New garret gtx4088 - sema

[Mikey]

Changing the 63.5mm cast wheel to a billet wheel will not change much.....when compared to the GTX4088r....IIRC, the compressor and exhaust housings are identical; however, the compressor wheel is larger....inducer 65mm vs 63.5mm and exducer 88.4mm vs 88mm and 54 trim vs 52.

I highly doubt Garrett would be willing to sell a new CHRA with larger wheels to retrofit my GT4088r. I'm guessing I'll have to either sell mine as is, refresh CHRA or look into Garrett's BB Service Program (my unit isn't damaged though....works great).

Yes true on specs, but billet wheels generally give a 50-100 hp gain? right?
Here is a bullseye billet used billet batmowheel found on ebay
Additionally, Batmowheels usually have a higher gain than standard billet wheels?right?

GT4088R Bullseye Billet Wheel
http://www.ebay.com/itm/111283009364?fe_1_3

 

[Evan@InglewoodTrans]

Yes true on specs, but billet wheels generally give a 50-100 hp gain? right?
Here is a bullseye billet used billet batmowheel found on ebay
Additionally, Batmowheels usually have a higher gain than standard billet wheels?right?

GT4088R Bullseye Billet Wheel
http://www.ebay.com/itm/111283009364?fe_1_3

So your thought is just because a wheel is "Billet" it makes 50-100 more HP?

 

[dmax711]

So your thought is just because a wheel is "Billet" it makes 50-100 more HP?

Everyone knows if its billet its better. And a sticker adds at least 20hp so that wheels gotta add 100

 

[JDub]

So your thought is just because a wheel is "Billet" it makes 50-100 more HP?

I agree. Why do people think that just because the metal is different it's going to flow more air?

 

[Cknight199]

So what DOES make billet better, the wheel is lighter correct? And what makes a batmowheel successful is both it's Lighter and a different design?

 

[Evan@InglewoodTrans]

So what DOES make billet better, the wheel is lighter correct? And what makes a batmowheel successful is both it's Lighter and a different design?

Billet wheels aren't even always lighter.

 

[Cknight199]

Billet wheels aren't even always lighter.

Well I mean the material density is lighter right? Meaning out of two wheels of the same design the billet will be lighter correct? A cast batmo will be heavier than a billet batmo (so to speak)

 

[JDub]

I won't comment on the Batmo stuff, but...

It's the wheel design and profile that determine how much air it will move and how it will move it. Design, pitch, inducer/exducer, etc... A billet wheel is going to be stronger and more durable, weight will be different as well. But just because it's billet, it isn't necessarily better. So wheels are designed for high pressure, some for high volume, etc... and bigger size doesn't always mean bigger power.

Borg Warner makes the K31 71mm compressor in both cast and FMW...guess what they'll make the exact same power (given all things with the truck stay constant), cast is cheaper but FMW is stronger. So each has it's place.

 

[jkholder09]

There are also drag racing classes that allow the vehicle to weigh less if they have a cast wheel.
I think that incenuates billet has an advantage.

I have to agree with jdub in my experience a billet wheel does not always outperform cast.

The gtx wheels are taller and potrude further into the mouth. This is a larger blade area which has the potential to move more air.

 

[Magnus]

The gtx wheels are taller and potrude further into the mouth. This is a larger blade area which has the potential to move more air.

This^ the blade profiles and total surface area has more to do with air movement than anything else. The wheel will be aerodynamically optimized and engineered for certain parameters.

The perception that a billet wheel is better is really just because a wheel for a strictly performance application can be aerodynamically optimized for a narrow operating window at high Shaft speed at the edge of the compressor map yielding more peak power. Look at where the GTX turbos outflow the GT series turbos. It's at pressure ratios of 3.5:1 and higher.

Billet wheels are sometimes lighter because the grain structure of the material can be oriented to maximize strength under load in the direction of peak forces, allowing more material to be machined away without the wheel falling apart under load.

You hear about more billet wheels failing because some manufacturers trying to sell billet wheels solely on hype and weight reduction get over zealous and machine performance billet wheels thinner than they should, and because the only people who buy billet compressor turbos are racers who are more prone to overspeeding and surging their turbos in the first place.

The vast majority of people on here would be better off not spending the multiple hundreds of dollars for the billet wheel, and would see a real performance boost putting the money towards connecting rods or anti-wrap bars instead. :thumb:

 

[JDub]

Great response Magnus. Most people would be perfectly fine running a cast wheel but the 'hype' is in billet. In reality, I doubt very many of the aftermarket billet wheels perform any better than an OEM cast. I'm sure Borg Warner and Garrett engineers have a little more time in development and money in research than most shops with CNC capability...

 

[MarkBroviak]

Great response Magnus. Most people would be perfectly fine running a cast wheel but the 'hype' is in billet. In reality, I doubt very many of the aftermarket billet wheels perform any better than an OEM cast. I'm sure Borg Warner and Garrett engineers have a little more time in development and money in research than most shops with CNC capability...

While your assumption may true for some, it is definitely not true for all. For shops like me that have all the test equipment to test the parts back to back to see the differences it's pretty clear. If the cast oem parts flowed as good or produced the same power as the aftermarket billet we would be selling a lot more of them because they are ALOT cheaper! Drag racing may be alittle different since they aren't limited on air flow but in the sled pulling world you will not find cast parts in the turbos of the winning trucks. That is a fact not "hype". You have to decide what you need and go from there. As far as everyone hating on Batmo's and saying they are just "Hype", umm... They (BullseyePower Batmowheel and Jerry Morgano) currently hold the 10.5 Outlaw Small block record with a 4.15@175mph beating out ALL other turbo manufactures which is a huge deal. I am glad to be part of that program as I built the custom turbine housing for that car! They work!:thumb:

 

[JDub]

While your assumption may true for some, it is definitely not true for all. For shops like me that have all the test equipment to test the parts back to back to see the differences it's pretty clear. If the cast oem parts flowed as good or produced the same power as the aftermarket billet we would be selling a lot more of them because they are ALOT cheaper!

Oh, absolutely. I was not implying that everyone is like that, as some places, such as yourself have the data and results to back it. I was just stating that just because it says 'billet' it doesn't mean more power. It's the design/profile that matters, not the material.

 

[Magnus]

While your assumption may true for some, it is definitely not true for all. For shops like me that have all the test equipment to test the parts back to back to see the differences it's pretty clear. If the cast oem parts flowed as good or produced the same power as the aftermarket billet we would be selling a lot more of them because they are ALOT cheaper! Drag racing may be alittle different since they aren't limited on air flow but in the sled pulling world you will not find cast parts in the turbos of the winning trucks. That is a fact not "hype". You have to decide what you need and go from there. As far as everyone hating on Batmo's and saying they are just "Hype", umm... They (BullseyePower Batmowheel and Jerry Morgano) currently hold the 10.5 Outlaw Small block record with a 4.15@175mph beating out ALL other turbo manufactures which is a huge deal. I am glad to be part of that program as I built the custom turbine housing for that car! They work!:thumb:

They do work and generally don't blow up when properly installed and not oversped, yellowchevy and his modded batmo-stockers get great reviews...

Google "GE turbofan blade" and check some images... Bullseye stole the profile from some VERY smart people and applied it to centrifugal compressors. Never seen any real analysis on it myself, but it seems logical that the profile enhances boundary layer behavior as you approach compressibility at the blade tips (high rpm, high performance as stated before). Same principle used on modern helicopter blades too, slows the spread of unstable boundary layer conditions when the advancing blade tip accidentally enters into compressobility.

But billet doesn't necessarily=better, just usually a more consistent material quality enabling more elaborate machining without getting too many random material related failures like a cast or forging can yield.

It's like how people automatically think powdered metal= weak when it comes to engine parts. Sometimes yes cheaper powdered metal is used, but by and large superior design is the difference in aftermarket billet and forged parts lasting longer. Anyone who thinks all powdered metal connecting rods are crap should take a look at the old Caddy Northstar rods from GKN.

 

[Magnus]

Also, Not trying to start a war by any means and I believe your VGT experiments and bullseye's wheel and housing designs bring a lot of innovation to our diesel world.

Most people on the outside have no idea the tech involved in making a modern superdiesel

 

[LWATSON]

Dont the billet wheels have one less blade also? I think my s475 has 6 blades and the cast 475 has 7?

 

[Magnus]

Dont the billet wheels have one less blade also? I think my s475 has 6 blades and the cast 475 has 7?

Design difference... A cast 6 blade with the same profile would do just as well

 

[LWATSON]

Can you get a cast 6 blade for an S475?

 

[Magnus]

Not actually sure of that one... All the off the shelf 475s I've seen we're 7 blade ETT cast wheels, so in your case the billet wheel probably performs quite a bit better because it's a superior aerodynamic design and you're probably squeezing a higher pressure ratio from your turbo since it's a single. Plus the 6 blade wheels seem to sound nasty.

 

[MarkBroviak]

Not actually sure of that one... All the off the shelf 475s I've seen we're 7 blade ETT cast wheels, so in your case the billet wheel probably performs quite a bit better because it's a superior aerodynamic design and you're probably squeezing a higher pressure ratio from your turbo since it's a single. Plus the 6 blade wheels seem to sound nasty.

X2, it was 100hp increase when the 6-blade 75mm Billet wheel came out from Bullseye over the stock cast wheel. Now if you run the cast S468mm wheel vs. the FMW BS468 there isn't a noticeable difference between them when you put them in the same cover because they are identical design other than material/manufacturing. I'm with you guys, to say billet is better would be too broad a statement.