Stu
11-04-2012, 11:27 AM
UPDATE.
Here's the deal. ZHPs are all guaranteed to come with the 712 rack. Three different racks have been used for the 330 over the years:
A TRW rack with no tag
A purple 678 rack with 3 turns lock-to-lock
A yellow 712 rack with 3 turns lock-to-lock
According to RackDoctor, the majority of standard 330s tend to send in the 678 rack, while ALL ZHPs are equipped with the 712 rack. Some 330s seem to be found with 712 racks, as other members with standard 330s have posted. The 678 rack has a smaller torsion bar, even though it has 3 turns lock-to-lock.
All 712 racks are identical. The difference is between the 712 rack and the other two. We do have the 712 rack.
One current running hypothesis is that people with overboosted steering got it fixed from BMW, who may have put in a 712 rack. Right now, we just don't know, but we do know that all ZHPs come with the heavier-steering 712 rack with slightly modified gearing and bigger torsion bar, but the same lock-to-lock as a 678.
http://forum.e46fanatics.com/showthread.php?t=862392&page=13
Post # 242
WOW I mean WOW
OK Lets start fresh from square 1
I have NEVER said that there was a difference in the 712 tagged racks THERE IS NOT…… NUFF said a 712 rack is a 712 rack
WHAT I HAVE BEEN TRYING TO SAY if you will stop long enough to read
There were 3 different racks used on the 330
1 a TRW rack this rack was manufactured by TRW and has NO TAG rack is stamped T R W
2. A purple 678 tag rack with 3 turns
3 a yellow 712 Tag rack also with 3 turns
I questioned what is the difference between the 678 tag and the 712 tag and was told the torsion bars were different giving a different feel. (not going to post the same dirty pictures all over again)
The gear in the 678 tag and the 712 tag are slightly different as well
Based on the 100’s – 1000’s of cores returned from customers based on what they order and tag numbers given to me on the phone on top of countless hours at core suppliers (where racks are tagged from junk yards) and hours buying cores in junk yards over 26 years. this is the data I have come up with.
What I have seen is anyone who has claimed to have a ZHP has ALWAYS sent in a 712 rack as a core apparently there were other packages as well that shared this rack I have even had a 712 rack returned from a 323
Yes I agree the 678 tag was also used in the 325 that would be why they have the same part number on my site as well (hmmmmmm weird)
If people are so inclined to believe that there is ONE rack and Only One rack used in every 330 so be it. If you would like the addresses for all of the customers that sent back other racks rather than that of the 712 rack from their 330s so you can go beat them to death with a baseball bat ……….. well I can’t help you there.
I find it a little funny how after 2 full hours of research you (Mr. Mango) have become angry, I have to wonder if you had done this for 25 + years how you would feel ?
This bickering is just one big circle and the facts have been very confusing, one would wonder if this is intentional just to move the forum up in google searches.
The racks I “WAS” intending to break down were the 678 tag vs the 712 tag and never the 712 vs the 712, they are the same to think otherwise would be silly. I don’t think this was EVER a debate. I was simply trying to convet that from all of my resources physically touching, holding, handling, building, and sometimes cuddling with rack and pinion as well as discussions with other builders also in the industry for 25 + years that there were 3 rack and pinions used on the 330’s
1. a TRW Rack (rack is stamped T R W )
2. Purple 678 tagged racks
3. Yellow Tag Tagged Racks
To answer an earlier question there is another yellow tag this was on the earlier 330 (2001) and was tag Number 599 this would be the same as the 643 tag (silver) a 3.4 turn unit.
I feel that regardless of any information posted it will turn into some end of the world debate. If I were to state that the pinion was splined, someone would argue that it was not really splined it was broached and splines are made from a broaching machine so they are not called splines ………..
Once again I was simply trying to help and seems some people get it and some don’t... I am only posting again to point out that I DID NOT claim the 712 racks were different only that there were different racks on the 330 models if I have not explained this well enough then I am sorry.
Be well
Rack Doc
A guy from Rack Doctor responded to a big debate about the ZHP steering rack being supposedly different, even though they have the exact same part number as standard 330 racks.
The difference in steering feel lies in something called a torsion bar. Thicker torsion bars make for tighter and heavier steering, while smaller torsion bars make for easier steering. Apparently the ZHP torsion bar is thicker than the standard 330 one, despite them both having the same part numbers.
When Rack Doctor receives an E46 330 steering rack and take it all apart, they separate out the racks based upon the size of the torsion bar. They can tell if it's a ZHP rack or standard 330 rack that way, and give you the appropriate rack for your car.
I don't know how BMW separated them out at the factory, but even though they're both made by ZF and have the exact same part numbers, they're different.
Hello I am reluctantly chiming in here in hopes that I may lend a point of view from a technical standpoint. I have had several PM's, e-mails, and phone calls asking me to explain this dilemma over the ZHP Rack. If I may say ahead of time I have no desire to argue fight debate or anything else about the subject I am simply going to try to explain this as it was explained to me By ZF engineers at the AAPEX Expo. as I too (after 26 years of building the rack and pinions) don't claim to know "EVERYTHING" and at times have questions that I need answered. If anyone would like to debate the information please contact ZF.
I am not here to make anyone right or wrong simply offer tech help when I can this is what I always thought that the forums were for a community of enthusiasts trying to help one another.
I took a little time to break down a few pinions to let you see what's on the inside and how they work.
YES the 330 and the ZHP rack share the same turn ratio (3.0 turns let's keep it simple) the racks function differently by the strength of the torsion bar that runs through the center of the pinion (or in simple terms the spool valve ..... I have heard 1000's of names for the pinion)
I am adding a few pictures to try and explain how the units are different I am aware the pinions are not BMW pinions as they are only for the purpose of illustration .
The easiest way to put it is the torsion bar is different in the ZHP rack. As torque is put on the pinion the the more fluid is passed through the pinion. The stronger the torsion bar the more the sport feel. (this is also where the famous over boosted steering comes from a weak torsion bar)
Below is a simple illustration of how a rack works. The torsion bar runs through the center of the pinion (in simple terms the pinion is the brain of the rack it tells the pump when it is turning (torque) give me more pressure to turn the wheels)
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27168
The next picture shows the pinions as they would have been removed from a steering rack
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27169
The next picture shows the barrel of the pinion taken off with teflon rings still attached
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27170
The next picture shows the barrel close up I wanted to show how small the fluid holes are in the pinion so I used a ball point pen for illistration. I wanted to show this so installers will have a better understanding of the importance of flushing the system out prior to installing a rack and pinion. It takes very little to clog these small holes
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27171
Ok Moving on the next picture shows the pinion broken down by components the thin bar that runs through the pinion is the torsion bar. This is where the units differ.
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27172
The next picture is just a closer look at the torsion bar. Side by side again with a ball point pen so you can get an idea of the size of the torsion bar in the pinion
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27173
The last picture is the assembled pinion with a down view so you can see where the torsion bar is in the pinion while it is assembled
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27175
I would like to take a moment to thank the forum members for your valued business. I Hope you find the information helpful and we can agree that simply because a rack and pinion has the same turn ratio does not mean that they all perform the same, much the same as on the E36 models the standard E36 and the 96-99 M3 racks have the same turn ratio the racks perform differently. I have a good friend that works for a BMW salvage yard and he tells me that he sells the M power engine covers all the time for people to slap them on their 2.8 L engines we all know that what happens internally is what makes the difference. Adding a ZHP shift Knob to your car does not make your car a ZHP. :facepalm:
We at Rack Doctor go to great lengths to separate these units rather than lump them all together so that when you order a rack you will get the specific rack you are looking for.
Thank you for taking the time to read through this, and again I hope you find it informative. I hope I have explained it well enough, feel free to shoot me an e-mail if you have any questions, or give me a call I will try to help whenever I can.
Be well
Rich (aka the Rack Doctor)
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27176
http://forum.e46fanatics.com/showthread.php?t=862392&page=9
Post # 178
Here's the deal. ZHPs are all guaranteed to come with the 712 rack. Three different racks have been used for the 330 over the years:
A TRW rack with no tag
A purple 678 rack with 3 turns lock-to-lock
A yellow 712 rack with 3 turns lock-to-lock
According to RackDoctor, the majority of standard 330s tend to send in the 678 rack, while ALL ZHPs are equipped with the 712 rack. Some 330s seem to be found with 712 racks, as other members with standard 330s have posted. The 678 rack has a smaller torsion bar, even though it has 3 turns lock-to-lock.
All 712 racks are identical. The difference is between the 712 rack and the other two. We do have the 712 rack.
One current running hypothesis is that people with overboosted steering got it fixed from BMW, who may have put in a 712 rack. Right now, we just don't know, but we do know that all ZHPs come with the heavier-steering 712 rack with slightly modified gearing and bigger torsion bar, but the same lock-to-lock as a 678.
http://forum.e46fanatics.com/showthread.php?t=862392&page=13
Post # 242
WOW I mean WOW
OK Lets start fresh from square 1
I have NEVER said that there was a difference in the 712 tagged racks THERE IS NOT…… NUFF said a 712 rack is a 712 rack
WHAT I HAVE BEEN TRYING TO SAY if you will stop long enough to read
There were 3 different racks used on the 330
1 a TRW rack this rack was manufactured by TRW and has NO TAG rack is stamped T R W
2. A purple 678 tag rack with 3 turns
3 a yellow 712 Tag rack also with 3 turns
I questioned what is the difference between the 678 tag and the 712 tag and was told the torsion bars were different giving a different feel. (not going to post the same dirty pictures all over again)
The gear in the 678 tag and the 712 tag are slightly different as well
Based on the 100’s – 1000’s of cores returned from customers based on what they order and tag numbers given to me on the phone on top of countless hours at core suppliers (where racks are tagged from junk yards) and hours buying cores in junk yards over 26 years. this is the data I have come up with.
What I have seen is anyone who has claimed to have a ZHP has ALWAYS sent in a 712 rack as a core apparently there were other packages as well that shared this rack I have even had a 712 rack returned from a 323
Yes I agree the 678 tag was also used in the 325 that would be why they have the same part number on my site as well (hmmmmmm weird)
If people are so inclined to believe that there is ONE rack and Only One rack used in every 330 so be it. If you would like the addresses for all of the customers that sent back other racks rather than that of the 712 rack from their 330s so you can go beat them to death with a baseball bat ……….. well I can’t help you there.
I find it a little funny how after 2 full hours of research you (Mr. Mango) have become angry, I have to wonder if you had done this for 25 + years how you would feel ?
This bickering is just one big circle and the facts have been very confusing, one would wonder if this is intentional just to move the forum up in google searches.
The racks I “WAS” intending to break down were the 678 tag vs the 712 tag and never the 712 vs the 712, they are the same to think otherwise would be silly. I don’t think this was EVER a debate. I was simply trying to convet that from all of my resources physically touching, holding, handling, building, and sometimes cuddling with rack and pinion as well as discussions with other builders also in the industry for 25 + years that there were 3 rack and pinions used on the 330’s
1. a TRW Rack (rack is stamped T R W )
2. Purple 678 tagged racks
3. Yellow Tag Tagged Racks
To answer an earlier question there is another yellow tag this was on the earlier 330 (2001) and was tag Number 599 this would be the same as the 643 tag (silver) a 3.4 turn unit.
I feel that regardless of any information posted it will turn into some end of the world debate. If I were to state that the pinion was splined, someone would argue that it was not really splined it was broached and splines are made from a broaching machine so they are not called splines ………..
Once again I was simply trying to help and seems some people get it and some don’t... I am only posting again to point out that I DID NOT claim the 712 racks were different only that there were different racks on the 330 models if I have not explained this well enough then I am sorry.
Be well
Rack Doc
A guy from Rack Doctor responded to a big debate about the ZHP steering rack being supposedly different, even though they have the exact same part number as standard 330 racks.
The difference in steering feel lies in something called a torsion bar. Thicker torsion bars make for tighter and heavier steering, while smaller torsion bars make for easier steering. Apparently the ZHP torsion bar is thicker than the standard 330 one, despite them both having the same part numbers.
When Rack Doctor receives an E46 330 steering rack and take it all apart, they separate out the racks based upon the size of the torsion bar. They can tell if it's a ZHP rack or standard 330 rack that way, and give you the appropriate rack for your car.
I don't know how BMW separated them out at the factory, but even though they're both made by ZF and have the exact same part numbers, they're different.
Hello I am reluctantly chiming in here in hopes that I may lend a point of view from a technical standpoint. I have had several PM's, e-mails, and phone calls asking me to explain this dilemma over the ZHP Rack. If I may say ahead of time I have no desire to argue fight debate or anything else about the subject I am simply going to try to explain this as it was explained to me By ZF engineers at the AAPEX Expo. as I too (after 26 years of building the rack and pinions) don't claim to know "EVERYTHING" and at times have questions that I need answered. If anyone would like to debate the information please contact ZF.
I am not here to make anyone right or wrong simply offer tech help when I can this is what I always thought that the forums were for a community of enthusiasts trying to help one another.
I took a little time to break down a few pinions to let you see what's on the inside and how they work.
YES the 330 and the ZHP rack share the same turn ratio (3.0 turns let's keep it simple) the racks function differently by the strength of the torsion bar that runs through the center of the pinion (or in simple terms the spool valve ..... I have heard 1000's of names for the pinion)
I am adding a few pictures to try and explain how the units are different I am aware the pinions are not BMW pinions as they are only for the purpose of illustration .
The easiest way to put it is the torsion bar is different in the ZHP rack. As torque is put on the pinion the the more fluid is passed through the pinion. The stronger the torsion bar the more the sport feel. (this is also where the famous over boosted steering comes from a weak torsion bar)
Below is a simple illustration of how a rack works. The torsion bar runs through the center of the pinion (in simple terms the pinion is the brain of the rack it tells the pump when it is turning (torque) give me more pressure to turn the wheels)
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27168
The next picture shows the pinions as they would have been removed from a steering rack
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27169
The next picture shows the barrel of the pinion taken off with teflon rings still attached
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27170
The next picture shows the barrel close up I wanted to show how small the fluid holes are in the pinion so I used a ball point pen for illistration. I wanted to show this so installers will have a better understanding of the importance of flushing the system out prior to installing a rack and pinion. It takes very little to clog these small holes
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27171
Ok Moving on the next picture shows the pinion broken down by components the thin bar that runs through the pinion is the torsion bar. This is where the units differ.
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27172
The next picture is just a closer look at the torsion bar. Side by side again with a ball point pen so you can get an idea of the size of the torsion bar in the pinion
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27173
The last picture is the assembled pinion with a down view so you can see where the torsion bar is in the pinion while it is assembled
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27175
I would like to take a moment to thank the forum members for your valued business. I Hope you find the information helpful and we can agree that simply because a rack and pinion has the same turn ratio does not mean that they all perform the same, much the same as on the E36 models the standard E36 and the 96-99 M3 racks have the same turn ratio the racks perform differently. I have a good friend that works for a BMW salvage yard and he tells me that he sells the M power engine covers all the time for people to slap them on their 2.8 L engines we all know that what happens internally is what makes the difference. Adding a ZHP shift Knob to your car does not make your car a ZHP. :facepalm:
We at Rack Doctor go to great lengths to separate these units rather than lump them all together so that when you order a rack you will get the specific rack you are looking for.
Thank you for taking the time to read through this, and again I hope you find it informative. I hope I have explained it well enough, feel free to shoot me an e-mail if you have any questions, or give me a call I will try to help whenever I can.
Be well
Rich (aka the Rack Doctor)
http://forum.e46fanatics.com/picture.php?albumid=5243&pictureid=27176
http://forum.e46fanatics.com/showthread.php?t=862392&page=9
Post # 178