Si brakes on LX

Hey guys,

As I understand, Si has 5x120 bolt pattern and LX has 5x114.3, does it mean we can not use Si rotors? Or in this case it doesn't really matter?

LX
Power-Assisted Ventilated Front Disc/Solid Rear Disc Brakes (front/rear) 11.1 in / 10.2 in

Si
Power-Assisted Ventilated Front Disc/Solid Rear Disc Brakes (front/rear) 12.3 in / 11.1 in

Si doesn't have 5x120, it has the same 5x114.3 as the rest of the line up.

I think the Type R is 5x120 (same as last gen Type R) but SI and below have been traditionally 5x114.3 (for the last 10-15yrs). I've looked at a few websites and both 5x114.3 and 5x120 are listed for 2016 and 2017 civic's with no designation for trim level. From the other threads on this forum it was determined the 5x114.3 stated with for EX-T and below. If Honda stays with the tradition the SI has remained at 5x114.3

KYRGYZ said:

Hey guys,

As I understand, Si has 5x120 bolt pattern and LX has 5x114.3, does it mean we can not use Si rotors? Or in this case it doesn't really matter?

LX
Power-Assisted Ventilated Front Disc/Solid Rear Disc Brakes (front/rear) 11.1 in / 10.2 in

Si
Power-Assisted Ventilated Front Disc/Solid Rear Disc Brakes (front/rear) 12.3 in / 11.1 in

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all you should need is the caliper and bracket, plus rotors and pads and 17" or up rims. This was done a lot on the rsx but some people complained about their abs coming on to quick in regards to braking.

Don't want to hijack this thread but anyone know how much/ is it possible to fit the CTR calipers and rotors on the 2016 sedans?

Mannyp93 said:

Don't want to hijack this thread but anyone know how much/ is it possible to fit the CTR calipers and rotors on the 2016 sedans?

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Good luck. CTR is 5x120 and non is 5x114.3. The front design of the suspension knuckle is largely different which will make figuring out the caliper mounting an issue. If you swap the whole supension in, you will then have to figure out wiring in regards to the active dampers, etc. If that is a challenge you want to do, it can be fun!




OP:
Rotors probably fit, caliper bracket probably fits too. The issue I believe will be the master cylinder and brake bias being affected. The prop valve might be off and cause issues with braking.

derbo904 said:

OP:
Rotors probably fit, caliper bracket probably fits too. The issue I believe will be the master cylinder and brake bias being affected. The prop valve might be off and cause issues with braking.

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The proportioning valve should be the key to a good upgrade. Over in EP3/RSX-land, it was recommended to swap to a RSX Type-S proportioning valve if you did a Type-S brake swap. Otherwise, the front brakes would never reach their full potential because the rears would want to lock up too early.

I got a Type-S hub-and-brake swap, but I had also switched to more aggressive pads at the same time, and I had never driven a Type-S stock. So I don't have personal experience with how much performance was possible.

Another part to upgrade would be the brake master cylinder.

A Type R brake job will be so cost prohibitive. You'd need different wheels too.

BarracksSi said:

The proportioning valve should be the key to a good upgrade. Over in EP3/RSX-land, it was recommended to swap to a RSX Type-S proportioning valve if you did a Type-S brake swap. Otherwise, the front brakes would never reach their full potential because the rears would want to lock up too early.

I got a Type-S hub-and-brake swap, but I had also switched to more aggressive pads at the same time, and I had never driven a Type-S stock. So I don't have personal experience with how much performance was possible.

Another part to upgrade would be the brake master cylinder.

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@BarracksSi, I noticed we think alike on a lot of topics. ha!

My 93 civic EX coupe came with rear drums and when I installed DC2 integra rear disc brakes, I installed a larger non-ABS MC from a 91 EX sedan w/ disc brakes, the EX civic sedan prop valve (Model w/ rear disc assembly) and EX sedan Parking brake cables. I also did something similar with my 89 Accord LXi w/ the SEi rear disc brakes, prop valve, MC and cables back in the day.

@KYRGYZ,
If I was planning to do this swap, there is a fair amount of items to research on differences:

• Rotors (Obvious one)
• Caliper + Caliper Brackets (if mounting positions is the same)
• Dust Shield is different part number
• Master Cylinder
• VSA modulator (This is different part number on the Si)

While these all may not be 100% necessary for the swap, a proper swap would require all of it. The VSA modulator might be taking place of the Prop valve? I'm digging around the parts catalog and not finding the valve itself. Most of the brake lines seem to direct to the VSA module which in theory can do what a prop valve does.

derbo904 said:

• VSA modulator (This is different part number on the Si)

While these all may not be 100% necessary for the swap, a proper swap would require all of it. The VSA modulator might be taking place of the Prop valve? I'm digging around the parts catalog and not finding the valve itself. Most of the brake lines seem to direct to the VSA module which in theory can do what a prop valve does.

Click to expand...

Hmm. This complicates things. What we'd also need to know, maybe, is if the car's main computer -- can we call it the MCP, "Master Control Program"? -- sends similar signals to the Si's VSA modulator as it would to our other cars' VSA.

[edit] Probably NOT, because it would account for the Si's LSD, too. At least, that's my guess. [/edit]

Our older cars didn't have this VSA nonsense, so this wasn't a problem we had to deal with.

This isn't something I would want to get wrong. I kinda knew I was only partway there with my EP3 (brake swap without swapping the prop valve) and I'm probably lucky that I didn't really need full braking power on the street.

OP, we're not telling you to not do this; but we don't want you to end up with worse braking performance after all the effort. It'll matter the most when you need to keep from hitting something -- or somebody.

BarracksSi said:

Hmm. This complicates things. What we'd also need to know, maybe, is if the car's main computer -- can we call it the MCP, "Master Control Program"? -- sends similar signals to the Si's VSA modulator as it would to our other cars' VSA.

[edit] Probably NOT, because it would account for the Si's LSD, too. At least, that's my guess. [/edit]

Our older cars didn't have this VSA nonsense, so this wasn't a problem we had to deal with.

This isn't something I would want to get wrong. I kinda knew I was only partway there with my EP3 (brake swap without swapping the prop valve) and I'm probably lucky that I didn't really need full braking power on the street.

OP, we're not telling you to not do this; but we don't want you to end up with worse braking performance after all the effort. It'll matter the most when you need to keep from hitting something -- or somebody.

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Agreed!

As a comparison, when I installed an M3 LSD/subframe into my 330i, I had to recode the Dynamic Stability Control (DSC) to let it know I have an LSD. I unpacked the DATEN files on a computer and unmasked the HEX code to find the M3 values were available on my 330i Unit. I code a few paremeters: LSD = enabled, deccel value = M3 values, accel values = M3 values, rear caliper type = M3 to make sure it worked properly with my rear end.

Before the coding, DSC would not allow the LSD to do it's job and attempt to do the LSD's job electronically. After coding, the DSC allowed the LSD to do it's job and compliment it when things got hairy. Either way, I like it off when I do HPDE but it was nice to code it properly for driving on the street in sub-optimal conditions.


OP,
I think a large amount of research is required for the sake of safety. If this doesn't pan out and you are concern for stopping power, a nice set of pads + rotors would go a long way.

derbo904 said:

Agreed!

As a comparison, when I installed an M3 LSD/subframe into my 330i, I had to recode the Dynamic Stability Control (DSC) to let it know I have an LSD. I unpacked the DATEN files on a computer and unmasked the HEX code...

Click to expand...

F**** that.... lol

OP,
I think a large amount of research is required for the sake of safety. If this doesn't pan out and you are concern for stopping power, a nice set of pads + rotors would go a long way.

Click to expand...

A big +1 to this in general. Pads make a huge difference. Big brakes and cheap pads give no benefit whatsoever (other than posing at the local meet), but stock brakes and good pads can do great.

If a bigger brake setup is still wanted, I'd wait for a reputable firm to research and build a properly-balanced kit, with the right piston sizes and pad swept area to match with the rear brakes and the weight of the car.

so has anyone put on si rotors/pads/caliper/bracket on a non si? Im going with stoptech big brake kit thats made for the si on my non si sedan. if i cant get away with changing just the caliper bracket for the si bracket then ill be replacing the whole geometry with si suspension.

I think they will be a straight swap .You could also swap in EP3 calipers and rotor p&p .