I'll start a new thread...

Oldguy.. Sure!!!

 

Here is the motor on the dyno before anything has been touched, the top curve is my original dyno and I have drawn in the new curve below:

It is not particularly clear above but the maximum is 471PS @ 5950 with 671NM @ 4700.
RS reckon the most they will be able to get out of these turbos is 510PS.

I have asked them several questions involving what the power curve will look like, if it looks like the one above (but with more torque) then I may well go with it since the response of the stage 3s (something the dyno won't show since it is a WOT curve) is much nicer than the K24RSs.

 

I am very curious what the results will be.

Ever thought about letting Kevin do his magic like ZC and ceramic coating on the K24RS turbos?
Perhaps best of both worlds.

AFAIK RS-tuning works with a lot of overboost where it is save. You cant see this on the dyno, can you? But it is just this feature that makes the car so fast and fun in allday driving.
Do you have any idea how to 'measure' the improved 'overboost response'?

Do you know if the stated top speeds on the rs-homepage are real world or more theoretically? Seems that you need a taller 6th gear like ruf uses, but they dont mention it. I dont think that they overstate any values but 317kph with 448ps is a lot.

Sorry for all the questions but i am ready for engine tuning now

 

Stummel
The Stage 3s were supposed to wipe the floor with the K24RSs in all departments.
Yes the overboost feature is one of the reasons I may go with the 510PS remap on with the K16 Stage 3s since the overboost should be even tastier, and no I don't see how you can measure it, but you sure can feel it when you put your foot down.
Yes the top speeds are accurate but as you say depend on gearing - the 448PS would be about 6900rpm in 6th so I guess it depends on where they have set the limiter

 

TB,

It is interesting that the hp curve is flat. When I begin to see dyno results like that, I start looking for issues such as injectors maxing out, excessively lean conditions, uncontrollable wastegates. Without the torque curve plotted, it is difficult to understand what is happening. Do you know how long the dyno pulls are? If they are shorter than 300rpm per second, the turbos will not be spooling the same as on the road and you'll get a lower torque reading.

 

Geoffrey
I presumed a man of your expewrience would be able to "see" the torque curve just by looking at the power curve
The lower one below is the Stage 3 and the one above the original

 

well, I could have calculated the torque curve if I could read graph...You can really see the effect of the wastegate opening on the lower curve. Before I could comment, I would like to see the boost graph of the two runs. From the torque curves, it looks to me like the wastegate is opening earlier on the k16s than the k24s.

 

Overall it looks good for the fist pull. I'd be concerned if the RSK24 jumped ahead of the Stage 3's.. Something is limiting the output of the Stage 3's.. They clearly spinning up quicker and producing more torque till 3500RPM's. The wastegates appears to be opening, thus slowing down the turbine wheel, if this is happening it will take time to recover to rebuild tip speed.. Even the HP graph shows the immediate dip/stumble.. We need to slow those wastegates. RS has to see the boost that they are making at 3500.. 1.3-1.5bars..

 

Kevin
I agree, for a first shot its not a disaster.
On the road it was pulling about 1 bar by 3500. The 1.3 to 1.5 came between 4000 and 4500rpm, but it only happened in certain conditions (like holding constant throttle in 4th at 4000rpm then nailing it WOT sharply, this would give these sorts of numbers) and in the full power/full throttle dyno run it would not do it, typically on the street it would give about 1.1 to 1.15 bar. There is plenty to go at here. I wonder if RS has adjusted the wastegates as they were still set how I left them (was it 2 full turns from where you set them) and if not then this could be causing the erratic boost patterns, what do you think ?
It will be tomorrow before I speak to them again, but I am wondering how RS is guessing what maximum power he is going to get - possibly 'cos he is seeing 0.9bar now and knows he can give it at least 1bar before he reaches his limits ?

 

TB what boost presures were you running on the K24's vs the stage3's?

 

This is fully motronic controlled like Porsche did it - so anything from 0.9 bar to 1.5 bar
Edit
If you mean at peak power with the stage 3s - 0.9 bar from 5000to 6500rpm
EDit again
your question is difficult to answer since the programming for the RSK24s is now attempting to control the stage 3s - the RSK24s ran more like 0.95 bar to 1.05bar between 5000 to 7000rpm - is that what you mean ?

 

For the most part yes. I did not realize the boost varied so much. A 1.5 bar spike can't be good. I was just curious as to how close the boost was on the RSK24's compaired to the stage3 in the 4,000+ range. When I first looked at the dyno chart and saw the difference above 4,000 I assumed the boost levels were very different. I am not sure if .1 to .15 bar would account for such a drastic difference. Do you have any idea what the fuel ratios were? Are you sure the same gas was used for each test?

Do the RSK24's use a K26 compressor?

Good luck with the tunning! Look forward to the final results!

 

I am not sure if I am reading your questions right but his motor is on a real engine dyno not some guessing/assuming correction factor involved wheel dyno and for a road car german tuners always run pump ( super) gas unless a customer specificly requests a race gas mapping.

 

The maximum I can get from the K16 Stage 3s is going to be 510PS at around 5500rpm which will then fall to 6800rpm to be around the 470PS mark. The peak torque will be 685NM (503lb/ft) at 4500rpm.
What is the limiting factor - it is the heat generated by the K16 based turbo which is apparently much more than the K24 based turbo - The Rennlist experts can vent all they want about hybrid K16s but I have put my money (and plenty of it) where my mouth is and these are the facts I believe.
On a positive note, the K16s are undoubtedly a nicer drive and a peak of 510PS is pretty impressive and the car would give some phenominal acceleration times.
I don't want a peak, I want a broad curve, pulling to the red line. I feel staying with the K16s would be a backward step.
The K16s will be for sale when I eventually get the car back:
Stage 3 compressor, ported/polished, ported wastegate, ceramic coated hot housing/ cut back exhaust wheel -one careful owner and will make a real 510PS.

 

TB,

When you say they produce much more heat, are you talking about the compressor outlet, or something related to exhaust backpressure?