2007 GT3 meaningfull HP increase?
#16
11-30-2009 | 03:35 PM
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For me it's not just about peak horsepower and torque gains. IMO, you have to consider how throttle response is improved and how the power band (the area under the curve) is shaped. If I can pick up 100-200 rpm on the exit of a corner I know I will be entering the next braking zone faster. Maybe I am making fewer shifts because of this. With normally aspirated engines it's about incremental gains that individually may not be very perceptible. Accumulate these gains over 12-17 corners and your laps times go way down. There is also the practical benefit for a car that is a daily driver. On the street this yields a more driveable, tractable car that is ultimately more fun to drive.
All in all, with normally aspirated engines I think you have to consider the bigger picture and resist the urge to over simplify performance gains into 1 or 2 data points (see my sig below
) that, while easy to share, aren't fully representative of the end result.
All in all, with normally aspirated engines I think you have to consider the bigger picture and resist the urge to over simplify performance gains into 1 or 2 data points (see my sig below
) that, while easy to share, aren't fully representative of the end result.Yes yes. I just had a dyno run on my 6GT3 and saw some clear dips and valleys in the hp & torque curves. If a tune could flatten out the torque curve without necessarily adding peak torque number that may be significant. Or getting the engine pulling hp through the entire band without any flatspots would be attractive as well.
Again there has to be an objective measure. RSP Motorsports does before and after dyno runs to validate any claims they make and this has to be how it's done. Seat of the pants feel is very difficult for a 20-40hp gain in 300 hp plus cars.
#17
11-30-2009 | 04:26 PM
#18
11-30-2009 | 08:17 PM
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hey sharkwerks, you said its "very hard" to make power on these engines which i tend to agree with given that this is a high strung NA engine with a free flowing exhaust/intake. what do you make of the graph above with the 25hp claim from tuning?
#19
11-30-2009 | 08:33 PM
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I believe the Gt3 has room in the tune for sure.. Most come from factory with some room to work with as many places there is only 91 octane.. A 93 tune with a little extra timing can pickup some HP on these cars i am sure.. 25whp I dont know but its not completely unrealistic.. Now, an Exhaust picking up 20-40 like i have seen claims of is unrealistic.. You can roll a tennis ball thru the exhaust system and removing cats doesnt always mean more HP..
Mike
Mike
#20
11-30-2009 | 08:34 PM
If you look at this video about half-way through we show you some of the tuning process
http://www.youtube.com/watch?v=XzeLcvgOVzQ
For more info:
http://www.sharkwerks.com/products.php?pid=157
Last edited by sharkster; 11-30-2009 at 08:38 PM.
#21
11-30-2009 | 08:35 PM
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Yes yes. I just had a dyno run on my 6GT3 and saw some clear dips and valleys in the hp & torque curves. If a tune could flatten out the torque curve without necessarily adding peak torque number that may be significant. Or getting the engine pulling hp through the entire band without any flatspots would be attractive as well.
Again there has to be an objective measure. RSP Motorsports does before and after dyno runs to validate any claims they make and this has to be how it's done. Seat of the pants feel is very difficult for a 20-40hp gain in 300 hp plus cars.
Again there has to be an objective measure. RSP Motorsports does before and after dyno runs to validate any claims they make and this has to be how it's done. Seat of the pants feel is very difficult for a 20-40hp gain in 300 hp plus cars.
Mike
#22
11-30-2009 | 08:40 PM
I believe the Gt3 has room in the tune for sure.. Most come from factory with some room to work with as many places there is only 91 octane.. A 93 tune with a little extra timing can pickup some HP on these cars i am sure.. 25whp I dont know but its not completely unrealistic.. Now, an Exhaust picking up 20-40 like i have seen claims of is unrealistic.. You can roll a tennis ball thru the exhaust system and removing cats doesnt always mean more HP..
Mike
Mike
Porsche tunes these cars to the back pressure of theses exhausts so without tuning (and sometimes with...) you can actually loose some power, especially down low. Less backpressure is great on turbo cars but these NA cars are a different ball game... The cup cars use these very same headers
#23
11-30-2009 | 08:45 PM
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+1 mike.... it's not easy Porsche tunes these cars to the back pressure of theses exhausts so without tuning (and sometimes with...) you can actually loose some power, especially down low. Less backpressure is great on turbo cars but these NA cars are a different ball game... The cup cars use these very same headers
Porsche tunes these cars to the back pressure of theses exhausts so without tuning (and sometimes with...) you can actually loose some power, especially down low. Less backpressure is great on turbo cars but these NA cars are a different ball game... The cup cars use these very same headersStraight exhaust swaps alone might not show a gain but along with a tune they may pick up more than a tune alone.. We have an inhouse dyno and Ill see what my car makes as its modded before and after.. My m5 actually picked up some decent WHP all motor with sealed airboxes, drop in Bmc, Tune, & Pulley.. Thats another example of a very well tuned car from factory.. Some gains are there i am sure but you just need the right combo..
#24
11-30-2009 | 08:49 PM
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I believe the Gt3 has room in the tune for sure.. Most come from factory with some room to work with as many places there is only 91 octane.. A 93 tune with a little extra timing can pickup some HP on these cars i am sure.. 25whp I dont know but its not completely unrealistic.. Now, an Exhaust picking up 20-40 like i have seen claims of is unrealistic.. You can roll a tennis ball thru the exhaust system and removing cats doesnt always mean more HP..
Mike
Mike
Last edited by Bara; 11-30-2009 at 08:53 PM. Reason: spelling
#25
11-30-2009 | 08:59 PM
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i have heard that the factory tune has a little bit of 'fat' that can be trimmed using a tune to get a few more hp but doing so is basically going to eat into the safety parameters set by the factory designed to protect the engine in the long term. supposedly porsche has extracted out of this engine, all that can be done safely with 40k miles of reliability in min. what do you think?
Truly we are almost all HP junkies but i keep telling myself if its HP i wanted i should have bought the 997 Turbo.. The all motor powerband at 415 crank is still a handful on the track.. I cant imagine the low end Tq Gains with Sharks 3.9L.. I need some seat time before i even think about it..
Mike
#26
11-30-2009 | 09:07 PM
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i did a custom header and catless exhaust on my 996-3 and modded the airbox and got 30 rwhp or so on a dynojet...
here is a video of the car... i have quieted it down a bit since this was taken
http://www.youtube.com/watch?v=gOVcI7XkAyo
here is a video of the car... i have quieted it down a bit since this was taken
http://www.youtube.com/watch?v=gOVcI7XkAyo
#28
12-04-2009 | 12:59 AM
i did a custom header and catless exhaust on my 996-3 and modded the airbox and got 30 rwhp or so on a dynojet...
here is a video of the car... i have quieted it down a bit since this was taken
http://www.youtube.com/watch?v=gOVcI7XkAyo
here is a video of the car... i have quieted it down a bit since this was taken
http://www.youtube.com/watch?v=gOVcI7XkAyo
#30
12-05-2009 | 12:29 AM