Does an aftermarket exhaust make a difference?
#16
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Originally Posted by Mfletch
M, I have a 99 996 with a tipronic transmission. I added Billy Boat mufflers & headers, EVO cold air induction, and a RSS plenum. The stock 0-60 time for my car was 6.0 seconds. After the modifications, my 0-60 time dropped to 4.76 seconds.
I don't believe this was an "imaginary" performance gain. ![ooops](https://rennlist.com/forums/graemlins/icon501.gif)
![burnout](https://rennlist.com/forums/graemlins/burnout.gif)
![ooops](https://rennlist.com/forums/graemlins/icon501.gif)
![Roll Eyes (Sarcastic)](https://rennlist.com/forums/images/smilies/rolleyes.gif)
Any engineers here who can calculate the incremental HP/torque needed to get that improvement in 0-60 times for your ~3,400 lb car?
![ooops](https://rennlist.com/forums/graemlins/icon501.gif)
#17
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Originally Posted by Wellardmac
Mfletch - I have the same setup
Here's a link to what it sounds like.
http://youtube.com/watch?v=okru3YLgRHI
Tough sound to beat and way better than stock.
I drove mine and a stock car back to back and the stock sound was like flacid lettuce on a cold day old burger. Not a hard decision to buy the car I did.![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Here's a link to what it sounds like.
http://youtube.com/watch?v=okru3YLgRHI
Tough sound to beat and way better than stock.
I drove mine and a stock car back to back and the stock sound was like flacid lettuce on a cold day old burger. Not a hard decision to buy the car I did.
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
![thumbup](https://rennlist.com/forums/graemlins/thumbup.gif)
BTW - what does B&B stand for?... Belly Button?
![evilgrin](https://rennlist.com/forums/graemlins/evilgrin.gif)
I know it is Billy Boat.
#19
Three Wheelin'
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Holger, I'm not an engineer, but I do know that my car weighs 2990 lbs, not 3400 (Randy Leffingwell-Porsche 911 Buyer's Guide). I'm not sure what isn't scientific about starting with a baseline and measuring the difference in 0-60 times after the addition of each modification. 0-60 times are very repeatable with a tiptronic transmission. I can't think of more accurate way of measuring performance gains. You and I live pretty close, I'm sure that we will run into each other at Infineon or Thunderhill...I'll be happy to let you take mine for a spin and see if you disagree after driving it. I would love a ride in your GT3.
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Last edited by Mfletch; 08-18-2007 at 12:13 AM.
#20
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"Curb weight.....3149 lb"
http://www.caranddriver.com/longroad...era-page4.html
And the Tip weighs ~100 lbs more, plus the driver, fuel, fluids ,etc, easily equals ~3,400 lbs.
Let me point out the obvious: how accurate can that gizmo be (certainly not the 100th of a second)?, same route?, same conditions (very unlikely, that's why chassis dyno numbers are so suspect and easy to manipulate)?
If you're happy with it, that's all that matters. But, the gains you claim are highly suspect given those mods (a turbo or sc would be a different story). Common sense says that you'd need to a big jump in power to lower your 0-60 time by that margin and there's no way those mods are going to get you there.
http://www.caranddriver.com/longroad...era-page4.html
And the Tip weighs ~100 lbs more, plus the driver, fuel, fluids ,etc, easily equals ~3,400 lbs.
Let me point out the obvious: how accurate can that gizmo be (certainly not the 100th of a second)?, same route?, same conditions (very unlikely, that's why chassis dyno numbers are so suspect and easy to manipulate)?
If you're happy with it, that's all that matters. But, the gains you claim are highly suspect given those mods (a turbo or sc would be a different story). Common sense says that you'd need to a big jump in power to lower your 0-60 time by that margin and there's no way those mods are going to get you there.
#21
Three Wheelin'
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Holger, the article you quoted from Car and Driver put the 0-60 time for a 40,000 mile 99 996 at 4.8 seconds. At 4.76, it sounds like I'm pretty close. All I did with my modifications was make up for the difference between a tip and a 6spd.
I relied on Porsche's factory claimed 0-60 time of 6.0 seconds for a 99 tiptronic 996 as my baseline...I never measured my car stock. When I rebuilt it, I tossed the factory mufflers and air box. My slowest measured time was 5.4 seconds with the B&B bufflers & headers and a first generation EVO CAI. My 0-60 time with the second generation EVO CAI dropped to 5.0 (the first gen EVO CAI caused problems with my car). The RSS plenum dropped my time to 4.76.
The Gtech is one of the timing devices used by car magazines to do their timed runs. I bought it after reading an article in Road & Track or Car and Driver comparing the accuracy of the different timing devices.
Redridge has a S/C on his 996 and has shared both 0-60 times and 1/4 mile times...I'm not even in the same league. His car will do the 1/4 mile in the 11s.
I have a pretty extensive library of Porsche books. I think Car and Driver is inaccurate on their weight of the 99 996. The 99 non egas 996 is the lightest of all the 996 models. I have three Porsche books that put the weight at 2911 lbs for a 6spd and 89 more lbs for a tip.
I relied on Porsche's factory claimed 0-60 time of 6.0 seconds for a 99 tiptronic 996 as my baseline...I never measured my car stock. When I rebuilt it, I tossed the factory mufflers and air box. My slowest measured time was 5.4 seconds with the B&B bufflers & headers and a first generation EVO CAI. My 0-60 time with the second generation EVO CAI dropped to 5.0 (the first gen EVO CAI caused problems with my car). The RSS plenum dropped my time to 4.76.
The Gtech is one of the timing devices used by car magazines to do their timed runs. I bought it after reading an article in Road & Track or Car and Driver comparing the accuracy of the different timing devices.
Redridge has a S/C on his 996 and has shared both 0-60 times and 1/4 mile times...I'm not even in the same league. His car will do the 1/4 mile in the 11s.
I have a pretty extensive library of Porsche books. I think Car and Driver is inaccurate on their weight of the 99 996. The 99 non egas 996 is the lightest of all the 996 models. I have three Porsche books that put the weight at 2911 lbs for a 6spd and 89 more lbs for a tip.
#22
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Mark, if you're comparing the factory 6 second time with your Gtech time, that's clearly apples and oranges (you know PAG is conservative for obvious reasons), so if there are any gains they're not as substantial as you would lead people to believe. Like I said, do the math on the amount of power increase it would take to decrease your time by over 20% as you claimed. There's no way your mods are doing that. Also, there a number of other factors (environmental, fuel, engine & tranny temp, traction, etc) that are going to influence the results between different runs.
I had a 99 C2 and it didn't weigh less than my GT3 and certainly not sub 3k lbs. It's funny that when it comes to P-cars & F-cars, none of the owners that weigh their cars ever come close to the factory numbers (which used to be with no fluids, no a/c, etc...not a real number by any means). (There are currently some interesting comments regarding this over on the RS board.) I don't know if C&D actually weighs the cars, but even their number sounded low to me from my own experience.
I had a 99 C2 and it didn't weigh less than my GT3 and certainly not sub 3k lbs. It's funny that when it comes to P-cars & F-cars, none of the owners that weigh their cars ever come close to the factory numbers (which used to be with no fluids, no a/c, etc...not a real number by any means). (There are currently some interesting comments regarding this over on the RS board.) I don't know if C&D actually weighs the cars, but even their number sounded low to me from my own experience.
#23
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^^I agree. For G-tech, the road has to be perfectly flat for it to be precise since it measures G forces (hence the name), any road imperfection or inconsistency would lead to faulty data.
#24
Three Wheelin'
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Holger, you are corect about my baseline time...if the posted factory claim of 0-60 in 6.0 for a tiptronic is not accurate, then my gains may not be as dramatic. I never drove my car stock, so I never had the opportunity to test it in stock condition. I have found that it is very easy to repeat results with the tiptronic transmission and traction is not an issue with my car (I was running 285/30/18...I'm now running 295/30/18 rear tires). My goal from day one was to make my tip as fast as a stock 6sp car.
I have never weighed my car personally...I am relying 100% on what I have read in both Porsche books and magazines.
I am looking at purchasing a GT3 identical to yours..would you mind if I PM you to ask a few specific questions?
I have never weighed my car personally...I am relying 100% on what I have read in both Porsche books and magazines.
I am looking at purchasing a GT3 identical to yours..would you mind if I PM you to ask a few specific questions?
#26
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Originally Posted by Seeeu911
Not sure why one guy is running down another owners results. Perhaps too much unconscious display of cognitive dissonance about the superiority of his gt3... ![Roll Eyes (Sarcastic)](https://rennlist.com/forums/images/smilies/rolleyes.gif)
![Roll Eyes (Sarcastic)](https://rennlist.com/forums/images/smilies/rolleyes.gif)
#27
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Originally Posted by Mfletch
Holger, you are corect about my baseline time...if the posted factory claim of 0-60 in 6.0 for a tiptronic is not accurate, then my gains may not be as dramatic. I never drove my car stock, so I never had the opportunity to test it in stock condition. I have found that it is very easy to repeat results with the tiptronic transmission and traction is not an issue with my car (I was running 285/30/18...I'm now running 295/30/18 rear tires). My goal from day one was to make my tip as fast as a stock 6sp car.
I have never weighed my car personally...I am relying 100% on what I have read in both Porsche books and magazines.
I am looking at purchasing a GT3 identical to yours..would you mind if I PM you to ask a few specific questions?
I have never weighed my car personally...I am relying 100% on what I have read in both Porsche books and magazines.
I am looking at purchasing a GT3 identical to yours..would you mind if I PM you to ask a few specific questions?
http://www.hookedondriving.com/category.cfm?category=1
And those different sized tires will also impact your car's performance.
#28
Intermediate
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Welcome to the Board!
I'm using Tubi/Champion Motosports Headers and Sport Mufflers. I had them dyno the car before and after and got a 19 rwhp gain and 20 ft.lb. increase in torque. At the drag strip I was not impressed as my best time prior to the upgrade was 13.12 at the 1/4 mile, but was only able to reach 13.35 afterwards. Weather conditions were about 10 degrees hotter and much more humid. Testing conditions were also uneven as the prior run was achieved by reaching the track on empty and filling up with 100 octane race gas. Hoping to clear up the performance gap the next time at Moroso.
BTW - The sound is incredible especially over 2700 RPM. Sounds like a cup car when you run into the 6000+ range.
____________________
SpeedPhreak
02 996 C2 - K&N Aircharger, B&M SSK, Tubi Headers and Mufflers
I'm using Tubi/Champion Motosports Headers and Sport Mufflers. I had them dyno the car before and after and got a 19 rwhp gain and 20 ft.lb. increase in torque. At the drag strip I was not impressed as my best time prior to the upgrade was 13.12 at the 1/4 mile, but was only able to reach 13.35 afterwards. Weather conditions were about 10 degrees hotter and much more humid. Testing conditions were also uneven as the prior run was achieved by reaching the track on empty and filling up with 100 octane race gas. Hoping to clear up the performance gap the next time at Moroso.
BTW - The sound is incredible especially over 2700 RPM. Sounds like a cup car when you run into the 6000+ range.
____________________
SpeedPhreak
02 996 C2 - K&N Aircharger, B&M SSK, Tubi Headers and Mufflers
#29
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Thanks to al for the welcome message. I think i am moving forward on Fabspeed exhaust and 19" Rennworx wheels as a beginning to the long list of upgrades. I will post the newbie pictures shortly.
M
M
#30
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I have GHL exhaust on my '03 and find it to be too quiet! It's about the same volume as the stnd stock system. My understanding is that there are two systems, one quiet and one louder. Mine is definitely the quieter of the two. Is there any way that anyone knows that I can modify it to be louder?