Re: Headers & exhaust
 

I found my OBX HAB055; something that Jeff [Shrek] said when I picked up the 3'' PE pipes from him, was leading me to believe that they were dis-continued.

Both places are eBay sellers however. Anyone dealt with MOTORSPORTAUCTIONS, or Racing Parts Depot???

Anyone know of other OBX sellers?

Re: Headers & exhaust
 

I purchased my OBX headers directly from Racing Parts Depot. Everything went great! Lowest price on the web that I found for the headers is directly through RPD.

Re: Headers & exhaust
 

Performance is quantifiable, sound is more subjective.

Performance wise, Marc suggests the Corsa with headers, sans cats, if allowed. The package delivers performance gains w/o resonance (I'm told), but they do have a "tinny" sound that some like and others do not.

The 3" Magnaflow system gives a nice, deep tone w/o resonance. However, the resonator chokes down the inlet to a single ≈ 3" perforated tube running the length of the resonator. Furthermore, there are several abrupt(!) choke and sudden transition points throughout the Magnaflow system (6 on the right side, 5 on the left) (which I believe any flow dynamics expert will tell us is NOT conducive to performance. FWIW).

The B&B has evolved from a pretty much wide open 3" cat-back with significant drone in the 1900-2200 rpm range, to a more restrictive system and "lesser" drone.

Pete, ever experimenting to get the most hp, is running a modified version of the earlier B&B system with Watson headers, and now using the NPP valves to control in-cabin drone. (The word is he can now carry on a conversation since installing the NPPs. Others too have gone that route and agree). Nobody is going to convince Pete that a Corsa is better for performance.

Experimenting goes on. I'm a Warrior (at least in my mind and I try to be:p) which means I'll put up with a little racket if there's hp to be made. I've watched the FBI efforts with great interest, and I believe the gurus have come up with what I consider the best of both worlds - to date at least:

The system that impresses me is the headers (SW or Watson), sans cats, SW type X pipe, no resonator, the Dynamax 17228 muffs with the NPP type gate affixed to one of the two active muffler outlets.** It is a true 3" system from the header collectors to the muffler inlets for least restriction and max performance, and the valve on one of the muffler outlets reduces resonance to a very tolerable level. What's not to like???

I'm not sure what Marc's setup is, but I don't believe it is a Corsa. And, I know he likes quiet for normal driving and has a pair of the Flowmaster dual outlet muffs on the back with 4-bolt flanges on the inlet side so they can be easily removed at the track. A variation of that is to install cut-outs just behind the differential which is perhaps an alternative to the NPP and perhaps just as effective.

Fact is, all of them are a compromise in some respect. Sound, vs. performance, vs. cost... Always room for more experimentation - and new "stuff"!;)

Re: Headers & exhaust
 

Paul,

As you know several of us are also adapting a Mild 2 Wild capability with the
C6Z NPP exhaust valves. Hoping to get mine re-installed sometime next week weather depending.

Re: Headers & exhaust
 

Yes - thought I alluded to that system. Yours, BTW, to me is the best sounding one so far.

And, speaking of NPP conversions, "Mike 100" has installed a very well thought out and proven electro-mechanical modification to the passive vacuum-only NPP conversion approach. It was engineered to addresses some low plenum pressure issues the simpler conversion that us "FLAT LANDERS" don't run into, e.g, Mountains and high altitude (low manifold) pressure issue. A really well documented and tested system!

Registry members have first DIBBS. It will be a feature article in the next HOTB!

Re: Headers & exhaust
 

What's the difference between resonance & drone? I know one of them means inside the cab is very loud, the more research I do the more these catback system have drone or resonance from what I'm reading on various forums especially b&w triflow, not to much with older style flowmaster with squarish tips wich I'm leaning towards. Or leaving on stock exhaust and putting on sw headers, and see if I can find a high flow resanator ?

Re: Headers & exhaust
 

So basically most hp gain with no annoying noise in cab.

Re: Headers & exhaust
 

My b&b with x-pipe isn't that bad. Sounds good to me and I can talk on my cell phone and drive without the exhaust being a problem.

But I have not installed my headers yet.

Re: Headers & exhaust
 

My b&b with x-pipe isn't that bad. Sounds good to me and I can talk on my cell phone and drive without the exhaust being a problem.

But I have not installed my headers yet.

Re: Headers & exhaust
 

If I could do it over I would install an x-pipe to replace the resonator and swap out the mufflers and connect everything to a set of full length headers.

The factory system is overall 2 3/4" & stainless steel.