eclou

The marked section is cannot be a gear change at all. As you noted it has to be 6th gear since the speed is over 240kph. The 16s dip looks to be a sudden loss of accel like a gear change but perhaps it is a timing/boost pull?

TB993tt

Gene
I think it is just after the gear change 5th to 6th ?

I am going to send the file to Racelogic for them to take a look.....

Regardless I'm pretty sure the big numbers are right

TB993tt

Spoke to RL - it is a satellite "drop out" , you can tick the # satellites box like below..... he said doesn't affect rest of curve

Todd/A.W.E.

It's not really a question of power, as EGTs do not necessarily "climb" as you add more power. It is a question of how the power is being added.

Here is what we consider safe, and EGTs are one of the PRIMARY parameters we measure when tuning these cars:

Stock 997TT EGTs are 850-900 deg C.

Stock 997GT2 runs a little hotter at ~920 deg C peak on 93 octane, and 950 on 91 octane.

We like to keep the EGTs when modified to less than 970 C on these cars. We measure both on dyno and on track via software and hard probes.

Todd/A.W.E.

No, this is a very common wrong assumption.

If the ECU was stock with stock software: yes

If the ECU has been modified, all bets are off.

The good software tuners keep the "safeties" intact.

Yet, the majority of software tuners turn off most of the safeties in order to make their tuning job easier. With the limited third party tuning tools out there, it is beyond the scope of most software tuners to actually write programs that can push the envelope the way Bosch or Siemens would. Thus, they rely on shortcuts they can buy with these tuning suites that do a lot of the "tuning" for them, and allows superficial mapping to be touched only.

There is a massive difference between the software tuners actually writing their programs in hex code, as the factory would, vs the ones using WinOLS or Dimsport, etc. that are essentially "dumbed down" limited user interfaces with the complex base coding of the ECU. The true software tuners use their own tuning suites, not ones prepackaged for them.

TB993tt

Todd, thanks for the info.... I just logged 981DegC EGT on a 30-130 run full bore in 2nd 3rd 4th gears to their limiters (26degC ambient)... Is this indicative of maximum EGT or can it get hotter the more one loads....?

Did you ever get any acceleration numbers from the 7GT2 which you did ?

Freak997tt

Here is an UPDATE Toby

While intend to to check 0-300 time...when i reached 240km/h ( The car on 4th gear and the RPM on 5800-5900 ) the IAT was 78c and the boost droped to 1 bar

Temp was 47C, pumpgas

What do u think?

TB993tt

I think 47DegC is scorchio, very hot, probably too hot to realistically expect a tuned turbo engine to produce decent hp !
78 is 31 over which is probably not too bad but getting to 300 in that heat is going to severely impact the power isn't it ?

TB993tt

Despite the acceleration 0-300kph in 26s I was not happy with the tuning box set up running with headers and 200 cell CG cats..... I logged EGTs at 991degC which is too high. The seller of the "tuning box" couldn't really tell me what was going on other than the manufacturer would visit and do some tuning with a laptop on the road to bring the EGTs down and check other parameters (thanks to Todd at AWE for the advice on EGTS)....

I do not like this style of "tuning" and don't think it is befitting of a Porsche and not MY Porsche....

So car is at RS Tuning now (see pic below filling up on the way down) - they are going to test the power on the engine dyno with the tuning box fitted and then do some tuning of their own. I am not looking to change the character of the car too much so stock turbos will probably stay....... will keep posted as it happens

BTW they will be testing my intercoolers and comparing to Secan - they will be an important component in the outcome of the tuning..

mando

guy in the back looks like Gordon Ramsey, haha

greetz mando

TB993tt

RS have road tested my car with the tuning box on and apparently the tuning box is working the VTGs too hard. RS say stock they work at 20% (of what I'm not certain) they say that they go up to 40% but that the tuning box had the vtgs working at 55% and on the autobahn near top speed they saw 78DegC intake with my intercoolers....

They said they were surprised how high this IAT was since my cores looked good so they swapped over to a set of Secans and went out again....... they saw 75degC IAT with the Secan so basically the tuning box is super heating the IATs but of cours ethis means that for this test my intercoolers are working nearly as good as Secans...... I think I am fairly safe in saying to expect some RS Tuning engines to be sporting a set in the near future

My engine is now on the engine dyno and will be there for a few more weeks since their ECU electronics guy is off for 2 week holiday tomorrow

YearOne

Have you spoken to Manthey about their GT2 tuning? The keep the turbos but change the I/C's for their 600bhp package.

TB993tt

I know thw spec of Manthey's GT2 quite well including who did the ECU tuning for the conversion. I have seen his intercoolers up close and the cores do not look to be in the same league as mine/Secan.
My car with the tuning box was substantially faster than the Manthey car (although the tuning box seems only suitable for "explodamotor" type usage like standing mile or 60-130/dragging) and I want the car to be faster still......

Although it would be ignorant to disrespect Manthey's Porsche expertise, they actually only race with standard Porsche engine stuff, nothing specially developed so in the engine department they are not the best although like all the top Euro tuners they know how to charge like the best

Close up of the Manthey cores:

TB993tt

What I was worried about with getting a typical RS Tuning tune on the GT2 was basically having too much torque. The way RS likes to tune he gives as much area under the power curve as possible by bringing on the boost early, this will also limit the unltimate maximum peak power as the early boost onset heats up the IAT to the detriment of maximum peak power however it does make for a very fast car IF the car can deploy the torque to the road.
This IF is the important bit. For a 4WD turbo no problem. I have scanned in my power curve for my 993tt 3.8litre 8.4:1 CR



You can see it has over 550hp from 5000rpm until 7000rpm. This was difficult to achieve and involved specific cams and timings. The result is a very fast car but the power (torque) from 5000 to 7000 is very savage and puts the 4WD system right at the limit of grip even in the dry. I did try and run the 993tt in 2WD mode for a while and it proved just too dangerous with this power curve.

I felt that for the 997GT2 I didn’t want to upset the car’s power delivery as it felt really “right” with the factory settings.

I knew roughly how much torque and power one could expect from various components and especially since I now had the special intercoolers. I actually got hold of an RS engine dyno torque diagram and plotted my own torque curve to what I felt would be right for the car. It basically had lower peak torque ~820NM but then keeping that level as far up the rev range as possible which basically results in a 45 degree straight line power curve with power rising in a linear manner and peaking right at maximum revs.

I left my hypothetical dyno diagram with explanatory notes to why I wanted said curve and truly expected to be ignored since RS usually DO know best.

As mentioned in posts above my intercoolers were tested and were deemed to be virtually as good as Secan, controlling the very high GT2 intake temperatures effectively.
Once I had indicated that I would go with the bigger turbos (the lure of 650hp was simply too great) RS tried their two offerings on the dyno. They have a unique design of compressor wheel which apparently was designed by a student who works for KKK Race dept, they had the wheels made in three sizes and the biggest size did not work causing a stalling at specific revs. My engine ended up with the bigger of the two effective wheels which fits inside a new bigger compressor housing.

The engine was on the engine dyno for two days for programming. This programming should not be read in the same way as the chassis dyno tuners, this is done as the manufacturers do it with ALL the maps being altered and is very meticulous and can only be done with the correct tools and the experience of turbo race engines and focuses on making the engine completely like standard to drive with no hiccups or holes or surges or silly noises (I am intrigued that some "tuners" offer a device to switch programs – why on earth would one need to on a properly programmed engine ?).

RS use a water cooled intercooler for the tuning and he uses this device to replicate on road intake temperatures so he knew that my intercoolers had Secan like effectiveness so could use lower IATs for the tuning (for standard intercoolers it would be pointless using lower IATs as the timing would be pulled immediately once on the road).

Bottom line is that RS did as I asked !!! 827NM max at 3000rpm then a straight 45 degree line as a power curve peaking at 6880rpm and 660hp.

The car is perfect on the road driving just like standard, no noisier than the 200cell cats (wears 100 cell now) and response in lower revs feels very similar to stock. The torque (apart from not breaking the rods) is perfect in the dry with the smooth delivery allowing the rear tyres to maintain traction, the engine revs up the range like factory curve but just a lot faster with the power just “pouring” on as the revs rise.

Driving back through Germany I did lots of logging of IATs and in the 30degC ambient the maximum intake with prolonged blasts up to 300kph never rose above 54degC. I couldn’t find the conditions to do a proper 100-300 run although from the stuff I did I am confident that this is a 25 second 0-300kph car.

Back to the topic of the thread. It looks very likely that RS will be using these intercoolers and discussed the possibility of getting one made for a Ford GT which they have their, apparently they are attempting to tune to 700hp and the IATs are the problem, it needs proper (Secan style) intercooling.

I will share some more acceleration numbers etc as/when I do them but for now am enjoying the engine in all driving.

BTW the uprated clutch is a joy to use as a DD, it doesn’t feel heavier than before yet somehow seems smoother to use than the stock one !

MOD500

Great write up TB

Look forward with great anticipation to the acceleration numbers