2007 Spec B Final Drive and Ratios

This is what I managed to get:

 

Final Drive- 3.454

1st-3.636

2nd-2.235

3rd-1.521

4th-1.137

5th-.891

6th-.707

 

So, overall taller than '06 in every gear. But I have also found different info. Can anyone confirm? Driving empressions of the '07? I am considering buying one....Thanks.

This is what I managed to get:

 

Final Drive- 3.454

1st-3.636

2nd-2.235

3rd-1.521

4th-1.137

5th-.891

6th-.707

 

So, overall taller than '06 in every gear. But I have also found different info. Can anyone confirm? Driving empressions of the '07? I am considering buying one....Thanks.

 

Thanks I was waiting for this info.. Will post up shortly rpm vs. speed calculations...

 

EDIT: See below for detailed comparison between 6 speed cars, vs 5 speeds.

Here you go:

 

05 Leg GT

 

5th Gear:

 

65mph: 2700 rpm

70mph: 2860 rpm

75mph: 3070 rpm

80mph: 3300 rpm

 

I run about 3400 at 80 mph (typical cruse speed in Michigan...) if I remember, I will double check EDIT: After checking 3300 is more accurate, it may be a hair over that rpm, but it is not quite 3400.

 

07 Leg Spec B

 

6th gear:

 

65mph: 2040 rpm

70mph: 2240 rpm

75mph: 2380 rpm

80mph: 2520 rpm

 

BIG difference, I am scheduled to test drive a spec b when one is at my dealer, and I will report how accurate these numbers are...

 

EDIT, so people don't read this and have a cow, these are the correct estimates, with 3.9 final drive, keep reading for more information:

 

65mph ~ 2300 rpm

70mph ~ 2480 rpm

75mph ~ 2600 rpm

80mph ~ 2900 rpm

85mph ~ 3050 rpm

Have you figured in increased tire circumfurence with the 18s?

 

At 75 mph I'm turning almost exactly 3000 rpm in my 06 Spec.

Have you figured in increased tire circumfurence with the 18s?

 

At 75 mph I'm turning almost exactly 3000 rpm in my 06 Spec.

 

Yes, I used the same tire size as your 06, as I could not find the numbers for the 07.

 

And for your 06, 3000 at 75 in 5th is exactly correct (according to my program), about 80-100 rpm less than the smaller wheeled GT.

wow thats pretty low, i only got to 4th gear when i test drove the 07 Spec B.. the Tranny feels good, but it does seem like i have to shift a lot more..

 

2520 at 80 mph? wow that seems kind of LOW.. there would be like NO passing power whatsoever!

wow thats pretty low, i only got to 4th gear when i test drove the 07 Spec B.. the Tranny feels good, but it does seem like i have to shift a lot more..

 

2520 at 80 mph? wow that seems kind of LOW.. there would be like NO passing power whatsoever!

 

 

Maybe compared to what we have now, which is completely obscene passing power at 80 in 5th.

 

The power will be in line with other cars at highway speeds i think. A downshift will be necessary for passing maneuvers

80mph is almost exactly 3000 RPM in mine.

70 is right on 2500.

Thanks for the input, those drive ratios must be off then.

I got the ratios from SOA, in Cherry Hill, NJ. However, the Final Drive has been published in few publications as being 3.9.

 

I am new to Subaru, but it seems something as simple and very relavent to a car as gear ratios should not be a mystery. What gives?

Does anyone own an '07 Spec B. Are the ratios and final drive in the manual?

I don't know what gives...but this guy shows the same Fianl drive and ratios on the Spec B that I got from SOA.

 

http://www.cars101.com/subaru/legacy/legacy2007.html

The six speed is the one out of the STI isnt it?? So it should have the same ratios as the STI yo, and I heard that the whatchamacallit in the middle, the transfer case I think, is like the one in the STI too now. If you can just find someone with an STI and Spec B and find out what RPMS there going at what speed.. viola!! (sp?) Theres gotta be people on this forum that have an STI, and someone with a Spec b.. The ratios that yall posted up there for the tranny sound real close to the ones in the STI..

Maybe compared to what we have now, which is completely obscene passing power at 80 in 5th.

Agreed, it's kind of fun when you have someone else in the car that understands all that stuff. They always giggle when you accelerate in 5th gear and it pulls.

Yes, I used the same tire size as your 06, as I could not find the numbers for the 07.

 

And for your 06, 3000 at 75 in 5th is exactly correct (according to my program), about 80-100 rpm less than the smaller wheeled GT.

 

ZrrBrrt said 3k rpm @ 80 mph in his 07 Spec. Can your program extrapolate from there?

Its probably a 3.9 final drive, that is what Australia is getting also...

 

3.9 final with all the rest of the ratio's the same yields similar results to those reported by Zrrbrrt:

 

65mph ~ 2300 rpm

 

70mph ~ 2480 rpm

 

75mph ~ 2600 rpm

 

80mph ~ 2900 rpm

 

85mph ~ 3050 rpm

 

 

These sound like what Subaru would do, the previous numbers were VERY low rpm, these at least allow the turbo to get a little boost in top gear.

 

DISCLAIMER: Remember there are a LOT of factors that can change these numbers including but not limited to:

 

1. Speedometer inaccuracy. Mine is off sometimes by +3 mph at certain speeds, but perfect at others, so the speedometer is not accurate, plus it depends where you read the speed from the top, center, or bottom of the pointer.) When I use a GPS it makes my numbers that I get from my program MUCH more accurate. If you read from the top of the pointer at a speed that is already 3 mph+ off, then you could be almost 4 mph optimistic.

 

2. Tachometer inaccuracy, (this is mostly where you read the pointer from, from top to bottom of the pointer is ~100 rpm)

 

3. Tire circumference calculation limitations. My program takes the dimensions of the tire 215/45/18 and calculates the circumference, but every tire is a little different because of the the manufacturer, or tire wear or even inflation pressure, to make this accurate, we would have to take the tires off and measure the circumference and plug that into the program.

 

So remember these are GUIDELINES, your mileage may vary

Does anyone own an '07 Spec B. Are the ratios and final drive in the manual?

The gear ratios for the 2007 spec.B and 2.5GT can be found in http://vocuspr.vocus.com/vocuspr30/Newsroom/ViewAttachment.aspx?SiteName=Subaru&Entity=PRAsset&AttachmentType=F&EntityID=100395&AttachmentID=e3353ed8-609d-4470-9b0f-50bcc6a195c3.

;761566']The gear ratios for the 2007 spec.B and 2.5GT can be found in http://vocuspr.vocus.com/vocuspr30/Newsroom/ViewAttachment.aspx?SiteName=Subaru&Entity=PRAsset&AttachmentType=F&EntityID=100395&AttachmentID=e3353ed8-609d-4470-9b0f-50bcc6a195c3.

 

 

That indicates a 3.9 final, thanks Jon!

From what I have found, the Spec. B uses a "modified" STI transmission. The Spec. B ratios are closer to the new '07 STI ratios than those used in the earlier STi 6 Spds, however the Spec. B has taller 5th and 6th gears.

 

The following information was found on NASOIC courtesy of JiveMasterT:

 

2006 STI 6-speed

1st - 3.636

2nd - 2.375

3rd - 1.761

4th - 1.346

5th - 0.971

6th - 0.756

 

2007 STI 6-speed

1st - 3.636

2nd - 2.235

3rd - 1.521

4th - 1.137

5th - 0.971

6th - 0.756

 

As you can see... slightly longer gearing. I don't have the numbers for the old gearing but I do for the new ones.

 

2007 STI 6-speed (redline speeds)

1st = 35.4

2nd = 57.6

3rd = 84.6

4th = 113.2

5th = 132.5

6th = 170.2

Here is the answer. The ratios were correct. The final drive was wrong....I even got recerse in there....So now the math works!!!

 

Dear Mr. Loureiro:

 

Thank you for visiting the Subaru web site and for your message!

 

The final drive ratio for the Spec B (2007) is 3.90. The gear ratios are as follows:

 

1st 3.636

2nd 2.235

3rd 1.521

4th 1.137

5th 0.891

6th 0.707

Rev 3.545

 

If you have any other questions, do not hesitate to reply to this email!

 

Best wishes,

 

Samir Hasan

Subaru of America, Inc.

Customer/Dealer Services Department

 

2007 STI 6-speed (redline speeds)

1st = 35.4

2nd = 57.6

3rd = 84.6

4th = 113.2

5th = 132.5

6th = 170.2

 

That max in 2nd is going to hurt the all important 0-60 times the car mags love so much.

That max in 2nd is going to hurt the all important 0-60 times the car mags love so much.

 

Probably not, the '06 STI couldn't reach 60 in 2nd either. The '07 gear raio is actually taller so it's redline speed is higher in 2nd than the '06.

I have decided to revive this dead thread to continue this discussion. Also I am tired of seeing people talk about 0-60 and how it will be slower in a 6 speed.

 

In an effort to fully disclose, I will say that I am in favor of the 6 speed. I like the idea of having the next gear. I like the idea of possibly getting better gas mileage. I like the cachet associated with the 6 speed. I like the known durability of the 6 speed, and the possibly better clutch.

 

That said, I tried to be as scientific as possible about this, I did not try to skew the results to benefit the 6 speed in any way. I used the same HP numbers, and same driver shift speeds. Both cars are using the optimum shift points (not always redline), and have the weights adjusted appropriately.

 

I use a program called Car Test 2000. It is a vehicle acceleration simulator. I use it very often to compare acceleration times. It is, in my experience, accurate to within .1 in the 1/4 mile, and 3-4 mph in top speed. I highly recommend it.

 

It will accept actual at wheels hp numbers and is very customizable. For example, I found I was regularly getting better numbers at the track than it estimated, so I lowered the shift times and the numbers lined right up (I guess I am awesome at shifting).

 

I have attached 4 PDF files with acceleration plots comparing the 07 spec B to a 05 GT. Stock gear ratios and stock wheel sizes.

 

The first plot is Stock engine (also default shifting speeds). The spec B is teal, the GT pink. You can see that as predicted the 0 to 60 is slower for the spec b because of the shift point. You can also see that the 6 speed is faster to 50, 70, 80, slower to 90, but much faster to 100, and continues to pull away at higher speeds. This is to be expected because how the car makes power at high rpm when stock. This is why peaky cars like a s2k or TSX really need that extra gear. *NOTE: I did not take into account the fact that spec b's may actually be making more power when stock, as discussed in Rallitek's dyno comparison. For this test (and all of the other ones), both cars are EXACTLY the same in power.

 

What about a stage 2 car? It makes its power at a lower rpm, and makes a LOT of torque at low rpm, it is advisable to short shift the 5 speed a little, let alone a 6 speed, so how does the spec b do?

 

For the stage 2 comparison, colors are the same (pink: GT, teal: Spec B), I used my actual dyno plot, higher redline (7200 rpm) and quicker shifts.

 

As you can see the 0-60 that people care so much about is exactly the same. In fact the plot shows identical performance except during those tenths of seconds where the GT is in the lower gear. I am calling this a tie, but if you want to get technical the GT is faster to a couple of points, and MIGHT have a slight edge at the high end of the speeds recorded here.

 

For Shifts and Giggles I plugged in the dyno numbers from the TDC 40BB turbo, which has Stg2 VF40 spool, but a MUCH better top end. Even this turbo is falling off at the high rpm, most likely because of the still stock cat back in this dyno. Same colors, same shift speeds and high redline as in the stg 2 plot.

 

Here the VERY slight edge goes to the spec B, probably because of the higher rpm power.

 

To conclude, the better driver of any of these cars is going to win. Same driver, the winner will swap back and forth, no matter the power levels. The differences are so small as to be inconsequencial in terms of actual acceleration between the two cars. The only differences come when there is high end power (like a big turbo), then the advantage will go to the spec B for its ability to keep the rpm up, because of the closer gear ratio's. Also if you run the 1/4 a lot, and have BIG power, you may have to shift out of 4th to cross the finish line (like with traps over 118 mph), this could hurt a little. Also the slightly shorter 2nd gear might be bad in a fast autocross.

 

Since acceleration is the same, the other benefits of the 6 speed seal the deal for me. Better theoretical gas mileage, less wear and tear on the engine at highway speeds, better gear choices on the twistys, or a road course, being cooler because of the 6th speed . The ONLY downfalls are the extra cost associated with the Spec B, and possibly having less power to pass at highway speeds (although I have also plotted this, and the difference above 65 is minor). I plan on stepping up to a 08 spec B, and not looking back at my 5 speed GT.

Stock.pdf

Stage 2.pdf

Stg 3 40BB.pdf

Speed in Gears 7200 redline.pdf

Nice work Trabbic! I have this software as well, and find that it under estimates 1/4 times & trapspeeds as well. It also has some wrong data, like CD, frontal area, etc... It doesn't affect under 120mph, but over it makes a huge difference.

 

I'm curious, for the vf40BB, and GT30R, did you simply increase the max power, or did you use specific car parameter's, and plugged in dyno plots for each rpm zone? Cause I have found that this also makes a difference. Particluarly since the stock vf40 plot makes decent power til redline, whereas any modded Stg1/2 car will not maintain the same power increase across the board, as the software suggests.

Nice work Trabbic! I have this software as well, and find that it under estimates 1/4 times & trapspeeds as well. It also has some wrong data, like CD, frontal area, etc... It doesn't affect under 120mph, but over it makes a huge difference.

 

I'm curious, for the vf40BB, and GT30R, did you simply increase the max power, or did you use specific car parameter's, and plugged in dyno plots for each rpm zone? Cause I have found that this also makes a difference. Particularly since the stock vf40 plot makes decent power til redline, whereas any modded Stg1/2 car will not maintain the same power increase across the board, as the software suggests.

 

Thanks!

 

I have had your same experiences as far as frontal area. I have been able to get the 1/4 mile times close by drastically reducing the shift time from .5 sec to .05 sec. I know I am probably not shifting THAT fast, but it seems to be much more accurate, not only for me, but for other people and cars I have put through my system. My best last run was within .03 seconds, and .2 mph from the actual time.

 

I always use the car specific parameter's if I can find the actual dyno plot. For the Stage 2 car I actually used my dyno, and the other plots I used dyno's found on this site...

 

I know you and I have also discussed shift points before. I use the shift points in the software and have had pretty good results (my 12.8 for one!).

 

That is where using the actual dyno comes in handy, is estimating shift points, because it tells you where you will be better off in the next gear, especially when the power falls of like on a stage 2 car.