DIY Exhaust Mod – Gain of 10+ HP!!!

[geraintthomas]

Apologies if this has been answered, but if this allows air to flow more freely and has gains of up to 10bhp, wouldn't the PSE or bypass pipes have the same affect on power?

I've got the bypass pipes on mine and wondered if this had any performance gain.

[particlewave]

Ger: performance gain was kind of a joke by Crios. You can increase by allowing the exhaust to flow more freely if combined with a larger intake and throttle body (and may need a tune if airflow is increased by more than 25% because that is the most the ECU can compensate for).

There may be a very slight increase in hp, but it's mostly for the sound.

[geraintthomas]

Originally Posted by particlewave

Ger: performance gain was kind of a joke by Crios. You can increase by allowing the exhaust to flow more freely if combined with a larger intake and throttle body (and may need a tune if airflow is increased by more than 25% because that is the most the ECU can compensate for).

There may be a very slight increase in hp, but it's mostly for the sound.

Ah!

Aye I was aware of the throttle body and intake it's on my list of things to do, along with the underdrive pulley. Thanks for the confirmation though!

[Jgkram]

So PW, what's the verdict?

[particlewave]

The Universe hates me.
It started to snow today before I finished up replacing the o2 sensor, so looks like it may have to wait a few days. I'd hate to start it up without being able to drive it to warm it up.
On the plus side, the local muffler shop only charged me $20 to weld small patches over the holes. I would have done it myself, but even with a good mask, welding gives me terrible migraines.

I would have been ready to go this morning, but had to take the family pet in for surgery. Broken tail...had to be amputated.

[Jgkram]

Really sorry to hear that and hope everything is going to be alright.

[particlewave]

Originally Posted by Jgkram

Really sorry to hear that and hope everything is going to be alright.

Thanks for the concern. He is doing much better today.


Now, if only the weather would cooperate. Sure is purdy, though.

[particlewave]

The internal bypass sounds great! It definitely added low end burble and is louder throughout the RPM range without being obnoxious. No drone.

Here is an iPhone video, but it really doesn't convey much without good headphones or speakers (sounds awful on my phone).
https://www.youtube.com/watch?v=ch0rsKOL5NQ

[Boxtaboy]

Originally Posted by particlewave

The internal bypass sounds great! It definitely added low end burble and is louder throughout the RPM range without being obnoxious. No drone.

Here is an iPhone video, but it really doesn't convey much without good headphones or speakers (sounds awful on my phone).
https://www.youtube.com/watch?v=ch0rsKOL5NQ

Neat trick you did there. I wonder if there's a way to get rid of the whine that you hear so prevalently on these early Boxsters as it's winding down from the up rev. In yours, you hear the whine as you rev up too. It's a feature I hear on pretty much every rev video of Boxster exhausts except a muffler delete like the one below, or a GHL muffler. My dansk exhaust exhibits very little of that whine, although I can still detect it a little. It must be the back pressure of the exhaust?

Muffler delete on Boxster:
https://www.youtube.com/watch?v=YbCwcWaJkGI

[particlewave]

Update: I've driven the car a few more times and am very pleased with the sound. If I did it again, or opened the muffler back up, I'd probably go just a bit louder with a 3rd 1" hole, but I'm satisfied for now and worry that too much more would be obnoxious.
As is, it's definitely tasteful and sounds more like I feel a Porsche should sound.

Just do it!

[Jgkram]

PW,

When you say "opened the muffler back up" did you actually separate the halves? Your photos look like you just drilled through the shell and then through the internal pipes on each end. Also if you did not separate the halves, I assume that you would have to drill another hole in the top to access a second hole in the internal pipes, correct?

I really really like your stab at this modification as there are no external pipes needed for the bypass and therefore it looks much cleaner and is a MUCH more elegant solution.

[particlewave]

Originally Posted by Jgkram

PW,

When you say "opened the muffler back up" did you actually separate the halves? Your photos look like you just drilled through the shell and then through the internal pipes on each end. Also if you did not separate the halves, I assume that you would have to drill another hole in the top to access a second hole in the internal pipes, correct?

I really really like your stab at this modification as there are no external pipes needed for the bypass and therefore it looks much cleaner and is a MUCH more elegant solution.

Sorry, poor wording.
Yes, I only drilled a 1" hole in the muffler to gain access to the inlet pipes. If I pulled the muffler off again, I'd probably just drill through the patches I had welded on and remove them the rest of the way with a chisel. Because of their location, I'm sure I could access more of the inlet pipes (rather than drill more holes in the inlets, I'd probably just make the holes that I already made oblong).

Originally Posted by Boxtaboy

Neat trick you did there. I wonder if there's a way to get rid of the whine that you hear so prevalently on these early Boxsters as it's winding down from the up rev. In yours, you hear the whine as you rev up too. It's a feature I hear on pretty much every rev video of Boxster exhausts except a muffler delete like the one below, or a GHL muffler. My dansk exhaust exhibits very little of that whine, although I can still detect it a little. It must be the back pressure of the exhaust?

Muffler delete on Boxster:
https://www.youtube.com/watch?v=YbCwcWaJkGI

I have no idea, though I noticed that it's still there, too.

[professorman]

I finally did this mod on my 01. It gives a nice rumble, but not really significant.... now, I want it louder..

[Nine8Six]

Originally Posted by professorman

I finally did this mod on my 01. It gives a nice rumble, but not really significant.... now, I want it louder..

If I were you I'd just call Cecilia, The Deep-Hole Drilling Expert

[mgfranz]

Originally Posted by Nine8Six

If I were you I'd just call Cecilia, The Deep-Hole Drilling Expert

Got her number? She can drill all my pipes!

[maytag]

Originally Posted by mgfranz

Got her number? She can drill all my pipes!

Dood, that's my sister.....

Sent from my SM-G970U using Tapatalk

[mgfranz]

Originally Posted by maytag

Dood, that's my sister.....

Sent from my SM-G970U using Tapatalk

I'll have here home before the sun comes up... Walking funny.

[Slate 01]

Originally Posted by Nine8Six

If I were you I'd just call Cecilia, The Deep-Hole Drilling Expert

She's a mid-western 10 and a California 6

[mgfranz]

Originally Posted by Slate 01

She's a mid-western 10 and a California 6

If your under 40, yes, a Cali 6. When you hit 50, everything is a 10 regardless of location!

[particlewave]

Originally Posted by Slate 01

She's a mid-western 10 and a California 6

What a coincidence! Your "California 10's" (fake face, lips, breasts, butt and caked on make-up) are midwestern 4's!
We like actual real women.