Quote:
Originally Posted by Ecky
Trying to decide.
3.4 FD, stock 165/65r14 tire size
2180rpm @ 65mph
1680rpm @ 50mph
3.4 FD, common 185/65r14 tire size
2085rpm @ 65mph
1605rpm @ 50mph
4.105 FD, stock tire size
2635rpm @ 65mph
2025rpm @ 50mph
4.105 FD, 185 tire size
2520rpm @ 65mph
1949rpm @ 50mph
Honda Insight 1.0L gearing - 3.208 final drive
2350rpm @ 65mph
1810rpm @ 50mph
I really think a 3.4 FD is a good idea, but it adds considerable cost to the build. I suppose the 4.105 wouldn't be the end of the world if I moved to a larger diameter tire too.
|
Quoting myself here because I need to update this. Hybrid Racing's K series transmission guide had the wrong ratio for the 2012 Civic Si's 6th gear - it's actually a bit taller.
Looks like I'm not going to be able to get ahold of a 3.4 FD, no matter how much money I throw at it. The one person who makes these will only make them if there's a group buy-in, so 4.059 is the tallest I can reasonably get.
That said, with the new ratio, it looks like this:
Honda Insight 1.0L gearing - 3.208 final drive
2350rpm @ 65mph
1810rpm @ 50mph
Civic Si transmission + 4.059 FD
2556rpm @ 65mph
1966rpm @ 50mph
Civic Si transmission + 4.059 FD + 185/65r14 tires
2444rpm @ 65mph
1880rpm @ 50mph
^ To me that looks pretty reasonable. Ideally I'd have taller gearing to go with the bigger motor, but at least it's not significantly shorter.
In theory, if I
could get the 3.4 FD
and put on 185/65's though...
Civic Si transmission + 3.4 FD + 185/65r14 tires
2047rpm @ 65mph
1575rpm @ 50mph
What a dream. I might even be able to nearly match the 1.0's fuel economy with a 6th like that.
Here's this dream transmission, graphed again'st the Insight's stock ratios:
