If there was just one mod you could do and none else, OAP would be the one. Such a major enhancement of the overall driving experience.

 

💯

 

World of difference the OAPs make, now another easier mod is clear sidemarkers if you haven't done so already.

 

Is the difference in the sound only? Any other benefit? Is there any major difference between the various OAP vendors? How does it impact the warranty on the car?

 

Primarily sound since it gets rid of the OPFs. Most of them claim power and torque increases in the low teens but its negligible. Some vendors offer better warranties and customer service for the most part. Should not impact warranty but that can be dealer dependent.

 

the GT4 OEM tune allows 100% throttle position, where in the GTS models, the WOT setting is < 100%. The engine control software is the difference between the two 4.0 engines 394 vs. 414 hp (SAE net)

the GT4RS 4.0 engine is the GT3 engine adapted for the mid-engine layout and different from the GTS / GT4 version

 

the GT4 OEM tune allows 100% throttle position, where in the GTS models, the WOT setting is < 100%. The engine control software is the difference between the two 4.0 engines 394 vs. 414 hp (SAE net)

the GT4RS 4.,0 engine is the GT3 engine adapted for the mid-engine layout and different from the GTS / GT4 version

Even the GT4 sees gains with a tune of about 20 to 30 horsepower according to the tuners.

 

Best thing I did to my car. Dealer doesn't care and has honored the warranty (albeit for an electrical gremlin..) since I fitted it. I settled on a lightly used Flat 6 OAP from one of the board members here, mainly because of the heat shielding.

 

OAP is a must!
Now if you really want to dive deep... look into changing out the muffler section. I did the Soul Valved rear section, along with their OAP. Really gives it that high-pitched scream in the last 1000rpm you expect from a flat 6 motor. It is my understanding the stock muffler never lets the two cylinder banks blend, which is where that higher pitched noise comes from.

 

General summary is OAP = louder, rear section = change in tone, potentially louder depending on what you get. One of the best and most affordable mods you can get for this car!

 

OP, do you feel like volume is the only thing that changes with the OAP or do you feel like the tone and personality also changes?

 

My impression is that it really changes the character of the car

 

Have the same OAPs. They’re great. 2023 718 GT4. I looked at valve controllers but installation is a pain in the butt and I would have left them always open anyways. So I did the $6 metal collars holding open the valves on the vacuum actuators. Took about 10 minutes and sounds awesome. Plus easily reversible any time I need to.

 

I just put the 2 mode cargrpahic on , also easily reversible . I had my mechanic do it so it was easy …. But I doubt I’ll ever want to hit the factory mode button , so I like your approach!!

 

I just picked up a 24 GTS 4.0. Installed Flat 6 OAP’s and capped if the vacuum lines to keep exhaust valves open. This completely changed the car. It sounds insane and pulls so hard at high rpm. Amazing

 

I am guessing I am in the munition that I love my 23 CGTS purely stock. I don’t track her, just enjoy the drive experience. Could be that I am nearly 70 and have owned a ton (40) of sports cars… close to perfect (for me) right from the moment I saw her in Stuttgart….

 

GT4 and GTS have the same torque and Porsche is obviously designing for durability and not trying to gate keep or hold back. Jumping from my GTS to GT4 didn't even notice the power difference more so the chassis differences.
Flat6 motorsports youtube channel reviewed a number of 4.0 exhausts but more on the back box than OAPs but honestly you really have to hear them in person. Like full race setup sounds ridiculous but too loud for normal use for most.

 

Yes, twenty HP with no additional torque translates to nothing. It's the 991 GT3 suspension set up that differentiates the GT4, though it's not a true GT car without the racing engine. I'll have to find a way to hear some of these pipes in person. Specifically, how do you like yours? Any negatives? Which ones did you get again?

 

I just installed OAP‘s on my GTS. DEFINITELY worth the effort for both the sound, which is just enough without being obnoxious, and the power.

 

Didn't you get yours from Alibaba? They are Chinese knock offs I believe, but, I'm not sure who they're knocking off. Flat6? Much less costly than most others. but, maybe a cause for concern. I've worked with many offshore vendors, including from China and they are notorious for (among other things) substituting materials.

 

OAPs 100 percent increase power without a tune. Most OAPs will sound the same. It’s literally a relatively straight pipe connecting two other pipes. Backbox will have the largest effect on tone.

 

Yeah, between the cats and the OPFs. In terms of sound, It's hard to tell as there are so many variables with the YouTube recordings. Actually, the ones I've heard that I like the best are from Cartographic. They require both their muffler / cross pipe with the OAPs so its quite (too) expensive.
I've noticed a lot of heat coming from the stock pipes (from under the rear wells) even after short trips. I watched a video of a guy installing a set of used OAPs which had no heat shielding, so, he wrapped them himself. After running the engine for a while, he measured (off the pipes) a temperature drop of about 25 to 30 degrees as compared to stock. He measured the stock pipes, which are shielded, to about 250 degrees plus. It may be that the OPFs are inhibiting the hot exhaust gasses from flowing freely to the point of generating more heat. This is mitigated somewhat by eliminating the OPFs. Of course I'm speculating, but, it seems heat shielding is a must. I think I might have found an incentive for doing this mod and that is removing the OPFs which are not required in the US.