more dyno results, tuning software test, etc ...
11-14-2007, 07:46 PM
#1
Drifting
Thread Starter
more dyno results, tuning software test, etc ...
- Was at the dyno again to test a few things.
- I posted last week that since moving, I wanted to pick a new dyno shop to do a baseline before I tested any products
- The dyno that the car was on was a Dynojet 224x and the gas is 94 Canadian Octane (with 10% ethonol)
- Last week i dynoed the car to test the Sharkwerks rear exhaust replacement. I was disappointed as the car lost torque low and mid range torque. After discussions with Alex at Sharkwerks, as well as 2 very knowledgeable tuners, I decided that the Porsche computer had not likely had enough time to adjust to the change and was likely puting the car in a safer mode and would slowly work back to "normal" if the rear exhaust was as claimed - i.e. it won't rob power, it is just lighter and louder
- well good news, I can say that the re-dyno after 200 street miles with 20 or so WOT runs and the tq curve is back where it sharted and horsepower is stock like as well maybe even 1 or 2 higher but this is all noise in my opinion
- so, if anyone wants a louder lighter rear exhaust, i can say that the Sharkwerks is worth a try and that Alex is a very nice guy to work with
- As also posted previously, I decided to give FVD software a try today. First of all, Rhonda and the FVD people are very helpful and good to work with so2 thumbs up to them.
- before doing the FVD reflash, 2 runs were done as mentioned above to retest the Sharkwerks rear muffler
- I then loaded the FVD software (very easy to do - you need an internet connection so i had to run down the street and pick up a cat5 cable to connet to the laptop as the car was strapped to the dyno
- the process takes about 10 minutes to load, took me 10 minutes to get the cable and then another 10 minutes to get the dyno process started again so the car was given about 25 minutes of cooldown time before the 3 dyno runs we did with the software in combination with the Sharkwerks exhaust
- as you can see from the next 2 charts (if your eyes are good) the FVD software runs the car a tiny bit richer early on, then the same, then a little leaner up top (13.6 a/f versus 13.3 stock)
- when tuning an already highly tuned naturally aspirated engine big changes just can't be expect
- the fvd/sharwerks tq is similar to stock/stock at 288
- the fvd/sharkwerks average hp (3runs versus 2) is 386 vs 380 but one of the stock runs was quite a bit lower than the best run that you can see on the dyno pictures
- also, each fvd/sharkwerks pulls got a little bit higher hp so maybe it will still adapt higher with time
- from the data i have, it would maybe be a fair statement that the FVD adds up to 5hp on a stock exhaust setup
I may consider trying aftermarket headers and 200cell cats to see if more hp can be achieved up top - haven't decided this yet.
Next project is to secure the 996cup R&P (part number 996 302 911 80R) - can anyone help with this or do you just call Porsche Motorsport and order it?
Hope this is useful information
Many thanks to Sharkwerks and FVD.
Paul
- I posted last week that since moving, I wanted to pick a new dyno shop to do a baseline before I tested any products
- The dyno that the car was on was a Dynojet 224x and the gas is 94 Canadian Octane (with 10% ethonol)
- Last week i dynoed the car to test the Sharkwerks rear exhaust replacement. I was disappointed as the car lost torque low and mid range torque. After discussions with Alex at Sharkwerks, as well as 2 very knowledgeable tuners, I decided that the Porsche computer had not likely had enough time to adjust to the change and was likely puting the car in a safer mode and would slowly work back to "normal" if the rear exhaust was as claimed - i.e. it won't rob power, it is just lighter and louder
- well good news, I can say that the re-dyno after 200 street miles with 20 or so WOT runs and the tq curve is back where it sharted and horsepower is stock like as well maybe even 1 or 2 higher but this is all noise in my opinion
- so, if anyone wants a louder lighter rear exhaust, i can say that the Sharkwerks is worth a try and that Alex is a very nice guy to work with
- As also posted previously, I decided to give FVD software a try today. First of all, Rhonda and the FVD people are very helpful and good to work with so2 thumbs up to them.
- before doing the FVD reflash, 2 runs were done as mentioned above to retest the Sharkwerks rear muffler
- I then loaded the FVD software (very easy to do - you need an internet connection so i had to run down the street and pick up a cat5 cable to connet to the laptop as the car was strapped to the dyno
- the process takes about 10 minutes to load, took me 10 minutes to get the cable and then another 10 minutes to get the dyno process started again so the car was given about 25 minutes of cooldown time before the 3 dyno runs we did with the software in combination with the Sharkwerks exhaust
- as you can see from the next 2 charts (if your eyes are good) the FVD software runs the car a tiny bit richer early on, then the same, then a little leaner up top (13.6 a/f versus 13.3 stock)
- when tuning an already highly tuned naturally aspirated engine big changes just can't be expect
- the fvd/sharwerks tq is similar to stock/stock at 288
- the fvd/sharkwerks average hp (3runs versus 2) is 386 vs 380 but one of the stock runs was quite a bit lower than the best run that you can see on the dyno pictures
- also, each fvd/sharkwerks pulls got a little bit higher hp so maybe it will still adapt higher with time
- from the data i have, it would maybe be a fair statement that the FVD adds up to 5hp on a stock exhaust setup
I may consider trying aftermarket headers and 200cell cats to see if more hp can be achieved up top - haven't decided this yet.
Next project is to secure the 996cup R&P (part number 996 302 911 80R) - can anyone help with this or do you just call Porsche Motorsport and order it?
Hope this is useful information
Many thanks to Sharkwerks and FVD.
Paul
Last edited by 997gt3north; 11-14-2007 at 09:51 PM.
11-14-2007, 08:09 PM
#2
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Hey Paul, seriously thank you for giving things a go and for taking the time to do an independant test like this. I know it's a hassle/time consuming and as you can attest these ECUs are adaptive, finicky and very sensitive to slight changes! During the testing that we did we found the very same things. Put an exhaust on of any sort and then jump on the dyno and the car in laymans terms "freaks out" and pulls timing etc... They really do need a few miles to adapt, adjust and so forth. We saw the very same things, whether it was a Cargraphic system, our own etc... In some of the tests we even saw small gains at times but with such a small delta it wasn't worth proclaiming anything that way. It's actually quite "easy" to skew things one way or the other. I could certainly make one exhaust look "good" or "bad" based on how the car is dynod and when. I'm glad that we did achieve what we set out to do- in terms of the lack of annoying resonance, more sound (subjective on if it's better and that's for you guys to decide), a bit less weight and no loss in power (important).... The last part was/is important because we've seen on bypass systems on the 996GT3s where folks have lost some at the low end. This is why we stuck with stock diameter tubing and tried to mimick the center exhaust exhaust flow as much as possible. The only difference being that there's less "sound deadening" if you will with our exhaust. If you look at how it's routed when the sport button is on it's exactly the same part... and hence there's really no significant "reduction" in back pressure when using the stock cats, headers and side mufflers to keep things close to stock.
11-23-2007, 04:18 PM
#3
According to this info, is it safe to assume that if one removed the rear muffler and put it back on again, you'd initially lose power until the ECU 'relearned' if though technically there was no change in the exhaust components?
11-23-2007, 05:54 PM
#4
Drifting
Thread Starter
- if you mean by remove, drive the car, then re-install and then drive the car, i think the answer is yes
- this is a very highly tuned engine and it appears that the computer will very quickly pull timing if it senses changes and will then slowly return timing once it has determined slowly but surely that it is safe to do so
- the above is what happened to my car when i put the sharkwerks rear exhaust replacement section on the car - even after 50miles or so of driving the computer still had the car in a less powerful / safer timing section of its program - it took another 100 miles or so plus some WOT acceleration runs for the computer to restore the power levels that ws appropriate for the fuel i was running
Last edited by 997gt3north; 11-23-2007 at 10:45 PM.
11-23-2007, 05:58 PM
#5
- if you mean by remove, drive the car, then re-install and then drive the car, i think the answer is yes
- this is a very highly tuned engine and it appears that the computer will very quickly pull timing if it sences changes and will then slowly return timing once it has determined sowly but surely that it is safe to do so
- the above it what happened to my car when i put the sharkwerks rear exhaust replacement section on the car - even after 50miles or so of driving the computer still had the car in a less powerful / safer timing section of its program - it took another 100 miles or so plus some WOT acceleration runs for the computer to restore the power levels that ws appropriate for the fuel i was running
- this is a very highly tuned engine and it appears that the computer will very quickly pull timing if it sences changes and will then slowly return timing once it has determined sowly but surely that it is safe to do so
- the above it what happened to my car when i put the sharkwerks rear exhaust replacement section on the car - even after 50miles or so of driving the computer still had the car in a less powerful / safer timing section of its program - it took another 100 miles or so plus some WOT acceleration runs for the computer to restore the power levels that ws appropriate for the fuel i was running
11-23-2007, 11:10 PM
#6
Do you think the flapper valve helps with low end tq? We know that in sport mode, the flaps are full open at idle, but when there's load the valve closes and slowly opens to full between idle to 3500 (4000 in normal mode).
I ask because w/ my Sharkwerks exhaust, I have my flapper unplugged so it's full open at all RPM range. My guess is the flapper produces some back pressure resulting in tq gain vs. full open. But it sounds soo much better under load < 3500-4000 RPM with the valve unplugged.
I ask because w/ my Sharkwerks exhaust, I have my flapper unplugged so it's full open at all RPM range. My guess is the flapper produces some back pressure resulting in tq gain vs. full open. But it sounds soo much better under load < 3500-4000 RPM with the valve unplugged.
