Headers & exhaust

[Gunny]

Originally Posted by Paul Workman

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.

Corsa w/headers, sans cats has absolutely no resonance but is LOUD. The sound is different (subjective observation). I had this system but grew weary of the LOUD (i.e. I could no longer drive around my small town without attracting a LOT of unwanted attention; resonance was never an issue.

My current solution is headers, no cats, and an LT-4 stock exhaust from the collectors back. No resonance and sounds stock in the cabin, but somewhat louder outside. Without a dyno comparison I can't comment on HP loss but in real-world driving it doesn't seem that I lost much, if any, and it "feels" like I picked up a little torque. Again, without a dyno that doesn't really mean anything but I'm reasonably happy with the system ... for now.

Originally Posted by Paul Workman

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 haven't heard this setup yet but this might be my next direction should I want to change the exhaust again.

[emmvette]

What's the FBI set-up consist of?

[Paul Workman]

Originally Posted by emmvette

What's the FBI set-up consist of?

Marc favors the Corsa cat-back, but what Pete and others are using with success (in a fashion) is a "work in progress", but this may come pretty close as of now:

• SW or Watson headers,
• 3" pipes throughout,
• sans cats and resonator,
• SW or B&B type X pipe*,
• Dynamax 17228 or B&B muffs 3" in, twin 2" out
• NPP** valve on one of each twin outlet, OR cut-out valve at the differential
• B&B or C6 Z06 tips.

* Bob G is using what could be described as an X "box"
**NPP valves are controlled by simply supplying vacuum from the plenum to the valves, or manually electrically activated.



Note: The simple vacuum system works well in relatively flat terrain. However, in mountainous areas, the simple plenum vacuum approach results in the valves being open "too much". The fix is what I was alluding to in the next HOTB.

P.

[Blue Flame Restorations]

Pretty sure the 17228 mufflers are 2.5" dual outlets. Not 2"

FYI

[Schrade]

What did you end up doing there Tomz?

Take any snappics? Did you pull the FlowMasters on there now?

I'm about to put on OBX's + PE pipes, and looking for more shots of the work...

[WARP TEN]

Originally Posted by Gunny

Corsa w/headers, sans cats has absolutely no resonance but is LOUD. The sound is different (subjective observation). I had this system but grew weary of the LOUD (i.e. I could no longer drive around my small town without attracting a LOT of unwanted attention; resonance was never an issue.

My current solution is headers, no cats, and an LT-4 stock exhaust from the collectors back. No resonance and sounds stock in the cabin, but somewhat louder outside. Without a dyno comparison I can't comment on HP loss but in real-world driving it doesn't seem that I lost much, if any, and it "feels" like I picked up a little torque. Again, without a dyno that doesn't really mean anything but I'm reasonably happy with the system ... for now.

George, this is exactly what I went through. Primarily Corsas over the years but just got tired of the Loud. I have headers, no cats and last year had Marc reinstall my stock '95 system from the headers back. The only difference is I had him add electric QTP cutouts and I installed a rocker switch hidden under the carpet on the right side of the console. The only issue is I had to sacrifice the spare tire carrier. On longer trips away from home I carry the spare in the back. I added small tips to direct the exhaust to the side. So far I like the setup a lot. It is stock quiet when I want and when open I can scare children and pets and set off car alarms. I normally run slightly open for a little rumble.--Bob

[TomZR1]

Hey schrade,ordered flowmaster catback actually yesterday took a while to find them cause they were discontinued but I found them,will figure out how to post pics when done installing them,headers will be next what's difference between obx & sw? Is it sound,looks I know thers big price difference . Thanks ill keep you posted.

[Schrade]

Originally Posted by TomZR1

Hey schrade,ordered flowmaster catback actually yesterday took a while to find them cause they were discontinued but I found them,will figure out how to post pics when done installing them,headers will be next what's difference between obx & sw? Is it sound,looks I know thers big price difference . Thanks ill keep you posted.

I don't know much about the differences - when I said I know less than most on the boards, I was meaning exactly that...

Cliff [Dynomite] has one method step-by-step for uploading snappics here. You can practice a few carshots upload before the hardware gets here... Learning stuff like that has application in how some of the Z diagnostic stuff works too - promise.

Work shots are good in MANY ways - it forces you to take your time (always good), gives you more time to see where stuff is, good for re-assembly reference, feedback from others, if you ever sell, you got photo-doc'ed proof, you 'learn' the stuff better (I will NEVER forget steps involved in the Top End Resto thread ('til tomorrow anyway )

[edram454]

Originally Posted by TomZR1

Hey schrade,ordered flowmaster catback actually yesterday took a while to find them cause they were discontinued but I found them,will figure out how to post pics when done installing them,headers will be next what's difference between obx & sw? Is it sound,looks I know thers big price difference . Thanks ill keep you posted.

Tom,

where did you find them?? I have flowmaster force II system and they are discontinued so I thought. Are they making them on a custom order method or did you just get lucky and find an old set somewhere?

ed ramos #3028

[TomZR1]

Hi Ed, i got lucky typed 17115 flowmaster and bunch of company's popped up called every one,and all but one said nope don't have discontinued,finally one company said I have one on shelf,holy crap ill take it!!! So if you can't find something don't give up its out there somewhere.