TB993tt

Areyou considering the V flow blinger special ? I am sooooo sceptical about this item. If they work then why don't people like Manthey not use one on their 70K Euro 700hp 0-125mph in 8.9s engine

Stummel

TB, thank you for posting the numbers. Should not be long until you killed all the myths out there on the other forums

The numbers of the ZC K16 are impressive especially with the ECU not finally mapped to the ZC K16 S3.
It exactly fits the driving experience on the autobahn you posted back then.
It is up to 70NM more at 3250!

One can not see what the overboost does on the street to the torque numbers, can one? Do you know what the difference in boost / power is on the dyno vs. on the street when at overboost?

PS: next week I am hopefully going to have a ride in a 510PS SHK 993tt. I am quite curious...

Jean

Well it seems that TB wants to keep me busy
OK I have added the recent data related to the RUF R Turbo and the PSI 540 in the magazine. After looking at length at the data, I decided to separate it into two charts, one with the K16-24-26 hybrids, and one with larger turbos in order to give it some sense..

While not getting to a conclusion obviously, as the data was not measured based on the same paramteres and dynos, you can pretty much get an idea of how the sizes impact the lag.

- The RUF turbo K16 seems to be a hybrid with smaller compressor than the K24 and the K16 ZC..It spools up faster than all others up to around 3000RPMs.and then flattens out a little.
- The ZC comes really alive at around 3K RPMs and pulls strong after.
-The RS K24 has a considerable lag up to 3500RPMs, from where it flies afterwards
- The factory K24 runs out of steam at 3500RPMs and flattens out.
-The PSI turbo seems to be the weakest, while it is a very fast car, therefore it leads me to believe that the way the dyno run was measured is different, I know they have a MAHA.
-The RS K24/26 of TB are outstanding, while the RUF pulls somewhat stronger up to 3000RPMs, the RS turbos have an amazing curve breadth all the way up. It is a bit surprising to see how the regular RS K24 starts pulling ahead of it (RS K24/26) after 3750RPMs while being smaller, leading me to believe that maybe a smaller turbine size is pulling faster than the K24/26? TB, any acceleration comparisons that you can share with the 2 different turbos?

IMO, there is no better or worse, it all depends on your usage. In acceleration terms, (0-100mph, 0-120mph etc..) you need turbos that spool strongly after 3500 RPM and upwards, as this is where usually your powerband is under acceleration. In a 0-60mph run, turbo lag of these levels will not really impact performance in high hp engines, lag is in microseconds.

I am sure many have a different point of view, this is just one of them
Edit: The upper black curve is the RS K24 line, the lower is the PSI.

Jean

And here is a chart showing what I believe to be the difference between a Superflow WinDyno (engine dyno) and a MAHA Chassis dyno run.

Both my car (Protomotive) and the RS Tuning Car that TB posted (or was it only RS I/C ?) have been dynoed on the the same type of engine dyno, and the results are very comparable. They both are 3.8 Ltr twin plug engines if I recall correctly and both have been done with a 600RPM/sec run. The difference between the two is that one uses Garrett turbos whereas the other uses probably K26 race turbos, also, my engine uses external boost controller. My run on the engine dyno was done at 1.1 Bar. TB do you recall if the RS car was Motronic controlled?
The MAHA curve however shows much more torque at the low end of the curve, despite the fact that my engine was detuned before the Chassis dyno run.
In both cases lag is noticeably higher than the smaller turbos, however on the street you hardly feel it because of how fast the RPMs climb I guess. The car is very fast from standstill.

Please all feel free to comment, no right or wrong questions. Any additional data is welcome and will be added, I will not however add data from any other chassis dyno run to compare, unless it is under a DIN standard, and run on a MAHA or similar calibre dyno, in order to avoid having a soup of meaningless numbers.

TB993tt

Here are some numbers which are off Ruf's engine dyno for a UK customers Turbo R
2000rpm = 267lb/ft
2500rpm = 375
3000rpm = 404
3500rpm = 411
4000rpm = 449
4500rpm = 535
5000rpm = 523
5500rpm = 468
6000rpm = 395
Phenominal low end torque from the k16s, but the power tails off after its peak 506hp @5500rpm giving only 460hp @ 6000rpm. This just shows, there is a difference between them 'cos Bill S's sure isn't tailing off at 6000rpm
These were published in 911 & Porsche world Sept 1998.

Woodster

Jean,
thanks for all the work on this:
The PSI 540 car (this is a kit for a 993tt?)
What turbos are they using?
(Orton Performance's website is currently incorrect for 996tt/PSI 550 kit: should say K24/K26)
Thanks again!
MK

Jean

Marty
You have to keep in mind that this article is from 1998, therefore things have progressed quite a bit since then. I have not seen however any rocketship coming from PSI both on the 993TT and the 996TT front, other than the one-offs lightweight etc... Many of these houses (PSI, Roock, etc..) use the same ECU tuner, who is an independent.

I will translate some of the relevant parts:

Apparently “this engine was prepared by a guy called Christian Shumacher in Germany, who worked with PSI Motorsport as well. They commissioned the turbo work to a company called “Turbo Tap” in Germany,” which I have not heard of myself previously, but they seem to mention that “they are THE turbo gurus and leaders in Germany”. “They fitted K24s, that were modified with larger wastegates and they also wanted to reduce the turbo revs to around 120K RPMs vs. 180k RPMs in order to improve reliability and allow for overboost under WOT to 1.2 Bar spikes and 0.95 Bar steady state, same as what the factory did”. For that to happen , “they modified the compressor wings” (They could be mistaken here, I would have thought they modified the turbines instead to larger ones in order to reduce revs and backpressure?) and they “got a reading of 1.6Bar of backpressure as measured behind the racing cats cats, which is 0.1Bar more than the stock readings” (not very clear, as I would think it should be lower). They also “fitted an ECU with EFI origins” (it is not clear whether it is the Motronic or not, as the technical sheet at the end of the article says Motronic M5.2/EFI PSI Motorsport) that was prepared by a racing house in Italy that prepares the mapping for Sauber and Ferrari (TAG, or Thielert?).. They also fitted “GT2 racing cams (EVO?) with 1.6mm lift and mechanical lifters.” Other than that, “a 4 bar variable FPR, K&N filter and the likes”.

TB, I think you raise a good point about the RUF K16 turbos, Bill what have you got under the lid, those ain't the typical RUF K16s

Kevin

My observations are that,

In the turbo business we call it clipping to free up the backpressure, usually this is done on the turbine wheel, but interesting enough, the OEM manufactures are now bringing there new high efficiency compressor wheels to market with this feature, along with aero tip and back-cut leading edges.

When Bill S had his Ruf package installed he posted pictures on Rennlist years ago that showed his turbochargers, interesting enough I have 2 sets of Ruf's finest on my build bench right now..

My Stage 3 Z/C units that are shown I feel would bring to the table maybe 5-15% in the low RPM range and in the middle if RS had spent TB's money for a afternoon and tuned for them.. (smile)

Jean

Kevin, since you have had the chance to inspect them up close and personal, care to share your POV on these K16s? Thanks

Woodster

Jean,
Christian Schumacher owns PSI Motorsport.
They employ a full time ECU/programmer.
PSI used to do alot of Programming for other European tuners like Roock, etc.
PSI should have a good solid idea of how to do it now dont you think?

Rob 97 993c2

Seems like TB's RStuningK24/26 has an awesome torque curve.
Should more people be using these? Or, do they only work with higher modified or higher boost setups?

Jean

Marty, not to divert this thread, but you have been misinformed. PSI Motorsport never did any programming for Roock as such. The same guy who does it for PSI does it for Roock, PSI has a good dyno facility that others use (rent). They also told me that PSI did the tuning for 9FF's world speed record beater and the Manthey Motors GT3 kits ..... When Roock was racing Le Mans, PSI was not even born, let us not even get close to Manthey.

I was with Michael Roock last month and I can confirm that this is BS. PSI is one of the newest Porsche tuners of the bunch, and their palmares is short of non-existent in the Porsche world, there are dozens in Europe that are more succesful and people never heard of them, only that Olivier Nameche was good at this marketing game and quite well introduced in the racing and magazine community through his ex-company, he is now gone. A representative of PSI seriously thinks and told me that RS Tuning and Manthey Racing are quite in the same league of PSI, if at all. This same source in PSI deleted all his posts in Rennlist when his numbers were challenged, and were he stated that they do the tuning for Roock.

Edit: Just to be more precise, it might be that now the tuner works for PSI, but in any case it is/was not PSI doing the tuning for the others.

K24madness

Rob,

One of the reasons for the nice torque curve on the RS K24/26 setup is the exhaust. TB is running larger diameter pipes on the cats and mufflers. This increased volume works wonders in reducing lag on the K24 hot side. The reason most people hate the lag on K24's is because thay have not addressed backpressure of the stock system. The compressor does not have much of an effect on lag. The additional "bite" on the air does not contribute much to lag.

Here is how it works. These are not accual numbers but are resonably close.

If your Turbine inlet pressure is 25lbs and stock back pressure after the turbo is 10 lbs there is only a 15 lb delta.

If you reduce the backpressure to something more realistic like 2 lbs then you have a 23 lb delta.

Guess what happens to spoolup then?

FWIW my K24 hybrids (not Kevins) spool up real fast due to the attention in the exhaust area.

Woodster

Jean,
First of all this is hopefully nothing but friendly information gathering/debating.
I have no affiliation to PSI Motorsport other than I am interested in a kit
for my 996 TT. It makes me crazy to see all the high horsepower claims
ie, 600, 640, 700, 750 etc. and these cars usually do not outperform RUF's
550 and rarely do they outperform Ruf's Turbo R 590. How can cars with
800-1000 supposed horsepower and traction not run under 10 second 1/4 miles?. (that is another subject entirely).
The facts about PSI Motorsport as I understand them:
1) they have their own MAHA DYNO. (like RS TUNING) which provides very
good baseline and accurate modification numbers for good tuning!
2) they have a full time ECU Tuner (intials A.W.), and he has in the past
worked for, freelanced, consulted with, etc. many of the top European
Tuners, IE Gemballa, Roock, Helped develop Manthey's GT3 program,
etc. If we are talking about the same guy and PSI has him, then they
probably will have some very strong, torquey, solid programs!
3) Neil Orton is the PSI Motorsport Distributor and is treated roughly by the
Rennlisters. (I also noted how everyone jumped all over Kirby and Steve
at 969 when they posted how strong the new PSI 550 kit was/is).

I am interested in the PSI 550 kit and would like to see Rennlisters give it
more of a "fighting chance" I apoligize for hijacking a very good thread
about K24's and am very interested in how well k24/k26's work on 996TT's.

Marty

Kevin

We also have to add that with the RS K24/K26's on TB's engine he has camshafts and rods and custom programming to make this all come together.