Planet-9 Porsche Forum banner
1 - 20 of 21 Posts

·
Registered
Joined
·
10 Posts
So I recently purchased a 2007 Boxster and having just came from a fire-breathing Corvette I was looking for a good exhaust option to replace the anemic factory exhaust. Mine is the 2.7 base without the PSE.


After finding that cat-back exhaust systems for the 987 were ridiculously priced I set out to see if I could build something that could give me what I was looking for: fairly loud (the Corvette was very loud), low to no cabin drone, and an aggressive sound. Thus begins my journey.


I started by removing the factory exhaust just after the first set of catalytic converters:

IMG_0078.JPG IMG_0079.JPG


Then I had some muffler delete pipes fabbed up and simply attached them to factory tip. The exhaust hangers were some that my local shop just had laying around that happened to work perfectly in the factory location - they just utilize the two lower mounting bolts:


IMG_0081.JPG IMG_0083.JPG


I drove it this way for about 2 weeks - it sounded mean as hell - but it had awful, mind blowing, forget-about-having-a-conversation drone and between 2-3k rpms under moderate acceleration it also had an equally awful raspy tone. So, I started looking for a solution ... and I found it!


IMG_0080.JPG


These are exhaust inserts (baffles) made by a company called car chemistry. Now, without sounding like too much of a sales pitch from these guys, these little things are awesome. I spoke to the owner Ken who was extremely responsive and helpful and I decided to give it a shot since I really had nothing to lose (I'd only put about $100 into the project at this point). Here they are installed:


IMG_0082.JPG


If you look closely you can see them in there. These were installed right where my muffler delete pipe gets welded onto the factory exhaust (again, just after the factory cats).


I can honestly say it's cut drone 75% in the cabin - it's no worse than what I can imagine all of the other aftermarket exhausts produce - if not less judging by what I've heard about Borlas (with exception of course of the even-more-ridiculously priced ones). It has completely removed the nasty-raspiness. And it only took about 25% of my out of cabin noise away.


The car honestly sounds ferocious now - clean and exotic all the way through the rev band regardless of throttle application.


The best part - total spent for entire exhaust including labor: ~$200


I'll be posting up some pictures of the final setup installed on the car, sound clips, and decibel readouts either tonight or tomorrow morning but I can honestly say I'm 100% satisfied in the results.


Note that should you try this, it's not for the faint of heart. While it's not as loud as my Corvette or dozes of other cars you see on the street you still get a nice doppler effect as you pass other cars - it definitely turns heads but in a good way. Since I've been running this setup I've had numerous people come up and ask me what I had done to the car - their face when you tell them you're running straight pipes is priceless.


As always, comments welcome.
 

·
Registered
Joined
·
144 Posts
Hey there jnance .. we're gonna need a vvvvideo of that there frankenstonian exhuberance!

oh heck, two vids .. the idle-rev shot, and the drive by

let er rip
 

·
Premium Member
Joined
·
2,563 Posts
dkky996 and I had the same thought. On face value, these would seem to really block the flow of gas rather than using some baffling and expansion to control the sound. Any thoughts on dyno?
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #7 · (Edited)
Video! This does not do it justice - the idle doesn't sound so "boat like" in person and it's not as "airy" - working on a drive-by.



I was initially concerned with flow as well, but from all of my reading on these it doesn't seem to be a huge issue based on dyno numbers provided from other vehicles. The restriction from the inserts seem to be less than that of the factory exhaust judging by the volume of the car. If anything, it added some back pressure back that I had lost from the straight pipes (mildly noticeable in the low-to-mid range).

I will try and get to the Dyno next week and see how it does.
 

·
Registered
Joined
·
408 Posts
Now, without sounding like too much of a sales pitch from these guys, these little things are awesome.

As always, comments welcome.
Too late... nice try, guys.

jnance - user #34683
Bigdawg - user #34685
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #9 · (Edited)
Too late... nice try, guys.

jnance - user #34683
Bigdawg - user #34685

Hey - I just bought the car. I've been lurking the forum for 2 weeks now just getting ideas and never actually registered to post anything until today.

I'm not affiliated with Car Chemistry in any way nor do I know Bigdawg or anyone else on this forum (as far as I know anyway). I was just trying to share my exhaust build and plugging a product that actually saved me a bundle of money by producing the results I was looking for.
 

·
Registered
Joined
·
107 Posts
The baffles remind me of something from an old school MX bike minus the fiberglass packing.

The mod does sounds pretty bad a$$, I dig it!
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #11 · (Edited)
Thanks man! Yeah the guy over at Car Chemistry did tell me I could pack the baffle with Steel Wool to quiet it down more - they also have a 3 disk that's meant for the street and even quieter (I opted for the 2 disk meant for racing purposes).

I know everyone says "the video doesn't do it justice", but that's really the truth. If you listen to the rev - that's a more accurate representation. From the video the idle sounds like a farm tractor - in person it sounds a lot more refined. I'll try and get a video with a different camera tomorrow as well as a drive-by. Also I'm told that as the computer adjusts over the next 500 miles or so the sound will change slightly - I'm interested in what that's going to do.

Next up: Dual tips. I think that it'll speed up the exhaust flow instead of creating more turbulence as it is now. This should smooth out the tone and reduce the drone a little more. I'm just trying to decide between X-over type (like the dream 2) or to do true dual tips with no connection. I'm a little afraid of the latter making it louder (which it definitely does not need), anyone have any opinions / experience?
 

·
Registered
Joined
·
83 Posts
I didnt see the videos yet, but have you tried the "Free flow mod" which actually costs nothing? by sliding/cutting the connector between the two mufflers?
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #14 ·
I didnt see the videos yet, but have you tried the "Free flow mod" which actually costs nothing? by sliding/cutting the connector between the two mufflers?
I did try that first. I liked the sound of it, but it wasn't quite as throaty as I was hoping. And, I know that people have reported running it for years but I couldn't get over the idea of dumping exhaust under the car no matter how little it may be.

That, and I can be overly ocd at times and the thought of essentially purposely creating an exhaust leak I couldn't get over, regardless of how good it sounded.
 

·
Administrator
Joined
·
34,474 Posts
Too late... nice try, guys.

jnance - user #34683
Bigdawg - user #34685
Yes one does have to wonder when a brand new member shows up and is all excited about some product that no one on this site has ever discussed/used/tried before only to be followed by another brand new member whose first post is to chime in that they want one of these items. Heck they are even only 1 state apart, practically kissing cousins. :)

Now with respect to the item itself I did some research and note that this product has been around for more than 10 years and has been discussed on various other automotive forums. The consensus of other sites and people who have tried the product seems to be that the product does help quiet the exhaust down, especially if you are running open pipes, however, the product also reduces power, especially at the upper end. Is it a magic silver bullet as a solution for a replacement exhaust vs. a system designed for our cars? Not likely. Could everyone else easily replicate the path that jnance50 took for $200? No, there are some caveats in there and some things jnance50 did that others would have to pay more for.

As with any exhaust you need to hear things in person before you decide whenever possible so perhaps jnance50 will bring his car to some Porsche meet and let others listen/drive. I've heard people claim that their exhaust makes little/no drone and then when I drive it in person the drone is awful, and of course rarely shows up on video. Ultimately everyone needs to be happy with their choices, but I would caution people that if claims are made that are too good to be true, then they probably are as we've seen with other supposed "discount" exhaust systems.

Thanks for providing videos, always interesting to hear how much difference there is between different exhaust systems / solutions that are out there. Here's hoping that your posts will continue on the site beyond the excitement over this particular exhaust pipe insert. :)
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #17 ·
Thanks K-Man! Posts will definitely continue. I actually found the idea of the baffles from a 997 guy on the forums who was using it in his tailpipe to quiet down a Fabspeed muffler delete. I did a bunch of research both before and after I bought the car and this forum and your posts have been a huge help thus far - from IMS worries to a slight ticking my engine has - I guess I need to get used to the engine being behind my head the first week I listened to every noise and cut the oil filter open, etc ...

As for it sounding "farty" - it did sound that way a little with open headers between 3-4k but now is nonexistent. I will definitely be attending Porsche events this summer around the south - I'm pretty sure there are several around Barber Motorspeed Park (Birmingham, Al) and Road Atlanta (Atlanta, Ga). I'm looking into joining some clubs soon. I'm really looking forward to what people have to say in person - I personally love the sound - that drive by is a much more accurate reproduction of the sound.

As for the product itself, it's definitely not for everyone and is definitely not a magic silver bullet. After running open pipes for the past couple of weeks I think I let my excitement of being able to drive without a headache get the best of me. I was just overly-excited to share because it seemed no one in the 987 world had tried this yet and for me - it was cheap and it worked. Make no mistake, the drone is not gone - it's still substantial enough that you're aware of it and I still find myself using the radio to drown it out a bit. However, for me, the baffles made enough of a difference that I can drive it fairly comfortably now and judging by what I've read about Borla's and others I can't imagine the drone I have being much worse than what others have described - but of course only time will tell until I get out to some events and hear other's cars.

As far as cost, I was fortunate that in small-town Alabama exhaust work is pretty cheap - but really the only part that had to be fabbed was the muffler delete pipe - which is essentially only about 24" of pipe with a 90 degree bend. I can't imagine it would cost much more anywhere else in the country.

As for the power, this was my understanding of it:
When using open pipes, you lose low-to-midrange torque due to the loss of back pressure. However, you gain upper-rpm horsepower due to less restriction. Theoretically, by adding these (and thus some restriction) sure, I lose some of that upper-rpm hp - but I should also gain some of the low-to-midrange back (which is verified by my butt-dyno). And from what I've read the loss from restriction isn't that significant and if it quiets my exhaust enough to make it fun to drive again - I don't really mind. Of course, I still need to make it over to a dyno and confirm all of this but that's my thinking anyway. I will say that between going from stock exhaust, open pipes, and now baffled that my butt-dyno confirms my theory (of course that could all be in my head - in which case the loss/gain was not significant in any configuration). Also, keep in mind I'm running a stock 2.7 otherwise.




Yes one does have to wonder when a brand new member shows up and is all excited about some product that no one on this site has ever discussed/used/tried before only to be followed by another brand new member whose first post is to chime in that they want one of these items. Heck they are even only 1 state apart, practically kissing cousins. :)

Now with respect to the item itself I did some research and note that this product has been around for more than 10 years and has been discussed on various other automotive forums. The consensus of other sites and people who have tried the product seems to be that the product does help quiet the exhaust down, especially if you are running open pipes, however, the product also reduces power, especially at the upper end. Is it a magic silver bullet as a solution for a replacement exhaust vs. a system designed for our cars? Not likely. Could everyone else easily replicate the path that jnance50 took for $200? No, there are some caveats in there and some things jnance50 did that others would have to pay more for.

As with any exhaust you need to hear things in person before you decide whenever possible so perhaps jnance50 will bring his car to some Porsche meet and let others listen/drive. I've heard people claim that their exhaust makes little/no drone and then when I drive it in person the drone is awful, and of course rarely shows up on video. Ultimately everyone needs to be happy with their choices, but I would caution people that if claims are made that are too good to be true, then they probably are as we've seen with other supposed "discount" exhaust systems.

Thanks for providing videos, always interesting to hear how much difference there is between different exhaust systems / solutions that are out there. Here's hoping that your posts will continue on the site beyond the excitement over this particular exhaust pipe insert. :)
 

·
Senior Porsche Financier
Joined
·
733 Posts
I used the cChemistry inserts with my latest tip assembly to reduce the gen 1 borla's drone, all attempts documented here. For the latest attempt, search on the words 'porcine rhinoplasty'. Really.

The inserts are for-real and cut the drone nicely. I'm actually thinking of reverting to my X-pipe effort, once I clean it up and have it jet-hot coated; the current Y-pipe pig's snout doesn't wail as much as I like, while the previous effort really does. I have a year of use on my Y-pipe effort.

mmmv,
-PM.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #19 ·
I was hoping you'd show up! I looked at your post numerous times before embarking on my exhuast journey. I'm considering getting rid of my factory tip in favor of going either true duals or an x-pipe at the tips (similar to the dream 2) - what's your take on what that would do to the sound?

I used the cChemistry inserts with my latest tip assembly to reduce the gen 1 borla's drone, all attempts documented here. For the latest attempt, search on the words 'porcine rhinoplasty'. Really.

The inserts are for-real and cut the drone nicely. I'm actually thinking of reverting to my X-pipe effort, once I clean it up and have it jet-hot coated; the current Y-pipe pig's snout doesn't wail as much as I like, while the previous effort really does. I have a year of use on my Y-pipe effort.

mmmv,
-PM.
 

·
Senior Porsche Financier
Joined
·
733 Posts
I was hoping you'd show up! I looked at your post numerous times before embarking on my exhuast journey. I'm considering getting rid of my factory tip in favor of going either true duals or an x-pipe at the tips (similar to the dream 2) - what's your take on what that would do to the sound?
Going true dual will result in a fundamental difference: the main exhaust note (fundamental) will be half that of the combined exhaust ... twice as deep. depending on your tolerance, it could sound amazing or make your gums bleed on any trip longer than a grocery run. After living with the true dual borla for a couple of years, I ended up in the latter camp, especially highway cruising in 5th and 6th gears.

[Sciencey bit: it's a lower note because each side fires alternatively, reinforcing the other. Combine them cancels that effect.]

So. First decision is dual or combined. you can *try* the dual by getting a couple of small radius 90 degree bends in the same tube size as you've used for your work. enlarge one leg of each 90 to slip-fit over the upstream pipes. They turn and come out the back, where your stock tip does.

And to revert to your combined tip, make a couple adapters ... short pieces of the same straight tube, with slip fits on both ends. just leave enough exposed tube on both sides (when you cut) for adapters ... gives you a test bed to play with, as is my borla, sans tip assembly.

Some suggestions in no particular order:

1) when you decide on a final configuration, don't use press bent tubing as you currently have, it's a restriction. And go stainless.

B) get to know the nice people at Columbia River mandrel bends. immaculately bent tube and straight pieces, and they do custom cutting, slip fit expansion and welding. and they have both stainless and mild steel pieces. it may be possible to order the pieces you need and then have them welded up locally.

To understand what size bends, understand their use of "center line radius" to describe a given 90.

iii) extend the tube out the back as far as you can (allowing for a sane appearance) but not so far that they're the first thing hit when you back into a wall. will cut down on the drone some.

d) play with ceramic coating ... The temp of the exhaust gasses is fundamentally (rrr) tied to the resonance frequency produced.

Give it a try ... whatever you go with, can be slip-fit to clamp to the upstream plumbing, which you retain in either case. just get a couple more exhaust clamps the same style as is used on the stock exhaust. no need for gold-plated dealer pricing on the clamps, jegs and others have them for very reasonable prices.

Good luck!

mmmv,
-PM
 
1 - 20 of 21 Posts
Top