06 wrx PPG 5spd

any reason that i shouldn't be able to get a 06 wrx 5spd with ppg straight cut

1 - 4th and helical 5th to work in my 05 LGT 5MT?

I already have the wrx single mass flywheel and ACT HDSS clutch install in my current 5speed. I know I need to get a rear end with a 3.7 Final Ratio but are there any other things that i'm overlooking?

 

http://img44.imageshack.us/img44/566/ppgtransmission.jpg

You might need different front axles but I don't see any stubs in that picture, so maybe the 06 WRX tranny takes the same style axle as the LGT.

I believe the 06 to be a stubless design. I know someone in the front LSD thread mention about using a 06 wrx trans after some if the hardware on their LSD failed and punched a hole in their case.

Besides the rear end it seems to be a pretty straight forward deal.

However if anyone knows differently i would love for them to chime in!

-clinton

it should work no problem. id take your own front ring and pinion gear and put it with the ppg stuff so you dont have to buy a new rear end.

I'm planning light auto x and lots if road course action for it. Would the 4.111 FR be more conducive to that than the 3.7?

What gear ratios does the PPG set have?

(3.08 / 1.87 / 1.32 / 0.95 / .738[oem])

LGT stock gearing:

1st: 3.166

2nd: 1.882

3rd: 1.296

4th: 0.972

5th: 0.738

 

The PPG gear set is really close to the stock 5 speed gears.. If you run a 3.7 Final drive, I think the end result would be too tall. 4.11 would match up the best IMHO

 

2005 STI gear ratios:

1st 3.636

2nd 2.375

3rd 1.761

4th 1.346

5th 0.971

6th 0.756

I understand why you posted the LGT gearing, but why the STi gearing?

 

i'm guessing the lgt runs a 4.111 FR due to the weight of that car compared to a relatively light 06 wrx with 3.7 FR?

There are a bunch of reasons for various gear ratios.

 

It's going to cost a few hundred bucks to swap the ring and pinion, so keep that in mind when you consider the cost of the transmission.

 

That one also has a Cusco transmission mount. I'd ask a few questions before jumping on it. It could have been beaten on pretty hard, and the "warranty" that PPG provides doesn't even remotely extend to used gearboxes.

There are a bunch of reasons for various gear ratios.

 

It's going to cost a few hundred bucks to swap the ring and pinion, so keep that in mind when you consider the cost of the transmission.

 

That one also has a Cusco transmission mount. I'd ask a few questions before jumping on it. It could have been beaten on pretty hard, and the "warranty" that PPG provides doesn't even remotely extend to used gearboxes.

 

right now the only two ratios i would be considering are the 3.7 our of the wrx ( matches what is currently in the transmission) and my 4.111 FR which will be what's in my rear end. I know with the 3.7 i would lose a lot low end but get more mph's up top... how big of a difference is that going to make?

 

there are no miles on the transmission, previous two owners sold it before they ever got the chance to install it. Almost positive it was built at andrewtech, still working on verification with them

 

i was wondering what mount that was, i already group N. so i guess one of them is going to have to go.

The Cusco mount is WAY harsh.

 

So long as the trans was built by Andrewtech, and you have some lineage of where it's been and what's been done, then you will probably be in good shape.

I understand why you posted the LGT gearing, but why the STi gearing?

 

i'm guessing the lgt runs a 4.111 FR due to the weight of that car compared to a relatively light 06 wrx with 3.7 FR?

 

It's not a weight concern. I've driven an 05 STI and my 5-speed LGT extensively. I think the LGT 5-speed ratios with 4.11 FD are almost perfect for all-around use. The STI gearing is way too short, which is why I included that too.

 

For comparing the gear ratios. The STI has a 3.90 final drive.

You want to run a 3.7 FD with 5 gears...

Unless it cuts out a shift in the 1/4 mile I wouldn't recommend it. Getting out of the hole with such a tall first gear will make getting a decent 60' difficult. I do not recommend running a 3.7 FD with those ratios

 

calculator: http://www.car-videos.net/tools/speedrpm.asp?Car=Select&Num1=225&Num2=45&Num3=17&AxleRatio=3.9&Ratio1=3.545&Ratio2=2.11&Ratio3=1.448&Ratio4=1.088&Ratio5=0.78&Ratio6=&Ratio7=&Redline=6250&Increment=500&B1=Recalculate

I used that calculator to compare the 4.11 and 3.7 FD

Do you really need your car to top out at 183 MPH?

See attached CSV file

gear ratios.csv

oh, OH my!

i don't think i need to go that fast... i don't think. that would be quite interesting though... hmm

FWIW, some of the fastest street cars at Road America (one of the fastest US road courses) top out at 160.. many pushing 500 to 600 whp.

 

Also I've tested it in driving simulators.. shorter gearing yields faster acceleration, if the number of shifts is the same

Was fun in Forza2 to tweak the gearing perfect for a particular track

yeah i think i definitely want to keep the 4.111 FR like you all are saying. since i am going to have everything apart anyways i might as well look at upgrading diffs too. i know the one available for the front, but is there an easy solution to a mechanical LSD in the rear?

^quaife makes one to fit the rear.

The Cusco mount is WAY harsh.

 

So long as the trans was built by Andrewtech, and you have some lineage of where it's been and what's been done, then you will probably be in good shape.

 

Just got 100% verification that it was built at AndrewTech

They are the best in the business, so pending their blessing I'd say go for it!

 

Keep in mind, swapping the ring-and-pinion isn't something you can do yourself. They might be able to do that for you, and install the new transmission at the same time!

They are the best in the business, so pending their blessing I'd say go for it!

 

Keep in mind, swapping the ring-and-pinion isn't something you can do yourself. They might be able to do that for you, and install the new transmission at the same time!

 

yeah i was planning to get a F LSD too, so there will be fun had by all parties involved.

I won't have the trans until after xmas so i have plenty of time to figure out my setup.

PPG makes a really nice helical front LSD. For the rear, I'd probably go with a clutch-type. The KAAZ is nice because it's innexpensive (relatively), and works pretty well. As with all clutch-types, though, it's a bit noisy.

anyone know the price on the ppg unit? i would only assume it's right in line with the rest of their stuff. would the OEM subaru one be a worthy stand-in? or could i get away with the $400 OBX front diff?

It's like $1300 or something like that. Not terrible. Andrewtech would know for sure.

 

I wouldn't use the OBX diff. The risk of failure isn't worth it to me. Plus, it's just a knockoff of the Subaru diff. Companies that produce knockoffs typically don't have the engineering knowledge to know what they are doing enough to make a reliable product. I'd stay away.

 

At minimum, get the Subaru diff.

i would say i'm looking for the 5mt DCCD center diff. but i know how rare they are and how much they go for...