SI vs NON-SI

[BoostedSiCoupe]

But, knowing Honda, they always overbuilt their cars.. they also know that people bought the Si for the performance, and most likely to modify it to increase the power level..

The +9psi doesn't give much increase from +6psi, and as long you don't do the Scramble mode and improve throttle response, the torque curve feels pretty smooth, that's good for your internals.

Not to mention this 10th gen civics have lower redline.

But that's my 2cents though, i trusted my Civic Si with +9psi more than my friends 94 built Del Sol Si with increased 10k rpm.
Aaaaaand i spent less money than him LOL

how long have u been running +9?

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[Sly_Si]

how long have u been running +9?

Since my car off the dealer, about 6 month and 2500 miles now

 

[ApexEight]

Actually the hardness difference it quite significant if you understand the scale. That said they are only designed for stock boost levels.

If performance is what you want and you cant swing an R. The Si is your choice. It is much more performance orientated. The LSD is worth the cost increase alone.

Can you expand on the significance of a ~10% harder rod?

Also, I read somewhere on here that the following parts have different part numbers for the Si: pistons (lower compression ratio), intake cam, turbo (more exhaust side vanes), fuel injector system, DI fuel pump, and I may be forgetting some others. The only super significant one, imk, is the piston. If they are essentially the same with a little different dome design to lower the CR, then that's no big deal. Idk though, because if Honda went through the trouble to give the Si its own pistons, there may be more to it than that. I wish someone would make a thread about the pistons like the guy did about the rods.

 

[Micah]

Can you expand on the significance of a ~10% harder rod?

Also, I read somewhere on here that the following parts have different part numbers for the Si: pistons (lower compression ratio), intake cam, turbo (more exhaust side vanes), fuel injector system, DI fuel pump, and I may be forgetting some others. The only super significant one, imk, is the piston. If they are essentially the same with a little different dome design to lower the CR, then that's no big deal. Idk though, because if Honda went through the trouble to give the Si its own pistons, there may be more to it than that. I wish someone would make a thread about the pistons like the guy did about the rods .

Si (and CRV) turbo has less vanes, 9 v 11 if memory serves.

The biggest difference in my mind is the factory LSD, followed by the upgraded front seats, larger MAF, and everything else that's already been mentioned.

 

[Micah]

how long have u been running +9?

Hondata flashed with +6 around 3000 miles, +9 around 6000 miles, over 14k miles on the engine and zero issues. Bone stock besides the Flashpro and some LED swapped low/high/fog lights.

 

[Robotaz]

I bought a coupe after only driving sedans and the Si coupe is definitely a sportier ride. I don't know the technical differences, but it can be felt.

 

[BoostedSiCoupe]

I bought a coupe after only driving sedans and the Si coupe is definitely a sportier ride. I don't know the technical differences, but it can be felt.

different wheel bases perhaps?

 

[Robotaz]

different wheel bases perhaps?

It feels a lot tighter and jarring to me.

 

[BoostedSiCoupe]

It feels a lot tighter and jarring to me.

the sedans are slightly heavier and look like boats. at least theyre not as huge as the accords those things are fuggin fat

 

[Fazzster]

There are differences in the internals as many here have pointed out. I believe the valves on the Si are sodium filled and the pistons are different than the regular 1.5.

 

[Ruskee]

different wheel bases perhaps?

the sedans are slightly heavier and look like boats.

They are basically the same weight, and have the same wheelbase.

 

[Ruskee]

It would be great if I can drive a non-SI for a day to appreciate how good is this LSD.

In civilized daily commuting it's not that noticeable, but when you start pushing it hard through some curves it is a night and day difference. You can literally feel it pulling you into the corner.

I used to have an EX-T with summer tires and rear sway bar. Did plenty of spirited driving with it on my local canyon roads. First time I took my bone stock Si (w/ factory all-seasons) through the same roads, I was able to comfortably go just as quick as I ever did with the EX-T. It only got better after I added a rear sway bar and learned the car more. Can't wait to see how it does on a good set of summer tires.

 

[TypeSiR]

If you don't mind the stick and sedan format, the Si's increased power, LSD, adjustable suspension, larger wheels and better tires make it a no-brainer. One can easily spend more on mods on an EX-T/L to match the Si's power and handling but will still be without the LSD and adjustable suspension.

 

[ApexEight]

There's a guy in the autocross section with a GS prepared Si that then drove his friend's similarly prepped HS Spot Hatchback and was within .3 seconds of his time. And as for the valves, I believe they share the same part numbers. I believe I covered all internal engine differences in my previous post. Most quotes on engine internals, expect for the rod hardness difference, are heresay, until you look up actual part number differences. At least as far as my research has shown me. The Si is the better deal at the price, but I don't think I can get over the sedan body style, especially since the hatch looks so good and offers a lot more functionality. LSDs are awesome, and usually not cheap.

 

[coopermidnight]

450-watt audio system (same as EX-T coupe vs. 180-watt in EX-T sedan)

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