CamMan83

Is there anyway to fit ABS brakes on a third gen camaro? Thanks

MrDude_1

lotsa hard work.

first you need to have your wheel speed sensors... 3 or 4 depending on what system you're using.

the rears no prob if you can use a 4thgen rear and its sensors.

the fronts need to have the "hub" of the rotor machined to work. neck it down, press on a exciter ring, ect..


then you need your ABS unit.. and brake line plumbing...

and to top it all off, you have to have some way of programming and setting up the ABS...


now alot of that can be eliminated using a 4thgen setup...

Matthew91-Z28

Can be done as MRDUDE stated. Check out howstuffworks.com and research ABS. Looks simple enough.

4th gen rear and machined front rotors from a early 90's chevy ABS car w/ same bolt pattern (S10), C4/LS1/C5 front brake setup or something similar that uses a hat with separate rotor.

I'm gussing there are diff designs in the speed sensors on thr hubs as ABS got more sophisticated. So, I guess you'd have to find a donor S10, get the rotors with sensors, the prop valve, find the ABS brain, and get all the wiring.

As far as plumbing, I don't think that any lines have any ABS hardware in them. So you could use your stock lines and plumb in new fittings as needed to hook them up.

Basically, the wiring run from the 2 front sensors in front (from each front wheel) and from one sensor the back (I think) to the ABS brain. From there all sorts of things are taken into consideration and signals go out through 3 separate wires to the prop valve to control the L. front, R.front, and the Rear as needed.

The signal operates a valve in the prop valve that causes the decreased brake line pressure to whichever line needs it and prevent lock-up. Some of the more sophisticated systems can cause those lines to pulse at freq of 60/sec.


I think the biggeset pain would be finding a donor car with all the parts. Or...you could go to GMparts direct and find them all. Actually...the biggest pain is probably hooking all the wiring up. The computer won't need to be programmed. Just plug and play. There is no connection between the ABS brain and the car's computer. I believe they work indipendantly of one another.


Someone WILL successfully do this soon. It can be done. Having LS1 brakes on our cars seemed impossible until a few simple observation were made less than 1 year ago (the first being use of a "hat" from a stock rotor, and then someone noticing that an aftermarket bracket might be modified a bit).

Just a matter of time....

MrDude_1

Shhhhhhhhhhhhh!

CamMan83

Well, I'll start looking into it then. Thanks for the info! IF you think of anything else be sure to post! Also, I think third gens should have been fitted with it anyways considering the power they can produce...I know it was invented in the late 80's but those could have had it and the early 90's as well...idk what they were thinking. Oh well, we'll get this figured out!

robertg

iTrader: (2)

be carfeful when you look at s10's.....

some have 4 wheel abs, and some have rear wheel abs only.

Dewey316

something along these lines may help...

http://www.racelogic.co.uk/wsp.htm

not sure what you would do for the computer part of it, and getting the correct pulse number determined by the ABS computer, but that makes for an easy way to mount the sensors on our cars.

Matthew91-Z28

MRDUDE:: I figured this was kind of a quiet topic because someone wanted the fame from being the first to do this. I thought the same. Then figured it might be best as a group effort for trial and error stuff.

CamMan:: I'll tell you why the last of the thirdgens did not get it: $$$$$$$$$$$$$. What would it have costed GM to do this when they already had it developed for others in the fleet? Not much. They did not do it , I'm dead sure, because 4th gens were already off the table and ready to be put into production before '93. GM wanted to increase sales on newer f-bodies by holding ABS, rack/pinion, etc for the new body style. Kind of makes you feel like the red-headed step child doesn't it??

***I've been looking at GMpartsdirect and found the parts numbers. I have no idea where each one goes. I tried to bring up the graphic but can't because I don't have a TIFF viewer. The graphic would demonstrate where each item goes I hope. If someone else can bring it up.....mail it to me or post it here, please.***

Else I'll have to buy a Chilton for an S10.

I assume RWD S10's are 3 channel (1 sensor somewhere in the rear...maybe in the differential, and 2 sensors at the front rotors). Hell you could just run the two front channels to test it.

Jeez....depending on how similar the sensors for the 91 S10 and the 4th gen, you might be able to run with a 4-channel 4th gen ABS computer, 4th gen rear rotors, and S10 front sensors.


HMMMMmmmm.....I wonder how similar the S10 rotor is to 3rd gen rotor. Maybe someone can take a trip to a yard and check it out or know anyone at a parts store to make a comparison.

Matthew91-Z28

WOW...just checked out that racelogic link.

Now that is cool. Would be really neat to get 4-wheel ABS going and then add 4-wheel taction control. That would be pretty close to the ultimate in handling (of course, assuming that you've already got the suspension hardware bloted on).


If you have 4-wheel ABS all you need to do is splice in the traction control wiring. That's friggin cool!:rockon:

I think the chevy ABS sensors are already built into the rotor hub. So I don't think mounting them is the issue. The issue is finding a rotor with sensors that is a direct replacement (unlikely) or finding a rotor with sensors that can be turned into a hub.

alloy

iTrader: (16)

Guys, FYI:

For my brake kits I make, I used a old rotor of my kids 1991 S10 to make into a hub. As a matter of fact, that particular hub is on Dewey's car right now behind his C4 brakes.

So, if you can find out if a newer S10 rotor will fit onto a 1991 S10, then your in business.

I mentioned this in another ABS brake thread some time ago, but seems that everyone has forgotten about it.

CamMan83

Matthew: What are those part numbers from GMDirect....I can look those up tonight...or whenever you send them to me and I can most likely get the pics to pop up and then i can try to post them on here or i could mail them to ya too...Also....if it doesnt snow here in kansas on saturday i'll take a trip to a couple of junkyards and see how things are looking for the S-10's, I'll look at the rotors, abs control module, and the rear axle and i'll get the prices for all of them too. BTW, out of curiosity, what year would be the best to get just a three channel abs setup. That would be adequate enough.

Matthew91-Z28

You guys have perfect timing. Alloy...You friggin rule! Thats exactly what I needed to know. Good timing. I'll explain.

This info is all from Chilton for 83-93 S10 Blazer, S15 Jimmy/ Typhoon, Bravada.

RWAL (rear wheel anti-lock): Standard on S/T series trucks in 1989, also on 89-90 + 91-92 2Door versions of all cars listed above. **Typhoon + ALL 91 4-door versions and later came with 4WAL (four wheel anti-lock).**

RWAL consists of a control valve (aka isolation/dump valve, aka anti-lock pressure valve) located under the MC. This will hold, incr, or decr pressure to brakes as per ECU. ECU recieves signal from VSS (vehicle speed sensor.....located at instrument cluster) which recieves signals from speed sensors at the wheels. The VSS is susceptible to changes in axle ratio and tire size.


Thats not the one we want. The RWAL only monitors the rear brakes and only adjusts pressure in the rears.


The 4WAL is the system we want. DO not get this from a 4WD vehicle as engagement of 4WD disengages the ABS. Doesnt really matter as we don't have 4WD (but I thought it could complicate things).

4WAL: found in 91 4-door vehicles and standard in 92 and later. 1991-1992 were unique in that they had 4 wheel sensors instead of 2 front sensors and VSS for rear wheel speed.

Consists of 1) wheels sensors, 2) brake pressure mod valve (aka BPMV or EHCU or BPMV/EHCU 3) ECU.

The BPMV is located next to the M/C and combnation valve assemblies. It has 3 multi-pin connections.

The ECU (I think) is located close to these assemblies. Its wired into the ignition and has a lead running to the guage cluster that lights up for 2 sec when starting the car. Any malfxn in the system will cause the light to remain on. (Do we really need to run it to the guage cluster? I think not. At least not right now.)

That takes care of the plumbing and brain. No problem. Done easy enough. Lines from the M/C to the BPMV and then out to the brakes. ECU only connects to the BPMV to control solenoids within to hold, incr, or decr pressure per line as needed.

The Sensors. Ok....this really consists of two things...1st, the SENSOR itself and then the TONE WHEEL (a little ring of metal with teeth at its outer diameter). The sensor monitors the speed of the metal teeth as it turns and thus the ECU can monitor a sudden decrease in speed at a wheel and send signal to the BPMV to decr pressure to that wheel.

For the FRONT::

The sensors (low and behold) are mounted on the outside (facing the tire) of the BRAKE ROTOR SPLASH SHIELD, and sit on the outside of the splash shields center hole, through which the spindle inserts.

The TONE WHEEL is located in the depression of the inner part of the rotor. Thus, it turns at the speed the rotor is turning. This is for 2wd vehicles only. 4wd is a different story and should be avoided entirely.

For the REAR::
IN 1993 and later, all 4WAL vehicles controlled the rear brakes via the VSS mounted inside the tranny (4l60-E) at the left rear side.

For 1991-1992 vehicles, there are 2 sensors per wheel located on the backing plate of the DRUM setup.

WHAT THIS ALL MEANS::
As alloy said (Thank *** he chimed in and actually thats where I remember hearing about S10 rotors for this in the first place) S10 rotors can be turned into hubs for your LS1, C4, C5 brake project. Dont know if you can use a stock rotor as replacement though (maybe). So, as long as you get the rotor splash shield (which has the sensor) and the rotor-turned-hun (which has the tone wheel), we are golden. Then as far as the front ABS goes, its a matter or running wires and plumbing in hardware.

But for rear control......I don't know. Does the 700r4 have a VSS inside it? If so, can a VSS be used from a 93 version of one of these vehicles and screwed into a 700r4? BUT, the VSS is suscpetible to changes in axle ratio and tire size.....so maybe a VSS from the appropriate 4th gen f-body. But will that signal jive with an ECU from a early 90's ABS ECU?

Alternatively....the 1991-1992 had a sensor at eahc rear wheel instead of VSS. Only thing chilton said was that it located on the backing plate of the drum. SO too bad I guess if you have disc. But can these be used on a 3rd gen backing plate? Or even transfer backing plates from one to the other?

But it may not even matter if the fronts control most of the braking. Same plumbing would be involved and just not let the ECU recieve a signal from the rear. In that case, the solenoid in the BPMV would allow the brake line to remain open for business as usual.

SO conceptually, front ABS is entirely possible as we know it right now. Lets figure a way to get the rears into business too.

Sorry for the long post.

alloy

iTrader: (16)

Matthew91-Z28-Thanks for the compliment. Just trying to help a little if I can.

I'm not sure if the complete rotor without modifying it into a hub will directly interchange, so don't count your chickens before they are hatched yet. May be different back spacing and other differences . All I know is that they will fit onto the spindle and use the exact same bearings. I've never tried to swap a complete rotor over. Just used the old scrap rotor to make a hub out of.

Now I've not seen an ABS S10 front rotor, so those of us with upgraded front brakes may not be able to use a S10 ABS rotor that's cut down. The tone wheel may not be there once the rotor is cut down to make it into a hub. But, at least you know the rotor fits onto our spindles and that's a start anyway.

Good luck with this project.

Matthew91-Z28

With the rotor shaved into a hub.....it will work. I wish I had a graphic to show what I mean. But after seeing the picture in the chilton manual and how the tone wheel fits to the inside of the rotor, turning the rotor into a hub won't affect it at all. The tone wheel looks to be about 2 in" in diameter. It will be there....You'd have to cut all the to within 1 inch of the center of the rotor to cut into it.

Complement is deserved, my good man, after all the work you did with the C4/LS1/13in rotor upgrades. Glad to see you add your 2 cents to this discussion.

If the whole rotor swaps, its fine. That means basically stock brakes with ABS. If the whole rotor doesn't, but the hub does, thats fine too. Means though that you;d have to spend $500 on upgrading the front brakes first though before you could attempt the swap over all the other ABS goodies. But all the better for performance. This conversion isn't for the weak at heart anyway.

Just got to figure out the rears....any thoughts? Does a 700r4 have a VSS (vehicle speed sensor)?

Matthew91-Z28

These are all the antilock parts for 91 S10 pickup:


ABS PRESSURE LIMIT/ DUMP VALVE

Add to Cart Application Part Number View Graphic
All application models 15661378

ABS SPEED SENSOR

Add to Cart Application Part Number View Graphic
4WD 15693490
RWD 15693489

DCMB SIGNAL RELAY

Add to Cart Application Part Number View Graphic
All application models 25097359

ELECTRO-HYDRAULIC &/OR CONTROL MODULE

Add to Cart Application Part Number View Graphic
Part number shown is for pricing only. For proper application, refer to local supplier. 15976820

PRESSURE MODULATION ABS VALVE

Add to Cart Application Part Number View Graphic
All application models 15661378




As far as I can tell, for 4WAL, we'd need 1). the "ELECTRO-HYDRAULIC &/OR CONTROL MODULE" aka BPMV or brake pressure modulation valve, 2) DCMB SIGNAL RELAY (ECU??)
and 3). ABS SPEED SENSOR for 2wd.

But...these may be able to be pulled from the donor car for much cheaper. I'd prob be inclined to buy a new ECU.

alloy

iTrader: (16)

I've got an 87 with a 5 speed. And the 700R4 I have for my 55 chevy is a mechanical speedo also. But I believe the newer 90 and up maro's and bird's use an electric speedo. Maybe be able to do something that way.

Or, get one of the zexel posi take outs with the tone ring on the carrier body and swap it and the sensor into a older 10 bolt rear.
Or maybe find a way to mount sensors to the inside of a rear brake rotor. I've seen never S10's Blazers with rear disk brakes. Not sure if they were ABS equipped though.

Anyway, just a thought or 2 on my part.

Matthew91-Z28

Attached free-hand graphic of sensor and tone wheel. Cant see tone wheel b/c its inside the rotor (about same diameter as sensor).


You see, alloy, I was thinking about how 4th gen f-bodies fashioned their rear ABS. Is it a tone ring on the zexel torsion that they use? Interesting.

Well...according to chilton, If it was a 91-92 Blazer, it should have sensors at each rear wheel. Amd the only graphic they had showed them on a drum rear.

IN 93, all used a VSS in the trans case [be them drum or disc].

This is IMPORTANT here because I think that Chiton mentioned that the spring resistance in the rear drums made difference into when ABS was triggered. I think its important b/c I don't know how similar S10 drums are to 3rd gen.

I THINK that 4th gen f-bodies use a very similar setup for ABS. I would imagine that they use sensors and tone wheels just like the S10's (and other vehicles like it ) up front, but that they use the a different mechanism for the rears that may be more applicable. (i.e tone ring on the posi carrier).

Here is my idea of the best fitting ABS setup::
1). 91-91 S10 rotors turned into hubs (tone wheels included) with a C4/LS1/etc upgrade.
2). Either S10 or 4th gen sensors for the front (I don't know where 4th gen sensors fit...but prob on the rotor splash guard too).
3). 4th gen ECU + BPMV
4). 4th gen rear w. tone wheel on the posi carrier

Now you could do either and just not set up the rears for ABS. Prob does not matter. But if you wanted to eventually get all 4 wheel abs......I'd use 4th gen parts.

I need to look in a 4th gen f-body Chilton

CamMan83

Okay Matthew...sorry the pictures as well do not come up for me. Hopefully someone will get those to show or find them through another website and post them.

Secondly, I have a 1983 camaro with a 700r4 tranny. The VSS is located behind the gauge cluster. Whatever else info you need on the vss, i will provide. I have a 1983 shop manual for my car as well, so i have much info, it is about 4 inches thick, so there are tons of pages. Tell me what ya need.

355SS

iTrader: (1)

MRDUDE posted in another thread that he thought that he was the only 3rd gen with abs so maybe he can shed some light on how he did it and save the rest of you guys some work.

MrDude_1

for the rear, a 4thgen rear swap seems easiest IMO.

the early 4thgen setup (basicly LT1 cars) are 3 channel.

later 4thgens got a 4 channel.


i do not know right now if the number of teeth on the ABS S10s front rotors are the same as the fronts on a later model 4thgen (4 channel) fronts, however if it is, that would be money and make it hella easy.

Matthew91-Z28

Okay.....GM is such a sneaky bastard. I went to Autozone to compare a stock non-1LE rotor from a 3rd gen to a rotor from a 1991 4-door S10 Blazer 2WD with ABS.

ITS THE SAME DAMN STINKIN ROTOR WITH A TONE WHEEL ON THE INSIDE!!!!!

The tone wheel (yellow in the graphic below) is an approx 2in dia wheel with multiple teeth on the outside diameter. It slips over the round inner housing of the rotor that the spindle slides through.

Rotor is same thickness (I think...because the rotor I had was older and already decreased in thickness from wear), same diameter, same bolt pattern, same shape in every aspect.

I have an extra spindle too. The rotor splash sheild bolts on in the same way too. Only diff b/t a 3rd gen splash shield and a 4WAL is the sensor around the center hole that the spindle slides through.

So...you can use these rotors as DIRECT replacements for the stockers. Again, the only diff being the tone wheel.

***Now with (2) 1991 2wd S10 Blazer rotors, (2) rotor splash sheilds, a BPMV, ECU, and all wiring, Youve got a retro-fit ABS for the front of a 3rd Gen camaro!!!!! *****

Now for the rear.....as I said earlier, '93 models used the VSS signal for the rear wheel brake control. Assuming its the same signal (car speed), why can't a wire be spliced from our existing VSS into the ECU??

But I thought that the VSS in '93 models ABS was located in the tranny. CamMan says its in the guage cluster. What is the diff in these parts? Where does the VSS in the guage cluster get information about car speed from?? Something in the tranny?

MrDude_1

you didnt by any chance count the number of teeth on the back of the wheel did you?

ebmiller88

iTrader: (7)

HA HA!! Check out this bunch o' hot roddin' going on...BRAVO BOYS!!

I can only input a little here.

I think the tone wheel on the Z/T posi isn't for the ABS, it's for the traction control, as the earlier 4th gens didn't have it. I got a set of 4th gen brakes and backing plates from a '94 (IIRC) and only one backing plate (passenger side) had an ABS sensor in it. The driver's side had the provision but no sensor, so I would suspect that the rears only have one up until the point where the General went to the 4 wheel ABS, hence the provision on the driver's side.

I'm no ECU guru, but it looks like one of you guys will be able to put this all together eventually. All I can think of is that the front sensors can be located somewhere in the caliper bracket or around the dust shield, but I'm curious as to how it would interfere with any of the parts of the brake upgrades.




Ed

MrDude_1

it wont.

you can take a hub. machine it to take a LS1 car exciter ring, press it on, and mock everything up.

you need to run new rear hardlines since you need 2 now instead of 1. (one for each wheel.)

if you do that and use a 4thgen rear and 4thgen ABS system, plumb it all, it SHOULD work.


i wasnt going to post anything about mine until i knew if i could get it to work or not. so far, i just have the hubs. the spindle i have is junk, but can be used for mocking stuff.
id go alot further, but the money isnt there to finish the project right, and id rather wait and do it correctly then halfass it.

MrDude_1

btw if the S10 rotor is the same and the exciter ring is the same number of teeth as the 98+ 4thgen ones, i wasted alot of time.

ebmiller88

iTrader: (7)

Kewl beans.... Ed

john5.7 87Iroc

As far as I know about the VSS, in 82-89 Camaros had a mechanical speedo. There is a cable attached to the trans that leads to the back of the speedo and somehow turns the VSS (located on back of speedo) mechanically. Cars with electrical speedos 86?-92 Birds and 90-92 Camaros have VSS mounted directly to the trans where the cable would be, and wires that go to a buffer box on the Birds, that lead to the speedo, ecm

Matthew91-Z28

Some NEW things I found out:: The BPMV is the ECU and modulation valves combined. They are not two separate entities as I prev thought. The BPMV gets two inlet lines (1 front and 1 rear) and then splits into 3 outlet lines (LF, RF, and rear). Since the M/C only has 2 outlets, I assume the M/C pushes fluid to the BPMV first. But I don't know where the combo valve is in this, unless its in the BPMV. The BPMV also has 3 connectors (an 8-way for the front sensors, a 2-way for the BPMV link to the batt, and a 10-way with BPMV ground, ignition, VSS, etc.).
The wiring looked a little tricky at first, but after looking at the connector diagrams its not that bad.....only one or two I was confused about (and I have nearly no electrical experience).

I'll have to take this one at a time:

JOHN5.7 87 IROC :: Good timing. So 86-92 birds had a buffer box and not maros?? I can't find one in the wiring diagram for a 91 5.0 TPI camaro. Anyway, I assume the wires from the VSS hit the buffer box and then splits into two signals; 1 goes to the speedo and another set goes to the ECM?? I ask because on the 4WAL vehicles that used a VSS to monitor rear brakes, the signal from the VSS hit a VSS buffer box and then split into 3; 1 to the ECM, 1 to the speedo, and the other to the BPMV. If this is the case, we'll need a buffer box from an ABS vehicle.

In the 91 camaro diagram, the VSS signal goes directly to the ECM....then to the speedo from there?? I know that it goes to cruise control after the ECM. I guess thats fine.....Will just have to use the ABS buffer box and just not use the out signal for the speedo.....just 1 to the ECM and the other to the BPMV.


ED :: Was it a backing plate from a '94 drum rear? Interesting. And hey...hot rodding what's we're all about. Its the poor man's attitude "if you can't afford to buy it, figure out how to make it yourself".


MRDUDE :: Don't know. I didn't count the teeth. For an early 90's 4th gen rotor, I can't see any reason GM would have changed it, but I've never read/seen any info on LT1 brakes (same as LS1??). But I can see them doing somethign diff on 98+ just b/c they like to be pains in my butt. Heres an idea....Can you pull/pry your tone wheel off?? If the inner diameter of the tone wheels are the same and they can be pried off.....they can be interchanged.


SO HERES WHERE WE ARE:
Doing ABS up front is not prob (at least on the drawing board) with hardware from 1991-1993 S10 pickups/blazers/etc.

Its the rear set-up thats giving us trouble. And we'll have to find a way to use the ABS brain from whichever make/model/year vehicle that has the most applicable rear ABS monitoring.

1). 1991-1992 S10/blazer/jimmy = 1 sensor at each drum backing plate (still feasable but not looked into yet).

2). '93 S10/blazer/jimmy = VSS (still researching).

3). 94 f-body = 1 sensor at passenger side backing plate (feasable, but we don't know about any of the ABS hardware, nor how the front sensor/ tone wheels are set up).

4). 98+F-body = ?????

I think that while we're still looking into the two rear options from the S10/blazer/jimmy , we should look into 4th gen ABS. ANyone have access to a Chilton/Haynes. Hell I might even buy one just to satisfy my curiousity.

Matthew91-Z28

Update:

1). S10 tone wheels (exciter rings) have 52 teeth.

2). Trash the idea of using 93-98 front sensors; BOTH The sensor and ring are integrated into the hub. From what I understand, 4th gen hubs can't be used on 3rd gens. Am I right...or was this just an assumption someone made? I could not find a book on 98+ front hub, but I assume they are the same.

3). 93-94 f-bodies used a rear sensor mounted ON (i.e. externally) the differential. One signal for both rears.

4). I just remembered that 1991-1992 4WD 4WAL blazers/S-10/jimmies use an externally mounted speed sensor too. One signal for both rears. 4WD use the same BPMV as 2WD. We could just externally mount a 4WD speed sensor and go with that for the rears.

5).95-98 f-bodies use two separate sensors for the rears and they attach to each rear caliper. Assuming rear speed sensors located within the calipers.


MY POINT:: We should trash the idea of using any ABS parts from a 4th gen. The front setup looks too sophisticated to retro-fit. And the 1991-1993 4WAL bpmv probably won't be able to interpret signals from any 4th gen sensors.

Ideally, we'd figure out how to mount that Blazer 4WD external sensor; that way, you could use stock S10 front rotors or modify them for the LS1/C4/C5 brake upgrade. You could also run any rear assembly you wanted without having to change out ABS parts. Its not 4-channel ABS....but hey. I'd be satisfied with just having 3-channel.

On the other hand, we might be able to rig this VSS thing to work as the rear speed sensor. Need more time to see. But that would exclude use for anyone without a VSS in earlier 3rd gens.

On the other other hand, if you are happy with rear drums, we could look into the sensors for the drum backing plate (1991-1992).


As I said earlier....the front set-up ABS is pretty well figured. Now got to decide best way for rear sensor (VSS, 4WD ext sensor, drum plate sensors) and be able to stick with all the 1991-1993 hardware.

john5.7 87Iroc

the speed density cars which I think were both 90-92tpi firebirds and camaros did not use a buffer box, The signal went straight to the ECM. IIRC Only the tbi cars with electric speedos and 86-89 firebirds used the buffer box. heres a litte info on what the wires of the buffer box do https://www.thirdgen.org/techbb2/sho...hreadid=209837

Matthew91-Z28

Need to go back and correct myself.....the rear speed sensor on the 93-94 f-body is not as 'external' as I thought. I does have parts that extend into the differential. Ooops. And along the same lines the 4WD rear speed sensor is prb the same, excpet its mounted on the transer case. Who knows...I could not find out any more information about the the 4WD sensor for the rear in 1993 vehicles.

john5.7 87Iroc::

If you've got a bird with a buffer box and VSS, you could (theoretically) replace the buffer box with an ABS one from a 1993 vehicle. Only diff would prob be the extra connector on the buffer box that goes to the BPMV. Hopefully, the wiring on the other connector would be similar for both.

In 90-92 maros, the VSS connects to ECM via yel and ppl wires. Theoretically, you could clip those and connect them approp to an ABS buffer box.....then you could use the 2 brn wires in the connector to go to the ECM, connect your ABS wires up, and then ground the box.


SO...if you plan on modifying your buffer box and using your current VSS for rear speed signal to the ABS, you'll need your BPMV from a 1993 vehicle.

I have been looking at the rear set-up on the 1991-1992 vehicles. Those were (again) the only years to use individual rear wheel sensors. If you want a 4-channel system....this is prob the closest. The BPMV recieves signal from each wheel. First problem is that the sensors fit onto the DRUM backing plate. You may be able to rig something for DISC....who knows?

Second problem is that the tone wheel (exciter ring) LOOKS like slides on the axle itself between the hub and the backing plate. The graphic in Chilton was horrible and I have no idea what the rear tone wheel looks like or exactly where it fits. If the axle slides through it....more than likely, you'll have to pull your axle, slide the tone wheel on it, and reattach it. But I don't even know if those tone wheels are tac-welded on there or not. I don't even know if you can just buy a tone wheel by itself.

Guess its time to check out some yards.

Seems easiest to just use your VSS and a buffer box and because its independant of drum or disc brakes.

Matthew91-Z28

ABS PRESSURE LIMIT/ DUMP VALVE

*I think this is the combo valve
All application models 15661378

ABS SPEED SENSOR

*probably the VSS for the rear
4WD 15693495
RWD 15693494

DCMB SIGNAL RELAY

*I think this is the relay for the wire running from the combo valve to the guage cluster brake warning light
All application models 25097359

ELECTRO-HYDRAULIC &/OR CONTROL MODULE

**ABS brain**
Part number shown is for pricing only. For proper application, refer to local supplier. 15976820

PRESSURE MODULATION ABS VALVE

*No clue....maybe a part that goes in the EHCM (aka BPMV) that may already be present if you pull it from the yard**
All application models 12547215

Matt87GTA

Here are some diagrams of a 93 S10 with 4WAL:

Matt87GTA

Sorry, they're kinda huge....

Matthew91-Z28

Thanks Matt, heres the bare-bones version:

8-WAY CONNECTOR:

A-
B-LF SENSOR (BLK)
C-RF SENSOR (WHT)
D-
E-
F-RF SENSOR (BLK)
G-LF SENSOR (WHT)
H-



2-WAY CONNECTOR:

A-FUSIBLE LINK WITH 12V BATT (RED)
B-GROUND (BLK)



10-WAY CONNECTOR:

A-BPMV POWER (PNK/WHT) [M4] TO BRAKE FUSE 12V IGN
B-ANTILOCK LAMP (WHT) [P4] TO CLUSTER
C-BRAKE SWITCH (PPL) TO BRAKE PEDAL SWITCH (CLOSED WHEN PEDAL RELEASED)

D-FRONT AXLE SWITCH (4WD ONLY)
E-REAR SPEED SIGNAL (DK GRN) TO VSS BUFFER
F-DIAGNOSTICS REQUEST (WHT)
G-
H-BRAKE LAMP (TAN/WHT) [L4] TO CLUSTER
J-
K-BPMV GROUND (BLK/WHT)



My question is...what doesn't have to be connected in the 10-way connector. The 8-way and 2-way are a no brainer. In the 10 way....can cut D for sure; F goes to the diagnostic box and I have no clue where it might be located (under the dash somewhere...we'll have to refer to chilton).

I'm, most troubled about the brake switch (C).

And the lamps in the cluster: The antilock lamp comes on for 2 sec at ignition and then turns off if there are no problems. Could run (B) to an aftermarket light installed in the dash (if you felt like it).

Don't we have a wire at the e-brake and the combo valve running to the brake lamp in the cluster?? Could just splice (H) in. What is the point of this lamp for ABS when the anitlock lamp lights up when trouble??

Matthew91-Z28

Holy crap...I just studied the diag and this wiring is much easier than it appears.....

OK, like I said the 8-way (front speed sensors) and the 2-way (power) are simple.

On the 10-way....what does NOT have to be wired in??

C-BRAKE SWITCH:: after looking at the diagram....this basically turns off the cruise control when the brake is applied and then released. Am I right?? This is already wired in to our ECM...don't mess with it because its

H-BRAKE LAMP :: This is the Park Brake Warning Switch "closed with unequal pressure". S10's have 2 cables attached to their parking brake. 1 goes to the front and the other to the rear. This is definately for a thirdgen.

D-as before, unless you've got 4WD in your 3rd gen.

B-ANTILOCK LAMP :: Of course this light stays on when there is trouble. Could be spliced into the brake lamp in the cluster....or to an aftermarket light if you feel like it.



This leaves us only 4 wires to run:: the BPMV to the ignition, rear speed signal, diagnostic box, and ground the sucker (antilock lamp optional).

Now all we have to do is figure out the VSS buffer and we are set. I have looked at GM parts direct and cant find it. Matt87GTA....do you have a wiring diagram for the buffer?

MrDude_1

ugh! the s10 box is old tech... its not as fast reacting, and it doesnt "learn" as well.... so it wont compensate for the HUGE diffrence in weight(aka momentum), pad pressure, lines ect.....

this is a nice MUST READ... http://www.stoptech.com/whitepapers/...ake_122701.htm


and like ive been saying for MONTHS!


the wires are simple. the plumbing is easy, the front sensors are the problem, and theres a ton of shiznit for the s10 boxes but not the better late model 98+ 4thgen stuff that im attempting to do.

Matthew91-Z28

"ugh"??? Why are you all about 4th gens? The 92-96 vette has a way more sophisticated suspension than a 4th gen. Vettes have seperate brake lines for each rear caliper...as well as selective ride control and lateral control. Do you see that on a 4th gen? No. You dont. Even 86-91 vettes had ABS. Besides, where is your contribution to all this?

You are attempting to run a 98+ ABS computer and front and rear speed sensors? Have you even seen what a 4th gen or even a vette hub looks like? Yeah...there is no spindle.

Maybe if you transferred the entire front clip with all the suspension from a 4th gen f-body as I've seen one (1) other person do, you'd be set.

No one is saying this is the ONLY way to run ABS on a third gen, but until a few weeks/months ago, there was NO way to run ABS on a third gen. Confronted with the current limitations and parts we have to deal with, this is the most reasonable aproach as we know it.

You are way more than welcome to provide this site with information on how its possible to run a 4th gen computer and sensors to have 93+ (even 98+ ABS technology). Hell....I'd love to have it.

But until you make an informative contribution, please find a way to curb your childish mannerisms.

(I hope the mods don't lock this because of my response. I want to see this through to application.)

Ram Air TTA

Guys,
I don't if anyone has looked into this but 94-96 impala ss and caprices have 4 wheel disc ABS too. They also use separate tone rings and wheel sensors and they have spindles. Being a little newer maybe they would be more compatable for the fronts.

Matt87GTA

Yep . (again, pretty big but it gets unreadable if you shrink it too much).

Matthew91-Z28

Accding to last diagram:

ppl and yel from the VSS

H-pnk/black :ower input from ignition

C-grn/blk :: gage cluster

F-brn :: ECM

E-red :: cruise control

D-not used :: but recieves a signal (4000 pulses per mile)


Matt87GTA....just to make sure we are on the same page, what vehicle is that buffer from?? '93 S10 should have a dk grn wire going to the ABS module.

Assuming from the Vin info in the diagram (V8= VIN F (305)) and V8=VIN 8 (350)) this is from a 3rd gen bird. Or not? I thought the buffer box on the bird had two (2) brn wires that hooked into the ECM.

MrDude_1

yes ugh. sure you can hookup a S10 truck ABS setup, but im intrested in stopping faster... not just "adding ABS for the hell of it.".. a S10 setup is not really the best way to do this.. for starters, someones going to have to crack its electronics and redo some of its constants....


YES! im attempting to do that.... ive been talking about it for months. everytime i mention it, it turns into a ABS sucks thread... and now that it finally hasnt, you guys are looking in the wrong direction... its a system. theres more to it then just slapping everything together. and NO. im not running a 4thgen front clip. while fatal88s car is cool and all, (and ive seen it in person, its nice) its not a true 3rdgen IMO... like he says, its basicly a 4thgen in 3rdgen clothes.. or somthing along theoes lines.




im complaining about your choice in control box. nothing else.... the idea of the s10 rotors is great... just as long as its wheel has the same number of teeth (thanks for counting them BTW, i need to dig out my hubs and count the 4thgen ones)

if they arnt the same, you're going to have to machine em like i did.... its kinda costly if you dont have a lathe too.


the ABS is stand alone from the ECM. and 98+ is the better one, so that is the one id presue... esp since you can bolt in a 98+ rear, add the teeth to a "machined down hub" and run a full 4thgen ABS setup... solving the electronics programming problem as well.


its all in how you read it. but given my track record, i doubt my "childish mannerisms" will ever be completly curbed..... just realize i mean no harm buy them.

Matthew91-Z28

Well said...I've been doing alot of research into this and lots of thinking and you frustrated me when it felt like you were trashing all this work because its not 4th gen. Please accept my apology.

I know I've been going down this avenue using S10 parts. But, when I saw that the rotors and rotor splash guards from an S10 are nearly exact copies of 3rd gen f-body (minus the ABS) I figured this was an opportunity too good to pass up. The BPMV electronics are a done deal. Only 4 wires to hook up and it won't be difficult. The VSS electronics are still being pursued....just need some more information before that problem is cracked. BUT...thats only if you want to use the VSS and a 93 computer.

If you have drums in the rear, you can press an exciter ring down the axle shafts and bolt on the sensor to the backing plates and use a 1991-1992 BPMV. That would be a 4-channel setup. You cant run them with disc b/c the BPMV sends pressure to the rears based on how much pressure is needed to overcome resistance in the springs in the drum.

3rd gen f-boy owners want ABS....here is one solution.

If we put enough work into it, maybe we could run 4th gen parts. But I'm really not sure there will much of a difference in ABS performance. Both S10 and 4th gen computers/sensors monitor and do the same thing basically. When the wheel looks like its going into a skid based on info from the sensors, brake pressure is decreased to that wheel. Now.....4th gen may be able to monitor this faster and thus get better performance while braking. They are prob faster and better at what they do.

The problem is that if you wanted to run this setup you'd have to spend $$$ on a 4th gen rear as well as run LS1 brakes up front. Well maybe not (95-97 rear sensors plug into the calipers). Could just have 4th gen brakes all the way around and not have to get the entire rear-end. And, who knows how much more complicated the wiring would be.

The ONLY thing preventing doing that is the front sensors. I don't think they can be mocked up exactly due to hub differences. The front sensor and exciter ring are built as 1 unit and housed in something that looks like a cylinder that attaches to the back of the hub. I follow you about machining an exciter ring. Help me with physics:: If we suppose that both rings have the same tooth number, would the diameter of the wheels matter? It appears that the exciter ring is smaller on the 4th gen. Is it??? You have a 4th gen hub laying around, right?

Wait a minute.....walk with me here; each time a tooth passes the pickup point a pulse is fired from the sensor; so at, say 40 mph, the sensor is firing 4000 times. You hit the brakes to slow down and 1 second later, the sensor is firing 3500 times (still not enough to trigger ABS), then you press harder on the brakes to stop quicker and you lock up the tire. So one second before (Time A) the sensor was firing 3500 times and now its firing at 2000 (Time B) which equals a deceleration rate of 1500 pulses per second. ABS recognizes this deceleration rate and ABS is triggered reducing brake pressure to that tire. I'm getting somewhere with this.....please keep walking with me.



Here is from Howstuffworks.com...

"The controller monitors the speed sensors at all times. It is looking for decelerations in the wheel that are out of the ordinary. Right before a wheel locks up, it will experience a rapid deceleration. If left unchecked, the wheel would stop much more quickly than any car could. It might take a car five seconds to stop from 60 mph (96.6 kph) under ideal conditions, but a wheel that locks up could stop spinning in less than a second.

The ABS controller knows that such a rapid deceleration is impossible, so it reduces the pressure to that brake until it sees an acceleration, then it increases the pressure until it sees the deceleration again. It can do this very quickly, before the tire can actually significantly change speed. The result is that the tire slows down at the same rate as the car, with the brakes keeping the tires very near the point at which they will start to lock up. This gives the system maximum braking power. "

So...Wont a rapid deceleration in an S10 = a rapid deceleration in a 4th gen?? Doesn't matter which sensor you are talking about, a rapid deceleration is a rapid deceleration. An S10 sensor will send the same info to the computer as a 4th gen sensor. The computer in both will monitor the number of pulses at Time A compared to the number of pulses at Time B. And if the rate of deceleration is > a predetermined rate, then ABS will trigger the valves.

So speaking theoretically, why couldn't you run wires from S10 wheel sensors to a 4th gen computer without any modification to the sensors or tone wheels??

Matt87GTA

That buffer diag is from a thirdgen Pontiac. I thought that was what you were after... You want one for the 93 S10 application? (BTW, I am getting these from All Data).

I agree with you. I don't see where the 4WAL system off the S truck application would be somehow worse than running any other ABS system.... If there is a processing speed difference that is one thing, but otherwise it does the exact same thing as any other ABS system... A locking wheel is a locking wheel...

EDIT: There could be issues with pulses/mile of the different sensors and modules... So mixing and matching sensors/modules is probably something to stay away from.

I think we all are looking for BETTER braking along with the ABS functionality. I myself would like to do this and then wire it so I can engage and disengage it for different track conditions... And that is really the only reason I would want it. Of course I suppose I would leave it on for street driving, but my point is I certainly would not put the work into this just to say I have ABS.

MrDude_1

short answer is, no.

im great at learning things. i suck bad at explaining things. im even worse when i try to type it cause i leave stuff out.

read all of this, this guy explains it better then i ever could.

http://www.stoptech.com/whitepapers/...ake_122701.htm


after you read that, you may understand why i like the 4thgen setup better... its proven. the two cars weight and setups are almost exactly the same. theres no cracking the computer to change the Pressure-Volume constants or anything like that.

PLUS the later one "learns".. this is a big deal... that allows you to have diffrent components.. like SS lines for example, and it may not work great at first, but after a few cycles, it learns and remembers until the batt is disconnected. think of it as BLMs for the ABS system.

MrDude_1

btw, from a cost factor,

i need a new rear anyway... ive scored a '00 SS rear with 4.10s and a alum cover/brace for $300... ive deducted that cost from the project since i needed a rear anyway... plus i needed a posi, plus i wanted thoes gears....


looking in the LS1 brake thread, you can see the exact costs of NEW calipers and parts needed...


so, including lines, box and every lil thing from a donor junkyard car, i dont think it'll be too much..



if everything was worked out, i think a kit could be sold for 98+ brakes and ABS for the cost of alloys kit (not that im saying im even trying that, just a example).

so to be honest, you could get a better brake from him.... but you dont have ABS.. the real diff would only be seen in a street car in the standard ABS situation.... you could still steer while slaming on the brakes.

anyone whos done a 100 - 0 panic stop in a 98+ 4thgen should know how good thoes brakes are.. ESP compared to 3rdgens....

alloy

iTrader: (16)

Noy to get into the controversy in this subject, but I happen to have an old 4th gen front hub. I took a couple of pics to show everyone what is being said aobut a 4th gen hub not working on a 3rd gen.

Hope this helps.

Matt87GTA

MrDude_1: Ahhh... all good points regarding calibration of the EBCM in regards to pad/caliper/rotor/lines combo and pad torque. I was totally forgetting about how important that is .

So with that taken into account, it probably would be very advisable to adapt a 4th gen EBCM/BPMV to our cars and go from there. Even that is going to be off a bit unless you at least upgrade to some better pads at a minimum....

So really all we need now is to know how many pulses per revolution of the wheel each sensor setup emits.... Someone needs to pull one of those 4th gen hubs apart and check it out.

Of course, the problems with using different sensors with a given EBCM would be all but taken care of if we could program it (or at least it would follow that that would be the case but I've never seen anybody hack into one).

MrDude_1

inside that sensor is a spinning wheel.


we need to take apart the thing and count it.... or like you said, if i could just find its output per revolution, i could use a diffrent wheel/sensor combo.

Matthew91-Z28

MrDude...I don't know if you were saying 'no' to my question or not, but I now agree with you. I tried a mathematical model and it disproved what I thought, but raised other questions too. Here is the model::

A few assumptions:
1.The only information the ABS recieves is the number of pulses from the sensor.
2. The ABS measures the number or pulses per second (or some measure of time).
3. The ABS knows nothing about MPH or anything else.
4. The tone wheel moves at the same speed as the tire (1 tire revolution = 1 tone wheel revolution).
5. Someone has to define what a rapid deceleration is for the ABS to trigger when it sees one.


Lets assume that at 40mph, the tire and thus tune wheel are turning 10 revolutions per second.

You are in an LS1 and I'm in an S10 driving 40 mph. My tone wheel has 50 teeth...yours 60.

At 40 mph, I'm pulsing 500 times per second....you are pulsing 600 (#revolutions x #teeth).

Lets say that a deceleration of 20mph in one sec (20mph/s) could be defined as a rapid deceleration in a 4th gen ABS. Thus, anything > or = -20 mph/s would trigger ABS.

We both slam on the brakes and 1 sec later we are traveling at 1/2 or speed (20 MPH). Our tires are turning 1/2 as fast and our tone wheels are turning 1/2 as fast.

I am now pulsing 250 times per second....you 300.

So in the LS1 you have not only decreased by 20MPH in 1 second, but you have decreased pulsing by a rate of 300 pulses / sec squared. Guess what??? Thats enough to trigger ABS because it knows that anything = or > a deceleration of 20MPH/s (or as the ABS sees it, 300 pulses/s squared).

But in the S10 with 50 teeth, you only show a pulsatile deceleration of 250 pulses/s square even though you are also decelerating at 20 MPH/s also.

SO you lock up and the LS1 doesnt (at least until you decelerate @ 300 pulses/sec...meaning you have to be decelerating at a more rapid rate to trigger ABS.


Here is where I got confused::


Lets say that predictably....in a professional driver without ABS, the quickest he could stop a stock car (4th gen) with 245/50/16's in ideal conditions from 60 MPH to 0 = 5 seconds.

Thats a decel rate = 60 mph/5s = 12mph/s

So at 60 MPH....In an LS1, if you decel any quicker than 12 mph/s ABS will be triggered.

I don't understand this:: if you put on something as small as just better pads than stock (bendix TT for ex), you can go from 60 - 0 faster, right?? Maybe even decel at 13 mph/s from 60 mph. ABS will be triggered sooner....and be active throughout your braking. It must not matter, though, (even though stoptech says it does). As long as you are not in a skid, ABS has no effect on how quickly you stop. It just prevents yoour tire from locking up. Right??

Jeeze my head has been turned around so many times thinking about this!!!!