View Single Post
Old Dec 18, 2014 | 03:24 PM
  #18 (permalink)  
Padgett's Avatar
Padgett
Senior Member
Joined: Oct 2013
Posts: 2,152
Likes: 37
From: Orlando
Default Re: Rear Gear Change on a 6 Speed

I agree, Fiero V6 was an archaeic iron block, valve in body. Crossie 3.2 is a much more modern engine with a wider power band. Besides I kept looking for a gear beyond top in the Fiero also. Sweet spot for a gas engine these days is 1900-2000 rpm at 70 mph. That's about what the 3.6 in my Jeep GC (aka barn door) turns. A modern engine can pull a gear that tall without getting into PE and minimizes IHP/pumping losses that increase with the square of the rpm.

BTW my Jeep peaks torque at 4800rpm (hp is redline limited) but maintains 90 percent of its peak value from 1,600 to 6,400 rpm. 2k cruise is NP. Peak is really irrelevant, it it the torque curve that matters. 3.2 is a lot peakier but is still making 221 lb-ft at 2k. Anyone have any BSFC curves ?

ps I would rather start in 1st myself, but is so low and the gap to second so large that the only smooth way is a WOT speed shift. I have not found anything else that feels smooth. Starting in second is just much easier.
 

Last edited by Padgett; Dec 18, 2014 at 03:45 PM.
Reply