Sei rear disks are they worth it?

[MessyHonda]

one more drum advantage:
the handbrake works


by the disc, sooner or later, it does not.

trust me i love my set up...and i have a dx with stock brakes and it really sucks...my lx-i with brake upgrades holds good...sometimes when im going to park i pull my ebrake and i can lock up both rears.

[Tdurr]

I have locked up my rears with m rear disk. if you have good pads u will lock them up if you yank hard enough. But disk work better overall. Just look at cars with 4drums. ppl swap for disk or die lol
~TDR

[markmdz89hatch]

i think a lot of this is aesthetics and ease of maintenance.

As 2drSE-i said earlier, I personally hate working on drums. To me, they're a pain in the ass to adjust and replace. There's so many moving parts, from the adjuster, the little adjuster clip, the springs, retainter clips, and additional e-brake cable lever inside the housing. PITA.

....BUT...

As Carrot pointed out, drums do have a much better initial bite. ...an Cyra said, the e-brake works. I do have to disagree with the claim though that drums wear faster. In my experiences, the drums actually wear much better then disc. There's just so much more surface contact (ie. better friction=better initial stopping power) on the drums than on the disc. The shoes apply even pressure to about 85+% of the circumference of the drum all at once (theoretically, as long as all of the moving parts work as their supposed to), as opposed to the disc where only the 3~ish inch long pad makes contact to the rotor. I would guess that to be only something like 8-10% of the surface area of the rotor face. Just for arguments sake, let's say the drums are 8" diameter, with a 1.5" deep contact surface, with shoe surface of about 11" per shoe. Also, let's assume a 10" rotor with 1.5" height of braking surface, and an approximate pad size of 1.5x3 inches. Granted, I think that 8" diameter on the drums is a little low, and the 10" rotor might be at least 1/2" too big, it gives you the idea of what I'm getting at.

Drum Surface: [(8xπ) x 1.5] = ~37.70 in²
Shoe Surface: [(11x1.5) x 2] = 33.00 in²
That's 87.5% Surface Contact during braking. ...which also equals tons of heat ...which leads to much faster brake fade/failure


Rotor Surface: [((5²xπ) - (4.25²xπ)) x 2] = ~43.58 in²
Pad Surface: [(3x1.5) x 2] = 9 in²
That's ~20.7% Surface Contact during braking. ...much less than drum. Arguably greater pressure is applied, but although initial bite is less, so too is friction. Also given less surface contact and the open-air nature of disc, as opposed to closed (of drum) heat dissipation is incredibly more efficient.

That said, the reason most all race and high-perf applications are done in disc is because of their ability to dissipate heat and be less susceptible to failure from heat MUCH better than drum. Granted, this will not benefit you much if you use your car for just daily driving.

There should be a weight savings by going to disc, and disc is MUCH easier to work on/replace than drum (IMO of course).

That's all I got, sorry for the long ass reply.

[Accordtheory]

I still have a few questions about this. First, is the e brake really inferior on the disc setup? That would suck.. And so you do have to change your parking brake cables? I really don't feel like dropping my exhaust and heat shield..yet again.

I am now leaning toward the sei rear swap though..at some point. Hitting my rev limit (8500) in 3rd on my ls tranny, looking at my stupid oem tach (wondering why it stops moving past like 8200), then looking up and realizing that I can't stop in time for my turn is what changed my mind..
Anyone know if you can get the ebc pads for the rear discs too?

[russiankid]

Yes you have to swap the cables, the ends on them are completely different compared to the drum brakes.

I have locked my rear wheels with the e-brake before. I have rear discs, so as mentioned with good pads you will lock them up.

[2drSE-i]

yes you can get EBC pads for the rear disks. We use the same rear pads as several other honda cars

[2oodoor]

illuminating exchange of ideas and very colorful explanation sir Markmdzhatch

I am amazed at some of the other comments posted here. If and when I do a disc swap on this 2000 pound car I will use an adjustable prop valve even if I have to use hybrid adapter fittings at the valve.
Corvettes have been using rear disc's for decades.

It is absolutley true from my experience that rear disc wear a lot faster than drums. Where you would replace shoes every 40,000 miles if that, you will have put on three or four sets of pads and remachined/replace rear rotors by then. On some USDM models I see the rear pads wear out well before the front, which is arse bakerds from what we expect to see. I also half suspect some conspiring planned obsolesence by automakers to sell these parts sometimes

[AccordB20A]

yeah my rear pads dont last long for some reason lol

[2ndGenGuy]

Corvettes have been using rear disc's for decades.

They also have tiny drum e-brakes in the rear behind the rotors. Strangest thing I've ever seen, but probably never need replacing or adjusting unless you leave the e-brake on while you're driving.

[2oodoor]

^^^crown vics use the same thing, bad thing is the shoes are bonded not riveted and the linings come unglued all the time. Usually they do not get much attention since the cars are all automatics, plus you can throw them into a pretty predictable J hook without any e brake.

[Hash_man_Se_i]

I would buy them. I am putting mine on my new accord as soon as I have the time. I notice a pretty decent difference between my old sei's braking and my new car.

[snoopyloopy]

idk about installing, but i know they're not hard to remove. i've removed at least four on my own. all you NEED off the donor car is the disc knuckle, ebrake cables, and calipers/associated brake lines. everything else is identical.

[bullard123]

idk about installing, but i know they're not hard to remove. i've removed at least four on my own. all you NEED off the donor car is the disc knuckle, ebrake cables, and calipers/associated brake lines. everything else is identical.

Cool man thanks

[bullard123]

Wow a lot of good pros and cons

[russiankid]

Installation is very easy. Just disconnect all of the lines; remove the long bolt that holds the lower control arm to the spindle, then remove the 4 nuts that hold the spindle to the trailing arm and it slides out. It may be easier if you put a jack under the trailing arm when you install the disc spindle. I had a hard time holding the trailing arm while trying to put the spindle on. The trailing arm keeps moving side to side up and down.

[Accordtheory]

I will use an adjustable prop valve even if I have to use hybrid adapter fittings at the valve.

Same here. I suspect oems bias the brakes strongly forward, like they do with handling (understeering). (at least with "economy", mass transportation style cars) I've never been able to activate the abs on the rear brakes of any car either. Maybe once the front activated, the rear would have if I pushed even harder on the brake, but I've never tried that..

[snoopyloopy]

but of course, how much are you looking at for the set? if it's over $150-200, you'd be better off trying something bigger/better imo...

[Accordtheory]

Yeah, they are pretty small, aren't they..what upgrades exist though?

[MessyHonda]

Yeah, they are pretty small, aren't they..what upgrades exist though?

legend master was trying to figure something else...i have 1st gen rear calipers that i need to install...they have a bigger piston so it would apply more pressure.

[markmdz89hatch]

legend master was trying to figure something else...i have 1st gen rear calipers that i need to install...they have a bigger piston so it would apply more pressure.

As long as you get the prop. valve from it too, or get an aftermarket one. Otherwise, with a larger piston, and the stock propo, you'll actually get less performance out of those calipers.

[MessyHonda]

As long as you get the prop. valve from it too, or get an aftermarket one. Otherwise, with a larger piston, and the stock propo, you'll actually get less performance out of those calipers.

i am already running the se-i prop valve, my old calipers are started to stick...when i have my parking brake on and then after like an overnight when i get into the car ...it feels like they drag on the rotor for the first 20 feet then it stops

[russiankid]

i am already running the se-i prop valve, my old calipers are started to stick...when i have my parking brake on and then after like an overnight when i get into the car ...it feels like they drag on the rotor for the first 20 feet then it stops

That is why you should rebuild them before installing them.

I still have the LX MC and prop. valve. It takes a bit more pedal travel to get any pressure. So if you going to upgrade to bigger calipers, you will get the same effect.

[gp02a0083]

i swapped the front disks on my 87 lxi with the ones i had on my 89 lxi , i HAD to swap the MC b/c i didnt have enough pressure with the system , dunno with the rear discs, ive been reading tho there might be a slight difference with the rear trailing arms

[Accordtheory]

Weird, I have the 88/89 front disks with my old 87 master cylinder, and it works fine.

[gp02a0083]

Weird, I have the 88/89 front disks with my old 87 master cylinder, and it works fine.

my 87 lxi didnt work with the 89 lxi front brakes , well one the knuckles had to be changed, after that the brake lines that are on the 87 are a bit shorter than the 89's. however when i finished the front brake conversion i didnt have enough pressure, went and got a MC for an 89 lxi/sei installed it and it was fine (it very well could have been that my MC was going bad) however 3 things are preventing me from installing my rear discs. one is that i need to order the e-brake cables, 2 is that i want to get rear adjustable control arms to correct for alignment, and third is that i still haven't gotten a positive answer if the lower trailing arms on the 87's will work for the 89 rear knuckles or if i have to now go and find a new set of rear trailing arms