kencollinsjr

I've read most of the recent threads on Sharkwerks & IPE w/ people saying they are or are not getting them and how they like them, etc.

I fall into the category of being ~1-2 weeks away from delivery and will start w/ stock exhaust, but might consider a bypass system. I had the following questions:

1. Are there any other systems other than Sharkwerks, IPE, and Akrapovic to consider?
2. How do the 3 systems compare in terms of build quality, sound character, decibel level, ease of installation/removal, and aesthetics?
3. Do all 3 allow the continued use of the Sport exhaust button functionality (I know SW does).
4. What's the cost of the components and installation typically?
5. If you plan on doing lots of long-distance touring, anyone complain of the higher decibel level having too much of a fatigue factor vs. stock exhaust (i.e., getting a headache from being too loud for too long)?
6. How does the appearance of the tailpipe change? I've see the look of the IPE being a little more open and exposed in the back and I think the SW uses the standard GT3 tailpipe tips, but I'm not sure.
7. Any other considerations worthwhile? Impact on resale, ease of re-installation of stock center muffler, etc.?

Thanks.

bigkraig

GMG also has a bypass.

I've got a SW bypass on my C4S which replaces the side mufflers, so pretty different than what is available on the GT3. It can get a little droney while in certain gears and inclines.

I'm still expecting to get one of the bypass's for my GT3 next year.

pg103

I ordered SW bypass. From my understanding, IPE requires replacement of headers and etc which may effect the warranty. SW bypass just bypass the center muffler and reusing the current tips. IPE cost about 4k with install and SW is about 1500. Hope this help.

kencollinsjr

thanks. yes, looks like the SW system keeps things pretty simple. iPE site shows that it's a complete re-do for the exhaust system...including headers and mufflers.

http://www.ipe-f1.com/products.php?b...86552864342025

kencollinsjr

Although it looks like iPE also has a center muffler replacement option too, but it has the Sport Exhaust valves mounted on it. Scroll to bottom.

http://www.ipe-f1.com/products.php?b...86552864342025

Money2536

iPE can be purchased as in parts. There is the valvetronic muffler section that costs about $3,200 plus $200-$300 for the tips. Than you can also buy Headers w/ cat-bypass for $2,600. Add another $350 for 200 cel cats.

My problem with the GT3 exhaust is the sound it doesn't make at low RPMs. The bypasses available only make the stock exhaust louder. They don't address the lower RPM sound.

iPE valvetronic section can be installed several different ways. You can use the factory Sport button that would make it operate like stock. Or you can use their electronic key fob to chose open, closed, or auto. The key fob should allow you to open the valves at all RPMs.

My concern with this option is the possible drop in torque due to lack of back pressure at low RPMs. iPE's Dyno looks a little weird. I also really want to be able to use the factory button.

I called AWE and begged them to come up with a solution. They need a car though, and I'm in FL.

Dan@SharkWerks

Hi Ken - I can't speak on behalf of the other manufacturers but I'll try to help with these.

I've heard a lot and to be honest they all sound pretty good I think ours sounds best but of course I'm a bit biased! We make ours in California using American stainless steel. I'm sure any of these have good build quality. Akrapovic is made of titanium which is a bit lighter, but I believe more susceptible to cracks and failures. Any that replace the side mufflers will be harder to install and remove. Our center system installs in about an hour on a 991 GT3. No bumper or wheel removal is required. Aesthetics depends on your wants but our system looks like OEM from the outside, you can re-use the stock tips or use ours if you prefer. Not sure on dB measurements vs the others.

Not sure on the others but yes the center exhaust will let you use the Sport button. I'm guessing the others do too.

We charge $1500 for the exhaust and $150 for the install here of our system.

Again I'm a bit biased here but I've driven a 1500 mile drive in the GT3RS with our exhaust installed. With the sport button off it's about the same comfort level and cruising volume of stock.

Correct we use the stock tailpipe flange so you can re-use the stock tips or install our aftermarket tips:


Any of these systems can be removed within a few hours so I wouldn't worry about resale value. You can just remove them when you're done and sell the car as stock instead (or at least give the buyer the option). No matter which exhaust you install I'd recommend keeping the stock parts.


Our bypass does make it louder at low RPMs as well. It's bypassing the center muffler so it never mutes it as it originally intended, even at lower RPMs. The other option is to force the values open on the side muffler at low RPMs, which I recommend this device for:
http://www.carnewal.com/products/P97...Manual-Control

Not sure if this works on the 991 GT3 yet^^

kencollinsjr

Thanks, Dan!

bigkraig

So the sport button diverts the flow from the side mufflers to go straight out?

In that case, with the bypass and sport button on, you are not going through any mufflers?

And with bypass and sport button off, you are going through the side mufflers only and the center is disabled? If the center is disabled when sport is off, how is it still louder at low RPMs?

Pazzo009

Didn't realize you and I asked the almost the same question at the same time except your questions are more detailed. Cheers, enjoy your car.

Dan@SharkWerks

Yep basically - Here's a pic of the side muffler cut away:


This a 997 but the 991 side mufflers have the same design.

When the valve is open, the exhaust will mostly go straight through the side mufflers, but there's still a resonance chamber (in the side muffler) before the open valve (and exit pipe) so it does *something*. When the valve is closed it's pretty clear to see how much the side muffler does.

Then the exhaust travels through the center muffler:


There's all kinds of reasons why this muffles the car - whether or not the Sport valve is open on the side mufflers, it has a resonance chamber and different baffles, packing etc. and restrictions it must go through before it exits the tip.

So when you get rid of that:


- it's always going to be louder.

No, you're still going through the side mufflers, but they're mostly bypassed. With our bypass, it then exits via straight pipes. Without the bypass it goes through the center muffler regardless.

I don't know what you mean by disabled. It's always going through the center to the tail pipes, whether it's stock or SW bypass. The difference is that our bypass is not a muffler, it's a straight pipe so it doesn't muffle it further once it exits the side mufflers.

bigkraig

Great post! those cutaways explain a lot!

kencollinsjr

Dan: very helpful indeed.

Rovman

Very helpful Dan, thanks for taking the time to post this.

Guest89

I have a Sharkwerks bypass on my 997; the "best" option for your car and your usage is of course debatable, but you won't find anyone complaining about Sharkwerks customer service.