Just out of curiosity, how does it feel behind the wheel in actual driving conditions? My RS-Tuning TT pulls about 550hp and 560 torque at the flywheel according to RS. However, if I were to dyno the car and it showed "low" numbers at the wheels, I would still tell you that the car pulls so f***ing hard, it continues to totally amaze me 2 years and 25,000 miles later. What does your seat-of-pants dyno say?

 

Mine tells me my car is fast.

 

Wait a minute, you pulled in third!!??? You can't do that on a turbo. Not unless it is a 4 speed 930. Load and ratio is calculated best in 4th or 5th gear. The car will not create full potential in third from lack of load. If the dyno was not correcting in fourth something tells me that the dyno is not correct. Don't forget that an AWD Dyno should carry a much less number compared to the numbers we pull. The numbers we have on are on a 2WD which puts us at about a 15% loss rather than a 20. Farther more dyno bench racing is not a fair way to judge anything. I can tell you we dynoed a couple of cars, one a mustang that did 450 or so at the wheels and the other car did over 600 at the wheels on different dynos. Two different dynos, one corrected one not. If you want to compare like numbers you should do so on like dynos. Both Todd and I do runs on DynoJets and the gears in 4th or 5th, depending on the car. Those numbers then would or should yield similar numbers to what we get.

In regards to how it feels. Well spinning the wheels in the top of third gear on the highway never gets boring

 

Seat-of-the-pants impressoins are next to worthless. I've been around tuner cars for 10+ years, either modding myself or with friends. I can not begin to tell you how many times somebody says their car feels "so much faster" or "twice as fast" etc, only to know that on the dyno, the proof showed otherwise. Heck, a loud exhaust may give you 50rwhp in your head, but zero on the dyno... don't make claims based on your ***, because you'll end up talking out of it!

 

I want to chime in here and throw my opinion in the mix. I just got off of the telephone with John, the owner of the car. We both concur that the car is running great and this is not a power output reading one can expect to get from the Stage 4GT. We also have theorized a few factors that are causing the low reading. A few factors that we considered are as follows:

1. The dyno test was conducted in 3rd gear. Dyno testing in 3rd gear is not close to 1:1 ratio and not offering the proper amount of load, thus throwing off the results.

2. The dyno room that the car was in is a somewhat sealed room with little ventilation. There were fans on the car to cool it down, however the volume of available Oxygen is limited to the size of the room. In theory, during a dyno pull of a 600+ HP engine, it is possible to use up the available oxygen in a room thus causing a lower power output

3. The numbers measured are not consistent with the characteristics of this upgrade. How is it that that the motor can make 490 TQ at 4 wheels (490 x 1.3 (4 wheel correction) = 637 flywheel TQ) and not make similar HP? HP & TQ are derived from one another and should be somewhat close with this upgrade

4. DYNOS ARE DIFFERENT. It is very hard to have a standard when there are many different dyno's that all read power in different ways. Some are 2 wd, some are 4 wd, some are loadable and some measure as a calculation of acceleration. Some are in small rooms, some are in wind tunnels. Some have fans generating 75 MPH of airflow and some have fans generating 5 MPH of airflow.

With these 4 factors explained, my analysis is as follows: The dyno should have been conducted in 4th gear which is closer to a 1:1 ratio, it provides more load which will allow more resistance thus increasing the power and torque. In addition, the Horsepower output is significantly low due to the lack of oxygen in the room for engine to breathe. The peak torque number occurs at about 4000 - 4500 RPMS. At this point in the dyno run the engine has used all of the oxygen in the room thus the drop off and lack of top end power. Without the appropriate amount of oxygen, there cannot be complete combustion and maximum power. This motor makes peak horsepower at 7000 RPMS and there is literally not enough oxygen to generate the power.

I want to STRESS, this is my theory and it comes from many years dyno testing these 996TT cars. In addition, I have had our EVO 996TT on the dyno for the past 2 weeks straight. I can replicate 560 RWHP and 570 RWTQ on the dyno with 94-octane fuel very consistently @ 110 degrees. My car has the same Stage 4 GT upgrade that John is running. These numbers convert to 644 HP and 655 TQ (Flywheel) I hope this information is helpful and I am confident that John will get the numbers that he is looking for. I will be speaking with KTR performance where the car was tested so we can try and get some more accurate results.

 

02TurboX50, I think I should address some of your points. Stage 4 GT is advertised at 540-560 rear wheel HP depending on the car, octane level and other components used in conjunction with our system. My 2001 996TT with the stage 4 GT upgrade generates 540 Wheel HP on 91 octane fuel (621 flywheel HP) on our Dynojet. My same car with 94 octane fuel generates 560-580 Wheel HP (644-667 flywheel HP) utilizing some more aggressive programming. We have NEVER claimed 600 wheel HP with this kit on pump fuel only on race fuel where it generates about 615 wheel HP or about 700 flywheel HP. I am not sure where the information is misleading but hope that you can understand now. If not, let me know and I will clarify anything that is not clear. Take care, Todd

 

I would not worry too much about the low dyno numbers at KTR. Their dyno is very low on the number aspect as it tends to be at least 15% lower reading then that on a dynojet. You also have to remember that it was a bit humid today in the northeast and all the other factors that could have come into play. Dyno numbers should be taken very lightly IMHO.

 

StevenTi

As you say "Seat-of-the-pants impressoins are next to worthless."

But, I am telling you my car really is fast since I did the upgrade. STAGE 4 GT is by far the best I have seen, And I have been in Cars "tuned" by other companies. Their is no comparision.

 

Here is a example of how my Stage 4GT is running. I ran a stock X50 from 40 to 100 MPH. I was five car lengths ahead at 100. That was while I was fighting tire spin at all the way to 80 MPH.

I think my car dynoed at 410 on a incorrectly operated 4 wheel dyno.

 

Great responses and clarification EVO and ImagineAuto!! Thanks for the clarification and the prompt replies. Well done.

I think the 600hp at the wheels most people talk about on this board is from the dyno on Imagine's website, and I am not sure if it mentions what type of Octane it takes to make 600hp at the wheels. If it needs 100 Octane to make 600hp at the wheels, that's acceptable, but it may make sense to compare that to the Stage I-IV packages using 100 Octane as well. If you make 500+hp at the wheels with 91 Octane for the regular Stage IV, then is it reasonable to assume that you can make 550+hp at the wheels with a '100 Octane' program. This may be a better comparison.

Again, this is a perfect example of why EVOMS and IMAGINEAUTO have outstanding reputations. They care deeply about customer service; ensuring every customer is satisfied! Great work guys! Keep pushing the envelope of the 996TT performance. Continue to raise the bar so you can keep smiles on every owner's face.

P.S. Todd- Do you have a dyno chart you could post or send me of your car on 91 and 94 Octane. That would be a big help! THX.

 

The short of it is... put your car on another dyno to see what numbers you pull.

Just as a ref point, on a 2wd Dynojet pull (disconnected front driveshaft), a GIAC Stage II will pull about 430rwhp/505rwtq. Upsolute will pull about 455rwhp/505rwtq.

Also, a 30% 4WD correction is calculated (490/.7), not (490*1.3).

To calculate whp from crank hp, you take:
(crank hp * (1-parasitic loss))

To calculate crank hp from whp, you do the reverse:
(whp/(1-parasitic loss))

So, based on your assumption of 30% parasetic loss, 490 rwhp translates to:
490/(1-.3) = 490/.7 = 700crank hp QED

 

PS. 30% is way too high for our Turbo. All you have to do is a coast-down on a dyno, and you can derive the parasitic/drivetrain loss.

Keep in mind, if we are using 15% for our Turbos in rwd configuration, then in 4wd mode, it is not going to be double, b/c we've already taken into account in the initial 15% drivetrain losses such as flywheel, gearbox, and engine. The 4WD figure would not be double, but probably closer to 20%. I've yet to personally see a coast-down on a Turbo, but have seen it done on more than a few 4WD cars.

 

C'mon Orlando, you said the same thing after your first Evo Stage IV upgrade, but the dyno numbers were way off too... remember? What numbers did your Stage IV GT end up putting up anyways? May be a good reference point for this thread...

 

I can't believe no one has even bothered to find out what standard is being used as a comparison. This can make all the difference in the world.

 

Did you and Shank ever run again to see how things compare? I know previously, your Stage IV, Shank's Stage IV GT, and my Upsolute was pretty much even. Since tuning, Shank's car will put a few car lenghts on me from 60~130.

I'd love to check out your setup again the next time we have a get-together... it's been a while.