DIY Exhaust Mod – Gain of 10+ HP!!!

[crios]

DIY Exhaust Mod – Gain of 10+ HP!!!
10+, I wish, LOL, but it sure does sound better

I’ve thought about doing the PSE mod for a while now, but after doing some research I thought there was a cheaper and easier way, so I tried it.

My theory is this. The inside of a 986 muffler has the exhaust going from chamber to chamber before exiting, what if I could decrease the amount of chambers?

See image below, the RED is the where the exhaust comes in, and then it goes to AQUA, before existing via the TAN.
My mod is allow fumes to exit much faster by opening the exit pipes to the first chamber, see the GREEN line.

Below are directions what I did. Let me know your thoughts:

Take the Tips off:

Tool needed, I used a ½ inch drill bit:

Now drill away:

Both sides should be drilled into and then would look like this:

2nd Pic

Install Tips back on, after cleaning of course…and enjoy the new throaty sound without the deafening/annoying drone!!

I guess one could try larger drill bits and it would get louder, but I’m sure there’s a point before the drone comes into play.
I don’t have a sound file of the before, but here is the after for your hearing pleasure:
http://www.youtube.com/watch?v=RfRErzkyqNc

Thanks,
Cesar

[blueillusion97]

I have done PSE mod on mine, maybe i should try to do this as well to compliment PSE and if it doesnt work i could weld it back up

[RandallNeighbour]

Now this is a great little mod. Probably took all of a half hour, right?

I cannot tell from the video just how much louder it is, but it does sound "throatier."

Give us your opinion as to how much better it sounds. Do you still long for a different muffler that's louder if you could get one without the nasty cabin drone?

[crios]

30 min if that!! I'm wanting to drill wider to make it louder, but scared there might be drone past 1/2 inch. I'll post some more clips tomorrow on how loud it is, but I'd say it probably increased it by 10-20% at the most. Not as loud as PSE for sure, but better than stock.

Originally Posted by RandallNeighbour

Now this is a great little mod. Probably took all of a half hour, right?

I cannot tell from the video just how much louder it is, but it does sound "throatier."

Give us your opinion as to how much better it sounds. Do you still long for a different muffler that's louder if you could get one without the nasty cabin drone?

[wanna986]

Originally Posted by crios

I'll post some more clips tomorrow

[crios]

Hi all,
Below are some more clips I put together this mornig. I'd say the increase sound is anywhere from 10-20%, not huge, but then again, I only used a 1/2 drill bit. You hear the throaty sound more in the lower RPMs.

Boxster Exhaust Mod - Outside #1
http://www.youtube.com/watch?v=Dt0p0etZt7s

Boxster Exhaust Mod - Outside #2
http://www.youtube.com/watch?v=3uQYZj2xUfE

Boxster Exhaust Mod - Topdown
http://www.youtube.com/watch?v=EDGR78lMLF8

Boxster Exhaust Mod - Top Up
http://www.youtube.com/watch?v=GOumu9oH1pU

Thanks,
Cesar

[mdimant]

Originally Posted by crios

30 min if that!! I'm wanting to drill wider to make it louder, but scared there might be drone past 1/2 inch. I'll post some more clips tomorrow on how loud it is, but I'd say it probably increased it by 10-20% at the most. Not as loud as PSE for sure, but better than stock.

I was contemplating the easiest hack on my stock 00' S muffler & reading this found me with drill in hand in no time. Your'e idea is brilliant. I drilled 2 holes 7/16 in each side & with a reemer punched them out to about 11/16. Used a 2x2 chunk of fir with a 'v'groove sawn in it to guide bit. It is a perfect note w/ minimal cabin drone which goes away @ 2800. I rarely run less than that anyway. It just screams when whooped! I also recently swapped stock header/cats for chinese headers ($69.00 +32.00 ship). They are awesome for the $ & collectors/welding is just great. Extended all 02 sensors placing pre-02's near header outlet (fitting provided in hdrs) & post 02's in top of pipe right behind 2nd cats, behind rear wheel well. I am now remodelling intake. All this fancy stuff available for $3-400 is great for a neurosurgeon, but I can't see it. I got some 3.5" silicon tubing (50%+- larger than stock dia) & 2 3" abs Street 45 deg. plumbing fittings, cut them down, rasped & sanded the insides to elim drag. The stock air box provided the short section w/ MAF hub when sawn up & removed, & I'm now patterning 3/32' uhmv plastic (or whatever it's called) for a new AB to house a 4.5x5.25, 6" long Conical filter from local ap store. I opted for an oilless K&N look alike for $20.00. It will be more of a plenum than an air tube, not much sucking hopefully, the fixed dia @ MAF must be maintained to get the cfm reading though. It will throw cel's I know, but with what I've saved I'll find someone to remap ecu. Working on this car is the most fun I've ever had with mech tools. What a great car. $15K for 31K miles, are u kidding? Rich mans garbage i guess. I won/t have 18 in it for a really fun fast ride thats so addictive to drive!

[bigborian]

I was thinking about this too but i would like to ask about improving the flow even more. What if you cut a piece of pipe out at the Red arrow section? Or even at the Teal arrow section and have the exhaust just escape freely from there? Would the sound be too loud for street use?




This is what i'm talking about. If you cut the yellow parts out with a power saw or if u can get the muffler off you could probably use a hacksaw. The exhaust would go in and fill 1 chamber and get right out of your exhaust tip bypassing all the chambers. You could also probably fashion a straight pipe from that entrance to the exit. I think you would also have to block off the teal side of the muffler with something maybe weld a piece of metal, or some kind of metal clamp with a cap. I guess it wouldn't hurt your exhaust system if you left it open too because it would just recirculate to the first chamber.

[2000PorscheBoxster]

if christain H is right below and i have drilled as prescribed in this thread... then i must report i have noted no appreciable sound difference!!!

unless the 2000 porsche boxster base model mufflers were designed differently, i will probably have to try the PEDRO PENNY MOD instead for serious sound improvement...

oh well.

[HDManny]

I have been thinking of doing this to my 2003 tip since I first read about it. Now I just need to decide if I should start with 1 or 2 holes per side.

[crios]

Since it's a dual pipe, you need one in each side, so two holes

[HDManny]

I though that I read an entry saying someone had drilled 2 holes per side?

[msediqi]

Hey i got a simple question. im about to do this mod i have the screwable tip on my 03 boxster. Now when i drill the holes how far in deep to i drill? Do i drill al the way in ? am i supposed to make a hole in the frist chamber. How far exactly did u push the drill bit in ? Thanks for the help

[fishfood]

I can't see spending a grand for a new muffler,especially for the small gains it makes, but always wished the car sounded a bit more aggressive at lower rpms. Drilled two 1/2" holes, one on each side, using a 12" long bit, it made a small difference from idle-2500 rpm. Went up to a 9/16" and it sounds great now! That extra 1/16" adds over 25% more to the drilled cross sectional are, and it makes a big difference. Car sounds great at idle and normal cruising speeds, no resonace at all. Above ~3000 can't tell a difference at all, which is fine with me, it has always sounded good at higher revs. Just use a good sharp bit, push slowly and spin the drill slowly until the bit bites. The 9/16" bit fits tight on both sides as you put it in, but this helps guilde the bit and I didn't have a problem slipping. Thanks for the tip!

[MylesHye Clothing]

I did this tonight and it works great, just enough sound!!!!!

Everyone should do this mod!! i got my bit a lowes for 12.95.

Thanks for this great DIY.

[Jamesleeworks]

Crios

That is pretty cool, I think I am going to give that a try. did you have any modifications to your air intake?
You have any other clips?

[jhandy]

did the drills, love it, and plan on doing a second set of 1/2 inch holes strait back. Just a FYI. My drill bit was dancing all around. My tips do not come off, so the angle of attack was shallow. Some say to center punch. I used a large flat head screwdriver and pounded it into the pipe, poking a large hole, then drilled. Made the experience lasted about 2 mins per side. Obvious but someone may benifit from the suggestion.

James

[HDManny]

I drilled two holes (one per side) also but accidentally made them a little bigger then I intended and it sounds greats. As they mentioned on here previously, more noticeable when you go past 3000 rpms and it sounds louder not different.

[MN 986]

I started with 1/2"dia holes (one each side) on my 2002 2.7 and liked the extra sound. Eventually I wanted more, but could not find a larger diameter drill bit that was long enough to reach with the fixed exhaust tip. Then one day I ran across a 'stepped' drill bit and a drill bit extension, and slowly worked my way up to a 3/4"dia each side. I think it sounds even better. Definitely not too loud.

What have others tried?

[HDManny]

I used a 1/2" drill bit but as I said earlier, I got carried away then combined with the angle, I made my holes about the same size as yours. They are 1/2" by 1" so it should be the same, I like the sound and thought about going bigger.