Confirmed (Ongoing) List Of si's 1.5t/6MT differences

ByeVTEC

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I stopped by my local dealer where I used to work and browsed the parts catalog. To my surprise, the si schematics were already available. I only checked a few of the major parts (and I know some have been confirmed already) just to get a good idea what to expect and clear up some speculation. And to note, when I say "si exclusive", this means the si's part number is its own exclusive number and does not cross over to any other model/trim when coming from the factory. Here they are:

Turbo: From CRV (very old news)
Clutch: Same as other 1.5t civics
Flywheel: si exclusive
Complete Head Assy: same as other 1.5t civics
Complete Block Assy: si exclusive
Intercooler: Same as other 1.5t civics


Additions:
Pistons: CRV
Rods: CRV
Final Drive Gear: si exclusive
Transmission: Have yet to find anything that is si exclusive, excluding LSD, flywheel, and final drive
Turbo inlet hose piece: si exclusive
Intake Airbox + Resonator: si exclusive
Fuel Pump Module Set: si exclusive

Shifter assy: si exclusive
Shifter cables: si exclusive


Fr Rotors: shared with civic sport, accord sport, and accord V6
Rr Rotor: si exclusive
Sway Bars: si exclusive (old news) but they look extra beefy in the schematics, even though they can be very deceiving...

I didn't include most of the already known si exclusive parts (suspensions components, steering, etc.) Let me know if there's anything specific you guys want me to check. I knew we'd never really get these answers from Honda for awhile, so I took matters into my own hands:thumbsup:



If you have any questions with part numbers, you can also inquire to your local Honda Parts department (as long as the catalog keeps the si trim open).
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ByeVTEC

ByeVTEC

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Today by me, using Honda's parts catalog at the dealer. Both clutch pieces (friction disk/pressure disk) are the exact same part numbers for all 6MT civics, excluding the obvious Type R.
 

Metfanant

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Is the block assembly, just the block itself? Or does that include the rotating assembly? Interesting to see that it's different, wonder which component(s) actually are different...

Obviously we will need a complete tear down to know for sure...

Clutch makes sense...we're not dealing with enough of a power difference to really merit and more heavy duty of a clutch...nice to see the flywheel is different though...

Slightly disappointed there is no difference in the head, or intercooler
 

maggsgsr

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How about gear ratios?

So far:
Different engine block
Different turbo (CRV)
Different flywheel (hopefully lighter)
 
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JDM_DOHC_SiR

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Wonder is the gear sets are different for the Si? Final drive & 1st~6th gear:hmm:
 

zx2down

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Is the block assembly, just the block itself? Or does that include the rotating assembly? Interesting to see that it's different, wonder which component(s) actually are different...

Obviously we will need a complete tear down to know for sure...

Clutch makes sense...we're not dealing with enough of a power difference to really merit and more heavy duty of a clutch...nice to see the flywheel is different though...

Slightly disappointed there is no difference in the head, or intercooler
The down point I see is that in both the base 1.5T and Si the Clutch is the first upgrade needed. I the Si had a better clutch it would have been able to tune out more power before needed to change parts out.
 

Metfanant

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The down point I see is that in both the base 1.5T and Si the Clutch is the first upgrade needed. I the Si had a better clutch it would have been able to tune out more power before needed to change parts out.
Few things to consider...

How much power are you REALLY expecting to make?...because unless your going beyond CTR levels and you're planning to be throwing drag slicks on this thing launching from 5k repeatedly...I don't think you're going to have too much, if any trouble with the factory clutch...

It's going to be FAR from the first part you need to upgrade
 

zx2down

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Few things to consider...

How much power are you REALLY expecting to make?...because unless your going beyond CTR levels and you're planning to be throwing drag slicks on this thing launching from 5k repeatedly...I don't think you're going to have too much, if any trouble with the factory clutch...

It's going to be FAR from the first part you need to upgrade
Tuners with TUNE ALONE are already seeing the stock clutch slip on the dyno on the regular 1.5T. Throw a downpipe, exhaust, and the better Si turbo on that and yes, you WILL need a new clutch.
 

zroger73

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Wonder is the gear sets are different for the Si? Final drive & 1st~6th gear:hmm:
Good question. Rob Keough said during a TOV interview that "the gearsets in the Si gearbox are beefed up over the standard Civic manual transmission". There was no mention of gear ratios. The training material that was leaked about a week ago lists the ratios for non-Si Civics, but the ratios for the Si are listed as "TBD" (To Be Determined) which might suggest that the Si has different ratios.
 
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Metfanant

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Tuners with TUNE ALONE are already seeing the stock clutch slip on the dyno on the regular 1.5T. Throw a downpipe, exhaust, and the better Si turbo on that and yes, you WILL need a new clutch.
Then it's a shit clutch and should be replaced regardless if you're in an EX-T or an Si and going for a lot of power...

That being said...what I found through a quick Google search showed me clutch slipping results north of 250 ft-lbs at the wheels...that's a significant increase over stock which is in the 200 ballpark at the crank...of course YMMV, but I still think you're going to get away with some decent power increases before you really need to be replacing the clutch on a mildly modded street Si
 

zroger73

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Tuners with TUNE ALONE are already seeing the stock clutch slip on the dyno on the regular 1.5T. Throw a downpipe, exhaust, and the better Si turbo on that and yes, you WILL need a new clutch.
Even though the clutch disc may be the same, perhaps the flywheel could be made of a different material that will increase the torque holding capability. Just a thought.
 
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zx2down

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Even though the clutch (disc) may be the same, the flywheel could be made of a different material with that will increase the torque holding capability. Just thought.
It may help some, but I'd still prefer both it and a good clutch.
 

zx2down

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Then it's a shit clutch and should be replaced regardless if you're in an EX-T or an Si and going for a lot of power...
Which was exactly what I originally said.

That being said...what I found through a quick Google search showed me clutch slipping results north of 250 ft-lbs at the wheels...that's a significant increase over stock which is in the 200 ballpark at the crank...of course YMMV, but I still think you're going to get away with some decent power increases before you really need to be replacing the clutch on a mildly modded street Si
People are getting that from JUST their tune. I would say tune, intake, catback is "mild mod" and that's more than enough to make it start slipping.
 

maggsgsr

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Good question. Rob Keough said during a TOV interview that "the gearsets in the Si gearbox are beefed up over the standard Civic manual transmission". There was no mention of gear rations. The training material that was leaked about a week ago lists the ratios for non-Si Civics. For the Si, the specifications show "TBD" (To Be Determined) which might suggest that the Si has different ratios.
I think it's safe to say to say the trannys aren't the same. We'll have to find out more on the ratios. The clutch thing is weaksouce tho
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