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Discussion Starter · #1 ·

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I've been scoping this gear set for quite awhile. Knock on wood my oe setup has been holding up, but I keep coming back to this gear set.

I don't ever plan on being over 250whp, so the strength should be right on. Did the v6 RA run this w/ 3.9 or 4.444?

The gearing is more appealing to me as well vs stock. Reading your review- looks like labor was reasonable as well.

Big Sky
 

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Discussion Starter · #3 ·
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.
 

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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".

Thanks

Big Sky
 

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Discussion Starter · #5 ·
RalliSpec has this:

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.
 

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Here's the 4.44 ratio figured in on both oe and v6 RA, I don't know how to get speeds however.

______stock WRX (fd: 3.9)______
___ratio______overall_____mph__
1__3.454______13.471______038.5
2__1.947______07.593______068.2
3__1.366______05.327______097.2
4__0.972______03.791______136.7
5__0.738______02.878______180.0

______Type RA (fd: 3.9)________
___ratio______overall_____mph__
1__3.083______12.024______043.1
2__2.062______08.042______064.4
3__1.545______06.026______086.0
4__1.151______04.489______115.4
5__0.830______03.237______160.1

______stock WRX (fd: 4.44)______
___ratio______overall_____mph__
1__3.454______15.3 ______
2__1.947______8.6______
3__1.366______6.0______
4__0.972______4.3______
5__0.738______3.3

______Type RA (fd: 3.9)________
___ratio______overall_____mph__
1__3.083______13.7______
2__2.062______9.16______
3__1.545______6.86______
4__1.151______5.11______
5__0.830______3.68______

Again, very possibly overkill, but from a purely performance look- interesting.

Big Sky
 

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Discussion Starter · #7 ·
With a USB to serial port cable, Delta Dash works like a charm, at least to check and clear CEL's. (I sometimes get misfires at idle.) It gave speeds for those ratios:

_stock WRX (fd: 4.444)_
___ratio_______mph_
1__3.454______034.4
2__1.947______061.0
3__1.366______086.9
4__0.972______122.1
5__0.738______160.8

_Type RA (fd: 4.444)__
___ratio_______mph_
1__3.083______038.5
2__2.062______057.6
3__1.545______076.8
4__1.151______103.1
5__0.830______143.9
 

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I've got a DD too and never thought about the road dyno portion for looking at gear ratios! I also get misfire cels:mad: - 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!

You'll love your delta dash.

Mike
 

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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.
 

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Discussion Starter · #10 ·
Hey Chris, check out the link in my initial post up above. I'm certain that I'm happier with a 3.9 fd than a 4.44.
 

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I read that, but I was thinking it would (1) keep me from doing triple digits on the highway as often as I do it now. and/or (2) help me get into 12s on the stock turbo...I'm so close, yet so far.

Besides, I need a complete box, and I may just get a v6 STI RA box, with the differentials and all. :D
 

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Discussion Starter · #12 ·
with your quickness,

you probably need 4th for the quarter. IMO..

Stock 3.9____4th___97-137 (too weak and tall)
Stock 4.4____4th___87-122 (too weak)
RA 3.9______4th___86-115 (just right)
RA 4.4______4th___77-103 (too low)
 

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AH! I was trapping 103.90 with the stock box/clutch/flywheel...I'd hate to shift to 5th just before the traps. :rolleyes:

It's not too late, nothing's been paid for yet, but I don't know if I have anything reuseable in my box. Do you know how much is upgraded in the RA box other than the gearset?
 

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Discussion Starter · #14 ·
Don't know, but RalliSpec is great about answering e-mail about such questions.
 

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Thanks! I actually e-mailed them about getting their built WRX box with RA gears... 3.90 final drive!

Do you think they have it in stock, or is it one of those 6 week special order deals?
 

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Discussion Starter · #16 ·
Don't know, but I'd be very surprised if it takes that long. They're busy but fast and good. If there's a problem with a supplier, that's another story.
 

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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.

Big Sky
 

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The V6 RA gears are low enough. I'm not sure why anyone would want them lower. First is a bit high for a good launch but after that they seem perfect to me. Why would you want them any lower??????????
 

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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.
 

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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.
 
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