corvette90

hi all

i built a 415, and always wondered, why it wont like to rev, although it have a healthy but streetable cam in it..

i run a stock LT1 exhaust and everybody i asked told me, its a very good flowing system..for a stock system..

removed it, and tried some kind of a rather free flowing exhaust...

LT headers, bullet cats, x-pipe, all in 3"

i got some OBX mufflers, which are basically perforated steel wool wrapped tubes, one goes straight through, the other goes from the middle of the straight tube to the end tips...

needless to say, its very loud (if i plug the straight tube, it gets better..), with lots of drone but the engine revved and had power it never had before..so the LT1 exhaust is definitely a restriction in my case

next, i tried flowmaster 50 series, they were not so loud, then plugged again one pipe, they were really nice...the flowmasters are said o be a rather restrictive muffler...
http://www.summitracing.com/int/part...01-r/overview/

so, i need an exhaust that is rather silent for cruising, but opens up, when i need the power to get rid of the gases

i have the following options:

1)find quieter mufflers that wont restrict flow - difficult
2)add a exhaust valve to my flowmasters, like the Z06 NPP - mufflers still restrictive
3)add Z06 NPP take offs - that would be the best option, but i really dont think, i have enough space underneath
4) fabricate a muffler from pipe and sheetmetal like the Z06 NPP, just more compact, question is, if this is straight forward, or is the volume of the muffler needed..
5)find a muffler with a straight loud (which i can valve) and a winded, baffled silent pipe

some pics and topics what i mean:

i have a exact copy of the exhaust this guy uses...(found out afterwards)
http://www.thevettebarn.com/forums/c...ess-works.html

NPP muffler inside, the construction wouldnt be that hard for DIY (if you have possibility for sheetmetal working)
http://forums.corvetteforum.com/c6-t...fler-diff.html

here are some valves, looks like oem
http://www.ebay.com/itm/Exhaust-Control-Valve-with-Vacuum-Actuator-for-2-1-2-63mm-Pipe-/380606319348?pt=Motors_Car_Truck_Parts_Accessories&hash=item589de78af4&vxp=mtr#ht_888wt_868
controlling the vacuum for the valves is possible by using the 1-4 CAGS, which can be programmed in the ecm and is disconnected from the trans anyway from most of us (manual six), but thats another story

any input will be greatly appreciated, i will also keep you informed how the progress is going on

thank you

JackDidley

5)find a muffler with a straight loud (which i can valve) and a winded, baffled silent pipe





Power Effects used to sell this. They still have a web site but I dont know if you can actually buy them.

http://www.powereffects.com/indexmain.html

cv67

3" with some cubes will be loud. Corsas will help cut down on the drone

Tried a bunch of different mufflers, in combinatino with bullets etc it still sucked. Corsas cured it.

Too bad you cant get a 20" case turbo up under there