914RS4 Tube Chassis 996 Suspension Audi 2.7TT Stage 3, ADDED RECAROS Options

[Andyrew]

Regarding your clutch. A standard B5 RS4 clutch isnt the hot ticket now adays. Apparently the B7 clutch pressure plate is that much better. This might require a custom flywheel, check into the S4 forums to find out what they are doing. If I swapped out my clutch again ( I have a stage 3 S4 clutch) I might go this route.


Regarding your VSS You could simply count the pulses on the stock VSS pickup, fab up that many 1/8-1/4" steel teeth and weld them onto your CV flange, then fab a mount for the VSS.

[csdilligaf]

It may not be the hottest ticket but I think it will hold the power for now and was cheap. Now Rudy may want to look into that because I know he will be looking for more power than me. I will be at 375/400 with 550cc injectors and Ko4 turbos on E85. And may still have to go with something like the stage 3 like you have now. I just really like the ease of a build that is bolt together with no custom and expensive parts.
I have done the flange modification you mentioned for the VSS but it was on an LS swap and the sensor had the magnet in it and was an easy set up to do. It looks to me like the Audi VSS has the magnetic pick up in the reluctor wheel and if flips from North to South? I suppose I could use magnets in the flange this time and just flip them according to push and pull magnetic field?

[jd74914]

Now we just need to figure out the Vehicle Speed Sensor. Maybe something mounted on the CV joint. It is a magnet pulse type. Rudy has one from his parts Audi and I purchased the sensor and the pulse ring new. The pulse ring is smaller than a CV joint so we may have to try and replicate the pulse some how. Any electrical engineer types out there that know how to figure it out? Here is the basics of it.
http://forums.quattroworld.com/s4s6/msgs/228211.phtml
Maybe we can adapt the 996 abs sensor and reluctor ring to duplicate the pulse?

I'm very surprised it's a magnetic ring. It looks like the magnets close a reed switch so to produce a square wave, so you could likely switch to a hall effect gear tooth sensor and use an 8 toothed wheel added to the outside of your CV boot, etc. rather than add magnets to something.

[Andyrew]

Now we just need to figure out the Vehicle Speed Sensor. Maybe something mounted on the CV joint. It is a magnet pulse type. Rudy has one from his parts Audi and I purchased the sensor and the pulse ring new. The pulse ring is smaller than a CV joint so we may have to try and replicate the pulse some how. Any electrical engineer types out there that know how to figure it out? Here is the basics of it.
http://forums.quattroworld.com/s4s6/msgs/228211.phtml
Maybe we can adapt the 996 abs sensor and reluctor ring to duplicate the pulse?

I'm very surprised it's a magnetic ring. It looks like the magnets close a reed switch so to produce a square wave, so you could likely switch to a hall effect gear tooth sensor and use an 8 toothed wheel added to the outside of your CV boot, etc. rather than add magnets to something.

I was thinking the same thing (IMG:style_emoticons/default/smile.gif)

You could test it on a abs sensor before fabing it up to see if the voltages on the hall sensor read correctly in the ecu.

[eeyore]

Coming from ignorance here...

Why would there be a separate vehicle speed sensor when there are ABS sensor and reluctor rings on all four corners of a 996?

Maybe, as stated earlier, the wave form is different.

(I plan on doing a VW/Audi swap, too. Someday....)

[eeyore]

Rudy or Chip -- What is the hub face to hub face dimension across the rear suspension?

[jd74914]

Coming from ignorance here...

Why would there be a separate vehicle speed sensor when there are ABS sensor and reluctor rings on all four corners of a 996?

Maybe, as stated earlier, the wave form is different.

(I plan on doing a VW/Audi swap, too. Someday....)

It's a good question. In a perfect world they really shouldn't; vehicle speed should come from some combination of wheel speed sensors when so-equipped. Not sure of the VW/Audi/Porsche reason, but some cars have them because of the way the controls are divorced between ABS, traction control, dash, and engine. A communication bus will link all of the computers, but there can be a bit of latency or sharing problems in between legacy hardware pieces. Just speculation, but ABS controller isolation might be the primary reason. Or perhaps legacy engine management code, etc.

[eeyore]

Ah, yes. I remember hearing the early 986/996 had a 3 way ABS system that was virtually standalone.

[csdilligaf]

Rudy has his to a point he could check that. He says its like 5" wider than the stock 914 but maybe he can verify. I'm out east of you in Alpine if you ever want to stop by and check out my build so far let me know.
I suspect we will have to figure the pulse/wave thing. I see on my axles that the ABS ring has like 80-100 teeth so with modification maybe something can work out there.

[eeyore]

Hi Chip,

I visited you a couple of times five or so years ago, to see your 993-based car.

I am glad to see you are still tinkering on 914s. I have since moved to Idaho. But I brought my 914 with me. Gotta change my profile...

[Andyrew]

Coming from ignorance here...

Why would there be a separate vehicle speed sensor when there are ABS sensor and reluctor rings on all four corners of a 996?

Maybe, as stated earlier, the wave form is different.

(I plan on doing a VW/Audi swap, too. Someday....)

Audi typically builds in some redundancy. Many sensors only drive the gauge cluster.

For example Audi uses two coolant temp sensors, one for the fan control unit an one for the ECU.

[csdilligaf]

Andrew, When we get to that stage can we count on some help in the gauge cluster dept? We both are going to use the Audi one like you did. Looks close to the 914 and would nice to keep it. Did you have any warning lights that go off in the cluster or are they programed out by your tune? Like ABS, Check engine, air bag and the sort? I don't know what to expect really.

[Andyrew]

ABS triggers a chime in the back of the cluster that I disconnected manually. Air bag light is on, but the check engine light doesnt come on as all the sensors not used have been coded out.

I'll be putting some resistors for the air bag light or simply remove the bulb. I plan on using the ABS stuff from the Audi so that light will stay in.

[Curbandgutter]

Rudy or Chip -- What is the hub face to hub face dimension across the rear suspension?

Take a look at post 61 top of page 4. It has an Acad drawing with the dimension that you are looking for I believe it's 5.21' or 5' 2-1/2"

Rudy

[eeyore]

Rudy or Chip -- What is the hub face to hub face dimension across the rear suspension?

Take a look at post 61 top of page 4. It has an Acad drawing with the dimension that you are looking for I believe it's 5.21' or 5' 2-1/2"

Rudy

Hot diggity! Thanks

[Mike Bellis]

ABS triggers a chime in the back of the cluster that I disconnected manually. Air bag light is on, but the check engine light doesnt come on as all the sensors not used have been coded out.

I'll be putting some resistors for the air bag light or simply remove the bulb. I plan on using the ABS stuff from the Audi so that light will stay in.

I used a black paint pen and covered the back of the display where the lamp shines through. So my ABS light is on but I can't see it. I also cut the chime but left it repairable.

[Curbandgutter]

ABS triggers a chime in the back of the cluster that I disconnected manually. Air bag light is on, but the check engine light doesnt come on as all the sensors not used have been coded out.

I'll be putting some resistors for the air bag light or simply remove the bulb. I plan on using the ABS stuff from the Audi so that light will stay in.

I wonder how hard it would be to use the 996 ABS system in my car. I have the entire system. Huuuuuuum. We need to talk.

[jd74914]

I wonder how hard it would be to use the 996 ABS system in my car. I have the entire system. Huuuuuuum. We need to talk.

Easy peasy. The 951 guys use 996/Boxster ABS systems all of the time. The older Bosch ABS 5.3 systems (with 2 rows of pins) are standalone so you can run them pretty easily. All you really need besides the ABS valve/control block is the 4 wheel speeds and a power supply. By all reports they work pretty well for 3-channel ABS.

I'm planning on it actually... (IMG:style_emoticons/default/smile.gif)

[Cracker]

Rudy - ABS is for wussies...REAL men lockem up at great speed; REAL drivers do it occasionally too. You do not need braking nannies... (IMG:style_emoticons/default/poke.gif)

T

ABS triggers a chime in the back of the cluster that I disconnected manually. Air bag light is on, but the check engine light doesnt come on as all the sensors not used have been coded out.

I'll be putting some resistors for the air bag light or simply remove the bulb. I plan on using the ABS stuff from the Audi so that light will stay in.

I wonder how hard it would be to use the 996 ABS system in my car. I have the entire system. Huuuuuuum. We need to talk.

[jd74914]

P/N 99635575503 is the unit most people use IIRC. I've actually got one on order. (IMG:style_emoticons/default/laugh.gif) The hard part is finding the unpinned mating connector.