SI transmission in a Sport hatch project

[Shadowfighter]

I'm going to attempt to put a 2017 civic si transmission in to a 2017 sport hatchback. I will also be installing the type r front sway bar and a fx350.

I will be keeping this updated with pics and letting you guys know what problems I run in to.

I'm really excited to start this project. I think its going to be a lot of fun and beneficial to the 10th gen community.

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[Design]

Have you found any major differences between the two transmissions beyond the LSD, shifter cables and the shifter assembly itself?

 

[davemarco]

I wonder if the Type R front sway bar represents the same increase in stiffness as the read sway bar. Do you happen to know?

 

[bahndrvr]

I wonder if the Type R front sway bar represents the same increase in stiffness as the read sway bar. Do you happen to know?

It's higher increase in stiffness but unsure it will fit, the distances, and entire front suspension is different and superior in the TypeR, could luck up and have it work. Si model down is traditional mcpherson strut, TypeR is entirely different animal and superior in every way

Biggest difference he is goign to run into is the CV's are bigger going into the transmission side of the Axle Shafts.... From what I understand the outside axle's are identical but the Insides are different, However some research I have been doing shows some conflicting information so anxious to see myself

 

[pikwit]

This is excellent, the only thing I cared about that the Si got vs the Sport was that LSD...

 

[Shadowfighter]

subframe is out. After looking at the type r bar vs the sport bar I think its going to fit. Honestly a bit disappointed the type r bar doesn't look much bigger.

 

[ApexEight]

Awesome project. Where did you get the transmission and for how much? Do you plan on reusing the rest of the hatch components outside the transmission (shifter, cables, etc.)?

 

[Shadowfighter]

I found it on Ebay for $2000 shipped (I think the price for a useed si transmission will come down as more get wrecked).

I plan on reusing all of the hatch components.

 

[Shadowfighter]

I pulled my cv axles and test fitted them in the si transmission. They don't fit. I'm going to order some si cv axles and go from there. I think I'm going to have the same problem on the brake side.

I'm going to talk to my mechanic friend about how much work it would be to transplant the lsd in to my transmission. I don't think I will go that route but maybe.

I wish I had pulled a cv axle to test before dropping the subframe

 

[bahndrvr]

I pulled my cv axles and test fitted them in the si transmission. They don't fit. I'm going to order some si cv axles and go from there. I think I'm going to have the same problem on the brake side.

I'm going to talk to my mechanic friend about how much work it would be to transplant the lsd in to my transmission. I don't think I will go that route but maybe.

I wish I had pulled a cv axle to test before dropping the subframe

Mentioned at above, as I stated above as well it’s just the inside of the cv’s the outside is identical! You can swap the insides of both shafts and be fine, but it’s easier to just order the axle shafts, I just bought the passenger side Si replacement for 167 shipped yesterday.

 

[Matthyahuw]

Interesting project, good luck!

 

[Shadowfighter]

Got the transmission out and I ordered si cv axles.

 

[Matthyahuw]

Is there a good size difference, or is that just the camera angle?

 

[Shadowfighter]

camera angle

 

[ac143]

Stiffer front sway bar? I always thought that would change the handling balance towards understeer?

https://axleaddict.com/auto-repair/Anti-Roll-Bars-How-to-choose-the-right-sway-bar-for-your-car
https://mechanics.stackexchange.com...s-of-sway-bar-stiffness-on-rough-uneven-roads

Quick links from google, but they all seem to be mostly unanimous that a stiffer front sway bar would increase understeer.

The other stuff you are doing does seem interesting, what improvements do you expect with the SI gearbox?

just my 2 cents