Rear discs on VX: MPG impact?

[imawakenow]

The p/s drum assembly on my 95 VX is about shot because of worn contact points on the backing plate, which is no longer available from Honda. It's not something I'm likely to find in usable condition in a yard, either. So I'm contemplating swapping the drums for discs. I read a thread about drag being an issue (dragging brake pads, not aero drag). Assuming I can make sure that ain't happening, how much difference should this really add up to? Any guesses? Experience? Thanks.

[cosmick]

It won't cost you 5%, which is half what I'd give up for the 30% better braking. But since you're doing it, do a big brake upgrade while you're at it. Getting 11" rotors inside 14" wheels is easy. 12" inside 15" is also easy.

[Fingie]

It could be easier to swap the whole rear axle. Does the system have ABS and/or a ALB-valve.

[Frank Lee]

If it was me I'd get the welder out and fix those plates for almost free.

[Hicks]

Disk brakes are usually around 7lbs heavier than drums on civics and integra's, a proper setup should make a noticeable impact.

[War_Wagon]

Originally Posted by cosmick

It won't cost you 5%, which is half what I'd give up for the 30% better braking. But since you're doing it, do a big brake upgrade while you're at it. Getting 11" rotors inside 14" wheels is easy. 12" inside 15" is also easy.

VX's have 13 inch wheels though, assuming it still has the factory wheels. I'm with Frank Lee on this one, just fix the backing plates up. The front brakes do 90% of the work, and if you aren't autocrossing the thing you'd probably never make use of the upgrade to discs.

[E.Roy]

I'm with Hicks on the added weight of discs which adds inertia, however the stock disc brakes should fit inside 13" wheels though, just like the base 9.5" front discs do. The EX front brakes at 10.3" diameter require 14" wheels

[imawakenow]

Hey guys, I didn't mean to ask the question and then vanish, but I had some health problems over the past few weeks. Better now. Anyway, yeah, I understand welding is the solution, but it's not among my skill sets, so I'd have to take the backing plates off and find somebody who knows about this stuff and would do it for me (weld on more material, then grind it down to approximate the original level of material). Working on the drums again feels like a pain in the ass to me, so part of me is like, if I'm going to do all that again anyway, just swap in some discs and probably have a bit better braking feel altogether. Tradeoff is some efficiency loss and some reduced confidence in mountain-goat parking-brake situations (not unimportant, I've learned).

Just as background info, I bought my car from a kid who had put Integra brakes on the front, or got it from somebody who did. I replaced the front knuckles and brake calipers and pads and flushed the lines and rebuilt the steering rack... I could go on and on. But I wanted to put the original VX 13" wheels on the car for MPG purposes (I did this; there were some crappy no-name "rimz" on it when I got the VX). So I'm not about to go and beef everything up again, just thinking about swapping for the rear discs because in my experience they're easier to maintain and provide a bit more control through turns, etc. And fitting rear discs from a 92-95 civic ex/si or an Integra should present no problems with the VX wheels.

Thanks for all the helpful feedback. I will have to think about it some more. It's not super pressing, but I'd like to take care of the scraping noise on the p/s when I brake. And what it's telling me. I'm just particular, I guess.

[Ecky]

I'm fairly certain the drag losses will be lost in the background noise. A solid argument can be made for both sides, so I don't think there's an obviously wrong choice. You seem to be leaning toward discs, so my vote is to go for it.