Gcg Highflow Vs Gcg Highflow Billet Wheel

[GreenGhost]

Does any one know the difference between the old gcg rb25det highflow wheel and the new billet wheel spec wise

or is anyone currently running one of the new billet wheels

cheers

[scotty nm35]

Most realised they are sub par performance wise, and moved on to decent highflows, somewhere that actually tests and improves his turbo designs (rather than shoving a garrett core in the stock housings and hoping it will work.)

Hypergear all the way, unless you have the coin for a custom externally gated turbo setup.

[Blackkers]

A respected tuner said to me yesterday "gcg couldn't highflow their own arse"

He was also impressed with the hypergear unit on my car

[Badgaz]

'copied from high performance academy on facebook'

What’s a billet compressor wheel and why should you care? As with many things in our industry, the term ‘billet compressor wheel’ has become a popular buzz word yet many people don’t know what it means, what it refers to and why they may or may not need it. With more and more turbo manufacturers offering billet compressor wheels for their higher specced turbos, it’s worth finding out what this technology means to you.

In a conventional turbocharger the compressor wheel is usually cast from aluminium, but many would be surprised to learn that the material and the manufacturing method have almost nothing to do with the amount of airflow (and consequently power) a turbo can produce. The compressor’s airflow potential is solely down to the shape and size of the compressor wheel. With this in mind it’s possible to create exactly the same compressor wheel shape using either a casting or machining process and if the physical design is the same, the airflow potential of the wheel will be the same - There is no magic just because the billet wheel is shiny.

So why are billet wheels popping up everywhere if there are no advantages? Well we didn’t say there aren’t advantages. The advantages just aren’t what most people think they are so let’s look deeper. One genuine advantage from a billet wheel is that it is stronger than a cast wheel. Now this isn’t going to mean much to most people on the street, after all when was the last time your compressor wheel just plain fell apart? If you’re a serious drag racer though and you’re planning on running upwards of 80 psi boost, then the billet material can provide a strength and reliability advantage. The real reason that billet wheels have become so popular though is that it provides turbo manufacturers much more flexibility in bringing new compressor wheel designs to market quickly. The casting process in comparison is expensive for a low volume production and time consuming. Billet designs however can be manufactured in minimal numbers very rapidly on cnc mills. This is critical in the prototyping and validation process, allowing manufacturers to test a wide range of wheels and select the best performing.

We aren’t here to knock billet compressor wheels as this technology along with the cost and time advantages for manufacturers to bring new designs to market has seen some huge improvements in turbo performance over the last 5 years. It’s important to know what you’re buying and why. If you swap out a cast compressor wheel for an identical billet compressor wheel and expect to pick up 100 hp, you’re going to be sorely disappointed.

If you're interested in learning more about EFI Tuning, check out our catalogue of online courses here: https://courses.learntotune.com/school/catalog/

[GTSBoy]

That little quote is sadly lacking in information that is actually relevant to the real reason that billet wheels are (or can be) better. For the same total diameter and total mass, you can make a billet wheel with more flow and/or pressure capacity than a cast one. Bigger wheel for the same mass = fast spooling big turbo. Smaller wheel for less mass = faster spooling same size turbo. It's all goodness, honey and cream. Or at least it can be if the designer chooses to make it so.

[R31Nismoid]

^ that way my understanding as well... A slight performance advantage.

The comment about gaining 100hp is correct though (and you wouldn't gain 1000rpm by the same token)... None the less there are minor benefits.

GCG RB25 hi-flows, back 8-10 years ago, were excellent for what they were - there was not a lot else on the market and what products were - performed very poorly. These days there is more development and better options around.

Unless the GCG billet wheel is actually a different specification, trim etc, you are still better going elsewhere.

[GreenGhost]

i spoke to gcg today and they are now not using the new billet wheels in there rb25det highflows any more as had better results with the old wheel but that's only on there high flow

im vey happy with my gcg highflow had it for about 5-6 and well over 100;000kms now just starting to leak oil out the back of the turbo so that why i wanted to know the differents

I need a stock looking setup up as i need my licence for my work (lost it 5 times ) and dont need the attention nor do i want to spend more money then needed as im building a silvia

[KiwiRS4T]

I bought a GCG highflow probably same time as you. Best I ever got was about 245AWKW but I think you can get better results for less dollars from Hypergear these days...(on a stock looking turbo).

[scotty nm35]

im vey happy with my gcg highflow had it for about 5-6 and well over 100;000kms now just starting to leak oil out the back of the turbo

Have you checked the shaft play? If there isn't much you may just need another restrictor to slow the oil flow down. Good chance the bearings are toast due to high thrust loads though.

If it is a Garrett core you may be able to change it over yourself, as long as the housings aren't cracked or worn.