WRX 6MT Swap -- Introduction
12-19-2002, 07:46 PM
#1
Admin v2.0
Thread Starter
iTrader: (9)
Join Date: Nov 2002
Location: Alameda, CA, USA
Posts: 6,965
Car Info: 02 Black Legacy GT
WRX 6MT Swap -- Introduction
Please take a moment and try to answer the following question:
When Japanese high-performance cars finally make it to the North American shores, they...:
a. Get detuned by the manufacturer
b. Add-on few extra pounds of weight
c. Get stripped of some cool features
d. All of the above
If you answered "d", you are absolutely correct and that is a sad but true generalization about all Japanese (and other) import automobiles. In Subaru case, after many years the whole world have been enjoying the wonderful Impreza WRX, US and Canada finally got their version of that car a year ago. However, we ended up with the "base model" of WRX that lacked not only power, but also numerous performance goodies that most of the world's Subaru markets get to enjoy everyday in their STi's, while North American Subaru enthusiasts frantically try to add them on by themselves. Among some of those most common and popular upgrades is the STi 6-speed manual gearbox. That comes as no surprise, as a large number of US and Canadian WRX owners came to find out the term “glass transmission” that is well known in Japan, UK, Australia and other Subaru markets. That term is merely a very good description of 5-speed Subaru transmission based on its reliability on not only heavily modified cars but even the stock ones.
There is no one single reason that can be used to explain all of the known transmission failures. Of course, power and driver factor are among the most commonly used explanations used by the users and the dealers. Yes, an owner of a WRX that puts out %50 to %100 more horsepower than the stock breaks his gearbox, it is understandable. However, how can one explain numerous known cases in which transmissions failed or nearly failed on stock WRXs?
Based on my personal research, observations and first hand experience with 2 (!) broken transmission, I concluded that 5MT transmissions fail due to case weakness-related flex. See, when the weak case flexes for whatever reason (hard launch, extreme power, loose/stretching case bolts or simply manufacturing defect), the not-so-strong helical cut gears get out of their “alignment” with the mating gears, which causes premature excessive wear that leads to eventual or instant failure. Many popular “dog” gear upgrades address these issues by simply making the gears straight-cut, strong and big enough to be able to withstand that flex. In some cases, even the dog gears fail. Why? Because the case flex is still there. Not only that, but regardless of what the “dogbox” advocates say, they are not meant for the street. They make noise, they are hard to drive and they are expensive.
To address the issue of “glass transmission”, with the introduction of New Age Impreza WRX, Subaru also introduced its new 6-speed manual transmission. It is rumored, that Porsche had a part in the development of this transmission. Upon a closer examination, one can clearly see the structural improvements made to insure that case flex doesn’t occur. Besides that, there are lots of other improvements over the standard 5-speed transmission, that I will cover in the next articles.
As this transmission becomes a more popular solution to the North American WRX transmission-related problems, many people are looking for information related to this upgrade. Since I went through 2 transmissions within a month of my car making double the stock horsepower, I went ahead and purchased the STi 6MT. I found out a lot of great info while doing it and I am going to share with all of you.
In the next installments, I will go over the main differences between the 5MT and 6MT, parts required to do the swap, parts sources, average prices, swap instructions and other issues that related to this upgrade. Please stay tuned.
To be continued…
When Japanese high-performance cars finally make it to the North American shores, they...:
a. Get detuned by the manufacturer
b. Add-on few extra pounds of weight
c. Get stripped of some cool features
d. All of the above
If you answered "d", you are absolutely correct and that is a sad but true generalization about all Japanese (and other) import automobiles. In Subaru case, after many years the whole world have been enjoying the wonderful Impreza WRX, US and Canada finally got their version of that car a year ago. However, we ended up with the "base model" of WRX that lacked not only power, but also numerous performance goodies that most of the world's Subaru markets get to enjoy everyday in their STi's, while North American Subaru enthusiasts frantically try to add them on by themselves. Among some of those most common and popular upgrades is the STi 6-speed manual gearbox. That comes as no surprise, as a large number of US and Canadian WRX owners came to find out the term “glass transmission” that is well known in Japan, UK, Australia and other Subaru markets. That term is merely a very good description of 5-speed Subaru transmission based on its reliability on not only heavily modified cars but even the stock ones.
There is no one single reason that can be used to explain all of the known transmission failures. Of course, power and driver factor are among the most commonly used explanations used by the users and the dealers. Yes, an owner of a WRX that puts out %50 to %100 more horsepower than the stock breaks his gearbox, it is understandable. However, how can one explain numerous known cases in which transmissions failed or nearly failed on stock WRXs?
Based on my personal research, observations and first hand experience with 2 (!) broken transmission, I concluded that 5MT transmissions fail due to case weakness-related flex. See, when the weak case flexes for whatever reason (hard launch, extreme power, loose/stretching case bolts or simply manufacturing defect), the not-so-strong helical cut gears get out of their “alignment” with the mating gears, which causes premature excessive wear that leads to eventual or instant failure. Many popular “dog” gear upgrades address these issues by simply making the gears straight-cut, strong and big enough to be able to withstand that flex. In some cases, even the dog gears fail. Why? Because the case flex is still there. Not only that, but regardless of what the “dogbox” advocates say, they are not meant for the street. They make noise, they are hard to drive and they are expensive.
To address the issue of “glass transmission”, with the introduction of New Age Impreza WRX, Subaru also introduced its new 6-speed manual transmission. It is rumored, that Porsche had a part in the development of this transmission. Upon a closer examination, one can clearly see the structural improvements made to insure that case flex doesn’t occur. Besides that, there are lots of other improvements over the standard 5-speed transmission, that I will cover in the next articles.
As this transmission becomes a more popular solution to the North American WRX transmission-related problems, many people are looking for information related to this upgrade. Since I went through 2 transmissions within a month of my car making double the stock horsepower, I went ahead and purchased the STi 6MT. I found out a lot of great info while doing it and I am going to share with all of you.
In the next installments, I will go over the main differences between the 5MT and 6MT, parts required to do the swap, parts sources, average prices, swap instructions and other issues that related to this upgrade. Please stay tuned.
To be continued…
12-19-2002, 08:45 PM
#5
Registered User
iTrader: (5)
Join Date: Nov 2002
Location: Kandahar, Afghanistan
Posts: 1,305
Car Info: 09 E90 M3 SEDAN w/DCT
Hey Alex, you copied me on the tranny, and I am about to copy you on the rims!
My brakes did not even fit at all. Gruppe-s has a set of 18x8.5's sitting in their shop right now. Damnit, I loved these Racing Harts!
Andy
My brakes did not even fit at all. Gruppe-s has a set of 18x8.5's sitting in their shop right now. Damnit, I loved these Racing Harts!
Andy
12-19-2002, 09:05 PM
#6
Guest
Posts: n/a
Well, I would like to state one car that was an exception to this rule: The Lexus IS300 aka Altezza. The US version was actually more powerful with its 6 cylinder engine compared to the 4 banger JDM version. Of course, ours had a crap load of weight because of the emphasis for luxury and safety. Don't like it? Then move to Japan!
12-19-2002, 09:15 PM
#7
Admin v2.0
Thread Starter
iTrader: (9)
Join Date: Nov 2002
Location: Alameda, CA, USA
Posts: 6,965
Car Info: 02 Black Legacy GT
I disagree.
In Japan, the Altezza is sold as a performance car. In US it is sold under the LEXUS brand and LEXUS is not a performance brand of Toyota. The reason it got the 3.0L engine is not because it has more power, but just because customers that buy LEXUS would never buy a 2-liter car. Thats a fact. 35,000 4-banger? Yeah right.
Thats simple branding positioning strategy.
The 2-liter Altezza is actually a better performer as the weight distribution on it is much more performance orientated rather than "slap a motor that fits there" orientated. And don't forget that IS only came in automatic for the first few years and even now, they have a 5-spd and not a 6-spd.
So which US gets a bigger more powerful engine, it isn't here to add performance, but rather stimulate the buyes from within its target market. That is why it is possible to see the V8 IS430 here in the US.
Thats not really a discussion I want to get into here, though.
In Japan, the Altezza is sold as a performance car. In US it is sold under the LEXUS brand and LEXUS is not a performance brand of Toyota. The reason it got the 3.0L engine is not because it has more power, but just because customers that buy LEXUS would never buy a 2-liter car. Thats a fact. 35,000 4-banger? Yeah right.
Thats simple branding positioning strategy.The 2-liter Altezza is actually a better performer as the weight distribution on it is much more performance orientated rather than "slap a motor that fits there" orientated. And don't forget that IS only came in automatic for the first few years and even now, they have a 5-spd and not a 6-spd.
So which US gets a bigger more powerful engine, it isn't here to add performance, but rather stimulate the buyes from within its target market. That is why it is possible to see the V8 IS430 here in the US.
Thats not really a discussion I want to get into here, though.
12-19-2002, 09:27 PM
#8
Registered User
iTrader: (12)
Join Date: Nov 2002
Location: Reno, NV
Posts: 18,369
Car Info: 1993/2000/2001 GF4 mostly red
Re: As Humpty put it!...
Originally posted by BADWRX
WELL THE ANSWER IS D, ALL OF THE ABOVE!
I am absolutely positive that the answer is D!
Andy
WELL THE ANSWER IS D, ALL OF THE ABOVE!
I am absolutely positive that the answer is D!
Andy
12-19-2002, 09:29 PM
#9
Registered User
iTrader: (12)
Join Date: Nov 2002
Location: Reno, NV
Posts: 18,369
Car Info: 1993/2000/2001 GF4 mostly red
What's a rough estimate of total parts cost, if there were a group buy organized? No need to be terribly accurate, getting within $500-800 would be sufficient for most of us to determine if the budget will work out.
12-19-2002, 09:43 PM
#11
Registered User
iTrader: (5)
Join Date: Nov 2002
Location: Kandahar, Afghanistan
Posts: 1,305
Car Info: 09 E90 M3 SEDAN w/DCT
Originally posted by Imprezer
I disagree.
In Japan, the Altezza is sold as a performance car. In US it is sold under the LEXUS brand and LEXUS is not a performance brand of Toyota. The reason it got the 3.0L engine is not because it has more power, but just because customers that buy LEXUS would never buy a 2-liter car. Thats a fact. 35,000 4-banger? Yeah right. Thats simple branding positioning strategy.
The 2-liter Altezza is actually a better performer as the weight distribution on it is much more performance orientated rather than "slap a motor that fits there" orientated. And don't forget that IS only came in automatic for the first few years and even now, they have a 5-spd and not a 6-spd.
So which US gets a bigger more powerful engine, it isn't here to add performance, but rather stimulate the buyes from within its target market. That is why it is possible to see the V8 IS430 here in the US.
Thats not really a discussion I want to get into here, though.
I disagree.
In Japan, the Altezza is sold as a performance car. In US it is sold under the LEXUS brand and LEXUS is not a performance brand of Toyota. The reason it got the 3.0L engine is not because it has more power, but just because customers that buy LEXUS would never buy a 2-liter car. Thats a fact. 35,000 4-banger? Yeah right.
Thats simple branding positioning strategy.The 2-liter Altezza is actually a better performer as the weight distribution on it is much more performance orientated rather than "slap a motor that fits there" orientated. And don't forget that IS only came in automatic for the first few years and even now, they have a 5-spd and not a 6-spd.
So which US gets a bigger more powerful engine, it isn't here to add performance, but rather stimulate the buyes from within its target market. That is why it is possible to see the V8 IS430 here in the US.
Thats not really a discussion I want to get into here, though.
My brother in law has a pimped out silver Altezza that I am going to be buying next year.
Not to mention that a BRAND NEW ALTEZZA RETAILS FOR ABOUT 26 grand loaded. And the 6 speed...mmmmmmmmm
Andy
12-19-2002, 09:59 PM
#12
Registered User
iTrader: (12)
Join Date: Nov 2002
Location: Reno, NV
Posts: 18,369
Car Info: 1993/2000/2001 GF4 mostly red
I think you mean 36 G's. The all-time bargain among entry-level sport sedans is the G35 coupe, at 28k which includes 280 hp and sweet supsension tuning. (Double wishbone front and 5-link rear trump a 25k WRX and its 4 McPherson struts, sorry guys.) Not to mention the ease of Infiniti buying experience, the overall quality of the car, longer warranty... and the fact it is the first car in like 12 years to beat a performance-oriented Bimmer in a head-to-head by Car and Driver.
12-19-2002, 10:23 PM
#13
Registered User
iTrader: (5)
Join Date: Nov 2002
Location: Kandahar, Afghanistan
Posts: 1,305
Car Info: 09 E90 M3 SEDAN w/DCT
Originally posted by BAN SUVS
I think you mean 36 G's. The all-time bargain among entry-level sport sedans is the G35 coupe, at 28k which includes 280 hp and sweet supsension tuning. (Double wishbone front and 5-link rear trump a 25k WRX and its 4 McPherson struts, sorry guys.) Not to mention the ease of Infiniti buying experience, the overall quality of the car, longer warranty... and the fact it is the first car in like 12 years to beat a performance-oriented Bimmer in a head-to-head by Car and Driver.
I think you mean 36 G's. The all-time bargain among entry-level sport sedans is the G35 coupe, at 28k which includes 280 hp and sweet supsension tuning. (Double wishbone front and 5-link rear trump a 25k WRX and its 4 McPherson struts, sorry guys.) Not to mention the ease of Infiniti buying experience, the overall quality of the car, longer warranty... and the fact it is the first car in like 12 years to beat a performance-oriented Bimmer in a head-to-head by Car and Driver.
Andy
12-20-2002, 02:02 AM
#14
The new Z is well equipped here in US.
Brembo, optional volk TE37, HID... everything made it here and it's got 7 more hp than JDM.
The G35 coupe is not available in Japan, yet. US got to the first batch.
Nissan USA does a good job recently.
I wish they brought SR20DET....
Brembo, optional volk TE37, HID... everything made it here and it's got 7 more hp than JDM.
The G35 coupe is not available in Japan, yet. US got to the first batch.
Nissan USA does a good job recently.
I wish they brought SR20DET....
