997 TT power upgrade :D

[steverich]

Hiya,
Last week i had my 997 Turbo Dynoed with the techart exhaust and panel filter upgrade the result was 530.2 HP.

I then decided to have it Remapped a few days later, the was taken away by Paramount Performance they bought it back the next day with this power graph print out !!!

This was with Shell V-Power Unleaded
The car is still driveable everyday and when you press the loud pedal its a rocket heading to the horizon!!
What do you guys recon

 

[Alex L]

That can't be right. Over 600bhp?!

+50bhp from an exhaust and filter?!
+90bhp from a remap?!

That sounds impossible. Even the Ruf powerkit with exhaust, sports cat, remap and stronger clutch is 'only' 550bhp. Your stock car must have started on near 510-520bhp to get anywhere near that. Did you have it put on the dyno before your modifications?!

If the numbers are indeed correct then I would suggest you go and get a stronger clutch immediately before it starts slipping like some of the guys in the US around the 550bhp mark have seen.

 

[996_STEVO]

Yip! something aint right there, no way it would be making 620 full stop.

 

[Alex L]

This is what Ruf does to get it up to 650bhp:

Fine tuned engine electronics,
sports air filter,
conversion of exhaust with 4 round 76 mm end tips and sports catalytic converters,
2 larger turbo chargers in exchange,
titanium connecting rods,
3.8 litre cylinder capacity,
transmission oil cooler,
stronger limited slip differential for 6 speed manual transmission,
stronger clutch

So a major overhaul and costs 85,000 Euros!!

 

[sawood12]

You've broken the first rule of tuning - you've carried out a back to back test on two different dyno's. Unless you've demonstrated that the two dyno's are reading the same then you cannot assume that 1hp on one dyno is the same as 1hp on another. To really establish your true improvement in power you need to test the car on the first dyno.

Having said that the error between the two dyno's is unlikely to be as large as the two readings so wont account for the full 90bhp difference. What does the boost curve look like between the two plots. That amount of power cannot be achived via a remap, filter and exhaust. No doubt the boost pressure has been tweaked.

 

[Rintoul]

Ideally a run with the car standard should have been recorded so that the comparison could be made as to improved power output rather than the actual bhp figure. I believe that these dynos can vary quite considerabley. If it is so easy to get such a genuine reliable gain why is the GT2 only 530bhp?

 

[Grant]

Sorry to say i really don't rate all this dyno power reading stuff, every car I ever had on a rolling road put out more horse power than it was supposed to, its as though the guys that run them know we all want that bit extra []!!
No surprise there then, just giving us what we want!

 

[sawood12]

On the contrary, a good dyno is very very repeatable over different days and different ambient conditions - this has bee demonstrated with the 944 league using the Dyno Dynamics rolling road at Silverstone. However different dynos will read different HP values for the same car which is why it is essential you always use the same dyno when trying to establish power hikes. Also dyno's are not just about establishing headline power and torque figures. Someone who know's their stuff can look at the various plots you can get out of the dyno and tell alot about the health and performance of your engine. They will cross check your AFR curve against your boost curve and power and torque curves and tell you a whole world of stuff about your car. It's amazing how two seemingly similar cars in terms of age, milage, condition and mod standard can have very different curves though their headline power and torque figures are similar. There is no other way to tune your car accurately - your seat of the pants dyno is a very inaccurate way of telling if a mod or a change had had the desired effect.

 

[uktrucks]

Two issues here. The first test on a Dyno Dynamics RR had a difference of 28 degrees from Ambient Air Temp [11] and Intake Air Temp [39] this machine has an inbuilt correction factor to allow for testing the same car on differing days and weather conditions. This difference in temperature is huge and as such the uplift will be massive, thereby seriously overstating the BHP measured. Possibly as much as 8-10%.

Secondly a Porsche Turbo will always make more torque as an absolute number than horsepower. e.g 535 BHP & 580Lb-ft it will never ever be the reverse so 600+BHP and 535Lb-ft is definately not right. Not sure on why the two print outs look different or why the first one is Flywheel BHP & Wheel BHP and the second is Flywheel BHP and torque but torque is stated as at 6100 revs as well ?? Should be at c4000 on a turbo Porsche. Sadly it does not add up.

Without question the car will be faster after an exhaust/cats/filter and map but I would be surprised if it was actually producing more than 85 BHP & 100 Ft-lb overall improvment.

Cheers

Allan
ex owner of Weltmeister