The E46 BMW 330i ZHP has achieved true cult status in the last few years, and examples have easily doubled in value in the same period of time. I’ve owned two, both manual sedans, and I do know the magic of the ZHP. I’ve also called them out for being overpriced. But now we’re going to definitively explain exactly what parts make a ZHP unique, and what’s just regular old E46 stuff. Consider this your comprehensive guide if you’re trying to figure out if a ZHP is worth it.
Much misinformation circulates regarding just how special or unique these cars are, with many claiming that the car is full of precious, ZHP only parts that simply don’t exist. We’re going to look at the part numbers, do some research, and get to the bottom of it.
The most prevalent and legendary of all of these theories is that the ZHP steering rack is unique, or “modified” from a normal 330i sport package steering rack. There is plenty of forum chatter on ZHPMafia about this and a few experts have chimed in. Specifically, the Rack Doctor, someone who rebuilds these racks for a living, said the ZHP rack is the same rack the so called “yellow tag” or 712 rack of most 330i sport pack cars.
The part number for the steering rack in all ZHPs and the steering rack that comes in most, if not all 2003-2006 330is are the same: 7852 974 712. I verified this myself, in fact I removed the bad original rack from my ZHP and got another 712 steering rack from a 2003 330i sport package coupe from a junkyard. They are in fact the exact same part number. It’s the same part.
Both possess the same steering ratio, the same steering weight, and the same feel. I’m herby considering the “ZHPs have a special steering rack” myth busted.. I tried both and they felt remarkably similar.
Let’s move on to suspension next. BMW makes a lot of claims about the ZHP specific suspension and was clever with its wording around the suspension in brochures. If you read this official BMW brochure, it is claimed that the ZHP got special dampers, sway bars, springs, control arms, and a lower ride height by 15mm. It gets weird when half of these claims simply are not true.
Let’s start with what is true. The car’s control arms were ZHP specific until 2005 when the Z4 M came out with the exact same control arms. Part numbers match across the two models and there are no geometry changes even compared to a normal E46 arm. The only change is the front inner ball joint is made larger and more rigid for performance and ZHP arms have a blue sticker with the M logo and some text saying they are made for the Performance Package cars. Most ZHP parts are listed as M Sport Package II S338A or Performance Package S767A in parts catalogs.
The clarity ends there. The rest of the parts are either sport package carryover or BMW sneakily comparing parts to the normal non-sport E46 to claim a performance improvement. There are nearly two decades worth of debate on the dampers and nobody can come to a consensus. So let’s let the part numbers do the work. There is no ZHP-specific damper part number, it is only the 2001-plus E46 sport package shocks, also known as S226A Sports Suspension Settings in the BMW part catalog: 31 31 2 282 459 for the front left and 31 31 2 282 460 for the front right. Some forumgoers list the standard shocks as sport shocks but they are incorrect, and they have a different part number: 31 30 6 757 044 and 31 30 6 757 043.
It’s the same story with the sway bars. BMW claims a 23.5mm front sway and 18.5mm rear sway bar compared to the “standard” 23mm front and 18mm rear. This is a bizarre claim because there is no such thing as a 23mm front bar for an E46, there is only a 24mm front bar for pre-2001 models and convertibles. In addition, there is no 18.5mm rear sway bar listed in any parts catalog, only the normal 18mm rear sway bar. The parts catalog only lists one sway bar part number for front 23.5mm and rear 18mm with no others listed. The fourth post on this forum thread also shows an owner who measured his sway bars with a caliper.
Springs are another component that is entirely independent of the car having the performance package or not. Strangely, springs don’t have any listed part numbers but are marked with paint marks. The information is unclear and I’m not sure, but ZHP and Sport Package (this is known as ZSP, by the way) owners all claim to have each other’s springs. It seems that BMW chose springs based on weight and options, and it is likely that they share the same springs. Either way, the ride height is the same between sport and ZHP cars. The 15mm height difference claimed by the ZHP brochure is actually 15mm lower than a non-sport car. To cap it all off, ZHP alignment settings are the same as what’s in a normal Sport Package and the six-speed manual gearbox is the same as 2003 and later 330i sedans and 2004 plus 330i coupes.
To me, the part numbers don’t lie. The story isn’t all bad, however. ZHPs certainly got unique parts like the camshafts and the aforementioned control arms. I’d wager that the amount of aesthetic changes are just as important as the mechanical.
Much of the ZHPs appearance is BMW European parts bin stuff. The M-Tech II bumpers are off of a Euro-spec M-Sport, the Style 135M wheels seem to be as well. Most of the ZHPs color options are available on normal US-spec cars except for Imola Red and Mystic Blue, which are shared with the M3. Mystic Blue could be custom ordered with a non-ZHP, but Imola Red was exclusive.
The truly ZHP-specific parts are simple: the aforementioned camshafts, the 6,800-rpm redline gauge cluster with red needles, the black or silver cube trim standard from BMW Individual, the Alcantara steering wheel, seats, shift boot and parking brake boot were ZHP only, a slightly shorter ratio rear differential, and factory threadlocker applied to the nut that fastens the oil pump gear to the oil pump, part number 11 41 7 897 238 compared to 07 11 9 905 857 for the normal nut.
Those are not inconsequential upgrades, especially the oil pump nut. The 3.0-liter M54 engines tend to loosen them over 6,000 rpm thanks to unfavorable engine harmonics. Still, the mythology surrounding the ZHP suspension is interesting to say the least. Cutting through years of forum info has shown that it is alive and well, but the parts catalog tells a different story.
Does that make the ZHP any less special? Well, that is up to you to decide.