Dock

But they do have turbo lag.

Just after the 996 GT2 was released, a doctor from North Carolina brought his on a group drive of the Tail of the Dragon and surrounding curvy roads. He commented many times how hard it was to control the power in the twisties because of the turbo lag.

Tuning and exhaust alone can not eliminate k24 turbo lag. If it could, Porsche wouldn't have spent the time and money to perfect variable vane turbos.

Dock

About 44 lb-ft...after the turbo lag (turbo lag, that's the point of all of this).

420 and 450 are DIN numbers. We use SAE here in the U.S.A., so it's 415 vs 444.

Yard Dog

I would love to drive an X50 with the k24s, but none are on my short list. It sounds like the best or maybe the only way to get the advantage of K24s is to drive them close to redline and with the all the SUVs clogging the roads here, that is not much of an option for me. I figure I need the lower power threshold of the K16s, but it would be nice to have the upper end pull of the K24s.

K16/24 hybrids sound like the perfect solution, but what are the trade offs? Do the hybrids spool as quickly as the K16s? Seems like they would. When you purchase a stage 1 kit from any of the tuners that include 16/24 hybrids as part of the package, does it matter if your car starts with a K16 or K24, or are the OEM turbos swapped out for the tuner's turbos? Are there any complications?

From all that I’ve read recently, it appears that tune plays a large role in the hybrids success, and that different tunes yield dramatically different results. It seems very difficult to determine which tune will work best for any driver’s needs. How do you decide which tuner to go with?

autobonrun

Interesting discusion.

After a whole 3 months with my K24 turbos, I don't have an issue with the amount of turbo lag that's built in. The way I drive, it's not significant. With the 930 it was significant. With that said, it's purely physics and engine design. There's no argument that the K16's will spool up faster than the K24's if you start from idle or say 1000 rpm; purely based on mass of the turbos and physics.

However, when I want a fast launch, I don't start from 1000 rpm, I start from 2500 rpm which is not an abusive launch. With that said, the tale of the tape comes down to the torque curve. Take a look at the attached graph. It shows the torque curves for both the X50 and non X50 optioned cars.

https://www.google.com/search?q=996+...20%3B430%3B537

The K16 turbos reach their maximum torque at around 2200 rpm while the K24's do it around 2700 rpm. So the discussion of lag comes down to how much longer it takes a K24 to increase engine speed another 500 rpm. In my opinion, we're talking fractions of a second; insignificant. And as we've all agreed once the X50 optioned car does cross 2700 rpm, its torque continues to rise while the non x50 flattens out.

So it's clear why at low rpms, the K16 would be a better car to drive around town. It's also clear when you look at the torque curve why the K24 pulls harder in the upper range; upper meaning above 2700 rpm. Driving a turbo fast without lag is the same as with all small displacement air cooled Porsches; keep the revs up. I did this last weekend when I took some back roads through the woods in my area. The car flies when you stay up on the torque curve.

Either option kicks az. I wouldn't try to say one is the better option. It depends on how you plan to use it.

Th Dude

That's an ADDITIONAL 44 ft.lbs...after the K24 has already achieved the peak K16 torque at the SAME rpm's that the K16 achieved it.

"The maximum torque value of 560 Nm, already offered by the series engine at between 2,700 and 4,600 rpm, is available in the power-enhanced 911 Turbo at between 2,700 and 5,600 rpm. So its power can be called upon in an extremely wide range of revs."

As for "the point of all of this"....I thought it was someone asking the current value differential between X50 and non X50 examples.
Only after some questionable opinions were vigorously championed as the gospel, did I feel obliged to offer my direct and first hand experience.
Take it or leave it.

Dock

How much seat time do you have with k16s?

From a no-boost start, there is always turbo lag on both the k16 and the k24. It's just that the lag is not as bad going WOT at 4000 RPM as it is going WOT at 1000 RPM (for either turbo). So the k24s will always take more time to spool as compared to the k16s, regardless of the start RPM. Like you said, it's simply physics.

RugRunner

My takeaway: Neither are bad or slow. More X-50 lag due to physics…keep revs up and the problem is less significant, if non-existent.

Autobonrun: Hats off to a Seal Gray '05 S. Big thumbs up. Pic if you got it

Dock

No one here has questioned whether or not the X50 makes more HP and torque than the non-X50; of course it does (IMO not much more power in terms of bang for the buck; about $410/hp. My EVOMS + Europipe (an expensive exhaust) generated an increase of ~105 hp for ~$7200, or about $69/hp). The issue is lag; how long it takes to get to that extra 29/44 and how that time relates to street driving.

RugRunner

Dock, are you happy with the EVOMS / Europipe setup? A nice setup indeed.

Dock

Yes, very satisfied.

I also have: LWFW, EVOMS V-Flow air box, X73 suspension (comes with stiffer motor mounts), B&M short shifter, an FVD smaller diameter/thicker steering wheel, and the factory sunroof delete option.

"02996ttx50

same here dude. plus, i'm guessing the detractors of the x50 option have never even had the car with it, ( most if the criticism is characterized by "yeah, i've driven enough of them to know" etc ) so naturally one must attempt to disparage the car with the greater factory power option in the hope it will help to compensate their very real and genuine sense of the obvious inadequacies of the stock k16's. can i call it turbo envy?! could it be? nah, of course not... LOL. but all that talk of first gear not being readily usable in a k24 car is pure poppycock. does a k24 turbo lag? sure, a bit.. and i would ( again ) agree it possibly isn't the OPTIMAL setup for tooling around town, but a flashed k24 car tops the flashed k16 car. just look at their numbers, and listen to folks that have HAD x50 cars AND k16's.

that said, i STILL say the hybrid 16/24 is best lol. but to the guys point about "exclusivity"? oh yeah, find an x50 car w factory aerokit and keep it garaged. lol. THEN we'll see some appreciation in the coming years lol

hey man.. gonna drive up that road anyday now and surprise you. cheers.

"02996ttx50

tune is huge of course.

but please no, do NOT get the impression that an x50 power kit option somehow makes this car less "usable" drivable on the street! that is patently absurd. there is some lag on a stock x50 car and that i would presume is the base tune of the k24 car which is of course a remap of the k16 cars tune. it is after all the same motor lol

ya gotta drive one. pound for pound and all else being equal, and i mean ALL else. an x50 equipped 996 t is more "valuable" than a stock k16 car. how much more? is not for any of us to decide. but again(!) my insurance co gave me $5k MORE once we figured that option into a payout! capisce?

i know you do so yes, try to find one before you buy, see which you prefer. you're gonna mod it anyway, so yeah.. for daily drivability and INSTANT on power ( yes dan, 1.2 as low as 2750 LOL ) then you DO want a hybrid 16/24 turbo car. the 16/24 turbos such as umw or ruf or speed gallery make/sell

oh sorry. to answer your question, my advice would be to use a tuner/shop, whenever that sells the 16/24 turbos in concert with all the ( not that many ) supporting mods that the car will need to optimize the added available power. that said, if you began with an x50 car, you'd at least begin with the older gt2 intercoolers, which i still use in my 16/24 car. i dont get heatsoak as i'm short blasting all the time.
my point, in answer is the tuners of these have all this down to a "science" as to "power kits" and such. again, speed gallery and the links i provided, and kevin/umw makes/sell the parts all inclusively as it doesn't make sense not to do the car in "stepped" stages if one is happy to stay near 550/600 ( ish ) wheel hp.

RugRunner

Great stuff, I'm glad to have stepped into this thread when I did. And Dock, factory sunroof delete = awesome.

Dock

That's my point.

cdk4219

Maybe you fellas should drive cars that do both things well, low rpm torque, with a flat curve throughout. Best of both worlds and no real downside. Out of the 11 cars I currently own, all of them between 400 and 700 hp and all used as commuters, the x50 is definately gets the turbo lag no fun award.
How dare somebody says something detrimental to your beloved car!