Chickenman Posted October 19, 2015 Share Posted October 19, 2015 Since I've got insomnia I may as well make one more comment. The Fidanza Aluminium flywheel could be causing a harmonics problem. I've had aluminium flywheels on various Road Race and Autocross cars with no issues. With one exception. A Fidanza Aluminium flywheel on a Audi Quatrro Autocross car. With a Turbo, AWD, 20 lbs boost and tall 1st gear, you often had to launch with a fair bit of clutch slip. This would sometimes set the Fidanza flywhell singing like wine glass rubbed with a finger. I've never encountered this before with any other brand ( Tilton, McCleod ) that I've used. Very strange. After some research it seems to be a design flaw in the Fidanza flywheel. It was just a bit too thin in a couple of places ( It's 9.5lbs ) and was prone to flex. Strengthening webs can also reduce vibration. But one of the interesting things was that a lightweight billet steel flywhell was often nearly as light as an Aluminium flywheel and reduced harmonics and vibration considerably. Possible food for thought. I completely agree that for Amateur Road Racers racers with a Budget, keeping the revs down is a very cost effective way to ensure engine reliability. Give me a choice between more Torque or more HP, and I'll take more torque every time. Looking at your gear ratio charts, if you build the 3.3 L I'd drop the rear end ratio some. 3.9's possibly instead of the 4.11's. Run the numbers. Concentrate more on a nice juicy flat Torque curve and less on absolute Maximum HP and high rpms's. If you're running the SCCA Runoffs and shooting for a National Championship... then build a Atomic Bomb if you have the cash. But for a Regional Road Racer or Track Day car, I prefer a big fat Torque curve with reasonable RPM range every time While an big displacement L-6 at very high RPM may sound so sweet... less sweet is the accompanying sound.... the " Ka-Ching " of the cash register!! Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 19, 2015 Share Posted October 19, 2015 If you keep the SOHC Head, the port flow will limit the rpm potential of the larger engines. Just not enough flow available. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.