Hey guys, I just got the car back from the dealer after asking them to lower the vehicle on the OEM adjustable coilovers, and I noticed something odd on the alignment sheet. They are report a pretty big difference in SAI [Steering Angle Inclination] on the Front Left and Front Right. When I asked about it, the service manager [brand new to Ferrari] said this was normal and that Ferrari may have done this to compensate for crowning in roads (seems odd to me). I didn't think much of it, but did some searching after I got home, and most things regarding SAI point back to suspension damage. It's a brand new Pista, so I haven't even revved it over 5k, let alone really driven it much. Have you heard of this before on 458s or 488s? There's hardly any alignment data on FChat in general, so I'm hoping I could get some help here. Alignment sheet attached. Image Unavailable, Please Login
This is interesting. I don't know the answer and don't know anything specific about 458/488 suspension geometry, but I will make an observation. It seems to start with the "Included Angle". Notice that the SAI = Included Angle - Camber. It seems that the included angle is built into the design of the spindle. I have no idea why this would be different left to right. I do not buy the road crown explanation, especially on a track oriented car. Caster is sometimes set asymmetrically to compensate for road crown. If it was a road crown thing, then right hand drive cars would use different front spindles, and I am guessing that is not the case.
Rather then me trying to type it out..I did a quick google search. This is it in a nut shell. I'll run your numbers and see what we get..but you do present an interesting issue.. Steering Axis Inclination' is the angle in degrees between the 'steering axis' and vertical. Steering axis inclination (SAI) causes both front wheels to gain positive camber as they steer away from center. This acts with caster to provide self-centering of the front wheels.
I don't think that the question here is what SAI is, but why Ferrari would build a different included angle, and therefore different SAI in the left and right side?
I just had a 488 (not a pista tho) on the rack. I'll see if I can print out the readings. Hopefully it hasn't been over written.. those numbers are indeed strange..
@tbakowsky It would be awesome to get those numbers tomorrow if possible? Also, it would be super helpful to cross-check the OEM specs provided to me by the dealer. Not sure if those are default 458/488 values or if those are in fact Pista alignment specs. Thanks guys, I've been a bit down about this one mostly because of the concern if the SAI is in fact that far off, all Google searches and offline discussion I've had point to something up with the suspension [something bent]. If that was true, it could have indicated something may have happened with the car before I received it -- my first truly specced from the ground up VS Ferrari So, rather than sulk, I took the car to a good friend who has spent quite a number of years working on cars I've owned in the past. He also so happens to do a huge volume of BMWs and Porsches through his shop, so track cars are his bread and butter. He threw the car on the rack, and got some pretty different numbers. I've included them below. The good news is that it looks like the dealership made a serious error in the alignment measurement. I also feel like it was fairly disappointing and concerning for the new [to Ferrari] service manager to tell me he thinks the SAI difference may be due to Ferrari "tuning the car for crowning on US roads" rather than really looking at the numbers again. Image Unavailable, Please Login
This makes much more sense. If we trust your friend more, then either the dealer's alignment rack is out of calibration or the technician is not operating it properly. As I mentioned, I am not an expert in Ferrari suspension, but this forum is called Ferrari"chat", so I guess I can chat anyway. I think that your alignment looks good if you will be cornering hard. If it feels good, the only thing I might do is bring the toe in a little (front and rear). If you corner hard, the extra negative camber is probably good. If you baby your Pista (we hope not), then maybe make the camber less negative front and rear to keep the tire wear even. The extra positive caster will just make it self center a little more. The extra positive on the left will compensate for road crown some.
I tried to go back through the alignment machine and print off the numbers for the 488 we did a few months ago, but it has been over written. Sorry. I'll see if I can get a copy of the print out from the customer..
