I tried to find an answer before, to no avail. But as I was tinkering with my new Delta Dash, which doesn't work yet because it came with a serial port cable (whose laptop uses that these days?!), I found settings for the STi 5/6 R/RA gears. Their final drive reads 4.444.
Any idea what things would look like w/ a 4.44 final drive? Where did you get the mph's w/ your chart-is there a formula?
Obviously 4.44 adds substantial cost (three diffs to swap), but I'm curious how things would look. 5th gear cruising might be a bit of a problem (maybe more than a bit). I can't help but think the rest of the gearing would be "torquey".
4.444 Final Drive Ratio Conversion Kit
Complete kit to convert the US specification WRX or STi 3.900 final drive ratio to a tire-buring 4.444 final drive ratio. Perfect for those looking for faster acceleration and a higher "fun-to-drive" factor and are willing to sacrifice a small loss in top-speed and highway fuel economy (due to the higher cruising rpms in 5th gear). WRX kit includes front ring & pinion set, transfer gear set, and rear ring & pinion set. STi kit includes front & rear ring & pinion sets. These parts are group N homologated.
RST-1908kit US WRX w/ 5MT Gearbox -- $910
I don't know, but if you do a lot more auto-x/local than highway driving, this might be an excellent alternative. But a shade over 3750 rpm @ 80 mph in 5th is short enough for me.
I've got a DD too and never thought about the road dyno portion for looking at gear ratios! I also get misfire cels - mine are always 1-4 and always come in a no load -idle situation.
Looking at the road dyno some more they also show how many mph per 1000 rpms. The RA set w/ 4.444 (and like you said it shows it w/ that final gear setup) your looking at 4000 rpms cruising at 80. That wouldn't be tons of fun, but the rest of the time- Wow!
Exactly the person I was looking for. I remember meeting you at the backroads drive with Jim Nelson (PlatinumWRX)
I just nuked transmission #3, and I'm ready for this swap. I'm guessing you didn't change the final drive. How is acceleration compared to the stock ratios? Would changing to the 4.44 final drive raise my cruising RPMs even more? Sorry for all the questions, I'm just anxious to get my car back on the road, and I'm checking my options.
There's obviously extra costs involved w/ changing the final drive, but I see that 4.111 is commonly available. I can see that the 4.444 for my needs would be a little too much, but when the time comes I'm not ruling out the 4.111 w/ v6 gears.
Agreed I'm not going with the lower final drive for that same reason. For track use, it'd be great, but for a car that will see highway useage, it's just not a good idea. Cruising RPMs and gas mileage will suffer.
Even for track use the RA gearset will keep you in the power band no matter what speed you are running. I don't see how you can improve on these ratios. When shifting it sounds a lot like a motorcycle now... each shift sounds the same instead of getting lower each time. If you can keep the engine between 5500 and 7000 rpms for every shift I don't think you can do any better. I haven't verified this for every gear change but I did check it out for one shift and the drop wasn't below 5500 and each shift sounds the same. I could do the math based on the ratios but I'm too lazy.