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Old 05-14-2019, 05:28 PM
  #46  
FourT6and2
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Originally Posted by krell View Post
For all of us goofballs that have deleted the center muffler, I guess we need a company to design a diffusor extension or something to close up the open area.
I've actually been thinking about this ever since I get a center bypass a year ago. Basically something just like the stock diffuser but with an extension. Doesn't need to be some $3,000 carbon fiber bling bling either because it's gonna get scraped up. Literally the OEM piece, but extended. Or a center bypass with a panel welded onto it to cover up the gap.
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Old 05-14-2019, 05:48 PM
  #47  
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Anything plastic would require tooling for a mold and those up front costs are big typically. I'll talk to my shop when my car is on the lift to see what options exist that don't require both kidneys.
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Old 05-14-2019, 05:48 PM
  #48  
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Old 05-14-2019, 06:52 PM
  #49  
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Originally Posted by krell View Post
Anything plastic would require tooling for a mold and those up front costs are big typically. I'll talk to my shop when my car is on the lift to see what options exist that don't require both kidneys.
Bummer. I’ve already beat up my .2 GT3 diffuser. I’d love to get a different, wider, aftermarket diffusor after I remove my side mufflers.
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Old 05-14-2019, 08:35 PM
  #50  
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Originally Posted by Drifting View Post
Bummer. I’ve already beat up my .2 GT3 diffuser. I’d love to get a different, wider, aftermarket diffusor after I remove my side mufflers.
Would need more than just a wider diffuser. Would need something to cover the opening behind the rear wheel in the wheel arch (since there is no fender liner). Unless it's actually better to have that open and the tire wake flowing into the inside of the rear bumper. Who knows. Without actual testing it's all just speculation.
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Old 05-14-2019, 09:53 PM
  #51  
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Originally Posted by FourT6and2 View Post
Would need more than just a wider diffuser. Would need something to cover the opening behind the rear wheel in the wheel arch (since there is no fender liner). Unless it's actually better to have that open and the tire wake flowing into the inside of the rear bumper. Who knows. Without actual testing it's all just speculation.
I'm not an expert in the area and checking something covering that opening vs just a wider diffuser would be an interesting project.

However, basic principles of downforce and airflow would suggest that (in a car without side mufflers), you would have less turbulent airflow under the car and more downforce if you had a wider diffuser vs the standard diffuser.
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Old 05-15-2019, 01:17 AM
  #52  
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Originally Posted by tstafford View Post
100% agreed on the principle. Not sure about the 125mph threshold but I get your point.

Note: If you haven't driven a high grip car - slicks and loads of downforce (no street car counts) - you're missing out on a great track experience. It may not be for everyone, but it's incredibly fun. Pulling over 2Gs in a corner is very thrilling. Add to that no nannies and no ABS and you're in for some serious fun.
100%
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Old 05-15-2019, 02:26 AM
  #53  
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Originally Posted by Drifting View Post
However, basic principles of downforce and airflow would suggest that (in a car without side mufflers), you would have less turbulent airflow under the car and more downforce if you had a wider diffuser vs the standard diffuser.
Probably. I'm just saying the car might also benefit from some type of additional panel to deal with the tire wake when side mufflers are removed. Imagine a wider and longer diffuser to address the underside of the car, but it also has curved vertical sections to act as rear fender liners. Would be expensive I'm sure. All of this is assuming there's an adverse effect to begin with though. I have no idea either way.
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Old 05-15-2019, 10:49 AM
  #54  
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you would just design and 3D print it and 3D print various molds so you could tetris the panels together. Not that hard.
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Old 05-15-2019, 11:40 AM
  #55  
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My company has a commercial 3D printer but there's no way I could use it for a project. Does anyone else have access to one?
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Old 05-15-2019, 02:22 PM
  #56  
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Originally Posted by shapiroeric View Post
^^^^^Agreed
Eh, that's false. Most advanced wanna be racers, track day guys, can repeatedly hustle a GT3 to 90%+ of it's capabilities. For example, Josh Bilicki (pro driver) hustled a stock 991 GT3 at Road America in 2:29. Most track day guys are hitting high 30's low 40's. And all of those guys can go 110% of it's capabilities.
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Old 05-15-2019, 04:11 PM
  #57  
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Originally Posted by krell View Post
My company has a commercial 3D printer but there's no way I could use it for a project. Does anyone else have access to one?
Gotta make sure the plastic you use won't melt. And it's stiff enough to not flop around.
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Old 05-15-2019, 04:20 PM
  #58  
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Originally Posted by 3Series View Post
Eh, that's false. Most advanced wanna be racers, track day guys, can repeatedly hustle a GT3 to 90%+ of it's capabilities. For example, Josh Bilicki (pro driver) hustled a stock 991 GT3 at Road America in 2:29. Most track day guys are hitting high 30's low 40's. And all of those guys can go 110% of it's capabilities.
DE weekend warriors are doing 2:29s at Road America, so a pro should be faster than that.

Originally Posted by FourT6and2 View Post
Gotta make sure the plastic you use won't melt. And it's stiff enough to not flop around.
Yeah. The design would require the printing to be laid down in a manner that provided the most structural integrity for the direction of load. I think an aluminum skid plate of some shape may be the fastest option. Finding a way to secure it could be challenging. I'll be working on my car Saturday and will see if anything jumps out to make work and proves worth the time and effort.
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Old 05-16-2019, 03:42 AM
  #59  
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u guys should read how a diffuser works and how a working diffuser looks like to make own assumptions what those little thingies on the rear of street cars matter...
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Old 05-16-2019, 11:46 AM
  #60  
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Originally Posted by qbix View Post
u guys should read how a diffuser works and how a working diffuser looks like to make own assumptions what those little thingies on the rear of street cars matter...
Oh you're totally right! I've never googled diffusers before. How's the internet work again????
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