H12 ABS Swap
 

Started collecting parts for an ABS swap from an H12 GF-FD3S.

I probably wont get around to installing the parts any time soon since the engine bay, etc needs some paint but I figured I'd start a thread where we could toss ideas around and junk.

http://img151.imageshack.us/img151/4259/h12abs001.jpg
http://img27.imageshack.us/img27/6070/h12abs002.jpg

I have more 2 more units and computers coming so if anyone is looking for them stateside.. I got 'em:

How does the late model ABS compare with the S6's?

Well a part from being 32bit vs. 16bit and 4 channel vs. 3 channel - i wouldn't think much else would be different from a functionality point of view.
hardware wise, a good deal is different. The early model harnesses DO fit but are *probably* pin'ed incorrectly.

Once I find the H12 manuals I'll know.

My plans are to wire my EMS and ABS computer and build some traction control logic(s) within my EMS so I wanted the 4 channel / newer ABS unit.

ive always wanted to do this but the thought of wiring it up kinda put the kibosh on that idea. im staying tuned to see how far you get! :D good luck! if you get it to work i want one

Subscribed!

Well... guess what, the plugs are 90% the same. ;-)
The ABS (9pin) plug and the Power(2 pin) plug are correct but you'd probably need to spend $10 or so in a pin-extractor/de-pin tool and swap 'em around.

I still need to figure out the wiring on the newer unit but its likely not going to be much of a problem. Two things hold me back.. #1 I'm lazy and #2 I need the jspec manuals.

There are auctions I see for the manuals on CD(pdf format) but I do not speak enough Japanese fluently (or type for that matter). If anyone could help with communications...

thats the other thing that stopped me... not being able to read japanese. Also, what about running the separate brake lines to the rear, and are there different sensors from the rear or its the same thing we already have? if you figure this out ill buy one set of your parts with the instructions to put it together. dont mothball this thing so quickly LOL! if the engine bay needs paint, now would be a good time to mess with this thing, as you'll probably scratch it up some trying to put this all together. DOOO ITTTTT :D

Also subscribing to this thread.

Anyone care to contact this guy?

http://auction.jp.msn.com/item/120720569

Here is the Bosch Connector.. The computer wants a 55pin connector.. the one shown here is an 88way connector but it leads ya to the right place.


http://www.bosch-connectors.com/bogs...&attrv_id=2219
URL -> Bosch Connector

I did manage to pick up a huge harness lot from a 2001/GF-FD3S...
This contains just about everything I need to start manually tracing wires and such.

I removed the ABS unit, lines, brake booster, etc last night - seems the provided stock ABS bracket from the GF-FD3S will work out just fine with slight modifications.

...still learning about running brake lines myself. figured i'll run the rear brakes along the driver's side of the car (vs. up & over the firewall/vin area). it's going to be a loooong & cold winter ;-)


http://f20batchimg.auctions.yahoo.co...9091000028.jpg


Also replacing my brake stuff with newer parts from the same GF-FD3S

http://f14batchimg.auctions.yahoo.co...9090800009.jpg

hahaha that picture alone convinced me that I no longer want any part of this! DEAR GOD.

hwnd you're crazy. Good luck dude

FWIW, I would use the newer Cunifer brake lines which are easily bent, and are corrosion-proof.

The copper nickel alloy is DOT approved hard brake line, and the alloy is now being used by Aston Martin, Porsche, etc.

:-) neil

http://www.fedhillusa.com/

^very slick! good luck with the project, and if this goes down its gonna be epic!

subscribed to keep an eye on this, best of luck to ya.

you're missing the point - I dont need to *replace* all of that... I simply bought all of that "mess" since I can't seem to find the 2000+ factory service manuals. ...well I just need help buying them really. Anyhow, this harness (or collection of) is uber important for understanding how these components are linked together.

I'm replacing brake booster because i want a clean engine bay & it came from a 2001 FD, should be in great shape (and clean!).


neil.. thank you very much for that tip. very nice timing. ;-)

Wow I'm very excited about this and to see that you are slowly (well youre actually moving on this pretty fast) making progress!! :icon_tup: Is there anything in the FD brake system to the rear which is downstream from the ABS unit like check valves etc? I suppose the manual would list all that. Any difference between the 93 and 99 brake booster (besides being newer and in better shape?) I'm really glad you are undertaking this... it's been something i've been interested in for a long time!! -Heath

I don't think there should be anything inline (ieg: check valves) but you're right, the FSM will be the final word on that note. An interesting subject is "brake lines". How on earth do these shops manually fit brake lines on a chassis? Well I know how, just seems like a good deal of work for a less-than-ideal fit (IMO). I am looking at (only looking at this point) cnc tube bending process.

My idea about how the brake lines should run from the rear are pretty simple. I think the two should pair up on the passenger side and follow the underside of the body and head straight up to the abs unit. I am planning on using "service point" to be mounted on the firewall (down low). My lines will probably end up looking a lot like the Mazda lines - just on the other side of the car. Doing this will help free up the clutter from the firewall.

The idea about a cnc'ed tubing bender (for brake lines) is very interesting but i'm not 100% sure that i'd be able to give the proper bends... could always try though! :-)


I didn't notice anything majorly different about the newer brake booster. The clutch & brake line block sit on the other side of the fluids container but other than that... i didn't notice anything. I experienced a brake booster failing (internal boot failure) which ended up filling itself up with fluid. Mine is still in good shape and very low mileage but i really don't want to deal with that again - that might have been a major factor in the decision to remove the older one (hoping it might be an updated part).

I should take delivery of the wiring harnesses and other junk by next Friday which should leave that weekend free to explore the wiring differences.

I can't really explain why I decided to jump on this project. I couldn't sell this to anyone in terms of gain vs. loss or major advantages.. its just a 4 channel ABS system with a 32bit computer. It does mean that the computer is faster so it should be quicker to respond to a situation. But I think the main goal here is upgrading my car with the latest from Mazda. to me, an ideal FD would have been the last model RZ with a factory 20B. I think I would gladly drive it bone stock for years. ...anyhow, that's my long term / long view goal in short. this abs is just part of it. well i'll also be able to do some trick stuff with it once I'm up and going again.

If someone could package this for an easy install I would pay alot for it thats for sure. Im sure alot of people here would. I like your long term goal. Its somewhat similar to mine although I have given up on it.

feel free to PM me if you want to talk about this offline.

yeah.. this is going to be really easy.

i've got both JDM & USDM harnesses here (the interior harnesses) and i'm seeing exactly what it'll take. Shall give updates as they come.

Its functional - I have the ABS Computer mostly finished. I've got to double check the ABS Unit/pump wiring once more but I am positive that the swap can be done with minor (re)wiring. I do have a new set of ABS wheel sensors coming from AU. They've got a different part number but it doesn't mean they work differently (i.e. different output signal). What I'm very interested in now is a handle held device to purge the ABS Pump (open/close the valves).... maybe that's another project.

I am 99% lazy BUT I should have a full schematic laid out for the swap in terms of wiring in the next few weeks.

Subscribing

Great job man. You are progressing really quickly.

if anyone is interested in picking up the extra abs computer and abs pump - let me know.

i will not be installing the lines any time soon but there was a site pointed out Neil
http://www.fedhillusa.com/

From what I've seen, there's been three different types of wheel speed sensor, with just minor detail difference in the molding where the wire goes into the sensor itself...think S8 have the white collar at entry from memory. They all seem to test the same resistance wise and interchange freely, if they were the ebay ones, probably doing OK anyway, go for around $Au300 each down here new, eek!

If you come across a 95LHD rear harness might save a bit of labour, should already have the Bosch plug as that was equivalent to Japanese Version III on, which had the earlier ABS ECU change. Pump connections might require more thought though.

wow, i picked mine up for about that - pretty costly but the payoff is going to be huge!

Negative there mate, the 88-pin (3 row) Bosch plug didn't show up until 1999 for all cars. I think the older style has a pin count of 55 and the newer one is about 88 pins.

however there are still the same number of wires used plus 3 extras. swap has been easy. i wont be running the hard lines for a very long time however so i can't road test it. it'll either "lock" or it wont.

99+ brake booster is 20% smaller in size and needs more "hand power" to operate.At least thats what i experienced when i installed it.The only noticable difference with all the other parts being 93's is 10% less pad knockback effect...

interesting - i did not notice any size difference at all.

so pedal effort is increased with the newer one? This would make sense as they also dialed back the power steering 20% in 99+ (supposedly) which I'd also like to replicate. I wonder if they touched the clutch pedal force at all? I would think so as the newer cars were putting down 280. We need a parts manual to cross reference part numbers, that will answer all of these questions. I want a FULL 99 spec conversion lol

Me too!! I cant wait to profit of your hardwork.

Peculiar, given the number of vacant terminals in the old plug. Had a look at what I think are the "new" sensors too...all black - no chrome ring, ones with the white reinforcement are S7.

There's no change in the clutch hydraulics over the entire run. Gomez has linked to a slave that reduces pedal effort (going the other way!) from one of the Japanese aftermarket companies elsewhere. Any brake place worth their salt, could accomplish the same pretty easily, if there was that desire.

yes i see... wouldn't have thought to even compare the differences.
good info - thanks for posting the link to that!

I haz your parts manuals - well actually Japan has them currently but they're being sent to me very soon. I bought the entire FD manuals collection from '92 on up (this includes the parts guide for those models).

Old vs. New

Nice

Finished - managed to figure out where all the wires go and what they're used for.
Was a pain as some of the wires might start out as white but would turn into a different color & gage (22awg to 20awg or even 18awg).

ABS Pump / 10pin
ABS Computer / 88Pin
ABS Wheel Sensors / 4 * 2Pin
Diagnostics Port
etc

I'll be wiring one up in the car shortly - it'll be months before I am able to go out and test the ABS unit but I can at least wire it in.

Attached a photo showing what my wife allowed me to do with the spare sitting room :icon_tup: Laid out is a 2001 RX-7 RS body harness, dash harness & interior-rear harness.

Holy crap!!! and THATS why i was afraid to ever start on this lol. My hat comes off for all your hard work... this looks like medusa ! GREAT JOB!

If you have the patience to make a how-to guide or do this for a price, I promise you will have some interest!

Thats where I'm headed next - I'll probably have that guide finished soon.
still have some parts left over too;

Dual MC68HC11E9 Processor
 

The ABS Computer *might be* reflashable. It has two MC68HC11E9 processors on-board.

I have the adapter boards for programmer but I have no idea what I'd want to do to it or what changes I'd like to make.

However, would be nice to be able to open the valves and bleed the ABS unit on command! :-)

Haha damn, you are way smarter than I am when it comes to all those fancy computer thinkin boxes! Really glad to see some one take this on

i may have missed it but, what is the advantage to doing this?

Good question.. Here is what Mazda said about the 2000 GF-FD3S


Four-channel, four-sensor ABS - This is the best scheme. There is a speed sensor on all four wheels and a separate valve for all four wheels. With this setup, the controller monitors each wheel individually to make sure it is achieving maximum braking force without locking the wheel(s).

Three-channel, three-sensor ABS - This scheme, commonly found on pickup trucks with four-wheel ABS, has a speed sensor and a valve for each of the front wheels, with one valve and one sensor for both rear wheels. The speed sensor for the rear wheels is located in the rear axle. This system provides individual control of the front wheels, so they can both achieve maximum braking force. The rear wheels, however, are monitored together; they both have to start to lock up before the ABS will activate on the rear. With this system, it is possible that one of the rear wheels will lock during a stop, reducing brake effectiveness.


In other words, you can drive/corner the car harder without spinning out because the ABS computer able to pay attention to each wheel.

Earlier FD RX-7's used Three-channel, four-sensor ABS .. so each wheel was individually monitored but if either back wheel starteed to lock up bracks were released on both wheels.

Photos!~!
 

Here are some photos I took while disassembling the ABS computer and pump.

Computer

http://img200.imageshack.us/img200/143/abs001.jpg

ABS Assembly

http://img42.imageshack.us/img42/4167/abs004.jpg

http://img200.imageshack.us/img200/6844/abs005.jpg

http://img246.imageshack.us/img246/5369/abs006.jpg

http://img42.imageshack.us/img42/4410/abs007.jpg

http://img42.imageshack.us/img42/4407/abs008.jpg

http://img42.imageshack.us/img42/1192/abs009.jpg

http://img131.imageshack.us/img131/2426/abs010.jpg

http://img62.imageshack.us/img62/7668/abs011.jpg

http://img129.imageshack.us/img129/5205/abs014.jpg

...more

http://img62.imageshack.us/img62/1133/abs015.jpg

http://img129.imageshack.us/img129/9231/abs019.jpg

http://img113.imageshack.us/img113/6066/abs020.jpg

http://img337.imageshack.us/img337/1390/abs022.jpg

http://img200.imageshack.us/img200/7899/abs023.jpg

http://img131.imageshack.us/img131/2424/abs024.jpg

http://img42.imageshack.us/img42/6996/abs025.jpg

Wheel sensors measured in resistance

rear: 1.6ohm
front: 1.04ohm

I have other sets I could test but for the moment this is what I've decided to post up.