Jump to content
LegacyGT.com

6MT instead of 5MT - what I have to change?


Alex25

Recommended Posts

What I have to change if I want to install 6MT on Legacy GT? I know that I have to buy the transmission (6MT), cardan shaft and front axles. But should I buy rear differential (r180?) and rear axles or I could use stock ones. Will rear axles work with rear wheel hubs?
Link to comment
Share on other sites

There are a few people on here who've done the conversion. Most say it's not worth the effort and expense. I believe there is a lot of changes that need to be done on the axles and differential. You should be able to do a search and find the specific information though.
Link to comment
Share on other sites

There are a few people on here who've done the conversion. Most say it's not worth the effort and expense. I believe there is a lot of changes that need to be done on the axles and differential. You should be able to do a search and find the specific information though.

 

Never heard about anyone here who did such convertion on a Legacy.

Link to comment
Share on other sites

The 6MT has the same overall drive ratio as the 5MT, just more gears. It means that you have o shift more. You can keep the engine in the power band better, but its more work on the drivers part, and if you aren't that fast at shifting, it can be slower.

 

Are you sure?

 

It has different gear ratios vs the STI 6-speed. I am pretty sure it will rev a bit lower on the highway, not too much, but a little. It will also have close spaced gears, but not as close as an STI.

 

That is what I have read at least.

Link to comment
Share on other sites

Looks like the STI's 6th is 3.1% higher than the Legacy's 5th. That is a really marginal difference. The biggest reduction would come from using the Spec B box with the Legacy 3.9 final drive. That still only nets a 5% decrease in RPM for a given gear. It is worth noting that lowering RPM at a given speed won't always increase fuel economy. My Audi A4 1.8t turns 2800 revs at 65 and still gets great mileage. I get roughly 25-28 in town and 32-38 on the open road. Not bad for 3400 pounds and all wheel drive.

 

STI 6speed manual

1st: 3.636

2nd: 2.375

3rd: 1.761

4th:1.346

5th:0.971

6th: 0.756

final 3.9

 

 

 

LEGACY 2.5

5spd manual

1st 3.454

2nd 2.062

3rd 1.448

4th 1.088

5th .780

final 3.90

 

 

 

5spd manual available on sedan only including spec.B

1st 3.166

2nd 1.882

3rd 1.296

4th .972

5th .738

final reduction 4.111

Link to comment
Share on other sites

can someone explain how the gear ratios effect the cars performance/acceleration briefly?

 

Tighter ratios between gears means less RPM drop with each shift. Power output varies with RPM (check out any dyno chart). With the bigger turbos max power band is smaller so it's not as easy to stay in the power band after a shift. Thus tighter ratios can help, but it means more shifts.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.



×
×
  • Create New...

Important Information

Terms of Use