works best on the fronts along with 1/16" toe in. I would also go with the Firestone "Lifetime" alignment; pay one price and take your car back every 6 months (if you like) for an adjustment.
Good luck
Thank you....I will most certainly take into consideration all of your comments!
The Pfadt street alignment, from what I have read, is essentially the OEM alignment with considerably tightened tolerances. My car came from the factory with decent front and terrible rear alignment.
For street driving, as long as you're pretty close to the center of either set of specs, either will be sufficient.
I'm running the Pfadt street alignment, because I wanted to be sure that the specs were where they needed to be, and not just "close enough". I've experienced perfectly flat tire wear, which impresses me as the current set of PSS tires have seen 3 or 4 track days.
I've got around 18000 on them now, probably have another 2 or 3k left in them. Only got 11 or 12 out of the stock tires. I drive the hell out of my car (like, I've got 30k on it and will be putting on my 4th set of brake pads and 2nd set of rotors next week), so I'm confident that this alignment will be sufficient for anyone who's on track less than once a month.
Apparently my and the wife's driving style, which I think are different, must suit our vehicles well. None of our vehicles have ever had an alignment, nor worn tires abnormally in the last 20 years. The least mileage was 60K and the most 130K. I check tread depth about every 5-10K miles and have never found 1/32 difference inside to outside. If there ever is any problem, I want to catch and correct it before I kill tires.
However, prior vehicles have needed alignments and our method has been to take the car/truck to the alignment shop prior to buying new tires, so the tech understands exactly what was needed. Then doing any needed repairs (shocks, bushings, bearings, etc) and returning about 100-200 miles after the new tires were installed. A good tech knows more about what's needed for your car than any arbitrary numbers provided by the factory or other source.
If you want the least amount of tire wear on the street you can go with the Pfadt street recommendations. However, they are nothing more than refinements of the overall GM settings.
The FE4 suspension settings are for the Z06 and the FE5 settings are for the ZR1. I believe the GS has an FE3 (Z51) suspension, however, it could be an FE4. Your RPO Codes in the Glove Compartment will tell you which suspension you have. Basically, an alignment machine operator can get a green reading on a Z06 if the front camber is somewhere between -.4 degrees to -1.6 degrees (that is variance of 1.2 degrees that is permitted). Pfadt just selected narrower ranges of settings for desired outcomes.
When I purchased my 08 Z back in 09 I noticed the rear tires were worn out on the outside (corded) and I quickly found out the replacements wore the same way. Then I started looking at other Zs and noticed the same wear pattern even though there was a fair amount of negative camber in the rear. To reduce that wear you need to be very close to 0 toe in. You don't want toe out in the rear because it can reduce the car's stability but you need to be very close to 0 toe to reduce the wear pattern.
Bill
Last edited by Bill Dearborn; 05-04-2015 at 05:32 PM.
04-25-2015, 10:14 AM
Anyone here familiar with PFADT alignments?
