| Author | Message | ||
| J R K (Kenyon)
Member Username: Kenyon Post Number: 443 Registered: 10-2002 |
RIP............................................. Con saluti cordialissimi, | ||
| Craig Williams (Craigw)
Junior Member Username: Craigw Post Number: 151 Registered: 4-2002 |
maybe I'm speaking out of turn but perhaps we shouldn't continue this particular thread in light of recent events guys. | ||
| Dino Micalizio (Ingenere)
Junior Member Username: Ingenere Post Number: 56 Registered: 12-2001 |
My 89 348 has some tweaks.... I have added challenge wheels/tires (absolutely got rid of the on limit handling challenges) Brembo F40LM brakes Specialle front spoiler/lights/seats Superchips ECU chips Tubi exhaust All this lightened up the car by about 200+ pounds, added ~35hp....and more importantly for your question...find a set of Challenge wheels...they look great and are brilliant...don't forget the brakes!! | ||
| Jens Haller (Jh280774)
Member Username: Jh280774 Post Number: 813 Registered: 9-2001 |
Noel and Mitch, Thanks for the input! I will try to keep all this in mind when I speak with my mechanic in the next days! Con saluti cordialissimi, Jens Haller | ||
| Noelrp (Noelrp)
Member Username: Noelrp Post Number: 269 Registered: 8-2001 |
Jens, Also try upgrading to 18" wheels as well. The difference is very noticable. | ||
| Mitch Alsup (Mitch_alsup)
Member Username: Mitch_alsup Post Number: 753 Registered: 4-2002 |
Just to add to Robs geometry diatribe: The lowering of the instant roll center increases the scrub of the rear tires and creates a minute amount of understeer as the car rolls into a turn on steering input. | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 672 Registered: 11-2002 |
If your car is a '90, you may also have 175 lb/in front springs with 300 lb/in rears. One other modification you may consider is 350 lb/in springs (available for 348 in later years) in the front with dampers to match. I don't have the part numbers, I think the part numbers and spring color codes are in the latest 348 shop manual. The dampers are Bilstein, and can be revalved. You live in the best country to find a Bilstein representative capable of revalving. Again, I think even damper response information is in the WSM. | ||
| Jens Haller (Jh280774)
Member Username: Jh280774 Post Number: 810 Registered: 9-2001 |
Rob, Thanks for the good advice!  Will contact my dealer and ask about these mods and the costs. I was just surprised that the car is a bit unpredictable when coming to the limit! I am no race driver but compared to other cars the overstep of the grip limit comes very sudden and without a warning. Last result was a "tankslapper" at the N�rburgring. Kind of scares me and doesn�t improve the confidence you have when entering a corner... Con saluti cordialissimi, Jens Haller | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 670 Registered: 11-2002 |
Jens, what may help before making this modification, is to increase rear toe-in. This will aid in rear stability, though will slightly increase tire wear. Lowering the rear suspension relative to the front will also help. | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 669 Registered: 11-2002 |
Here's the thread that is relevant to your question: http://www.ferrarichat.com/discus/messages/256120/206021.html, look for Dr. Ferrari's post for assembly numbers. There is no "GTB spec". There are but two suspension mods (though there are also different spring rates run on early cars too), the rear suspension upper control arm mount being lowered, and the Spider/Speciale rear wheel offset. IMO, the offset change is marketing. The suspension geometry change will lower the rear instant roll center, and generally be a bit more comunicative, and potentially a bit more forgiving at the limit of lateral acceleration. You can make the modification on the car. Ten years ago there was a jig floating aroung the Authorized Dealer network, perhaps FNA has it back now, or it no longer exists. Back in 348 Challenge days, we were required to replace the entire rear subframe to do the modification. With careful measurement, it should be very straightforward for a race prep shop to perform. The rear suspension must be removed to gain access, measurements taken, new mounting tabs fabricated, old mounts cut out, and new mounts welded in. Then reinstall suspension and align the chassis. You should not require corner weight adjustments, just toe, camber and thrust alignment. | ||
| J R K (Kenyon)
Member Username: Kenyon Post Number: 373 Registered: 10-2002 |
Check out this earlier thread. http://www.ferrarichat.com/discus/messages/112/257896.html?1054898364 | ||
| Jens Haller (Jh280774)
Member Username: Jh280774 Post Number: 809 Registered: 9-2001 |
Does anybody know whether it is possible to change the suspension of an early (1990) tb to GTB specs to get a better handling? Sometimes I think that my car is a bit twitchy at the limit. It breaks out without warning or at least seems to skip a bit to the side. Kind of makes me nervous when it does. Any possibilities to upgrade to GTB specs? Note: I already have spacers on the car and am running on Bridgestone S-01 which need to be replaced in the near future. BTW: Any possibility to still get the challenge pack for the 348 from the factory? Con saluti cordialissimi, Jens Haller |