Fabspeed bypass pipes

[chitowndad]

I think it's like what you experienced when desnorkling so it's an extension of that process, one more step in the louder growl direction!

[jwade]

I have checked all over and seems like 495 is about the lowest I've seen for the fabspeed ones.

I plan to get an oil change here in a month or so, but have been debating about atleast having these installed at the same time. NHP exhaust makes some too.

[mts]

I think the pipes were worth getting (for me at least).

[jmatta]

I'm back in this a couple days late, but bypass pipes are worth the money spent. I really think Porsche put these on to comply with EU noise restrictions...why else would anyone put secondary cats on a sports car?

The mid range tones are wonderful going to an all out scream as rpm rise. The nice part is tooling around town, it's not that much louder until you hit the throttle.

For any of the Chicago guys, I will be an instructor at the PCA autocross school next month and I will bring the Box S down so you can hear it in person...maybe I'll even get motivated enough to do some recordings to post. You can then draw your own opinions.

[jwade]

Ok, seems that most people like these. Now do you guys still have the stock headers in place with these on or you running different headers?

On a side note, please look at this recent update regarding Fabspeed products.

Fabspeed has a new video uploaded for the 986 S. They do an interesting test where they install hardware "adding one piece at a time" from exhaust, headers, BMC air filter, EVO intakek, and then finally, an ECU reflash.

Total cost - a whopping $4795

Total HP gains - 229 stock
241 w/ headers & sport cats
245 w/ BMC (good value - 4hp for about 100 bucks)
247 w/ EVO (not a good value whatsoever)
252 w/ ecu reflash and all above hardware installed

Total Gains - a whopping 23 hp
Total price per hp - just under 210 bucks each

See video here:

FYI - Turbowerx headers cost 800 and hp gains on a 986 S 3.2 motor is 22hp

Don't you guys find this interesting? Hell, I'll "splurge" and add a BMC filter too.

For 1500 bucks, I can have the headers, by-pass pipes, and the bmc while I take the rest and spend it on my family at a 5 star resort in the cayman's......

[silver arrow]

Why not just gut the stock pipes or have a muffler shop weld some up. It's not a complex exhaust piece. Seem crazy to pay $500 for 2 pieces of piping with one mandrel bend.

[ChrisZang]

Originally Posted by silver arrow

Why not just gut the stock pipes or have a muffler shop weld some up. It's not a complex exhaust piece. Seem crazy to pay $500 for 2 pieces of piping with one mandrel bend.

The though that crossed my mind is to get a set of worn out secondary cats from a dismantler for super-cheap, get rid of the "filling" in the cat, and now you have your low-cost bypass pipes...

[edevlin]

"Total cost - a whopping $4795

Total HP gains - 229 stock
241 w/ headers & sport cats
245 w/ BMC (good value - 4hp for about 100 bucks)
247 w/ EVO (not a good value whatsoever)
252 w/ ecu reflash and all above hardware installed

Total Gains - a whopping 23 hp
Total price per hp - just under 210 bucks each"


Hey, thats quite a deal, my intake, chip and full exhaust ended costing around 7K and gave almost exaxtly the HP increase of the system above. That means it cost me over 300 bucks/hp, yikes. Nobody has ever accused me of being especially clever, but I am having a pretty good time....

Ed

:dance:

[mts]

here are some of the Fabspeed pipes on the car...they are larger diameter than the Stebro ones.

[Blue-S]

Originally Posted by jmatta

I'm back in this a couple days late, but bypass pipes are worth the money spent. I really think Porsche put these on to comply with EU noise restrictions...why else would anyone put secondary cats on a sports car?

The 2000 and newer Boxsters are Low Emissions Vehicle (LEV) certified -- not just in California, but all US-specification Boxsters. Presumably due to their (relatively) low sales volumes, Porsche certified all Boxsters to meet California emissions regs. So, that's why the 2000+ Boxsters have pre-cats in the exhaust manifolds and the main cats in the mid pipe.

My 2000 S recently developed a crack in the exhaust manifold where the pipe meets the flange at the cylinder head. It is hard to see, but a very close examination with a bright light reveals the crack on my car, specifically at the #6 cylinder. I suspect that other areas are cracked too, but I cannot see it. The symptom is a "tick" noise which is louder at startup and becomes quieter (but does not disappear) as the engine warms up. If you have ever heard a cracked exhaust header or a header that is just slightly leaking where it is bolted to the cylinder head, then you know the sound.

Therefore, I am looking at an inexpensive solution to this problem. Are the chinese headers (ebay) really of any benefit HP/Torque wise? If so, I could relocate the downstream O2 sensors behind the main catalysts and the car should still pass the cat efficiency monitor...avoiding the dreaded check engine lamp.

[ChrisZang]

Originally Posted by Blue-S

The 2000 and newer Boxsters are Low Emissions Vehicle (LEV) certified -- not just in California, but all US-specification Boxsters. Presumably due to their (relatively) low sales volumes, Porsche certified all Boxsters to meet California emissions regs. So, that's why the 2000+ Boxsters have pre-cats in the exhaust manifolds and the main cats in the mid pipe.

Hmmmm,

so I have two options:
a) replace 2nd ("main") cats with bypass pipes
b) replace pre-cats + headers with "hi-flow" headers w/o cats and relocate O2 sensor behind main cat

In your opinion which scenario has a higher chance to pass smog in CA?
Please note that I already went with option a

[Blue-S]

Originally Posted by ChrisZang

Hmmmm,

so I have two options:
a) replace 2nd ("main") cats with bypass pipes
b) replace pre-cats + headers with "hi-flow" headers w/o cats and relocate O2 sensor behind main cat

In your opinion which scenario has a higher chance to pass smog in CA?
Please note that I already went with option a

That's a good question. I bought my car in Jan 2009, and as such the prior owner had it smogged at a "corner garage" in Carlsbad...so I haven't seen a Boxster in the process of being smogged. I think that passing smog would depend on two factors:

1. The experience and work ethic of the smog inspector: If the inspector really knows Boxsters, then they will notice that your 2000+ Boxster only has the pre-cats but not the main cats. The VECI label inside the rear trunk mentions only that the car has 3-way catalysts, but it does not list how many. I have asked several techs and they tell me that the smog computer also does not list how many cats are supposed to be on the car. The main cats are much easier to see (vs the pre-cats) when bending down and looking under the rear of the car while it is parked. However, the pre-cats can be clearly seen when looking at the bottom of the engine, peeking in front of the rear wheels. Since many late-model cars have close-coupled cats (built into the exhaust manifold), I imagine that the bypass pipes would not look suspicious on a 2000+ Boxster as long as the pipes look stock. That presumes an inspector that doesn't know Boxsters well...

2. The composition of the pre-cats: I do not know for sure, but I suspect that the pre-cats are an oxidation "light-off" type of catalyst. If that is true, then there is a risk that your car might not pass the sniffer test - possibly failing due to excessive NOx. This could happen because (I think) the main cats are the 3-way type that oxidizes (burns) HC to produce CO2 & H2O, combines CO with O2 to make CO2 and reduces NOx to N2 and O2. I suspect that the engine management system (DME) controls HC and CO pretty well, but that good NOx control at light load would rely heavily on a properly functioning 3-way cat. For more detail on 3-way catalyst operation, check this out:

http://en.wikipedia.org/wiki/Catalytic_converter

Please let us know what happens when you go in for a smog check!