| Author | Message | ||
| Mitch Alsup (Mitch_alsup)
Intermediate Member Username: Mitch_alsup Post Number: 1124 Registered: 4-2002 |
Intake duration is 238 (16 BTDC 42 ABDC) Exhaust duration is 252 (16 BTDC 56 ABDC) (sorry) | ||
| Hubert Otlik (Hugh)
Intermediate Member Username: Hugh Post Number: 1475 Registered: 1-2002 |
Make the car LIGHTER. This pays dividends far beyond acceleration! | ||
| Mitch Alsup (Mitch_alsup)
Intermediate Member Username: Mitch_alsup Post Number: 1123 Registered: 4-2002 |
Just for fun, lets look at the airflow in the F355 engine (from users manual):  As you can see: A) it is straight B) tapered C) surrounded by thin walls D) throttle in exact center of passage This is the kind of information the intake systems of late 1970s F1 engines gave the engineers. 90 degree V8s with straight vertical passages fit very nicely with the 23 degree valve inclination, compact combustion chamber. Notice the exhaust has only 1/2 the downward bend normall associated with powerful V8 engiens. Notice the valve spring lands are periously close to the intake passage, so recessing spring seats is out of the question. Thus limiting valve lift to however close the builder is willing to mechanical lockup. The clever will notice a small aerodynamic lip just above the fuel injector. | ||
| Mark Eberhardt (Me_k)
Member Username: Me_k Post Number: 731 Registered: 5-2002 |
Boost is always your friend...it's there for you even when it seems like everyone else has deserted...but be careful, trying a little just one time will make you want more  | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 191 Registered: 7-2003 |
There is a little room to squeeze a few horsepower, but as Mitch says, there is not much. About 0.5mm lift can be gained from cams without machining, but the expense usually doesn't warrant the job....unless you're a cheating italian team running in the Challenge series.........GASP! Sharp intake of breath! What a thing to say! Noooo, of course I can't prove it, the bribe was too big. | ||
| spanky mcdoogle (Spanker)
New member Username: Spanker Post Number: 2 Registered: 9-2003 |
A good driving school usually extract more than a few hidden horsepower from a car... | ||
| Mitch Alsup (Mitch_alsup)
Intermediate Member Username: Mitch_alsup Post Number: 1119 Registered: 4-2002 |
"what about different CAM grinds and porting and polishing of the heads and intake?" F355 is already running a 255 degrees of duration from the factory, (a Vette for example is only runing 212-218). With the cam and valve geometry in the F355 heads, there is no room for more lift, the valves are already titanium. So, you could throw a few more degrees of duration at the motor with the result of less low end TQ and a higher RPM power peak (with attendent maintenance and rebuild costs). If you look at the airflow in the F355 head, you will find that a velocity stack takes air from the helmholts resonator (air box) and delivers it straight to the back side of the valve face through the throttle body (e.g. no bends!). There is only on point where there is a casting that has a chance of porting/polishing. For the same reason you don't hear of many people trying to port and polish a carburetor, you won't find many people trying to port/polish the throttle bodies either. If you look at the head castings, there are very thin walls everywhere, so any actual porting is bound to end up with ruined parts. Most of the walls are less than 1mm thick! (at their thinnest), and the airflow was carefully optimized to the castings and engine breathing characteristics. If you took the 5.7 litre Vette engine and put it in the same state of tune as the F355 engine, it would be producing 610 HP. The Vette guys have to bore and stroke the block to 412->427 CID, and run big cams,... to get into this range. Nobody gets a Vette engine to 610 HP with 350 CIDs! it just can't be done. (BTW this is not a slam on Vette engines) | ||
| Michael Calvo (Capt)
New member Username: Capt Post Number: 37 Registered: 5-2003 |
Ok, so an exhaust and chip doesn't do much over what the factory did but what about different CAM grinds and porting and polishing of the heads and intake? has anyone gone down that road? -Michael | ||
| Peter Pless (Aircon)
New member Username: Aircon Post Number: 18 Registered: 6-2003 |
Don't fall for the hype...see this.. http://www.ferrarichat.com/discus/messages/21/320250.html?1064540807 | ||
| J R K (Kenyon)
Member Username: Kenyon Post Number: 873 Registered: 10-2002 |
Engine Tuning from Dimex.... Engine power Specification Order No. Export price EUR Step 1 + 45 BHP * max. torque + 20 Nm Sports exhaust made out of stainless steel, motronics optimisation, optimised intake air flow, sports air filters, F.50.355.01S 5.614,- Fitting F.50.355.01M 510,- Step 2 + 60 BHP * max. torque + 28 Nm as above, additional sports catalysts F.50.355.02S 8.027,- Fitting F.50.355.02M 661,- Step 3 + 60 BHP * max. torque + 25 Nm as above, but with cat replacement pipes F50.355.03S 6.124,- Fitting F.50.355.03M 661,- * Prerequisite is full production power | ||
| J R K (Kenyon)
Member Username: Kenyon Post Number: 872 Registered: 10-2002 |
Check out www.dimex-automotive.de | ||
| Michael Calvo (Capt)
New member Username: Capt Post Number: 36 Registered: 5-2003 |
Folks, other than a full TUBI exhaust and a chip what other performance mods are available for a 355? How far have you taken your mods? Thanks! Michael |