I've heard a couple of times that changing the final drive to a 5.1 is an awesome upgrade to the SI. Can someone explain this to me. Thanks

 

Yeah I'm interested in it too. But what's it cost? How much is labor? can you DIY?

 

just did mine last week in my garage, best upgrade EVER! Did it myself and took me about 7 hours total, pretty good for a first time on this car. here are the pics:






Here are the new parts:



Transmission ready for disassembly:





Tranny Reassembled:


New Clutch and Flywheel installed:


Tranny back in:

 

wow man. very nice work. what do you max out on in each gear now?

 

I work at Silverhill Acura, so i'll go do so gear vs speed on a Stock 08 CSX Type S and My CSX Type S with the final drive and post stuff later today.

 

cool. thanks.

 

so a different final drive changes the amount of rpm drop in between gears, right? i'm curious what kind of difference in acceleration the 5.1 makes.

 

Gears will be about 6.5% shorter with the new FD (4.77/5.1 == .935). So...
@ 8300 rpm 4.77 -> 5.1 -> 8600 rpm (reflash)
......... 1st: 38 -> 36 -> 37
......... 2nd: 59 -> 55 -> 57
......... 3rd: 82 -> 77 -> 80
......... 4th: 109 -> 102 -> 106
......... 5th: 136 -> 128 -> 132

Cruising RPM @ 70mph goes from 3000rpm to 3200rpm. Based on that info the 5.1 FD + reflash (raised rev limiter) would make a mean Si. These #'s are all estimations and will vary depending on your wheel + tire combo.

 

No, the drop will be the same. It will just get there faster and you will shift at a lower speed.

 

makes sense. i thought that's what i read before but i wasn't sure

 

thanks for the posts. Nice photos. So in the end changing your fd to a 5.1 improves acceleration?

 

alot!!!

 

im kinda lost can someone please explain to me what the final drive upgrade actually is? you guys never explained it on this thread.....ty

 

the final drive is like the overall gearing of a tranny. the larger the # of the final drive gear the shorter each individual gear will be.

 

Can you post the part numbers required for this upgrade ?

 

how much does the new FD cost? and whered you get it?

 

How is the pedal travel with the HD pressure plate? I has the AR1-XTSS and the pedal travel was all the way to the floor with no action from the clutch. We adjusted to the clutch master cylinder rod to compensate, but this was a band aid until I had an adjustable slave cylinder made. The XT pressure plate is too stiff and the master cylinder blows out.

The 5.062 Final drives are on national back order from Honda of America with no ETA. I sell them for $435 plus shipping.