Read this yesterday.

Seems like the big "hype" over billet wheels was all for nothing.

 

No difference? What about price?

 

Its the same with almost any part… its all about volumes and cost. Most turbo companies uses "billet" fully cnc wheels for low volume applications or for design/prototypes. Since most aftermarket-marketed turbos are combinations of various existing OEM wheels, higher volume parts are going to be produced as castings and some will be machined forgings. In either case the performance is in the design not necessarily the manufacturing process. In most cases the cnc'ed wheel will always cost more regardless if it performs better (assuming its the same material as the casting). For the most part this applies to both aluminum and titanium wheels. It is funny to see people always drooling over "billet" parts. There is no doubt that it’s a neat marketing term that sells product tho.

 

Interesting...learn something new everyday.

 

How about a comparison to Ceramic Wheels, that's what I wanna see.

 

I saw that last year when looking for turbos, so when i see all the hype threads about billet i know it's all about selling another part that does nothing for performance, but costs the consumer more money.

 

But the site says "of the same design"

The Billet wheels people are making right now are taking advantage of the billet process and cutting thinner blades then possible with cast, and cutting closer to the center nut, meaning more flowpath with the same inducer diameter.


Therefore the article only explains why making a billet wheel exactly the same as a cast wheel is silliness. That article also defuncts peoples assumption that somehow the machining process magically makes the turbo make more hp, or even silly ideas like the machining lines directing airflow (yeah right).

 

this^

billet wheels are not designed like the cast wheels. its not the "billet" that makes them better, its the stronger material is able to be cut sharper and close to center. i love marketing strategies.. ofcourse 2 of the same wheels made from different material will flow the same

 

It pisses me off that a company like garret purposely misleads people like that.

Another fact they should mention is that Garrett sells so many turbos and has so much investment in cast technology (which saves them money) that their bottom line is probably much better with cast wheels.

They probably don't have as much of a monetary advantage when it comes to machined wheels because their manufacturing advantages disappear.

This kinda crap goes on all the time. Its just like computer processor technology always being held back from the public so it can be rationed out to create maximum profit, car makers avoiding building high MPG cars even though 30 years ago they built 4 door cars getting more then 50mpg.

 

On a side note.

The billet 67mm has not shown hp gains, just better able to deal with high boost (supposedly....ive heard evo guys running a few more PSI (43-45 vs 40-42) but not actual hp gains. While a dyno sheet will show the billet making more power at some rpms, it loses at others.

To me that has to mean the billet 67 is a bad design and a waste of money...
Also meaning that billet could be hot spit, or just a waste of money. How do you know with how adamantly people lie about their own products, especially for low volume stuff.

 

damnit! I have a 67mm billet

 

Yeah... I always laugh when people start hyping up machined billet compressor wheels...

you guys hit it on the head!


Now ceramic stuff? Is good with temperature and spool (especially a turbine), however... they can blow the hell up if over sped... just like the magnesium compressor wheels MHI has...

 

larger turbos usually run 80-120k rpms instead of 100-150k rpms. Ceramic might have more limitations then just rpms though. Increasing the size might just lower the RPM that it breaks at.

I think what a few of us are saying is that Billet wheels ARE worth the hype if you buy a well designed one. Even wheels from the same company may not always be good.

 

1. ceramic turbine wheels on one of the GTR models were notorious for shattering when boosted over 25psi IIRC.

2. Billet wheels are usually made from forged aluminum blanks, and are made for durability at high pressure ratios primarily, or in low volume production. MAN B&W diesels use billet compressor wheels almost exclusively, because of the high PRs, sometimes exceeding 5:1.