ZHP Steering Rack Mod

Originally Posted by zhp43867

And SeanC has had a zhp and non-zhp so Alex, Mango, and everyone else is out to lunch. You will not change his mind, and you shouldn't, because he has owned both and none of you others have. You just endlessly research part numbers and ETK diagrams. I too have owned both as well and concur with Sean's statements.

yeah because doing research and confirmation of part numbers along with just about EVERY zhp owner and site confirms the racks are the same. but it's cool, what do we know when it's better to say I believe in the "ZHP Santa Claus" compared to facts.

i'm not saying the car he drove doesn't feel better or different. I'm just saying the steering rack ratio is comfirmed in parts, publications and in full turn lock-to-lock to have the same ratio.

if you like to settle your deate, please call BMW with your 330ci-zhp VIN and ask them for a quote and part number. then report back with your findings. also have someone else call for any year 2002-2006 330Ci-zsp (non-zhp) and report back the part number they're ordering. i would do it myself but know you won't take my word for it.

everyone has already established it's the same ratio across the BMW community and forums. we do this for the benefit of others to save money and have correct info. if you are going to insist it's not correct then you have to do your small part to back this up. otherwise you're just being selfish wanting to say you have something unique. fair enough?

Originally Posted by SeanC

If there is a single ratio for the non-ZHP and the ZHP, why is there two part numbers for the steering rack (-650 for the ZHP and -651 for the non-ZHP, see pictures in the thread I linked)?

650 is what came on the cars from the factory. 651 is what is available as a replacement. 651 corresponds to a rebuilt part; BMW doesn't sell brand new steering racks, so the part number won't be the same as what's found on the factory.

I've seen plenty of non-ZHPs parting out the 650 rack.

The zhp does have a different steering feel. It's not the rack though. The control arm is likely the main contributor to the better feel. It is also possible that the ZHPs came with the LUK 20 instead of the LUK30.

Originally Posted by E46Mango

Alex is 100% correct. This info (including the difference in part#) has been explained numeruos times (in the past month alone) lets see if you can find it.

Originally Posted by Alex323Ci

that was answered in the 3rd post in this thread.

BMW on its remanufactured parts, BMW often uses the part number with an increment of one on last digit.

Let's see some pictures guys. All you say is it has been covered here and there, nothing else. I posted a link with pictures. Did you even read it?

Originally Posted by TerraPhantm

650 is what came on the cars from the factory. 651 is what is available as a replacement. 651 corresponds to a rebuilt part; BMW doesn't sell brand new steering racks, so the part number won't be the same as what's found on the factory.

I've seen plenty of non-ZHPs parting out the 650 rack.

The zhp does have a different steering feel. It's not the rack though. The control arm is likely the main contributor to the better feel. It is also possible that the ZHPs came with the LUK 20 instead of the LUK30.

I now have ZHP arms, and my steering feel in terms of quickness is exactly the same as what i had before. Granted, i have a pre-02 car, but I do not believe control arms make steering quicker. Tight, yes, but quick, no.

Also realoem doesn't support your theory. My experience is that it lists the correct part number, and if it's replaced later, it says so right underneath it.

If you say that there are non-zhp after 02 that came with the -650 part from the factory, i would love to hear more. If any owner can chime-in, please do.

Mango, crawl under there, and post a picture of your part number, will you? Or are you gonna say "this is already well known, etc." again?

Originally Posted by SeanC

Let's see some pictures guys. All you say is it has been covered here and there, nothing else. I posted a link with pictures. Did you even read it?






I now have ZHP arms, and my steering feel in terms of quickness is exactly the same as what i had before. Granted, i have a pre-02 car, but I do not believe control arms make steering quicker. Tight, yes, but quick, no.

Also realoem doesn't support your theory. My experience is that it lists the correct part number, and if it's replaced later, it says so right underneath it.

If you say that there are non-zhp after 02 that came with the -650 part from the factory, i would love to hear more. If any owner can chime-in, please do.

Mango, crawl under there, and post a picture of your part number, will you? Or are you gonna say "this is already well known, etc." again?

The ZHP is *not* quicker. I've driven both. It is tighter, but the actual ratios are identical -- 13.7:1. This can be mathematically verified if you don't believe me.

I'm not saying the part was replaced with an updated version. I'm saying BMW simply doesn't sell brand new steering racks. They only sell refurbished/remanufactured ones. BMW often increments the part number by one for refurbished parts. The internals between the 650 and the 651 racks are the same.

If you google the 6 757 650 part, you'll find a lot of references to European cars such as the 318d, 320d, 330d, and guess what: these cars also have 6 757 651 listed as the steering rack part number. There's no super secret ZHP rack that BMW never documented.

There are other BMWs where the steering rack found on the car does not correspond to the part number listed in E46 (in fact, I imagine all of the are such). The E46 xi for example has a steering rack with "6 751 036" stamped on the sticker. The part number in realOEM is completely different (6759815)

Originally Posted by zhp43867

And SeanC has had a zhp and non-zhp ...You will not change his mind, and you shouldn't, because he has owned both and none of you others have. You just endlessly research part numbers and ETK diagrams.

He had (back in '09) an '05 330i-zhp and NOW has an '01 330i. The '01 has the early 15.5:1 ratio. Of course it feels different!

Originally Posted by TerraPhantm

The ZHP is *not* quicker. I've driven both. It is tighter, but the actual ratios are identical -- 13.7:1. This can be mathematically verified if you don't believe me.

I'm not saying the part was replaced with an updated version. I'm saying BMW simply doesn't sell brand new steering racks. They only sell refurbished/remanufactured ones. BMW often increments the part number by one for refurbished parts. The internals between the 650 and the 651 racks are the same.

If you google the 6 757 650 part, you'll find a lot of references to European cars such as the 318d, 320d, 330d, and guess what: these cars also have 6 757 651 listed as the steering rack part number. There's no super secret ZHP rack that BMW never documented.

There are other BMWs where the steering rack found on the car does not correspond to the part number listed in E46 (in fact, I imagine all of the are such). The E46 xi for example has a steering rack with "6 751 036" stamped on the sticker. The part number in realOEM is completely different (6759815)

Ok thanks, that makes sense about the part numbers. However, I am still not convinced about the quickness/tightness issue, and have to disagree with you there. Whenever I drive a ZHP, it feels like there is something about the "rack" itself. I know exactly what to expect from control arms, from shocks, etc. None of them add up to the steering feel of the beast

Originally Posted by Alex323Ci

He had (back in '09) an '05 330i-zhp and NOW has an '01 330i. The '01 has the early 15.5:1 ratio. Of course it feels different!

I have also driven 02+ cars, that's I meant with "having owned/driven both".

Looks like you remember me just fine. Then you might also remember me participating in those discussions about the rack. I gave a break for a couple of years, and I'll give it to you, you guys look like you have made some progress about the part numbers, and what they mean.

What is still baffling to me is the steering feel of the ZHP. As I said above, the way I feel when I drive a ZHP forces me to isolate the feel as if it's the rack itself.

So I'm after what exactly is different on a ZHP rack. jpr at one point said it may be about its internal tolerances being tighter. Along these lines, I think it is very plausible that the M-Pack II internals might be the case here, as it does have specific part number for its rack.

And there is no research that has been done on this front, so I'd appreciate if you have something to post other than "part numbers", etc. Here's a thread that came very close to solving the mystery (which I have also participated back in 2008): http://www.bimmerfest.com/forums/sho...d.php?t=283973. People there talk about retro-fit kits, etc.

I'm confident it is not any quicker. Besides the control arms, the weight of the wheels may very well make the steering feel tighter. I know my winter and summer tires felt very different on the zhp

And as I mentioned, the ZHPs may have come with the LUK20 instead of LUK30

Originally Posted by SeanC

Ok thanks, that makes sense about the part numbers. However, I am still not convinced about the quickness/tightness issue, and have to disagree with you there. Whenever I drive a ZHP, it feels like there is something about the "rack" itself. I know exactly what to expect from control arms, from shocks, etc. None of them add up to the steering feel of the beast



I have also driven 02+ cars, that's I meant with "having owned/driven both".

Looks like you remember me just fine. Then you might also remember me participating in those discussions about the rack. I gave a break for a couple of years, and I'll give it to you, you guys look like you have made some progress about the part numbers, and what they mean.

What is still baffling to me is the steering feel of the ZHP. As I said above, the way I feel when I drive a ZHP forces me to isolate the feel as if it's the rack itself.

So I'm after what exactly is different on a ZHP rack. jpr at one point said it may be about its internal tolerances being tighter. Along these lines, I think it is very plausible that the M-Pack II internals might be the case here, as it does have specific part number for its rack.

And there is no research that has been done on this front, so I'd appreciate if you have something to post other than "part numbers", etc. Here's a thread that came very close to solving the mystery (which I have also participated back in 2008): http://www.bimmerfest.com/forums/sho...d.php?t=283973. People there talk about retro-fit kits, etc.

You've already been proven wrong about this magical ZHP "feel" with respect to the control arms. Remember your arguments? They all got stomped on and left for dead. You then apologized to me and whoever else. Not trying to be hostile, just saying. There's no magic to ZHP parts. I've driven both as well and of course a ZHP will feel "better" than a non-ZHP with the standard control arms and standard suspension. That feel has to do with the solid control arms, nothing more. (as long as you're comparing to a 330 with the "650" rack)

In fact I'll go as far as to say my car feels better than a stock maintained ZHP due to the fact Meyle control arm bushings are stiffer than the stock CABs spec'd for every E46 including the ZHP. Solid vs fluid filled.

It's not because Meyle is a "superior" part or WAY BETTER. it's just the way it's designed.

You can argue your parts are magical all day long but unless you come up with actual information rather than "OMG FEELS SO MUCH BETTER," you're basically arguing santa clause exists simply because you believe it.

Good job Alex and Terra for clearing this up for the millionth time. it's like this Sean guy and ZHP382082 guy have never seen these discussions before despite it being discussed for YEARS.

Same ratio, same part #, same sh!t.

Originally Posted by E46Mango

In fact I'll go as far as to say my car feels better than a stock maintained ZHP due to the fact Meyle control arm bushings are stiffer than the stock CABs spec'd for every E46 including the ZHP. Solid vs fluid filled.

I'll disagree there. I had both Meyle LCABs and OE LCABs on my ZHP... the latter felt better to me. Admittedly, I'm not sure if the Meyle's I had were the HD variant or not

Originally Posted by SeanC

I have also driven 02+ cars, that's I meant with "having owned/driven both".
Looks like you remember me just fine. Then you might also remember me participating in those discussions about the rack. I gave a break for a couple of years, and I'll give it to you, you guys look like you have made some progress about the part numbers, and what they mean.
What is still baffling to me is the steering feel of the ZHP. As I said above, the way I feel when I drive a ZHP forces me to isolate the feel as if it's the rack itself.
So I'm after what exactly is different on a ZHP rack. jpr at one point said it may be about its internal tolerances being tighter. Along these lines, I think it is very plausible that the M-Pack II internals might be the case here, as it does have specific part number for its rack.
And there is no research that has been done on this front, so I'd appreciate if you have something to post other than "part numbers", etc. Here's a thread that came very close to solving the mystery (which I have also participated back in 2008). People there talk about retro-fit kits, etc.

I have no problem with someone asking legit questions about something. I'm not knocking you at all. I have no issues with that or getting out the correct info .
I am not sure why you feel the zhp rack is different. I looked in that thread again, which I had back in 2008. Wow some zhp owners are so full of themselves. Obviously one reason why ZHPMafia was made is to create a barrier from the truth and their hopes. Just plain crazy how off they are in their wishful thinking.
Anyway Sean, in the comparison of the videos with the lock-to-lock, that is the same. And even if there was the slightest difference in where the steering wheel ended as you say, that is not a difference in 13.7 to a 15.5. So unless you're suggesting another ratio for the other 330s that should have put it to rest for you then.
The only other two things I can think of is that on your 330-zhp you were running a square 255 set-up (both front and rear). That's going to give a different steering feel. I don't know if you also had an underdrive pulley kit, that will make the steering firmer too.

Originally Posted by Alex323Ci

I have no problem with someone asking legit questions about something. I'm not knocking you at all. I have no issues with that or getting out the correct info .
I am not sure why you feel the zhp rack is different. I looked in that thread again, which I had back in 2008. Wow some zhp owners are so full of themselves. Obviously one reason why ZHPMafia was made is to create a barrier from the truth and their hopes. Just plain crazy how off they are in their wishful thinking.
Anyway Sean, in the comparison of the videos with the lock-to-lock, that is the same. And even if there was the slightest difference in where the steering wheel ended as you say, that is not a difference in 13.7 to a 15.5. So unless you're suggesting another ratio for the other 330s that should have put it to rest for you then.
The only other two things I can think of is that on your 330-zhp you were running a square 255 set-up (both front and rear). That's going to give a different steering feel. I don't know if you also had an underdrive pulley kit, that will make the steering firmer too.

Alex, thanks for going back and reading the thread again. First of all, going 255's all around made my steering less tight, not firmer. I have explained the reason why using simply math and physics in a thread years ago. I am talking about a %100 stock ZHP steering feel. The darn thing turns like a go-cart. That is the reason why I believe there might still be something different about the ZHP rack. BMW apparently had a "Msportpack II" rack in their arsenal. What could have prevented BMWNA to swap its internals to the ZHP's rack, when they were creating the package and not call it a ZHP specific part? It makes sense not to "publish" it as yet another part, when they could have installed a readily available 330 rack instead whenever they needed to. In that thread, a couple of ZHP owners mention about retrofit kits that were needed when they were having the -651 rack installed, as well as a mention of another hydraulic line to the ZHP's rack. Maybe those are part of the reason why ZHP turns this quick, maybe not.

Also, thinking along the lines when jpr said at one point about the internals being different, you may have the same ratio (same number of gears in a given length), but the feel might be completely different because of the way the gears came out of the CNC. I wonder if this might also be the case, but I guess we won't know until somebody opens up both and shows us the truth.

Originally Posted by TerraPhantm

I'll disagree there. I had both Meyle LCABs and OE LCABs on my ZHP... the latter felt better to me. Admittedly, I'm not sure if the Meyle's I had were the HD variant or not

"Better" is a subjective term, especially if we both have different opinions as to what is "better." We talking feel or isolation?

The two extremes are a) no bushing or a worn bushing and b) a solid race-style aluminum bushing. One will provide no feel at all and the other too much. So which is it?

We all know the Meyle HD bushing is firmer than OE fluid-filled stock. Of course there's probably a trade-off. That trade-off is increased feel/feedback with more vibration. Sometimes I feel my Meyle HD cabs are a bit firmer than I'd like... other times I like it when I'm driving in a spirited manner.

Cab firmness: OE>Meyle>Poly>Solid. Take your pick. What you prefer will be "better."

Originally Posted by SeanC

I publicly apologize to E46Mango and to those I have offended throughout the thread. I had apparently been misled by some of posts that I have read in the past (some by respected members), and the puzzling fact that ZHP's steering being sharper, even though the rack and other components have proven to be the same compared to non-ZHP's.

From your post-history, you clearly aren't as knowledgeable as you'd like to think when it comes to the basics of these cars. You have something to prove--prove it. Otherwise, it's apparent that you've been mislead yet once again.

Oh and...

Originally Posted by SeanC

... even though the rack and other components have proven to be the same compared to non-ZHP's.

Originally Posted by E46Mango

Oh and...

That's exactly what i mean. Everything, short of arms and shocks, is proven to be the same (by some respected members!), yet the feel is there. How come? It's not the arms, not the rack then, what is it? Maybe it's the sway bars... oh wait, it's not that either!

So Sean what are you saying now? You're on board with the 330s having the same 13.7 steering rack ratio but now suggest the internals and something else in the 330-zhp rack makes it better.
So when you need a replacement 330-zhp steering rack bmw doesn't make them anymore or you suggest they are all the same now? I really don't follow.

I can't say about the internals but do you really think BMW made a special rack run? Also without a replacement for the car? There are part numbers for everything else and with a cost.

I leave you with the term, "Occam's razor". It fits this best of any.

Simple question: What makes ZHP's steer the way it does? If you say it's the control arms and shocks, I don't buy that. Make me believe.

I don't know if BMW made a special run for the rack, but it could have as well been the Msports pack II internals in the regular 330 rack. Both were readily available when ZHP package was invented by BMWNA.

Part numbers are set by BMW, not BMWNA, correct?

Originally Posted by SeanC

Simple question: What makes ZHP's steer the way it does? If you say it's the control arms and shocks, I don't buy that. Make me believe.

I don't know if BMW made a special run for the rack, but it could have as well been the Msports pack II internals in the regular 330 rack. Both were readily available when ZHP package was invented by BMWNA.

Part numbers are set by BMW, not BMWNA, correct?

How can we make you believe without buying a ZHP and an 02+ ZHP, modifying the latter with ZHP control arms and wheels (springs and shocks are the same), and having you drive them?

You keep bringing up the M-sport II rack - why would BMW put this rack in the ZHP and not label it as such in either the ETK or on the part installed on the car? And why are there plenty of non sport/M-sport cars also equipped with 650 racks if the ZHP steering rack is somehow special? At the factory there would have been a lot of confusion if there were two different steering racks that had the exact same labels and housings.

Honestly, I think the difference you're talking about comes down to a romanticized memory of how the ZHP felt, and perhaps a better maintained front end on your former ZHP.

The ZHP package was not "invented" by BMWNA. It was designed by BMW AG as a US exclusive package.

Originally Posted by TerraPhantm

And why are there plenty of non sport/M-sport cars also equipped with 650 racks if the ZHP steering rack is somehow special? At the factory there would have been a lot of confusion if there were two different steering racks that had the exact same labels and housings.
Honestly, I think the difference you're talking about comes down to a romanticized memory of how the ZHP felt, and perhaps a better maintained front end on your former ZHP.

exactly

Sean you really believe there was an exclusive costly rack run with the same part number? if BMW was going to do that they would just give it a different part number and sell it for more. because if/when the part needed to be replaced they'd have it(not to mention profit). example: zhp control arms.

sorry you seem to be the only holdout. even ZHP34867 who got you all fired up has "cut n run" from the thread leaving you out to dry. answer me at least this(because you dodged it last post) Do you agree the late model 330s are the same ratio of 13.7??
because if weren't not making any progress here it's straight out denial and nothing is going to give you the answer you say you seek? you then have already made up your mind and us few are wasting our time.

I have no problems accepting the ratios being the same, or the part being the same for that matter. However, my experience, after driving both 02+ cars and ZHPs, is that there is a difference that I cannot associate the feel with the arms or shocks or any other suspension component up front. I have replaced shocks, arms, sway bars, etc. on the BMWs that I have owned, and I think I know exactly what to expect from each one individually. I also replaced the steering box on my wife's older 5er touring, and my expectation before and the feel after the install matched perfectly.

I would love to hear from a non-ZHP owner about the steering feel who had the ZHP arms and shocks installed on their car. Can't believe nobody did these mods...

As I said, the rack can be the same (thus no confusion at the factory), but there have been discussions about additional hydraulic lines and/or retrofit kits when people were having racks installed on their ZHPs. Any comments about those? I'd love to hear more. Maybe there is still some unexplored territory here.

Somebody PLEASE post a pic of the number tag on their non zhp rack. I'll post a pic of the number tag on my "zhp" rack. Supposedly the zf numbers are different