Talk about a back handed compliment. Nice save at the end just in case I beat your ***.

 

Lets take this out of AMS thread...i will call you..

 

Eric,

How much air are these K16's pushing?

 

that is dam fast. Is this the fastest K16 hybrid trap speed? Definite 10 second car if you can get a 1.7-1.8 60ft time. Did you figure out what is wrong with the clutch? is it just going out?

 

How much boost were you running?

 

what he said...

 

Everyone seems to think your ok so majority favor.... but I on the same page as you, after that much money spent on a setup I to would like to see more of a performance gain (specally with the time at the track put in).
My K24 car with 100 octane and simple bolt on mods is trapping at 127mph..

 

1.4 bar

 

Pretty impressive. For our education and without giving away the farm, of course, can you explain why, that up until this post, it was presumed that anything after 1.1-1.2 bar or so, the K16's just made hot air?

 

cause the compressor wheel has been inlarged and updated to flow more air i would like to know how much they Flow compared to gt28's and others

 

If that's the case, and if it's a bigger compressor wheel is it REALLY a K16? When you enlarge a K24 it becomes an 18G? One of the other ways to enlarge a K16 is to make it a 16G. What are these?

 

Just so you guys know were I'm coming from, I've been working with turbocharged cars for 10 years, I've tested, datalogged, compared probably 50-75 different turbochargers or combination thereof. I've also been tuning, designing/testing camshafts, and designing engine combinations that have made 700hp/liter.

On the compressor side, the turbocharger takes in air, compresses it and feeds it into the engine. Work is being put into compressing air and depending on the efficiency at certain pressure ratio's (boost level) it will increase the charge temperatures by a certain amount. Higher temperature means less dense air and makes the engine more susceptible to detonation.
Where a 16G compressor wheel may be way out of it's reasonable efficiency range at 1.2 bar of boost, another wheel may be still working efficiently. Depending on wheel designs, some are made for high pressure ratio use (high boost) and some for lower pressure ratio use. There are a lot of variables to this. Higher pressure ratios (high boost) mean an increase in shaft speed, meaning the turbo is spinning faster. Remember this later.

The turbine (exhaust side) drives the compressor wheel. The delta P (pressure differential across the turbine), heat energy, and exhaust mass flow rate all impact how the turbine wheel drives the compressor wheel. With a properly matched compressor wheel upgrade you can achieve higher charge air flowrates with the same shaft speed. meaning you will be flowing more intake side air without the drastic rise in exhaust back pressure. This has to be done carefully because too big a compressor wheel on a small exhaust wheel will at some point cause lag and no increase in power.

Sorry for the long explanation but there is no real quick answer. I could go into way more detail but I don't want to put people to sleep. I guess if i had to make a quick summary, it would go like this....

K16/16G's: You reach a point let's say 1.3 bar and 500whp (just a rough number for reference) and as you increase boost, the compressor wheel is out of it's usable efficiency range and the rise in charge temps climbs rapidly as does shaft speed and exhaust back pressure, all things that don't contribute to more horsepower.
Take that same turbo and modify it in a way that reduces backpressure and keeps the compressor side in it's efficiency range. This could be a larger A/R turbine housing or wheel, or it could be larger more efficient compressor wheel as in our case. Hope this helps!

If anyone has specific questions please ask away.

-Martin Musial

 

These turbos are hybrids. This is why they give the modified turbos hybrid names i.e. K16/16G,K2418G and so on. All of these turbos have three things in common, they still use the factory turbine/hot sides, center sections and compressor housings. They are also all modified in the same aspect: Changing out the cold side compressor wheel and machining the compressor housing for the larger wheel. They still utilize the K16 frame. At this point, its efficiency goes down to what Martin was saying:

"With a properly matched compressor wheel upgrade you can achieve higher charge air flowrates with the same shaft speed. meaning you will be flowing more intake side air without the drastic rise in exhaust back pressure. This has to be done carefully because too big a compressor wheel on a small exhaust wheel will at some point cause lag and no increase in power."

 

^To add, the billet wheels have extended tip technology, longer blades for a given diameter (the blades extend further into the hub of the compressor due to material strength and machining process) and they're presumably lighter than a standard 16g compressor wheel upgrade. All of this allows them to continue shining (maintaining efficiency) as the pressure ratio and mass flow goes up.

ttboost,
You're right its not a straight K16 but you could call it a K16/billet 46mm or something along those lines to keep in line with the K16/16g or K24/18g nomenclature.

 

Martin, thanks for the explanation.How does one adjust between pump and race gas boost settings?