crx hf to si brakes

[tastyratz]

so after talking to a retailer who sells hawk pads ive learned the HF pads are 4" wide by 1 3/4 tall, and the SI brakes are 5" long by 2" tall.
according to the buybrakes.com website brembo has listed the 88-89 SI/DX as the same rotor, but the 90-91 DX/SI as different part numbers. HF the same from 88-91

HF rotors show as:
Type: Ventilated Disc
Overall Diameter: 231mm
Minimum Thickness: 15mm
Overall Height: 43.8mmFits:

1984 - 1987 HONDA CIVIC HATCHBACK w/ Vented Front Disc
1983 HONDA CIVIC SEDAN
1984 - 1987 HONDA CIVIC SEDAN
1984 - 1987 HONDA CIVIC WAGON / WAGOVAN 4WD
1984 HONDA CRX 1500 DX
1985 - 1987 HONDA CRX DX / SI
1988 - 1989 HONDA CRX HF
1990 - 1991 HONDA CRX HF
2000 - 2002 HONDA INSIGHT


The SI brake rotors show as:
Type: Ventilated Disc
Overall Diameter: 242mm
Minimum Thickness: 17mm
Overall Height: 44mmFits:

1986 - 1989 ACURA INTEGRA
1988 - 1989 HONDA CIVIC HATCHBACK
1988 - 1989 HONDA CIVIC SEDAN
1988 - 1989 HONDA CIVIC WAGON / WAGOVAN
1990 - 1991 HONDA CIVIC WAGON / WAGOVAN 4WD
1988 - 1989 HONDA CRX DX / SI
1990 - 1991 HONDA CRX SI

This is a really hefty difference for me in friction swept surface area as well as just plain overall rotor diameter. I was wondering if anyone has tried swapping HF brakes to SI brakes? I dont want some ungodly huge poorly biased crappy brake setup.

What is needed exactly?
Will it still clear 13" hf wheels?
Do I need the SI caliper bracket or can I use the HF one? This is currently one of the bigger obstacle questions as it doesnt seem I can get my hands on the brackets anywhere.

EDIT: according to hondaautomotiveparts.com, the HF and the SI/DX have the same part # when searching for the knuckle. Great, that means anything that bolts to the SI bolts to the HF. I will edit the thread and post my results as I go, any input from others is appreciated.

im assuming crx's all have 56.1mm center bore

ok so I guess it doesnt matter much if the brackets line up, I just found them at a local junk. They are gonna pull the calipers and brackets then give em to me for 60 bucks shipped. I will install them, and probabbly measure between the 2 and post up whether or not the brackets are the same.

 

[tastyratz]

I certainly hope not as I have already ordered all the parts. I would think thats not correct based on the knuckle having the same part # for HF DX and SI

 

[tastyratz]

some stuff came in today. The HF bracket is MUCH smaller than the SI bracket. (not compatible) The SI bracket, caliper, and rotor fit to the knuckle like stock. NO issues, it is a direct replacement. If someone is doing a brake job to begin with on their HF its already going to entail rotors and pads in the least, you can do this at the same time and just pick up some calipers (I paid 60 shipped from a junkyard) for a much beefier upgrade as well as pad selection

 

[phunky.buddha]

Awesome. How's your wheel clearance?

 

[tastyratz]

Im still waiting on pads so I didnt end up putting the wheels back on afterwards, but I highly doubt I will clear 13" wheels now in the front with these just looking at it. The stock calipers look like they BARELY clear the wheels as it is and these are much larger. The caliper itself is just more bulky, the HF one seemed to be cast as dinky as can get by, and its not entirely that the SI is just a larger piston which it is, but overall the casting is alot larger, brackets thicker and longer, etc.

Definitely will add unsprung mass doing this swap but its almost stupid not too with the crappy dinky little HF brakes.

 

[phunky.buddha]

Go with 15s to be safe. There are tons of OEM 15s out there. Did you come over from another board?

 

[tastyratz]

yea ive probabbly got 3000 posts collectively amongst 240sx related boards like zilvia.net, 240sxone.com, 240sxforums.com, nicoclub, etc.

When I used to have a prelude I was on preludeonline.com with around 6-700 posts there (think I had some stuff that mighta made it to faq I dunno... maybe you had seen me there?)

 

[phunky.buddha]

Not sure. Maybe on KA-T?

 

[tastyratz]

bingo, probabbly. ive got atleast 600 posts on ka-t

 

[phunky.buddha]

Yeah. I just responded under a few of your posts there.

 

[tastyratz]

update:
There are no performance pad options listed for the CRX HF worth mentioning... but one thats not listed.....

I found the axxis metal master part #088-1231M to cross fit my HF brakes.

how did I find that out? I ordered performance crx brake pads and these arrived. I just assumed it was for the dx/SI since theres no real other performance options for anything else. they were obviously not the right size but when I tried they fit in the HF caliper bracket with no issues.

I also picked up a set of OEM 14s from my friends 89 mr2 (50$ couldnt beat the price and they fit fine). They have the same bolt pattern, but use a shank style lug nut... Wouldnt you know, that the CRX has the same lug thread pitch as the mr2 meaning the OEM shank style lug nut would thread right on.
Its funny looking at a 13" wheel with 155s, and a 14" wheel with 195s... looks twice as wide to me.

 

[tastyratz]

I stand corrected. The stock 13" wheels ACTUALLY clear the brakes. I didnt think they would, and man is it a tight fit in there... but they do!
Also, mr2 has the same lug pattern... and thread pitch... but not the same hub diameter. The mr2 hub is smaller than the crx by just a few mm, but just enough to make a problem getting the wheel to sit up right.


I just found these things out last night as they finally shipped me the correct metal master pads, and was able to successfully complete the brake install.