I know there is a different ("euro") cam timing recommendation for the 348 Challenge cars. Is there such a thing for the F355? Is it perhaps in "F355 Challenge: Regulations Manual"? Any way I can find out before I throw down $150? Thanks in advance, Jay
Are you saying that the cam timing for the 348 Challenge is the same as for the 355 Challenge? So to be sure, this would be: Intake Opens 14 degrees before TDC and closes 53 degrees after BDC. Exhaust Opens 53 degrees after BDC and closes 10 degrees after TDC. Thanks again, Jay
The ECUs are standard road car units they were not altered for the series. In fact mine have seals on them from Ferrari so you can't tamper with them. regards, Vern
Hi Jay, I'm not aware of any different timing specs for 355C vs. road car, the challenge book doesn't say. You have to remember tho in a general sense that adjusting cam timing really only changes in the RPM range where your peak factory stated HP and Torque are produced it isn't going change the amount of power so much as to where in the power band it's produced. Doing a fine tune of the cams with a degree wheel is the best way of getting your power where you want it in the RPM range for your particular application.
What change did they do to the ECU? I have a chip form a challenge car in my 95 that one of the teams used. Was this legal or done under the radar?
You stated there is different cam timing cam timing for (euro cars) No the cam timing spec's are the same for chall and street cars. only comp cars have different cam timing specs that I am aware of. The ecus for the (euro) cars have different timing map's then USA because of emission specs. So I was told by the factory. I am sure there is some room for change but dont know what the limit would be and you would only change the emissions and the power band. The euro cars also had different gearing in the box this made a differance in the top speed.
348 challenge cars were aloud to advance timing to "Euro" specs. There was preset advancement on the cams. According to 348 C manual the cam shaft timing is free but may be changed only by means of the pre-existing holes in the drive pulleys.The ecu's were supposed to be sealed by the factory. I'm sure 355's were the same. I bet cam's could be advanced. Vern is right it just cahnges the power curve. You would get more top end hp.
I have plugged all the cam numbers I have into a software program, and of course some of the numbers dont quite jive. Does anyone have seat to seat timing on f355 or 348? I have gotten all the intake numbers to match up, but I can't get the exhaust to jive between "euro specs" and "US specs", unless I actually change the cam duration, which would mean that the Euro cars had a different exhaust cam. I don't know about that. I will be sharing this when it is done. I can tell that you guys grew up around single cam V-8s, because you're telling me that the torque peak is only goind to be moved up or down the rpm range. Remember that a big part of the fun of tuning dual overhead cam cars, is that we can move the lobe centers too! When going from a very conservative LCA to an agressive LCA, there is a lot of ponies to be found, with minimal compromise. Here is a quote from, imho, an expert on the subject, David Vizard: "The most important factor is actually the overlap and the Lobe Centerline Angle, often referred to as the LCA. I realize this may fly in the face of everything you have been told or have read before, but it's not that hard to see it must be so." here is the article: http://www.popularhotrodding.com/tech/0607phr_camshaft_basics/ I know he refers to non flat crank motors, but the principles are the same, perhaps even more so. Plus, David Vizard is in agreement with my true hero Smokey Yunick, who built flat crank Chevys. Stay tuned..... Jay
