The reality of Billet wheeled turbo's. Lets stop the BS train

[flexer]

As you can tell by my post count I don't really post here a lot, but I come at least 3 times a week to read in the FI section to see all the projects going on, but tonight something really STRUCK a nerve with me.

People keep talking about getting this or that turbo because it has a billet wheel. WHAT WAS REALLY EMBARRASSING was one shop on this forum that keeps referring to billet wheel turbo's and referring there customers get them because there AMAZING performance.

Now look guys I'm sorry, I don't know if the BMW guys just didn't get the memo.....or you were all on vacation in Germany, but two years ago when billet wheels started getting popular coming from small private companies like Precision and Forced Performance and such people did there homework and found there was no gain. The only reason they do them in billet is BECAUSE THE HAVE TO since its the only material they can make it out of in SUCH SMALL PRODUCTION NUMBERS......not because they thought it gave them an advantage. Then companies like Precision INSISTED there was a gain, and the BIG DOGS answered. Here is a response from one of the big dogs at Borg Warner, but if you look Garrett engineers answered as well talking about how billet is only effective in short manufacturing runs of turbo's, and there is no performance gain:

Original is here:http://honda-tech.com/showpost.php?p...4&postcount=98

"BW AirWerks - In general... yes, we can make anything if you want to pay for it In the performance and/or racing world though, there is really no benefit to using a "billet" CW other than it's shinny. Basically, billet, or FMW (Forged Milled Wheel) compressors came about due to OE applications requiring them. When a turbo is constantly being cycled from high speed to low speed, the wheel becomes fatigued and can eventually lead to a hub burst (CW splits in half). Imagine the compressor acting like a big drag slick like you see on top fuel cars; during the burnout, you can see them get skinny and "grow" in height... On a much smaller scale, the CW sees this same process over and over again, and over time this weakens the wheel, eventually leading to a fracture and possibly a hub burst. Now ask your self how many times you've seen a race car's CW split in half... I have never, and I've seen a LOT of failures. Even the billet aluminum isn't enough in some newer applications and we've turned to titanium which in its FMW form, is nearly indestructible. I've heard all the propaganda surrounding the billet wheel myths: higher boost capability, higher flow, higher efficiency, etc... The higher boost capability is the only one which is true, but not because it's machined and not true for racing use. OE diesel applications using FMW compressors can run higher boost pressures more reliably simply because they are less susceptible to fatigue as they're cycled from higher speeds (required to make more pressure) to low speeds.
So, why would anyone offer a billet wheel to the racing/performance market? Couple/three reasons:
- Some people just want them because they look really nice... and are willing to pay the cost difference.
- Because it already exists in an OE production application and it's easily installed into performance turbos, sometimes they're even interchangeable with existing cast wheels.
- Applications where a cast wheel does not exist (maybe a larger inducer is needed) or production volumes are believed to never be high enough to justify tooling costs.
Are they cheaper than cast wheels? ...NO. Even in high production volumes, a billet wheel will always be more expensive than a cast wheel. However, if a company wants to make a compressor all their own (not using an existing "big" turbo manufacture's wheel ie. BW, Garrett, Holset) it would most likely be cheaper as they would have to tool up to make all the cast versions. If a company makes a mistake in the design of a billet wheel, they can simply keep changing the program until they get something that works... The OE manufacturer does all the development work up front to arrive at the best possible design for what's needed. Once the design is finalized, a "master wheel" is machined and used for the tooling master... that's right, all cast wheels get their start from a very nice billet wheel that when tooling is made, creates the same exact performance characteristics in a much cheaper and faster to produce cast version.
Phew... Sorry for the long-winded explanation, but hopefully this helps explain why billet wheels exist. Short version is billet wheels are no better than cast wheels for any performance or racing application I'm aware of... but they sure do look great!



I hope this new bit of information that has been WIDELY published on the net for years now helps a certain company on this forum to stop posting about how amazing Billet wheels are unless they have some concrete evidence showing how they really do spool faster. IF NOT PLEASE STOP FEEDING POOP to other BMW enthusiasts because you sell precision turbo's or something.

Sorry for my rant guys. Shoot I just hope for some of you, this is new information.

Weird this info never made it to the BMW guys. Well. You have all been informed.

[Mr Deagle]

Thank you!!!!!

[YellowBed]

Thanks for the info.

[M3GSX]

Ok. thanks for the input man.

However; billet is just a material. It's the design that makes more power...Again, the design of the turbo.

Garrett has GTX turbo's now. Garrett Engineers themselves claim a 10% increase in power and compressor map flow.


Again; I want to stress that the main reason that these newer "billett" turbos are making more power with the same size diameter wheel is due to the RE-DESIGN of the compressor wheel blades and aerodynamics.

You need to be more clear with your explanations.

If you have ever actually used any of these turbos rather than just post and read mumbo jumbo on the internetzz you would know exactly what point I am trying to get across.

Check out the compressor map on the bottom. Bottom two. GT4094 Vs GTX4094 (redesigned compressor wheel).

Basically what I am trying to say is. Most of these new billet wheel turbos are not just billet versions of older compressor wheels; they are completely new compressor wheels that just happen to be billet. It's the TECHNOLOGY behind the wheel design.

[got psi]

Sorry for my rant guys. Shoot I just hope for some of you, this is new information. Weird this info never made it to the BMW guys. Well. You have all been informed.

So what turbo company do you own or work for? ///J.T.///

[mazur]

Really? Some people actually thought that the wheel performed better just because of the fact that they were billet? lol


How many companies make their own wheels anyway? I thought there was only one major manufacturer that had a good design.

[tptrsn]

I don't think this was new information to many people on this forum, but I also think it's a bit misleading since it implies that the billet wheel options on the market are no better than the non-billet ones. I think it's pretty clear that since the billet wheel turbos are more quickly designed and produced in response to market demands that may be relatively low volume, better options exist for certain portions of the market.

All you really need to do is set a billet wheel turbo next to an old school turbo of a similar size to see the obvious difference--there is a lot more vane area on the billet wheel turbo due to the smaller diameter hub portion.

Similarly, that same comparison on the car makes a strong impression. The billet wheel turbo is WICKED in comparison to the conventional model.

But, that's just my opinion based on my limited experience. I know there are guys on here with MUUUUCH more experience with this very topic than me. The only question is whether they will be willing to share. Some times it's not worth it to put your opinions or experience out there on the internet for all of the bashing that inevitably happens. . .

EDIT: M3GSXes post above was right on point, mine was probably un-necessary.

[rt turbo]

I dont recall anyone saying that these turbos performed better for their being billet only. I have seen people say they may spool faster, which still may be true, but power gains? no.

As already stated, we know some of these new turbos do make more power for the same spoolup time as the previous generation of turbos. But that is wheel redesign and not because its billet. Thanks for the post, but I think if any shop is pushing a billet its because most of the new designed turbos that make more power are made of billet. Maybe they do this just to sell at a higher cost, but I havent seen any shop saying its only because it is billet.

[tptrsn]

For sure RT Turbo!

This whole thing is a bit odd to me though. It's like a distinction without a difference. Does it matter if these new turbos work better than the less recent ones because the compressor wheels are carved from billet material or because the process of making billet wheels means that the fluid dynamics technology in the wheels can be updated more quickly? I don't think so.

Maybe I'm totally missing the point of the original post.

[Ted B]

Weird this info never made it to the BMW guys. Well. You have all been informed.

And now, 'the BMW guys' will inform you.

The billet compressors used by the likes of Precision, Forced Performance, etc. feature improved aerodynamics, lighter mass, and better high PR durability as compared to Garrett GT series compressors, which are already a generation beyond the old school (e.g. T-series) Garrett turbos and some other brands.

It has been conclusively, independently demonstrated that newer billet wheels fitted to Garrett CHRAs are fundamentally superior to Garrett GT compressors in real-world running, which is evident enough to cause Garrett to respond (e.g. GTX).

My Forced Performance HTA3582 replaced a GT35R I used previously, the only difference being the compressor wheel. The HTA clearly outspools AND outperforms the Garrett compressor, despite both having the same overall (exducer) diameter. I am one of many tuners who has witnessed the difference first hand with logged data, and it is plainly evident on the dyno. To say that I am pleased with the difference is an understatement.

So perhaps you are missing the crux of the argument, that being it isn't only the fact that the compressor itself is lighter (resulting in faster spool and quicker transient response), but the advantage of advanced aerodynamics and number of available sizes/trims give billet technology a clear advantage to any consumer who knows something about turbo component matching.

But then again, if you can demonstrate a GT35R that can deliver 800+whp with no significant difference in spool characteristics without refitting it with a more advanced billet compressor, I'm all ears. As of now, the FP HTA3586 has demonstrated exactly that, and yes, it has a billet compressor.

[flexer]

Ok. thanks for the input man.

However; billet is just a material. It's the design that makes more power...Again, the design of the turbo.

Garrett has GTX turbo's now. Garrett Engineers themselves claim a 10% increase in power and compressor map flow.


Again; I want to stress that the main reason that these newer "billett" turbos are making more power with the same size diameter wheel is due to the RE-DESIGN of the compressor wheel blades and aerodynamics.

You need to be more clear with your explanations.

If you have ever actually used any of these turbos rather than just post and read mumbo jumbo on the internetzz you would know exactly what point I am trying to get across.

Check out the compressor map on the bottom. Bottom two. GT4094 Vs GTX4094 (redesigned compressor wheel).

Basically what I am trying to say is. Most of these new billet wheel turbos are not just billet versions of older compressor wheels; they are completely new compressor wheels that just happen to be billet. It's the TECHNOLOGY behind the wheel design.

When speaking with a garrett engineer...the ONLY reason they run a billet wheel is because of LOW PRODUCTION NUMBERS to save money on tooling, and not for performance. The GTX turbo's are going to be low production runs....so I am not surprised they are going to be made out of billet. Are you surprised M3GSX?

And I agree with you that they are new technology wheels with extended tip....Then M3GSX lets just say that.....lets just say go with this turbo because of this wheel like WE ALL USED TO DO. Why now do they say...oh go with this turbo because of the billet wheel.

m3GSX, I think you and me are agreeing perfectly......its the actual wheel design that matters, not the material the wheel is made out of. There is no gain from a billet wheel.



J. R.

And now, 'the BMW guys' will inform you.

The billet compressors used by the likes of Precision, Forced Performance, etc. feature improved aerodynamics, lighter mass, and better high PR durability as compared to Garrett GT series compressors, which are already a generation beyond the old school (e.g. T-series) Garrett turbos and some other brands.

It has been conclusively, independently demonstrated that newer billet wheels fitted to Garrett CHRAs are fundamentally superior to Garrett GT compressors in real-world running, which is evident enough to cause Garrett to respond (e.g. GTX).

My Forced Performance HTA3582 replaced a GT35R I used previously, the only difference being the compressor wheel. The HTA clearly outspools AND outperforms the Garrett compressor, despite both having the same overall (exducer) diameter. I am one of many tuners who has witnessed the difference first hand with logged data, and it is plainly evident on the dyno. To say that I am pleased with the difference is an understatement.

So perhaps you are missing the crux of the argument, that being it isn't only the fact that the compressor itself is lighter (resulting in faster spool and quicker transient response), but the advantage of advanced aerodynamics and number of available sizes/trims give billet technology a clear advantage to any consumer who knows something about turbo component matching.

But then again, if you can demonstrate a GT35R that can deliver 800+whp with no significant difference in spool characteristics without refitting it with a more advanced billet compressor, I'm all ears. As of now, the FP HTA3586 has demonstrated exactly that, and yes, it has a billet compressor.

Ted B,

Good response. I agree with it all. To go a step further why do you think HTA only replaced the compressor wheel? Because you can't make a billet exhaust wheel so what does that mean. SHOOT, they would have to do the tooling for there own exhaust wheels and that would be to much for a small time company like HTA.

I Agree with Ted B and m3GSX that these new billet wheels can have approved performance because there compressor maps can be tailored to a more specific flow chart, but even then you did get one guy above stating he things billet wheels will spool faster........

It they really did, being that the borg warner guy said they can offer improved durability in high boost applications, don't you think the major manufacturers would be pushing the billet wheel?

Another poster above talked about testing. The BMW guys might not know, but companies like Buscher and Full Race have done TONS of back to back testing with dyno charts showing differences between billet and non billet wheel turbo's.

The gains are always in the design of the wheel itself, not the material.

http://forums.evolutionm.net/evo-eng...el-60-1-a.html

http://forums.evolutionm.net/service...oll-gt35r.html

I would like to see a HTA35R go up against that S300sx borg warner though. My personal opinion is that it would woop that borg warner up.

Again that is just my opinion.

J. R.

[dcvee]

...so does this mean my billet shift knob won't make my shifts any quicker?

Don

[rt turbo]

Again flexer, I dont think anyone on here or in this thread believes that the material used is making 100+whp gains on a similar size wheel. I personally think the reason they spool faster is the design but it does make sense that a lighter wheel may be quicker to spool... HOWEVER, I think those differences would only amount to 5% of the total difference and the over 95% being improves aerodynamics design of the wheels.

This really is NOT news to us, sorry to rain on your parade but when anyone on here says "billets" are better they are likely making reference to the better impeller design the billets use over the previous generation. Its like referring to any dark soft drink as a "coke." You could not have been too much of a reader on here because there are many threads where this has been discussed.

[got psi]

What are we talking about here ? We all seem to agree that a billet wheel of the same design as a stock wheel will add NO performance gain. WE ALL GET THAT. Actually I don't know of a stock wheel design made in billet. So yes the billet wheels are a short run item and they are made to different specs to enhance performance, thus USUALLY a billet wheel will outperform a stock wheel. Thus billet is better. Most of the time. Seems you are fixated that SMALL companies are the only ones that do billet because of volume, so what's the point here? We need to get to the ceramic wheels next. ///J.T.///

[mazur]

Yah, I don't think anyone would realistically expect a "small" company to cast parts vs. machining them. Think about the flexibility in design you have by using a CNC versus making all new tooling for casting.

[highboostingm3]

When they start making cast wheels exactly the same design as the new improved design of the GTX, etc. BILLET wheels, then we will stop jocking the phrase "BILLET WHEEL".

What about a carbon fiber wheel? lol

[rt turbo]

When they start making cast wheels exactly the same design as the new improved design of the GTX, etc. BILLET wheels, then we will stop jocking the phrase "BILLET WHEEL".

What about a carbon fiber wheel? lol

Thats exactly what I was saying. Its basically like calling Pepsi/RC/Sams/costcola a "coke." I.E. go into a restaurant and order a "coke" and they bring you pepsi in a glass. We know its not a coke, but it got the job done. Right now the new wheel designs are almost all billet and these new designs do make a significant increase in power, but we know it is not strictly because it is made from billet steel.

[tptrsn]

I hate to come off like a thread-governor or something, but this really is one of the most useless threads I've seen in a while. . . I'm guessing "flexer" is laughing himself silly at us all.

[YellowBed]

He should, because we are stupid inferior bmw owners.
DSM owners are far more advanced we suck so much.

[Black Mamba]

...so does this mean my billet shift knob won't make my shifts any quicker?

Don

[tptrsn]

That is a nice, clean looking car you have there Black Mamba!

[flexer]

I hate to come off like a thread-governor or something, but this really is one of the most useless threads I've seen in a while. . . I'm guessing "flexer" is laughing himself silly at us all.

I had a good time reading the responses, and liked what was written. Sadly all the people that already know this chimed in, and so they said there witty comments, but hey, that comes with the BMW territory right? I didn't see the one performance shop that was the one talking about the billet material being better chime in. Maybe thats because they read the thread and learned something. Mission accomplished then.

Reality is this thread has been very informative....thing is only the informed people are going to chime in. Its why I love it when people are like "usless thread...." really, you think so?

So after reading this thread you think, "well why did he start that": Yet no one ever gets flamed for the: " which turbo should I go with" , or " how to add a boost controller".

I'm going to do this. This thread is currently getting bumped. I'm going to see if I can even make it one page without a "what turbo should I get?" thread.

[MikeE36]

What turbo should I get?


-Mike

[highboostingm3]

I had a good time reading the responses, and liked what was written. Sadly all the people that already know this chimed in, and so they said there witty comments, but hey, that comes with the BMW territory right? I didn't see the one performance shop that was the one talking about the billet material being better chime in. Maybe thats because they read the thread and learned something. Mission accomplished then.

Reality is this thread has been very informative....thing is only the informed people are going to chime in. Its why I love it when people are like "usless thread...." really, you think so?

So after reading this thread you think, "well why did he start that": Yet no one ever gets flamed for the: " which turbo should I go with" , or " how to add a boost controller".

I'm going to do this. This thread is currently getting bumped. I'm going to see if I can even make it one page without a "what turbo should I get?" thread.

Very few smartasses who already knew posted...it's the masses who watched and slowly went, "aaaaaAAAAAHHHHHHHHHAAAAAAAA!" and didn't post is where it counts.

[tptrsn]

Yeah, okay, upon reflection this is possibly a very useful thread. I guess maybe my previous point really was that the stated purpose for the thread was useless. It does seem to have turned out that there was a lot of good discussion that nailed down some points pretty well. Whatever, it's just one guy's opinion.

One thing I wanted to add though, was that I was not aware of a vendor claiming that the billet material itself was to credit for the performance of the current turbos. Somehow I missed that in your original post (if it is there), and if your purpose was to debunk that claim, it really does change the complexion of things. In that case, the original purpose of the thread would be perfectly valid, and I should have kept my keyboard to myself! Hah hah. . .