Hey all, I have some questions about the differences the way these cars are set up. People talk about these cars essentially having the same suspension geometry. I’m finding when I do the math from the wsm the 348 ride height is atleast 1/2” higher than the 355. My rear wishbone forks angle up, so I think they were swapped to 355’s. The wsm shows they angle up but all the pics and discussion it seems the stock ones go straight out. What I’m finding here is if I am to apply the ride height/rake numbers using the stock forks, the car will have old hot rod/stink bug like rake..? As I said above the specs are approx 15mm difference between 355 and 348, but if u take into account the different fork geometries, that raises the rear another 1/2”, putting it almost 1” higher in the rear than a 355? Just curious if this seems correct. People discuss rake on here for chassis set up so I’m trying to get to the bottom of this. What would be very helpful on 348 is: Ground clearance in rear to the low part of the frame in front of the rear tire. Ground clearance in front to frame rail seam (lowest part) right behind the front wheel. All the numbers for 355 are posted but the rear sun frame are very different and based on these numbers I’m finding the 348 to be setup very different. Thanks for feedback! Sean
Here’s a pic of a spreadsheet I did with all the 348 numbers but in the rear I’m using the dimension of the offset 355 forks. The 348 straight forks would raise the measurement to the frame by just over 1/2”.. Image Unavailable, Please Login
I added some 355 data that I took from some other threads. 85-115mm has been recommended as 355 ride heights (track set up) measured to the frame rails and u can see at 115mm how different the 348 measures. These numbers are written in pencil at the bottom…and these numbers would yield much less rake than stock.. just trying to get my head around why the 348 would be so different.. Anyone have data on 348 challenge springs also? We’re they similar to 355? Thanks View attachment 5362661
Starting with the Specialé, the 348 gained what would become the F355 suspension. The upper rear control arm was lowered at the chassis side by about ½". The lower rear control arms remained the same. it is not.
Thanks for posting Mitch. I thought I had read in several posts that the lower control arm mount forks are different between the 348 and 355. They look different in the pics at superformance and maranello parts. They look like the control arm bolt is in line with the mount stud vs offset up about 1/2” on 355. I’m trying to get a baseline for where my setup is. If the forks are identical I guess the 348 ride height was set up higher in the rear than the 355 and the difference is just the spec in the manual. So I guess that’s where I should start (just a tad lower overall ride height) vs 355 challenge set up I dunno.. and like my spreadsheet shows the measurement to the two points on the frame is “about the same” to have the factory rake.. if I hadn’t seen or read about these different rear forks I guess there would be nothing to question. Image Unavailable, Please Login
Also measuring the difference in the heights of the mounting points on a control arm will let me know where I’m at with regards to rake. Been having a problem with understeer. I thought it was camber related but fixed that. If the rear forks are different between 348 and 355 I’m still 1/2” too low in the rear based on factory numbers.. so I can confirm that with the difference in the ride height mounting points on a control arm. I guess that’s why they’re there silly me .
