Since I do not know how to do this correctly I'll do the best I can. I installed 25 mm rear spacers and 15 mm front spacers. The front spacers require the use of longer wheels studs while the rears reuse the OEM wheel studs. I drove my 348 up on my low profile ramps I made years ago for my 308 replica. I have to drive on these ramps to get a jack under my 308 replica. I made them out of two 2 x 12's. Have used them many times. Excellent to have. I see I need them for my 348 also unless I buy one of those very low profile floor jacks. Using the special aluminum lug bolt socket slightly loosen all the lug bolts on this side of the car. Image Unavailable, Please Login
Where to jack? I searched all the old threads on how to jack up one side. My 348 does not have the plates in the area that some have posted. So using the pictures others have posted I looked in that area and found where 3 pieces of steel all come together. I decided to try that area. I used my floor jack and piece of wood. Worked! Both wheels come off the ramps at the same time. No steel appeared to bend. The area I used is just left of the phillips head screw. You can see some slight scuffs in the paint where the block of wood touched the steel. Off hand I do not know if I made the scuffs in the paint or if they were already there. I should have made a note of that but did not as I did this over a week ago. Image Unavailable, Please Login Image Unavailable, Please Login
Remove the front and rear wheel. The two small bolts/studs on the rear rotors need to be removed. On the front these can be left on. Image Unavailable, Please Login Image Unavailable, Please Login
For the front all you do is add the spacer and reinstall the wheel with the longer lug bolts. I waxed the lug bolts first. Image Unavailable, Please Login
For the rear you add the 25 mm spacer with the short lug bolts included with the spacers. I found the limited slip was enough to keep the axle from rotating when torqueing the bolts. I torqued them to about 80 foot pounds. Image Unavailable, Please Login
For the rear you reuse the OEM lug bolts. I had to look thru the 10 OEM lug bolts from this side of my 348 to find the best 5 to use on the rear. Some of my lug bolts had some chrome damage. I bought and used the special aluminum socket. I waxed the 5 good lug bolts I used first before reinstalling them in the rear rim. Tighten the lug bolts firmly with the wrench front and rear. After you drop the jack - torque all the lug bolts. I went to about 80 foot pounds. Image Unavailable, Please Login
No jack stands were used and no one got hurt or died. To be safe you should use jack stands. Was basically an easy install. The biggest concern was where to put the jack! Rodney Dickman 1990 348 TS
Good job, but the first thing I would do is remove your front spacers. You are now dsriving with a 10mm stagger. The whole intent for the 348 SS, Challenge and Spiders was to have a 25 mm stagger. No spacers were on the fronts. Try this and see the handling difference. It may look cool now, but my guess is that the car will perform better with only the rear spacers.
I think your guess is correct Vince!! In addition, I like the look of the front offset 'without' spacers! I have 15mm rear spacers only and it handles noticeably better than before !!
No doubt about it -- ideal performance is 25 in the back, 0 in the front. Before I got my Challenge wheels, I ran 25/15 on the street but pulled the 15's off when I had track days. On the street, my reasons were aesthetic. On the track, performance/stability was obviously the consideration. For me (any many other non-track folks), the 15 does visually make the front look much nicer and fuller. It's really just a question of how you're using the car.
on a 348, my understanding is that 355 rims are +10mm, so yes, adding a +15mm space gets you to the +25mm total. This is assuming 348s and 355s have the same track
Theoretically, we could get the boyz on Monster Garage to put 72mm spacers on it, but IMHO 15mm is about the limit for the F355.
If the stock "stagger" was correct, then wouldn't putting the same size front / rear spacers be the best?
Why, are the offsets different? Also, Does the 355 have the same track? Are you suggesting the same spacers for the 355?
No spacers on Challenge wheels. The mounting face of the wheel is sufficiently thick. These wheels appear to provide the effect of 25/15 spacers (with OEM rims)in terms of visually filling the wheel well, but to be honest, I have not measured. Because they are 18", they trick the eye a bit too. Image Unavailable, Please Login Image Unavailable, Please Login
