348 Spin Out

Early 348s were faulted for having "twitchy" rears ends, which was corrected in the 1991 time frame. Duh...I can't remember exactly what the fix is, but I had it on my 348 and it controlled the twitch to the point where could turn it on or off.

 

yeah, mine breaks loose fairly easily!

 

Widening the rear track with spacers seemed to help tremendously on mine, although my driving "limits" may be way less than yours. Ha-ha!

 

I have spun mine before, but I was pushing it, and I lifted. Now I know better. Don't push to hard and don't lift. The early 348's had this problem. It is due to the rear offset of the rims. The rims on the earlier cars the rear track was too narrow. What they did was add more material to the inside of the mounting area of the rim. As a result the rim sat out a bit further, widening the rear track. Also when you lift on the throttle the weight gets transferd from the back to the front. This causes the weight pushing the rear tires on the ground to be less, and since the weight shifts quickly towards the front the rear end snaps around. On a track you can control this with the throttle, but it takes practice. A few solutions.
1) don't drive it so hard (yeah right)
2) Get spacers
3) get the later year 348 rear rims
4) get a set of 355 rims
5) go to a track and learn to drive it on the limit

 

Shan - I'm in the market for spacers, but I'm having trouble deciding what size is most appropriate for a 1990 348ts. What size did you use front & rear? From Hill Engineering, I assume? Any pics would be most appreciated.

-Daniel

 

Daniel - I went with 15mm front / 25mm rear from Hill Engineering. They are great quality, well priced, and make the car's stance appear just right. Best of all they improved the handling noticeably. Hard to post a pic of the wheels in place as my engine's out right now. Will do so when I get everything back together if you're interested.

Shan

 

IMHO some of the posts here are wrong. 1st remember you car is old and many people have touched it before. 2) the old twichy 348 issues are not problems with the rear end. In fact the car was just set-up too hot for the average streeter to handle. So there were shock revalving fixes that solved the high speed twitch which was really very agressive steering response. If you sneezed you were in the next lane. Not good for American on cellphone drinking coffee. 3) the sub assembly was changed move an a-arm attachment point to improve handling "technically". Some really good race drivers said they could feel the difference...I certainly cannot. I have the old subassembly. I'm not bragging and I am not a good driver but I'll go wheel to wheel with any 348 Ferrari with my old beater 348. 4) worn shocks, and worn bushings, on the first Ferrari to put Ferrari back into the gentleman racer days, makes for squirly handling. My 91 handled like a pig until shock spring and bushings were upgraded. Now it is a different car and I am totally neutral steering and I can choose when to oversteer. 5) many of these cars have been improperly lowered and the chassis rake improper making for oversteer/push conditions.

I have the most agressive 348 set-up I can do with full Pirelli slicks which can magnify suspension problems. I drive the track only and have solid delrin bushings, challenge suspension setting, revalved shocks and springs and huge brake ducts. Let me tell you this car handles and yours can too. Additionally, when the suspension is right you can threshold brake this car all day long with confidence in a straight line with no pitching. If you want to make your car handle better start with the basics and make sure you shocks are good and bushings are good and the alignment/chassis rake is good, and a corner weight balance is an easy luxury to afford too. Then let us know if you have a smile on your face.

 

Of these only 5 is correct.

384s and 355s has two suspension issues that a driver should become aware: 1) if the front end is too low, there is instability under braking and at the moment of steering input; 2) the rear end is setup so that after you start to add power while turning you are NOT ALLOWED to remove power.

1) When the front end is too low (on stock springs and shocks) the front tires have more grip until the car gets fairly large cornering loads transfered to the outside tires. This gives the car quick turn in, and can cause spins under brakes or non-judicious use of the steering wheel.

2) At the rear, the ride height can be used to adjust the oversteer/understeer relationship. When the rear end is too high OR the rear tires have too small a rolling radius oversteer is the result. These cars have adjustible spring perches, if you are having a handling problem that takes more than 2 PSI of tire pressure change to balance it out, then get the car aligned with a set of scales (corner weighting) AFTER adjusting the ride heights back to factory specs. Afteer this, you can dial in the oversteer/understeer relationship you want with 1 or 2 turns of the spring perch collars; UP give oversteer, down gives understeer.

I basically agree with fatbillybob on the rest of his comments.

Spacers only help if you car is pretty close to being set up correctly, and if it is setup correctly, spacers do not add very much gains in handling but compensate for not being spot on in the setup.

 

Turbo, you have any pics of your car you could post? Forgive me if you have before, especially the engine, your avatar looks so awesome I would like a better look. Thanks

 

This is interesting. Mine handles awesome: not squirerrely under hard braking, turns in faster than anything else I have ever driven, responds very well to throttle inputs during cornering.

I have never completely lifted during a corner...seems like a silly thing to do...but by lifting just a fraction or applying throttle the car goes where you want it to. IMO a well set up 348 is a Blast, and very involving to drive. A lot more to take care of than just the steering wheel.

Vincent.

 

Nice bit of info Mitch. But come one, you gotta admit that 3 and 4 can help. Not as much as setting the car up right then learning the limits, but they do help.