Question... Car feels slower after exhaust install!!!! WTF
04-26-2013, 06:39 PM
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My Ride: 04' 545, 6 Spd Manual, Blk Lthr, Sport Pkg, Sport Sts, Logic 7, Cold Wthr Pkg, Full L.E.D. Interior, Red Eng. Cvr, Mtech Front Bmpr, M5 Spoiler, Matte Blk Grill, Red Caps, Slttd & Drlld Rotors, 20
Model Year: 2004
Question... Car feels slower after exhaust install!!!! WTF
Installed and RPI exhaust today on my 545i, idk if its all in my head but the car feels slower after the install... Anyone else experience this? Or is there some type of explanation for it.
04-29-2013, 07:11 AM
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My Ride: 545i
Model Year: 2004
Engine: N62
I would give it time to adapt. Put some mileage on it and see if you notice any difference. I cannot speak to RPI, as I have a custom Magnaflow Quad Setup. Post back with an update and let us know how you make out. 
04-29-2013, 09:56 AM
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My Ride: 04' 545, 6 Spd Manual, Blk Lthr, Sport Pkg, Sport Sts, Logic 7, Cold Wthr Pkg, Full L.E.D. Interior, Red Eng. Cvr, Mtech Front Bmpr, M5 Spoiler, Matte Blk Grill, Red Caps, Slttd & Drlld Rotors, 20
Model Year: 2004
Yea that's what I figured. I think it might just be a mind thing for right now car sounds louder so my brain assumes it should be a rocket, lol... Ill post back in a week or two I drive about 300+ miles a week to and from work so that should be enough time. Did you feel a difference when you first installed your set up. I know RPI is a proven exhaust, so I'm not worried its just weird.
04-29-2013, 10:13 AM
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My Ride: 650i 6sp
Model Year: 2008
Engine: 4.8l V8
Replacing a muffler on a car as large as well engineered and already as powerful as a 545i. You arent going to feel any 5-8 possible HP gain in a butt dyno. The assumption you would has is probably why it feels slower as you said above.
04-29-2013, 11:22 AM
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My Ride: 545i
Model Year: 2004
Engine: N62
Yea that's what I figured. I think it might just be a mind thing for right now car sounds louder so my brain assumes it should be a rocket, lol... Ill post back in a week or two I drive about 300+ miles a week to and from work so that should be enough time. Did you feel a difference when you first installed your set up. I know RPI is a proven exhaust, so I'm not worried its just weird.
04-29-2013, 11:28 AM
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Aftermarket exhaust changes not only impact the maximum torque/HP, but can also move the power band/curve around. For instance, free flowing exhausts typically make their power later in the rpm range, which might be what is happening in your case. Unfortunately, the only way to know for sure is before and after dynos. As The_Sauce indicated, the "butt dyno" is pretty unreliable with low hp gains.
04-29-2013, 12:32 PM
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My Ride: 2008 550i Jet Black on Black Leather, SAT with Paddles, Logic 7, Comfort Seats, NAV, Sport Package, PDC, Xenons, Sirius, Trinity 12W LED Angel Eyes, RPi GT Exhaust, M rear spoiler, ACS Roof Spoiler, Tinted Tail Lights, Bimmian Carbon Fiber Pillar Trim, Bimmian Shadow 550i emblem, RPi Scoop, E60 Forum Cling, Mtec bulbs in fog lights, Mtec 2W LED for License Plate Light Bulbs, K&N Filter, Bimmian LED Smoked Side Markers, Blackout roundels, Carbon Fiber Kidney Grills.
Retired Rides - 1989 325i convertible, 1995 M3, 2002 X5, 2005 545i, 2008 X5 (Lemon)
Though the RPI should provide a FEW more HP's, the main effect is the SOUND! I have one on my 550i, and it sounds AWESOME!
04-29-2013, 12:58 PM
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Looking for an effect you can FEEL
04-30-2013, 08:29 AM
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My Ride: 04' 545, 6 Spd Manual, Blk Lthr, Sport Pkg, Sport Sts, Logic 7, Cold Wthr Pkg, Full L.E.D. Interior, Red Eng. Cvr, Mtech Front Bmpr, M5 Spoiler, Matte Blk Grill, Red Caps, Slttd & Drlld Rotors, 20
Model Year: 2004
Aftermarket exhaust changes not only impact the maximum torque/HP, but can also move the power band/curve around. For instance, free flowing exhausts typically make their power later in the rpm range, which might be what is happening in your case. Unfortunately, the only way to know for sure is before and after dynos. As The_Sauce indicated, the "butt dyno" is pretty unreliable with low hp gains.
Yea damn sure does its been raining last couple of days but when I first installed I couldn't drive without the window down. Lol.... That's for the response tho bro.
04-30-2013, 09:39 AM
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My Ride: 2009 535i Sport
Model Year: 2009
Engine: N54
My guess would be the power band moving up a little - shouldn't be a lot, but a few hundred rpm. I'd be surprised if you LOST peak power, or at least enough to worry about.
Main thing a catback will get you is the sound - it's a mistake to buy a cat-back for the horsepower benefit (on a modern NA vehicle), you will be disappointed every time.
Main thing a catback will get you is the sound - it's a mistake to buy a cat-back for the horsepower benefit (on a modern NA vehicle), you will be disappointed every time.