ok on my 95 LT1 i have longtubes, y pipe, no cats, and a spintech crossflow muffler. i have a 2.5" dynomax ultra flow muffler that came off of me and my dads ranger project. i dont think we are gonna re-use it. i thought of taking this muffler and putting it on my car and having a tucked away tailpipe like the mufflex systems. the flow of this muffler is 1133cfm. so even though it will be necking down from 3" to 2.5" it wont matter as the muffler flow is more than enough for me. so i really want to know more is how it will sound?

 

come on guys. anyone? i know someone on here has to have done something similar. ive tried searching and cant find what i want.

 

ok i guess no one has ever put on a single in/out dynomax muffler before.

 

I don't know how it will sound, but your exhaust is only as good as the biggest restriction and I am willing to bet that that running a single 2.5" muffler is gonna cost you some power.

 

so even though it is cable of flowing alot it could still be a restriction?

 

I really don't know, but I doubt that muffler will flow as well as the rest of your exhaust system. Also, if you are going to hide the tail pipe anyway, it would be easier just to dump the exhaust before the axle. This is just my opinion so maybe some other people can chime in and then you can see what the general consensus is.

 

I ran a ultraflow muffler on my car for a little while. It sounded good. I ended up going to a completely different setup and the ultraflow went on my Jeep. I would probably sell that 2.5" one on ebay and use the money to put towards a 3" ultraflow.

 

i know the spintech cant flow that well. i lose 3mpg with the cutout closed vs. open. i know there are alot of variables. but it consistently gets worse mileage on a tank with it closed vs. a tank with it open. same gas and same driving style.

yea i guess it would be kinda dumb to neck it down to 2.5" i may see if i can find a 3" bullet muffler for cheap and get it right after the y pipe and turn it down right at the axle. if i can stand longtubes, ory, and an open cutout on a daily basis i know i can stand this. and that cutout is staying open until i can afford to change the rest of the system. lol
good to know that the ultraflow does sound good though!

 

the 2.5 bullet will outflow that set up you have now. According to dynomax the 2.5 will flow 1000cfm and the 3" 1300 cfm but the 3" muf is cheap and the 2.5 will be a pain to adapt to a 3" system.

 

thanks for the reply. i got someone to calculate flow of a 2.5" pipe and it is about 600cfm i believe. so whoever makes the ads for dynomax put down the wrong flow numbers. a 3" pipe will flow about 800-900cfm or so. so i got me a 3" X 18" long dynomax bullet to put on the end of my y-pipe. so that will yield me my no loss system while still toning the exhaust note down from the current open cutout. i tested gas mileage(cutout open) again and got 20mpg with 95% city/ in town driving. with the cutout closed off and going through the spintech i got 16-16.5mpg no matter how i drove it. on spintechs website they claim 175cfm @5" H2O. that equates to 391cfm of true flow. thats good enough for a 175hp engine. lol! i called spintech and asked them why it was so restrictive and all he would say is "it should be fine for your engine. and then turns right around and tells me that i need to go to a 3.5 or 4" exhaust for a bolt on LT1. i will not use anything that isn't a straight through design from now on since i have found this out. the spintech was very quiet to me anyway. i like loud aggressive sounding cars.