Straight pipe exhaust
Straight pipe exhaust
Total cost was $24.85 from Ace Hardware for 1x24" and 1x18" 2.5" straight pipes, 1x30" 2.5" straight pipe with turn-down tip and two rubber hangers.
Before and after. No crappy guillotine clamps, just welds.
Mounted in place. I only used two hangers since the exhaust is so much lighter.
ROL Exhaust #511176 hangers. Cost was $1.76 each.
I'm actually surprised to find that both the resonator and muffler are straight-through designs with no baffles or packing. Both had a fair bit of carbon/soot trapped inside. (right is the inlet on both.)
Volume is not nearly as loud as having an open down pipe dumping under the passenger floor. The VNT significantly quiets the exhaust and opening the vanes makes it far louder.
Now its time for some fun, I'll be heading up to the summit of Pikes Peak tomorrow!
Nice tip and pics. I didn't realize the bends the exhaust has around resonator. The straight pipe cleans it up pretty good. Maybe I'll just go straight on resonator portion and leave the muffler.
(08-23-2009, 11:18 PM)ForcedInduction Now its time for some fun, I'll be heading up to the summit of Pikes Peak tomorrow!
(08-23-2009, 11:18 PM)ForcedInduction Now its time for some fun, I'll be heading up to the summit of Pikes Peak tomorrow!
In 3rd gear, 1700rpm, 5psi boost, 1100*f.
In 2nd, 2500rpm, 5psi boost 900*f.
I didn't have time to test boost response or acceleration near the top. Thanks to the fog, I reached the summit before I knew it and then the Weather Nazi ranger shooed me back down the hill almost right away.
Got a vid of this car running this exhaust? Wondering how feasible it would be for me...
These are what I have for now.
http://www.youtube.com/watch?v=8czY5s03Qo4
http://www.youtube.com/watch?v=g7HRDq3RdJU
I'm going to switch out from the 300D to the 240D for the winter tomorrow. Its got the T3 turbo but a stock exhaust so I'll try to remember to make a comparison video of the two.
Not bad. I think I might try the resonator first, though. Take it from there.
No way I'd pass VT inspection doing that.. The muffler is damn near the only thing the look for! Good to know the stock exhaust is straight through tho.
I keep hearing that the resonator is the bigger restriction out of the two, what's the theory behind that?
(11-25-2009, 12:09 AM)GREASY_BEAST No way I'd pass VT inspection doing that.. The muffler is damn near the only thing the look for! Good to know the stock exhaust is straight through tho.
(11-25-2009, 12:12 AM)CID Vicious I keep hearing that the resonator is the bigger restriction out of the two, what's the theory behind that?Its closer to the engine where the exhaust is hotter and expands more.
(11-25-2009, 12:09 AM)GREASY_BEAST No way I'd pass VT inspection doing that.. The muffler is damn near the only thing the look for! Good to know the stock exhaust is straight through tho.
(11-25-2009, 12:12 AM)CID Vicious I keep hearing that the resonator is the bigger restriction out of the two, what's the theory behind that?Its closer to the engine where the exhaust is hotter and expands more.
I did this too, and they forced me to put in a resonator as well, but it still dramatically changed the note of the car. For a generally simple mod, its SOOOOOO worth it, even if not for performance! I did it so I could hear the engine while blasting music.
Gives these cars a nice rumble at idle and kinda a small cummins engine note!
(11-25-2009, 12:06 PM)benztek I have already straight piped the resonators. I am cutting the muffler out next weekend and putting in S-600 tips. What does everyone think will look better? Both on one side, Both in the middle, or one on each side?
(11-25-2009, 12:06 PM)benztek I have already straight piped the resonators. I am cutting the muffler out next weekend and putting in S-600 tips. What does everyone think will look better? Both on one side, Both in the middle, or one on each side?
I have always liked the "in the middle look", especially on BMW.
Don't forget about soot, without a turndown you'll probably end up with a sooty back end.
(11-25-2009, 12:52 PM)ForcedInduction Don't forget about soot, without a turndown you'll probably end up with a sooty back end.
(11-25-2009, 12:52 PM)ForcedInduction Don't forget about soot, without a turndown you'll probably end up with a sooty back end.
I'm thinking of doing the resonator as permanently gone, and the muffler will be set up to be fairly modular. Even though my 616 with just a resonator wasn't all that bad, I did get followed by a cop one night because of it. So I might have the muffler in for general use, and swap it out for a straight pipe when I feel like getting frisky
does the straight effect the MPG?? does it offer any performance or slightly increased HP or TQ?
(11-25-2009, 08:36 PM)W116Lorinser does the straight effect the MPG?? does it offer any performance or slightly increased HP or TQ?
(11-24-2009, 10:16 PM)ForcedInduction I'll try to remember to make a comparison video of the two.Here it is: http://www.youtube.com/watch?v=OnWc425YxZs
(11-25-2009, 08:36 PM)W116Lorinser does the straight effect the MPG?? does it offer any performance or slightly increased HP or TQ?
(11-24-2009, 10:16 PM)ForcedInduction I'll try to remember to make a comparison video of the two.Here it is: http://www.youtube.com/watch?v=OnWc425YxZs
I got a turndown on mine, and still get soot all over my back side. I'm wondering if I didn't make it extend out far enough. Has anyone found a way to avoid the soot getting on the body short of putting a stack on? Next exhaust I'm gonna try making it extend out a couple inches..
The tip I use on my 300D doesn't leave any soot. Even my bicycle stays clean behind the trunk.
So the muffler is a straight pipe by itself so no need to remove it.... But how about the resonator? Is resonator straight flow also? Doesit rumble more/ soundmore aggrrssive with it removed?
(11-26-2009, 01:24 PM)W116Lorinser If both muffler and resonator are straight flow design anyway whats the point of straight piping it??They allow the exhaust to expand (and cool) through the holes/slots which causes restriction. Anything that changes the exhaust's sound, flow direction, gas volume or temperature will cause backpressure.
(11-26-2009, 01:24 PM)W116Lorinser If both muffler and resonator are straight flow design anyway whats the point of straight piping it??They allow the exhaust to expand (and cool) through the holes/slots which causes restriction. Anything that changes the exhaust's sound, flow direction, gas volume or temperature will cause backpressure.