FourT6and2

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.

krell

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.

ILLCOMM

Let's all split a day

https://www.aa.washington.edu/AERL/KWT/rateguide

Drifting

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.

FourT6and2

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.

Drifting

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.

porscheflat6

100%

FourT6and2

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.

C.J. Ichiban

you would just design and 3D print it and 3D print various molds so you could tetris the panels together. Not that hard.

krell

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?

3Series

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.

FourT6and2

Gotta make sure the plastic you use won't melt. And it's stiff enough to not flop around.

krell

DE weekend warriors are doing 2:29s at Road America, so a pro should be faster than that.

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.

qbix

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...

FourT6and2

Oh you're totally right! I've never googled diffusers before. How's the internet work again????