Civic SI trans with LSD
04-15-2018, 10:20 AM
#3
I like cars.
Thread Starter
I’ve never done trans work but I think you have to tear into the team to add lsd. I figured why not just throw in oem Honda lsd equipped trans. Just a straight swap I hope.
Just want that torque steer gone.
Just want that torque steer gone.
04-15-2018, 10:29 AM
#4
Latent car nut
iTrader: (2)
Join Date: Jan 2017
Location: Southern New Hampshire
Age: 68
Posts: 7,844
Received 2,005 Likes
on
1,407 Posts
I've driven a number of FWD cars with manual transmissions and LSD; some have obvious torque steer, others have less-so. Have you driven a Civic Si to confirm the absence (or at least reduction in the amount) of torque steer?
04-15-2018, 11:27 AM
#6
Latent car nut
iTrader: (2)
Join Date: Jan 2017
Location: Southern New Hampshire
Age: 68
Posts: 7,844
Received 2,005 Likes
on
1,407 Posts
The thing is, even with the best LSD in the world, there is still going to be some torque steer; fact of life with FWD cars. I would suggest you spend some quality seat time in a Civic Si to determine of the improvement is enough to warrant all of the work and expense you're going to need to put in to gain LSD for your car.
04-15-2018, 12:48 PM
#7
I like cars.
Thread Starter
Good lord man. Anything with lsd is going to be way better in my tsx. With the extra power that the supercharger gives me, I want the extra traction.
I don’t care about cost. Let’s focus on the point of doing this.
A good si trans costs less then $1000. I’ve seen them for as little as $600. Yes, I know the dangers of buying a used trans.
I do all my labor and that will save me the cash to buy an upgraded clutch.
Just wondering if anyone has done this on a cu2 yet.
I don’t care about cost. Let’s focus on the point of doing this.
A good si trans costs less then $1000. I’ve seen them for as little as $600. Yes, I know the dangers of buying a used trans.
I do all my labor and that will save me the cash to buy an upgraded clutch.
Just wondering if anyone has done this on a cu2 yet.
Trending Topics
04-15-2018, 12:51 PM
#8
Latent car nut
iTrader: (2)
Join Date: Jan 2017
Location: Southern New Hampshire
Age: 68
Posts: 7,844
Received 2,005 Likes
on
1,407 Posts
I think you're missing the point; often with LSD things can actually get worse for FWD cars (the 2004-2005 6MT TLs are a good example). It could be an LSD application helps your car, however, there is a very good chance if you spend the grand on the transmission and then put it in, you'll be very unhappy with the results; in cases like this a little due diligence can go a very long way.
04-15-2018, 01:18 PM
#10
Latent car nut
iTrader: (2)
Join Date: Jan 2017
Location: Southern New Hampshire
Age: 68
Posts: 7,844
Received 2,005 Likes
on
1,407 Posts
When FWD LSD is coupled with an excess of power the car can often become very difficult to handle as first one side bites and then the other side (meanwhile the car is all over the road); it isn't at all like how a RWD/LSD application behaves where you get two nice clean rubber marks on the pavement.
All I'm saying is to drive a Civic Si and decide for yourself; it is as simple as that.
All I'm saying is to drive a Civic Si and decide for yourself; it is as simple as that.
04-15-2018, 01:26 PM
#12
Latent car nut
iTrader: (2)
Join Date: Jan 2017
Location: Southern New Hampshire
Age: 68
Posts: 7,844
Received 2,005 Likes
on
1,407 Posts
Do what you want, it's your money.
$$$
04-15-2018, 03:04 PM
#14
Senior Moderator
subbed for build 
04-15-2018, 04:22 PM
#15
When FWD LSD is coupled with an excess of power the car can often become very difficult to handle as first one side bites and then the other side (meanwhile the car is all over the road); it isn't at all like how a RWD/LSD application behaves where you get two nice clean rubber marks on the pavement.
All I'm saying is to drive a Civic Si and decide for yourself; it is as simple as that.
All I'm saying is to drive a Civic Si and decide for yourself; it is as simple as that.
Last edited by Jaheri_cbp; 04-15-2018 at 04:27 PM.
04-15-2018, 04:25 PM
#16
Anyone who has complained about torque steer in their TL because it has lsd obviously prefers burnouts than go fast cuz torque steer can be controlled by the driver, unless said person just sucks at driving.
04-15-2018, 04:29 PM
#17
Optimusaccord dropped an lsd into his factory trans and loved it on his turbo setup, just FYI, don’t think the trans’ are interchangeable cuz the casings are different, but a factory lsd buy itself does drop right in if desired.
Last edited by Jaheri_cbp; 04-15-2018 at 04:33 PM.
04-15-2018, 04:31 PM
#18
Latent car nut
iTrader: (2)
Join Date: Jan 2017
Location: Southern New Hampshire
Age: 68
Posts: 7,844
Received 2,005 Likes
on
1,407 Posts
04-15-2018, 04:54 PM
#19
04-15-2018, 04:55 PM
#20
It was a 6 speed as well in case you were wondering
04-15-2018, 05:15 PM
#21
Latent car nut
iTrader: (2)
Join Date: Jan 2017
Location: Southern New Hampshire
Age: 68
Posts: 7,844
Received 2,005 Likes
on
1,407 Posts
04-15-2018, 05:19 PM
#22
I knew how to let out when it decided to pull to the right. Call it what you want lol
04-15-2018, 06:19 PM
#23
I like cars.
Thread Starter
I always read that both cars have almost identical motor/trans except for a few minor things. But mounting points are the same.
04-15-2018, 06:46 PM
#24
Sorry, didn’t mean to jack your thread with this nonsense iselfdevi, but I have a feeling you will love the lsd. The older cl and tl type s’ did have bad torque steer but they HOOKED, and I really only experienced heavy torque steer going wot in first gear and ripping into second sometimes, and if I’m not mistaken that was due to a poor halfshalft design in those cars, not the fact they had too much torque with lsd. Like I said earlier Optimus dropped an lsd out of a 9th or 10th gen SI and he loved it with his turbo setup. Pretty sure he just swapped the entire final drive out of the SI into a stock trans if I remember correctly, which makes the gears a little longer.
04-15-2018, 06:50 PM
#25
Well then rock out with the rooster out MAN!!! I just remember Optimus gutting a trans to do the lsd swap. Would be awesome to see your progress on this cuz Optimus was the only person I remember with the cojones to go lsd and write about it in these forums.
04-15-2018, 07:04 PM
#26
I like cars.
Thread Starter
Not sure if I’ll be going lsd anytime soon. I’m looking to get a tanabe catback first. The lsd thing is an idea I’ve had since I went boosted and my front right tire would spin while the left was like, nah.
But when I do it, I’ll be sure to post about it.
But when I do it, I’ll be sure to post about it.
04-16-2018, 08:50 AM
#27
ROTAREDOM
You're not gunna wanna swap out the trans, it's easier and cheaper to just buy the Si LSD and install it when you do your next clutch change. I almost did it when I went with stage 2 clutch, but the LSD was another ~$600. I didn't really have the money for it. Later on I really wished I had done it. I'd say definitely buy the Si LSD and do the swap when your clutch change is due.. especially if you're paying a shop to do it, no extra labor to add LSD.
04-16-2018, 09:00 AM
#28
Senior Moderator
02-07-2020, 05:56 AM
#29
10th Gear
You're not gunna wanna swap out the trans, it's easier and cheaper to just buy the Si LSD and install it when you do your next clutch change. I almost did it when I went with stage 2 clutch, but the LSD was another ~$600. I didn't really have the money for it. Later on I really wished I had done it. I'd say definitely buy the Si LSD and do the swap when your clutch change is due.. especially if you're paying a shop to do it, no extra labor to add LSD.
I want to ask, just for be sure... Does the Civic Si 2012+ LSD fit to Accord/TSX CU2 with 6MT?
04-27-2020, 10:45 AM
#30
Advanced
The exploded view diagrams are much the same, too. 2012 Civic Si:
2011 Acura TSX Sedan transmission:
I'm collecting everything I need for an auto-to-manual 6-speed swap int my 2011 TSX Sport Wagon, so I will try to update with any helpful info as I discover it. I have yet to find any online forum posts nor articles regarding a Civic Si 6-speed into a TSX SW swap, so maybe this topic will help others interested in doing the same.
I also found very little info regarding the gear ratios of the TSX 6-speed and Civic Si 6-speed, so I will edit and add those in a separate reply. Long story short, first through four gears are the same, while fifth and sixth gears differ.
04-27-2020, 11:16 AM
#31
Advanced
Here are the 6-speed trans gear ratios for a 2012 Honda Civic Si, as listed on the Honda Owner's site, found here: https://owners.honda.com/vehicles/in...s#mid^FG4A5CJW
Transmission
Back to top
Close-Ratio 6-Speed Manual Transmission Gear Ratios:
Helical Limited-Slip Differential
__________________________________________________ __________________________________________________ __________________________________________________
Gear ratios for the 6-speed manual in a 2009 Acura TSX, as found here: https://acuranews.com/en-US/releases...specifications
Transmission 6-speed manual
Gear Ratios (:1)
1st - 3.267
2nd - 2.040
3rd - 1.429
4th - 1.073
5th - 0.870
6th - 0.686
Reverse - 3.583
Final Drive - 4.764
2012 TSX 6-speed ratios are the same, and listed here: 2012 Acura TSX - Specs
The Civic Si trans has slightly lower 5th and 6th gears (5% or so), so if you put on significant highway/steady cruise miles, the Civic Si trans might be a better choice.
Transmission
Back to top
Close-Ratio 6-Speed Manual Transmission Gear Ratios:
- 1st: 3.267
- 2nd: 2.040
- 3rd: 1.429
- 4th: 1.073
- 5th: 0.830
- 6th: 0.647
- Reverse: 3.583
- Final Drive: 4.76
Helical Limited-Slip Differential
__________________________________________________ __________________________________________________ __________________________________________________
Gear ratios for the 6-speed manual in a 2009 Acura TSX, as found here: https://acuranews.com/en-US/releases...specifications
Transmission 6-speed manual
Gear Ratios (:1)
1st - 3.267
2nd - 2.040
3rd - 1.429
4th - 1.073
5th - 0.870
6th - 0.686
Reverse - 3.583
Final Drive - 4.764
2012 TSX 6-speed ratios are the same, and listed here: 2012 Acura TSX - Specs
The Civic Si trans has slightly lower 5th and 6th gears (5% or so), so if you put on significant highway/steady cruise miles, the Civic Si trans might be a better choice.
10-21-2020, 07:05 AM
#32
When FWD LSD is coupled with an excess of power the car can often become very difficult to handle as first one side bites and then the other side (meanwhile the car is all over the road); it isn't at all like how a RWD/LSD application behaves where you get two nice clean rubber marks on the pavement.
All I'm saying is to drive a Civic Si and decide for yourself; it is as simple as that.
All I'm saying is to drive a Civic Si and decide for yourself; it is as simple as that.
Tl;dr An LSD will help some, but good tires, shocks, bushings and driving ability are just as important and at the end of the day it is still FWD.
Last edited by Tourian; 10-21-2020 at 07:09 AM.
01-12-2022, 09:51 AM
#33
Here are the 6-speed trans gear ratios for a 2012 Honda Civic Si, as listed on the Honda Owner's site, found here: https://owners.honda.com/vehicles/in...s#mid^FG4A5CJW
Transmission
Back to top
Close-Ratio 6-Speed Manual Transmission Gear Ratios:
Helical Limited-Slip Differential
__________________________________________________ __________________________________________________ __________________________________________________
Gear ratios for the 6-speed manual in a 2009 Acura TSX, as found here: https://acuranews.com/en-US/releases...specifications
Transmission 6-speed manual
Gear Ratios (:1)
1st - 3.267
2nd - 2.040
3rd - 1.429
4th - 1.073
5th - 0.870
6th - 0.686
Reverse - 3.583
Final Drive - 4.764
2012 TSX 6-speed ratios are the same, and listed here: 2012 Acura TSX - Specs
The Civic Si trans has slightly lower 5th and 6th gears (5% or so), so if you put on significant highway/steady cruise miles, the Civic Si trans might be a better choice.
Transmission
Back to top
Close-Ratio 6-Speed Manual Transmission Gear Ratios:
- 1st: 3.267
- 2nd: 2.040
- 3rd: 1.429
- 4th: 1.073
- 5th: 0.830
- 6th: 0.647
- Reverse: 3.583
- Final Drive: 4.76
Helical Limited-Slip Differential
__________________________________________________ __________________________________________________ __________________________________________________
Gear ratios for the 6-speed manual in a 2009 Acura TSX, as found here: https://acuranews.com/en-US/releases...specifications
Transmission 6-speed manual
Gear Ratios (:1)
1st - 3.267
2nd - 2.040
3rd - 1.429
4th - 1.073
5th - 0.870
6th - 0.686
Reverse - 3.583
Final Drive - 4.764
2012 TSX 6-speed ratios are the same, and listed here: 2012 Acura TSX - Specs
The Civic Si trans has slightly lower 5th and 6th gears (5% or so), so if you put on significant highway/steady cruise miles, the Civic Si trans might be a better choice.
01-27-2022, 07:50 PM
#34
Advanced
im trying to pc this out to, my clutch is about to be replaced , I know a lsd from a 2006-2011 civic si would work , not the casing but the lsd can be added from those vehicles , although I wouldn’t mind just changing the whole tranny from a 2012-2015 civic si if it bolts right up to my 2009 6 speed cu2. Was anyone able to confirm this works ?
It's not clear to me what you would like confirmed. The Civic trans physically bolts in just fine. You'll need to change out the shifter cable mount on top, though, as the Civic part is different.
If you are asking if it works only to remove the trans, disassemble it, then swap out only the differential, it should work. Keep in mind you'd be swapping in a used differential, so unless you are able to thoroughly inspect it, you may be better off purchasing a new LSD instead. Factor in new differential bearings, too...right? I was only able to find genuine Honda bearings in Japan, so I had to pay a bit more.
FWIW, I pulled the Civic Si trans I bought apart after about 500 miles of driving, as one of the differential bearings started to go (my bad, I never did an internal check before installing), and while it wasn't difficult at all (only a large hex head socket is required), you do need to be sure everything is properly aligned after you change out the differential. You need to assemble dry, check end play, then adjust with shims as necessary. That part might be more than most would care to do, or have the tools (magnetic stand and dial indicator) to do properly. I priced a new ring gear and mainshaft at $700 or so and decided to stick with stock. Not sure what a new LSD costs.
Thread
Thread Starter
Forum
Replies
Last Post
smily_sleepyeyes
Member Cars for Sale
5
12-15-2014 01:10 PM
GK83
Car Parts for Sale
6
09-13-2014 12:48 AM
Black_6spd
1G TSX Performance Parts & Modifications
32
10-28-2008 06:50 PM