DIY Exhaust Mod – Gain of 10+ HP!!!

[joseph_number1]

Sorry to be a downer....but would drilling the exhaust cause the car to fail emissions?

[blue2000s]

Originally Posted by joseph_number1

Sorry to be a downer....but would drilling the exhaust cause the car to fail emissions?

The addition of holes in the muffler tubing can't effect emissions. It will effect noise level.

[JFP in PA]

Originally Posted by blue2000s

The addition of holes in the muffler tubing can't effect emissions. It will effect noise level.

And some states do have distinct noise level limits, CA for one comes to mind, so it can enter into the picture at inspection time..........

[crios]

Originally Posted by JFP in PA

And some states do have distinct noise level limits, CA for one comes to mind, so it can enter into the picture at inspection time..........

I just smog’d my car in CA last month, passed.

The sound is not LOUD, it's simply deeper. It's a growl, not a bark.

As for visual inspections, they check if you have done anything to the filter area, not the tail.

You cannot even see anything in my pipes, they are so dark with oil!

[JFP in PA]

Originally Posted by crios

I just smog’d my car in CA last month, passed.

The sound is not LOUD, it's simply deeper. It's a growl, not a bark.

As for visual inspections, they check if you have done anything to the filter area, not the tail.

You cannot even see anything in my pipes, they are so dark with oil!

Most of the conversations I’ve had with CA residents having problems with the noise issue resulted from them getting noise tickets which required them to got to a smog check station to have the car “certified” before going to court. From what I have been told, if you get one of these summonses, testing is required according to the CA specs, which use a sound meter behind the vehicle a specified distance and on an angle to the side. The car is then revved to prescribed RPM levels while in neutral and the sound level is measured in dB. Usually, once you pass the test, the ticket is dropped.

I know you guys have some draconian laws about modifying cars, so I’m not at all surprised they check sound levels.

[crios]

Listen to the sound clips again.

The car is not loud that it’s annoying to people and would get them to turn their heads. It just sounds like an aftermarket exhaust, but about $2K less.


http://www.youtube.com/watch?v=RfRErzkyqNc

[jenster91]

Fellow drillers....I have just completed this mod on my 99 no removable tip...Purchased long 1/2 bit from sears...drilled just left of straight Back....both sides...nice result I was hesitant...glad I went ahead...in my opinion:
Below 3000 rpm is noticable...idle and just off when acellerating sounds best lower and somewhat louder no unwanted rasp or drone....above 3k rpm induction with de-snork is more prevelant and SWEET by the way!...overall would recommend.

Tom D.

[truegearhead]

Has anyone actually done this on a weld on tip boxster? I tried but the angle of the plate and the distance makes it very difficult.

[hartids]

This sounds like an awesome free mod!! I'm gonna have to give this a crack tomorrow!! I had already put some time aside for my desnork and rear window restorer so I will now add this to the list!!!

Have peeps found that duct tape is the best way to prevent any scratching?...

[Spinnaker]

Originally Posted by truegearhead

Has anyone actually done this on a weld on tip boxster? I tried but the angle of the plate and the distance makes it very difficult.

2000 S with welded tips, see post #128. Didn't have much trouble at all.

"Have peeps found that duct tape is the best way to prevent any scratching?... "
The smooth surface of the extension did not leave any discernable marks on edge of the stainless steel tips.

[jesseborgelt]

Originally Posted by Spinnaker

2000 S with welded tips, see post #128. Didn't have much trouble at all.

"Have peeps found that duct tape is the best way to prevent any scratching?... "
The smooth surface of the extension did not leave any discernable marks on edge of the stainless steel tips.

I made a few attempts at this and walked away frustrated more than once. When I finally got it to work out the way I wanted it to, I was happy with the results. I had very realistic expectations for simply punching holes in a muffler and I like the sound better then stock.
My tips:
1) Take a shop rag fold it in half and line the inside of the tip with it while draping the excess over the outside of the tip and tape into place, both outside and inside. I used blue painters tape.
2) I got a cheap set of ridiculously long bits (like 30”) from Harbor Tool and Freight for under $15 for a set of 4. Using the smallest bit, I attempted to drill a hole which spun along the curve of the inside of the exhaust pipe to no avail. I peered into the pipe to see where I wanted the hole to be with the drill bit, then while maintaining my vision on the spot, removed the drill and replaced it with a long screwdriver. Bang the hell out of it because you must have a dent or small hole for the bit to catch on, otherwise you will get frustrated and the bit will spin everywhere.
3) With the hole punched, I set the bit in the hole and stepped up the sizes until I had a 3/4” hole carved out. I really had to put some effort into it, as I believe these are wood bits, but for $15 I don’t care about messing them up.
With the desnorkle accomplished at the same time, I felt like have done something good for the car.

[hartids]

Desnork and exhaust mod both achieved in under half an hour!! So so so worth it!! I really believe that the sound difference is instantly noticable... Not crazy loud but a definate deeper growl and at about 3200rpm through the lower gears it really buzzes nicely!! The only trouble I had while attempting both mods was getting the air intake off for the desnork... That thing really needed some brute force!! As soon as it was off no problems at all, hardly even had to pull the snorkel and it popped straight out!!

As for the exhaust mod I got a 12" hardened tip flat head and gave it a good few whacks right where I wanted the drill bit to take. Made a nice big dent which my 1/2" metal drillbit (12" long) grabbed hold of and went straight through with some heavy force. I went to do the same thing on the left pipe - gave the screwdriver a few whacks and actually punched straight through with the driver making about a 1/2" hole to match the first one!! Result - Didn't even need to get the drill out!!

The sound difference is clearly noticeable on my '98 2.5 man so I imagine it will sound really nice on the 3.2 S models with both mods. I'll upload a pic of where I punched the holes...

On another note has anyone ever considered tinting the rear plastic window? Mine is quite badly damaged and cloudy, can't really see a whole lot through it - tried a load of different specialist cleaning products but to no avail!! I know you can get pre-cut tint film for them but this is applied on the inside and I don't think it will cover up the damage.. I have some spray on tint but not sure if it will stick to the plastic? I'm up for giving anything a go to make it better as I can get a new window fitted for £195 if nothing works.

Any ideas?

Cheers all,
Hartids

[Idaho Red Rocket 3]

My window tint guy said it could be done but he would not guarantee it would stay on when the top is folded down. So I had him tint the wind-stop. Works great because whether the top is up or down, I always have a tinted rear window.