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[crimsone90]

The question regarding Low-pressure casting and Gravity casting has been asked a lot and it keeps getting ignored when asked so I`ll answer.

In a Wheel Manufacturing perspective:

Gravity casting is a method of manufacturing a cast wheel of an specific metal alloy, typically aluminum, although Magnesium is also used, which involves supplying molten metal to a mould cavity via a feeder through a running system where the molten metal entry point is located above the top of the mould cavity. In this manufacturing process all the metal entering the mould is subject to turbulence. This turbulence can cause severe defects such as oxide inclusions and entrapped gas porosity and in some cases mould erosion and hotspots.

Low-pressure casting in the other hand takes care of the disadvantages of Gravity casting by filling the mould through an in-gate just below the top of the mould cavity from a source under the mould through a method which allows complete filling of the mould. The force of gravity acts against the upward flow of the metal and eliminates the possible turbulence caused by the falling liquid metal. The molten metal is stored in a pressured container and by increasing the pressure metal is then forced into the mould.


Low Pressure Casting Compared to Gravity Casting

In low-pressure casting the method in which the metal is forced into the mould is the main difference/advantage over gravity casting and is absolutely controlled. As explained above it results in a low turbulence or turbulence-free mould filling with little to no corrosion.

The molten metal in the furnace is in a closed container under protected atmosphere. Because of this the metal absorbs less hydrogen and any other impurities as well as the oxide formation being greatly reduced. As opposed to gravity casting, the metal surface is not interrupted constantly since it is been forced from under the metal surface. What you get is a very clean quality metal.

Basically low-pressure casting uses positive pressure to move molten metal into the mold quickly thus resulting in a finished product with an Aluminum that is denser than Gravity cast. The cost involving the production of low-pressure cast are higher than gravity

As per Tirerack.com:

GRAVITY CASTING
Gravity casting is the most basic process of pouring molten aluminum into a mold utilizing the earth's gravity to fill the mold. Gravity casting offers a very reasonable production cost and is a good method for casting designs that are more visually oriented or when reducing weight is not a primary concern. Since the process relies on gravity to fill the mold, the aluminum is not as densely packed in the mold as some other casting processes. Often gravity cast wheels will have a higher weight to achieve the required strength.

LOW PRESSURE CASTING
Low pressure casting uses positive pressure to move the molten aluminum into the mold quicker and achieve a finished product that has improved mechanical properties (more dense) over a gravity cast wheel. Low-pressure casting has a slightly higher production cost over gravity casting. Low pressure is the most common process approved for aluminum wheels sold to the O.E.M. market. Low-pressure cast wheels offer a good value for the aftermarket as well. Some companies offer wheels that are produced under a higher pressure in special casting equipment to create a wheel that is lighter and stronger than a wheel produced in low pressure. Once again in the quest for lighter weight, there is a higher cost associated with the process.

In a Wheel Quality perspective

The advantages of low pressure die casting process are several :
- higher yield achievable
- reduction of machining costs
- excellent control of process parameters
- good metallurgical quality
- leads to an optimal use of the aluminum
- excellent mechanical and technological properties of the castings.

Disadvantages of gravity die-casting:
- High porosity rate
- High absorption of impurities
- Less dense material which results in a heavier wheel to be able to achieve the required load rating
- Very high process variations which leads to more defective units

Gravity casting does get the job done but with a higher rate of defective units as opposed to a stronger and lighter wheel made by low-pressure casting.

Feel free to post any questions you might have.

[JDLM]

yeah google told me the same always good to have info out for people

[vortex_tuning]

[ALUFELGEN]

Excellent post. Should help answer some concerns some people are having.

[blisstik]

It would be nice to list brands of wheels and types of casting they use. Then, sticky it!

Forgestar
VMR
Alufulgen
OEM
etc.

[Ron@Modbargains]

I think I wrote something like this a while back.

But lets add to the Heirarchy of the production method.


Gravity Cast
Low Pressure Cast
Double Chamber Pressure Cast
Flow Form Cast (Spun Cast)
Forged: Monoforged, 2PC Forged, 3 PC Forged

Originally Posted by darklocust

It would be nice to list brands of wheels and types of casting they use. Then, sticky it!

Forgestar
VMR
Alufulgen
OEM
etc.

From the company's we carry and those that I know in the BMW market. Lets add where they are made, I think that should be a factor as well. We could also add certifications.

If I need to add explanation on Flow Form or forged methods I guess I could.

(Someone can put this in alphabetical order make a master list, I grouped it by the casting method)

Low Pressure Cast

Miro - Low Pressure Cast, Taiwan (Except 935, made in Japan by NKB)
VMR - Low Pressure Cast, Taiwan
Alufulgen - Low Pressure Cast, Taiwan
Linea Corse - Low Pressure Cast
Axis Wheels - Low Pressure Cast, Taiwan
Beyren/TSW - Low Pressure Cast, Taiwan (except Borque 3pc)

Forgestar - Flow Form Cast, USA
BBS - Flow Form Cast, Germany
Advan - Flow Form Cast, Japan
Enkie - Flow Form Cast, Japan
Rays - Flow Form Cast, Japan

HRE - Forged, USA
iForged - Forged, USA
Kinesis - Forged, USA
Volk - Forged, Japan
DPE - Forged, USA
Neez- Forged, USA

[Zoeb@WheelDude.com]

is NKB really made in Japan?

I thought it was just a Japanese based company that buys wheels from various factories around the world?

I don't think they are actually made in Japan.

[Ron@Modbargains]

I think you are right zoeb, so not exactly sure where their manufacturing is done.

[crimsone90]

Originally Posted by Ron************

I think I wrote something like this a while back.

But lets add to the Heirarchy of the production method.


Gravity Cast
Low Pressure Cast
Double Chamber Pressure Cast
Flow Form Cast (Spun Cast)
Forged: Monoforged, 2PC Forged, 3 PC Forged




From the company's we carry and those that I know in the BMW market. Lets add where they are made, I think that should be a factor as well. We could also add certifications.

If I need to add explanation on Flow Form or forged methods I guess I could.

(Someone can put this in alphabetical order make a master list, I grouped it by the casting method)

Low Pressure Cast

Miro - Low Pressure Cast, Taiwan (Except 935, made in Japan by NKB)
VMR - Low Pressure Cast, Taiwan
Alufulgen - Low Pressure Cast, Taiwan
Linea Corse - Low Pressure Cast
Axis Wheels - Low Pressure Cast, Taiwan
Beyren/TSW - Low Pressure Cast, Taiwan (except Borque 3pc)

Forgestar - Flow Form Cast, USA
BBS - Flow Form Cast, Germany
Advan - Flow Form Cast, Japan
Enkie - Flow Form Cast, Japan
Rays - Flow Form Cast, Japan

HRE - Forged, USA
iForged - Forged, USA
Kinesis - Forged, USA
Volk - Forged, Japan
DPE - Forged, USA
Neez- Forged, USA

The manufacturers are welcome to join the thread and post their manufacturing method. There are several mistakes on your list. First I`m not aware of any flowforming done in the USA for Forgestar. Neez is not forged in the USA, is Japan. BBS are not only FlowFormed but Forged as well. I`m not aware of Miro being low-pressure cast and NKB is not made in Japan. Also VMR is gravity cast and not low-pressure cast.

We could have a list but unless the information is confirmed it`ll be pure speculation. Here it is.

Low Pressure Cast

Miro - Unknown, Taiwan
VMR - Gravity, Taiwan
Alufelgen - Low Pressure Cast, Taiwan
Linea Corse - Low Pressure Cast, Philippines? (Zoeb please confirm)
Axis Wheels - Low Pressure Cast, Taiwan
Beyren/TSW - Low Pressure Cast, Taiwan (except Borque 3pc)

Forgestar - Flow Form Cast, Unknown
BBS - Flow Form Cast & Forged, Germany/Japan
Advan - Gravity & Flow Form Cast, Japan
Enkie - Flow Form Cast, Japan
Rays - Flow Form Cast & Forged, Japan

HRE - Forged, USA
iForged - Forged, USA
Kinesis - Forged, USA
Volk - Forged, Japan
DPE - Forged, USA
Neez- Forged, Japan

[Zoeb@WheelDude.com]

yup, Philippines for Linea Corse

[crimsone90]

Originally Posted by Zoeb@WheelDude.com

yup, Philippines for Linea Corse

[vortex_tuning]

Originally Posted by crimsone90

The manufacturers are welcome to join the thread and post their manufacturing method. There are several mistakes on your list. First I`m not aware of any flowforming done in the USA for Forgestar. Neez is not forged in the USA, is Japan. BBS are not only FlowFormed but Forged as well. I`m not aware of Miro being low-pressure cast and NKB is not made in Japan. Also VMR is gravity cast and not low-pressure cast.

We could have a list but unless the information is confirmed it`ll be pure speculation. Here it is.

Low Pressure Cast

Miro - Unknown, Taiwan
VMR - Gravity, Taiwan
Alufelgen - Low Pressure Cast, Taiwan
Linea Corse - Low Pressure Cast, Philippines? (Zoeb please confirm)
Axis Wheels - Low Pressure Cast, Taiwan
Beyren/TSW - Low Pressure Cast, Taiwan (except Borque 3pc)

Forgestar - Flow Form Cast, Unknown
BBS - Flow Form Cast & Forged, Germany/Japan
Advan - Gravity & Flow Form Cast, Japan
Enkie - Flow Form Cast, Japan
Rays - Flow Form Cast & Forged, Japan

HRE - Forged, USA
iForged - Forged, USA
Kinesis - Forged, USA
Volk - Forged, Japan
DPE - Forged, USA
Neez- Forged, Japan

Updated:

Low Pressure Cast

Miro - Unknown, Taiwan
VMR - Gravity, Taiwan
Alufelgen - Low Pressure Cast, Taiwan
Vortex Tuning - Low Pressure Cast, China
Linea Corse - Low Pressure Cast, Philippines
Axis Wheels - Low Pressure Cast, Taiwan
Beyren/TSW - Low Pressure Cast, Taiwan (except Borque 3pc)

Forgestar - Flow Form Cast, Unknown
BBS - Flow Form Cast & Forged, Germany/Japan
Advan - Gravity & Flow Form Cast, Japan
Enkie - Flow Form Cast, Japan
Rays - Flow Form Cast & Forged, Japan

HRE - Forged, USA
iForged - Forged, USA
Kinesis - Forged, USA
Volk - Forged, Japan
DPE - Forged, USA
Neez- Forged, Japan

[crimsone90]

Originally Posted by vortex_tuning

Updated:

Low Pressure Cast

Miro - Unknown, Taiwan
VMR - Gravity, Taiwan
Alufelgen - Low Pressure Cast, Taiwan
Vortex Tuning - Low Pressure Cast, China
Linea Corse - Low Pressure Cast, Philippines
Axis Wheels - Low Pressure Cast, Taiwan
Beyren/TSW - Low Pressure Cast, Taiwan (except Borque 3pc)

Forgestar - Flow Form Cast, Unknown
BBS - Flow Form Cast & Forged, Germany/Japan
Advan - Gravity & Flow Form Cast, Japan
Enkie - Flow Form Cast, Japan
Rays - Flow Form Cast & Forged, Japan

HRE - Forged, USA
iForged - Forged, USA
Kinesis - Forged, USA
Volk - Forged, Japan
DPE - Forged, USA
Neez- Forged, Japan

PM'ed

[ModBargains.com]

Originally Posted by crimsone90

The manufacturers are welcome to join the thread and post their manufacturing method. There are several mistakes on your list. First I`m not aware of any flowforming done in the USA for Forgestar. Neez is not forged in the USA, is Japan. BBS are not only FlowFormed but Forged as well. I`m not aware of Miro being low-pressure cast and NKB is not made in Japan. Also VMR is gravity cast and not low-pressure cast.

We could have a list but unless the information is confirmed it`ll be pure speculation. Here it is.

Low Pressure Cast

Miro - Unknown, Taiwan
VMR - Gravity, Taiwan
Alufelgen - Low Pressure Cast, Taiwan
Linea Corse - Low Pressure Cast, Philippines? (Zoeb please confirm)
Axis Wheels - Low Pressure Cast, Taiwan
Beyren/TSW - Low Pressure Cast, Taiwan (except Borque 3pc)

Forgestar - Flow Form Cast, Unknown
BBS - Flow Form Cast & Forged, Germany/Japan
Advan - Gravity & Flow Form Cast, Japan
Enkie - Flow Form Cast, Japan
Rays - Flow Form Cast & Forged, Japan

HRE - Forged, USA
iForged - Forged, USA
Kinesis - Forged, USA
Volk - Forged, Japan
DPE - Forged, USA
Neez- Forged, Japan

I would prefer the Manufacturers to come and talk about it here.

As to BBS - http://www.bbs-usa.com/public/tech_advantage2.cfm - Flow Forming, However yes they do Forged as well like you said. You are right I ment Japan on Neez a typo from me. Forgestar is only a few miles from us - been to their production here in the US.
Miro have met with the owner multiple times - and been informed multiple times that the wheels are low pressure cast. Feel free to give them a call.

As to Velocity being gravity - not to my knowledge. Where have you heard this? Velocity is on the board here they can confirm this.

I noticed mention that Advan had a gravity cast wheel - what current wheel in their production is gravity casted? I wasn't aware of any.

[crimsone90]

Originally Posted by **********s.com

I would prefer the Manufacturers to come and talk about it here.

As to BBS - http://www.bbs-usa.com/public/tech_advantage2.cfm - Flow Forming, However yes they do Forged as well like you said. You are right I ment Japan on Neez a typo from me. Forgestar is only a few miles from us - been to their production here in the US.
Miro have met with the owner multiple times - and been informed multiple times that the wheels are low pressure cast. Feel free to give them a call.

As to Velocity being gravity - not to my knowledge. Where have you heard this? Velocity is on the board here they can confirm this.

I noticed mention that Advan had a gravity cast wheel - what current wheel in their production is gravity casted? I wasn't aware of any.

Forgestar, If you are saying that Forgestar have a flow-forming machine in their facilities I would schedule an appointment with them and will try to make it there next week.

Advan, please see attached.

VMR, please see below:

From Peter himself. Source: http://www.e90post.com/forums/showthread.php?t=14304 Post: 12

I have also heard Peter himself state this personally.

Originally Posted by VelocityMotoring

*** NON COMMERCIAL POST ***

Hi, our VB3 CSL wheels aren't that heavy. They weigh about the same as the Z15. They are single piece gravity cast wheels. Irregardless of the way it is cast, they all go thru the same quality testing before shipping. My .02, if you use the exact same tooling for spun cast, you'll get about the same volume of aluminum alloy in the wheel as gravity cast. It is theoretically possible to modify the tooling to reduce the volume of aluminum alloy, but the cost to benefit isn't there for us nor the customers. OE's have the luxury of doing so because producing 100k wheels is probably cheaper than making 1k wheels at gravity cast. Its just a matter of economies to scale.

On top of that, you'll be able to have a BMW roundel on the centercap.

I haven't seen the other guy's wheels in person, but I think forum members are more qualified to give their .02 on quality than the manufacturer themselves. But I believe the quality speaks for itself, knowing that it is hard to compare apples with apples on the internet, especially with "photogenic" pictures.

As far as offsets go, the E90 can use anything between 25-40 offset. I'm not sure why, but you can literally stick your foot between the stock wheel and fenderwell But yeah, hubcentric spacers on average are around $60ea, bolts $3ea, + shipping.

Any interest in our wheels please contact any of our retailers for pricing and availability.

Thanks!

Peter

Tom @ EAS, VMR largest distributor regarding the new V713 at M3Post. Source: http://www.m3post.com/forums/showthread.php?p=4813986 Post #15.

Originally Posted by tom @ eas

Wheels are gravity cast, there are no immediate plans for 20".

Expect all these posts to be edited/deleted after I post them here so check them quick.

[ModBargains.com]

I stand corrected Crimsone90 on the Velocity thing - pretty surprising actually cause I could have sworn they had told me it was low pressure cast.

Interesting that Advan is using a gravity cast - one thing is their method according to the picture is spun (like flow form) so I am guessing it's a hybrid method?

I'll see if I can find out on the forgestar but the cutting production process is done all here, some huge machines.

[crimsone90]

Originally Posted by **********s.com

I stand corrected Crimsone90 on the Velocity thing - pretty surprising actually cause I could have sworn they had told me it was low pressure cast.

Interesting that Advan is using a gravity cast - one thing is their method according to the picture is spun (like flow form) so I am guessing it's a hybrid method?

I'll see if I can find out on the forgestar but the cutting production process is done all here, some huge machines.

VMR, there are other that also have confirmation about this.

Advan, since they are flow forming they save on tooling cost by using Gravity. Low pressure+Flow forming will make a stronger wheel but not by much. Remember, flow forming first cast a wheel blank and then "flow forms" the rim.

[Peter@VMRWheels]

This thread is definitely a good collection of information, for whose who seek it. But it seems that the thread is also directed toward us and so we will be glad to provide input.

VMR Wheels has been providing quality aftermarket wheels to various communities for more than five years. On the BMW side, our selection spans three generations of 3-Series vehicles from E36 to E92. Our factory posess approvals including the ISO-9001:2000 certification. On wheel specific regulations, theres JWL/VIA certifications, as well as meeting or exceeding criteria as published by SAE and TUV.

Most individuals within the manufacturing community posess information about one another, with details including factory location, sales volume, country of origin, manufacturing specifics, choice of raw materials, where they come from, etc. In the sourcing process, I'm sure everyone has come across other brands being made, while walking thru the floors of various facilities. Every factory is put together differently, and without a complete analysis covering every field, the conclusions being made are subjective at best. Some might take a keen interest in seeing how the industry is connected with one another, but for others, their goal is to search out reliable vendors to purchase modifications for their vehicles.

Before purchasing wheels or anything on this forum for that matter, I would recommend using the "search" button to research material that will make you comfortable with making such a large purchase. You can search for past information such as track record, customer testimonials, or even the approach one takes when certain issues such as warranty pop up. I do the same thing when modding my car .

Any questions feel free to contact me directly.

[headsock]

kinda of topic, but figured some of you might find this interesting.

difference in performance of different manufacturing processes: hint cast wins (they didnt test durability though)

http://www.modified.com/tech/modp-09...ter/index.html

[crimsone90]

Interesting "test" but not quite conclusive.

[ALUFELGEN]

Originally Posted by crimsone90

Interesting "test" but not quite conclusive.

Check your PM.

[Alan l.]

So has it been confirmed that forgestar's are form flowed LP cast wheels?