My 348 still feels a little unstable over 110 mph. I've had the dampers refurbished, wheels balanced and aligned. - Running 15mm spacers front & 25mm spacers rear. - F355 wheels with pirelli PZero's Anything else I can try apart from fitting a front lip? (And no... I don't want to upgrade to a a 355 chaa!!!!)
Have ya had ya front and back ride hights measured Sy? Is the front measurment lower to that of the rear? I know you have had ya suspension rebuilt and played about with,but this may have been over looked. Put the car on a flat surface and measure the front of the sill and the rear of the sill. Having a higher rear can cause the car to feel unstable at speed.
Had the ride height lowered soon after the dampers were renewed. The rear is a slow as it can get, although still a little higher tha the front. according to the manual, the rear should be higher than the front. What I don't understand is that I can easily drive a Maserati Quatroport at up to 140 mph plus ( on a test track ) with no drama. Also a BMW 330 at over 120 mph. When I attempt it with the 348, I have to struggle to keep it straight. That can't be right???? I'll measure the heights now and post it up.
So the manual says that the front should be lower than the front!!! Whats that all about. I thought ferrari were supposed to be the masters of car handeling. The reason that a rear of a car is lower than the front is becourse of weight transfer, this means when you toe it the rear will squat for max tracksion and when ya brake the rear does not go light. I have always thought and read that a cars rear shold be some what lower than the front.I dont know why ferrari would say that the front should be lower than the front, would any one care to exsplain that one to me please. Suspension geometry is some what of a black art. Sy you cant just wind down the suspension mate they have to be mesured. With the propper front and rear measurments.
Have you had the alignment done??????? If not you need you take it to a shop and have them align the wheels. You may even want to have it corned weighed.
Just rememberd as well that if you lower the rear far to much compared with the front ride hight. This may bring on oversteer and also front end drift at high speed. Saying that are your shocks adjustable? Are they on the right settings front and rear or are they fixed?
I had the same problem with my 348, I think all of the these cars were like that something wrong with the factory suspension geometry. IIRC the factory settings on the toe were modified by the shop that aligned my car a few years back and it corrected the drifting quite a bit. I don't have the records anymore on the car since I sold it. Maybe there is someone here that can verify that that works, seems a little toe out is what they recommended and it worked. Regards, Vern
Looking at the 348 manual, I could be wrong as to the rear being higher than the front. The example given is: "To raise or ower the vehicle by 5mm, move the front washer 3.5mm and the rear washer 4.2mm". When I first got the car the rear was pitched quite high as seen in the pic below. I then asked the specialist (who raced 348's) to lower it. Their first attemp made the car look physically worse. The second attempt (as it is now) looks great, but crap at high speed. As stated earlier, the rear spacer is at the lowest position and can't go any lower. Below are the heights in centimetres. Front and rear heights were taken at the mid point of the bumper. Ernie, the wheels have been balanced and aligned. however, they were'nt done in accordance with the manual where they recommend a full fuel tank and 75KG sacks of sands. NOTE: That's an old pic before the car was lowered. Image Unavailable, Please Login
I've had mine 150+ and no problem whatsoever. Not sure if it will translate but I could give you the GTC toe/camber settings..?
the mesurment is taken fron the middle under sill only mate, not the wheel arch or bumpers. Sounds like it could well be the ride hights.I suspected this when you said that our shocks were being rebuilt and that your suspension was being played with. Take the car to have its ride hight geometry set up correctly mate. MB: Dude bring the car up to the middlands and i will set it up for ya Will involve lots of hard driving though but you can sit screaming next to me like ya did last year, but i will give ya whats left after i ride that horny MoFo PPS: Hey speak to AndyH
I have had all new bushes in mine and had all new shox and springs all round. Leda made all the parts and i like you need some one to set it up. I know leda can do it but have you to give them a call, but i know they will need a speck to work to. Andy HLS has a good set up spec he may tell all if yo ask him ??? Keep me informed
I recommend a front lip. Fitting one of only an inch stabilized mine to 150. It's an 89 with 15mm spacers rear.
Are you running the same tyres/pattern on both front and rear wheels? Different tyre patterns/tread/wear can cause handling and instability problems, especially at high speeds.
Mine is very slightly lower in the back- not noticable visually, but a cm or so if you measure, In addition I have run with and w/o the front spoiler lip. I'm stable to 140mph, lip doesn't seem to matter but then again, my nerve is running out at 135 or so....
Are you guys feeling your way in the dark? I'll bet anyone here lunch that 95% of the alignment shops you go to have no idea how to align the 348. You guys need to go by the WSM unless you really know what you are doing. You cannot use bumpers and fender lips to measure ride height and expect anything close to accuracy unless you think hitting the backboard is the same as making a basket. Your 348 will handle fine if you do nothing more than use factory settings and factory rideheights taken from FACTORY referrence points. You got to start from the chassis before you do settings. Only then can you begin to get really technical and tune out/in things for specific tires and tracks. Racers like me go even one step further to set chassis height and corner weight before alignment settings are done. If you have lowered your car you need to lower it so that the factory "rake" is the same otherwise the factory alignment setting don't work. You can tune with chassis rake but then you need to change the settings to match that. It not not really a black art but you need to know where to start from and what your objectives are and how to ge there. You need to know that along the way if you make one change how it will effect other things. The problem with suspension is that my compromise is not your compromise.
Mine is a dream. The only time it felt unstable was at speeds I cant post (Ho Hum), I have a spider and it was a windy day.
I've been struggling with the balance of the car too. I have a late '93 so all the suspension upgrades etc have been done. When I first drove the car at high I thought that all the bearings had lost their bullits, really unbelievable after all the cars I had. First I rebalanced the wheels and allignment. Nothing notorious. Then I bought the spacers at Hill's, 25mm at the rear and 15mm at the front. It was certainly an improvement but still I wasn't satisfied. Still unstable above 125mph. Then I got a tip from a F-dealer which helped quite a bit. He told me to keep the 25mm spacers at the rear, but REMOVE the 15mm on the front back to original. That really helped a lot ! Together with the recommended (sticker) 2,4 bar front and 2,6 bar in the rear tires I have the best setup for the moment. In fact the car becomes dangerous when the highway shows deep tracks from trucks. Then the car get real twisty, especially on the breaking. I've read a lot of remarks on the site here, and please don't get me wrong as I don't want to offend anyone, but must people who say that their 348 is rock stable only see big mph numbers on a closed track with a superb flat road. Here in Europe (Holland / Germany / France) we can do 150 mph 20 miles in a row on the highway (when not to busy etc.) without getting sentenced for life. And to my opinion this is where the 348 fails, on the worn daily road with high speeds. The tracks in the tarmac, the real issue ! And hey... I love the 348 ! I have seen over 285km/h on the speedo a lot of times. Apart from the crap heater / AC system it only lacks a 6-gear transmission. Man, that would have made the car so much faster everywhere.
Yes I have. As the Pirelli's show 80% rubber I didn't replace them to 355's. And I have to admit... I love those 355 wheels, but they are very seldom for sale. Image Unavailable, Please Login
Just because one side(front or rear) is lower, it doesnt mean that there is more weight there. So you still should be right about what you said.
Sy, I tried to get Ferrari "official" approval (to be absolutely legal) for fitting the US rear 348 wheels (= 25mm less offset than Euro wheels - i.e. the identical effect to 25mm spacers). Their technical guy replied that they wouldn't approve this in Germany becasue it will have a detrimental effect on stability at high motorway speeds.
Sorry guys my car is getting serviced so handbook not with me. I have found a PDF version tho. <disclaimer> Please, if you use these settings, it is at your own risk at they are for a 348 GT Competizione street version not a TB/TS/GTS/GTB/Spyder and I have no idea what effect they would have on such a car as there may be suspension/wheel/tyre differences etc etc. Therefore if you use, you use at your own risk! <end disclaimer> The wheel sizes are as follows: Front: 8J x 18" Rear: 10J x 18" Tyres Front: Pirelli Pzero 225/40 ZR 18" Tyres Rear: Pirelli Pzero 265/40 ZR 18" Rolling circumference Front: 1929 Rolling circumference Rear: 2022 Tyre pressure front: 32psi Tyre pressure rear: 30psi Front settings: Camber: - 0deg / - 0deg 50' Caster: 2 / 3 mm Toe in: 5deg 30' +/- 15' Floor chassis height: 130 +/- 1mm Rear settings: Camber: - 1deg 20' / 1deg 40' Caster: 2.5 / 3.5mm Toe In: - Floor chassis height: 135mm +/1 1mm --
