Why K16 vs K24 turbo units ?
 

Porsche uses the K16 for base TT and K24s for the X50/GT2 , which have 35-45 or so more HP. Is that to minimize turbo heat build up or bearing wear , since you can merely "chip" the K16s to same or more HP .

Normally you move to a larger turbo to create more HP without over spinning the unit. In other words both units at 1 bar the K24 will naturally create more power without over working. The K16 can create the same power but it has to be over spun to do so. There is a limit to that, but in a nutshell this is the reason

Thanks for the response , Stephen ! Is it correct to think that Porsche upsizes to the K24 s to meet it's long term reliabilty/ warranty needs requirements for such a "small" hp bump ? Is there a problem running the K16s on modded ECUs ( assuming total hp stays under 470-500 hp)if you are not running the autobahn at 160 mph for 2 hours as Porsche must engineer to , but just occasional on ramp or car passing burst ?
I can see how this line of reasoning has no end point , i.e., ECU, then K24 for longevity, then intake/exhaust mods to benefit having K24s, then uprating tranny/brakes/susp to cope , then even more engine/turbo/fueling mods .... <img border="0" title="" alt="[Eek!]" src="eek.gif" />

MKW;

With a modded ECU, it will push the limits of the K16. The K16 and K24 share the same internals. To solve this issue, we will install a larger compressor wheel ie:K24 or larger in the K16 frame. This will slow the Turbine wheel down and end the end provide more air quicker than a K24.

Kevin, won't that create very high exhaust back pressure? You would be trying to force 480 HP of exhaust flow through the small K16 exhaust housing. Does that hybrid perform in between a K16 and K24? Do you have to change the impeller to match the bigger compressor housing? How much does it cost for that mod to good stock K16's? Are there any other plumbing issues with that conversion?

ebaker;

No, flow restrictions have not been and issue, in fact the design of the K16-24 is very efficient compared to other turbo's. The performance of the hybrid meet and or exceed the K24's. The reason is that the shaft in the K16 can speed up quicker than the K24. With the larger compressor wheel borrowed from the K24, more air is available at lower RPM's sooner. There are no plumbing issues. Email me.

With the Turbos installed that Kevin fabricated I picked up a Dyno'ed 40 H.P. over the stock K16's. Other mods on board, but only the Turbo change and reprogramming to enhance the new air pushers.

Hi Guys,

I d like to recall this post as I am having the chance of buying an used pair of k24 turbos for my 96tt 03.

my car has 147K km and has already mapped to 1.0bar. I was thinking in the future to rebuild mines to k16/24 but as I found there k24 for more or less 1K USD each, I was thinking what should I do?

In addition, if i switch from k16 to k24 do I have to flash it again?

has anyone knowledge about how long k16 should last? I know it depends on use and flash... but...

thanks for comments!

yes, and no. 16/24's are sick for a mid level powered car. i guess that's ( presumably? ) why umw still makes them?

it's really the best of both ( 16 VS 24 ) worlds and virtually ZERO lag if the other component matching bolt on's complement one another. I've had mine for years, and they suit my power goals and needs perfectly, with a 1.2 tune etc. never an issue, reliable as stock. need at least a 5 bar fpr from the oem 3.8 though, to "trick" the system into thinking it has enough fuel lol

So, it is better K16/24 than standard K24? even paying the same for the turbos?

The main idea with the K16 hybrids is keeping the low lag/early spool up benefits.

You do NOT need to purchase a set of K24 to build a set of K16/24's... I have all the conversion compressor wheels and machined compressor housing in stock.

yes, I would say so, absolutely. as kevin here says ( and he actually makes them,..) it spools very quickly and has the top end performance you'd expect to get out of a k24 turbo ( since it is ). but I'm not kidding when I say there is no lag. my x50 had k24 turbos and I joke waiting for spool was like waiting for them to hit their stride. but once they hit, you knew it.

16/24's are about as old school tech as mods get on this 96t platform, but it's time tested and they work. they really suit the car ( again for me ) no doubt about it. best of both the 16 & and the 24.

talk to sam by design in cali. they have a k16/68hta setup that silly rabbit motorsport was able to make 912rwhp on e85 with all the supporting mods of course. the k24/71 wheel can see over 1100 rwhp

Kevin's K16s with all trimmings on 91 octane... Fully emission compliant. I went to these from RUF K24 hybrids which were very very good turbos. No comparison.. At 4K rpm, Kevin's K16s are producing 500whp and over 670ft.lbs of torque and pull all the way to 7500. Output is limited by the capacity of the MAF. (ignore the A/F ratios as the probe was not fully inserted in the tailpipe. Actual AFRs were right at 12.0 across the board according to onboard data).

https://farm4.staticflickr.com/3780/...f8839a2c_c.jpg

There has to be something wrong there... HP curves should not be flat from 4-7.5k. That's making ~520whp at 4200RPM and 598whp by 7500RPM. Seems like there's a pretty big restriction somewhere.

No offense intended, it just seems alarming.