caen fred Posted May 9, 2009 Share Posted May 9, 2009 I am slowly finishing the car. I am waiting for some more parts to really finish the head work. Yet, as the car is running fine, I took my racelogic box to record a few pass at the 0-60. I went with a street approach, hard launching but not drag style either. With the old 3.54 rear diff the best consistent time is 8.9 seconds. All things equal but with a 3.9 rear diff, guess what would be my 0-60 time. (the rear diff will be on the car at the end of the month, will see who will be the closest ) Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted May 9, 2009 Administrators Share Posted May 9, 2009 caen fred. First of all, please read this thread; http://forums.hybridz.org/showthread.php?t=130441 As for guessing your 0-60 MPH with a different diff? what the is RPM at which you are shifting? I am assuming your hitting 60 MPH at the top of 2nd gear with 3.54:1 currently with tires that have approx similar overall diameter to OE. launch-one gear change! The run is over. With the deeper diff, first and second will pull a little harder, but you will be forced with another gear change to 3rd to remain in the optimum power band, or you can "stretch" 2nd gear to avoid the gear change though the engine will be far out of its power band. (based on an 8.9 sec 0-60 blast the engine, intake and exhaust system is bone stock!) My guess, no changes other than the diff only, 0-60 will be slower! 9.0-9.2 seconds. Final answer, 9.1 seconds. Quick tip. Check your ignition timing at idle, probably stock settings? Bump up your ignition timing at 750 RPM idle speed to around 17-20 degrees. Be sure you are using quality fuel. Then run it again... Quote Link to comment Share on other sites More sharing options...
caen fred Posted May 9, 2009 Author Share Posted May 9, 2009 Thanks Braaaaaaaaaaaaaaaap I don't get the punt to the http://forums.hybridz.org/showthread.php?t=130441 link so? It's a guessing thread in the gearbox section? Ss for my spelling, I cannot do better, after all I don't speak English But you're spot on the gear change story. I change gear at 6 000 rpm, and I need to put the 3rd for the last second Engine is an F54 with flat top and an Mn47 head with a strange fast road cam. The car is running with 2 SU TBI. Advance is at +-8. Tires are 205/65r14. Quote Link to comment Share on other sites More sharing options...
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