Rumbling on JB2R?

littleyellowm3 · 02-04-2009, 06:39 PM

Hello

I have a JB2R. I tried 109 octane today, and let me say Wow!! when I flipped that little switch. I also turned the dial back as recommended with stock DP and exhaust. I started to notice that on the highway, in 4th, 5th, or 6th gears that the car would rumble or vibrate quite heavily under full throttle at peak boost. It was enough that my GF who knows nothing of cars mentioned that it sounds like a semi. It seems to only happen after peak boost is reached, and only under full throttle at relatively low RPM, such as 6th while passing at 55, or 3rd from 25.

Anyone experience this? Do I still have the dial set too high for my set up.. which is only the tune and a dual cone? Im my head, it feels like the engine starts making peak power, and is pushing with all its mite against the gearing, unable to raise RPM fast enough.

turb0 · 02-04-2009, 07:21 PM

does it feel like your going over the lane on the highway next to the median? (not the actual lane, the side of the highway? lol)

my car did that when i accelerated in a gear too high (usually 3rd when i should be in 2nd..etc)

theres a thread somewhere in the forums with people with similar problems

littleyellowm3 · 02-04-2009, 07:35 PM

Quote:

Originally Posted by turb0

does it feel like your going over the lane on the highway next to the median? (not the actual lane, the side of the highway? lol)

my car did that when i accelerated in a gear too high (usually 3rd when i should be in 2nd..etc)

theres a thread somewhere in the forums with people with similar problems

YES exactly like that. I tried searching, but I couldnt come up with anything relevant.

Sniz · 02-04-2009, 10:36 PM

I suggest a new tune or at least a tune up

hotrod182 · 02-04-2009, 11:13 PM

I have heard that on several cars. I think its just intake tract resonance or something with diverters possibly leaking at times. If you listen carefully, it seems to come from the intake side of the engine.

rcracer_tx · 02-04-2009, 11:16 PM

A JB3 will take care of that problem

02-04-2009, 06:39 PM	#1
littleyellowm3 Second Lieutenant 38 Rep 215 Posts Drives: MR E90 M3 Join Date: Nov 2006 Location: NC iTrader: (0)	Rumbling on JB2R? Hello I have a JB2R. I tried 109 octane today, and let me say Wow!! when I flipped that little switch. I also turned the dial back as recommended with stock DP and exhaust. I started to notice that on the highway, in 4th, 5th, or 6th gears that the car would rumble or vibrate quite heavily under full throttle at peak boost. It was enough that my GF who knows nothing of cars mentioned that it sounds like a semi. It seems to only happen after peak boost is reached, and only under full throttle at relatively low RPM, such as 6th while passing at 55, or 3rd from 25. Anyone experience this? Do I still have the dial set too high for my set up.. which is only the tune and a dual cone? Im my head, it feels like the engine starts making peak power, and is pushing with all its mite against the gearing, unable to raise RPM fast enough. __________________ Melbourne Red E90 M3 - E39 540i The original user of the animated Bert and Ernie avatar. Except no substitutes.
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02-04-2009, 07:21 PM	#2
turb0 First Lieutenant 31 Rep 307 Posts Drives: g05 x5 45e Join Date: Jan 2008 Location: Southeast iTrader: (6)	does it feel like your going over the lane on the highway next to the median? (not the actual lane, the side of the highway? lol) my car did that when i accelerated in a gear too high (usually 3rd when i should be in 2nd..etc) theres a thread somewhere in the forums with people with similar problems
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02-04-2009, 10:36 PM	#4
Sniz Lieutenant General 661 Rep 10,587 Posts Drives: e92 335 - gone // e36 M3 turbo Join Date: Mar 2007 Location: Ellicott City, MD iTrader: (1)	I suggest a new tune or at least a tune up __________________
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02-04-2009, 11:13 PM	#5
hotrod182 . 829 Rep 3,982 Posts Drives: 2023 i4 M50 Join Date: Dec 2006 Location: California iTrader: (0)	I have heard that on several cars. I think its just intake tract resonance or something with diverters possibly leaking at times. If you listen carefully, it seems to come from the intake side of the engine. __________________ 2011 Alpine 335d M-Sport 12.34 @ 110.48mph 2019 i3s Terra, 2008 Black 335i Sedan. 11.11@ 129.47 mph 2008 Monaco Blue JB3 2.0 335i Coupe. 11.33 @ 132.77 mph, 60-130mph: 6.95 seconds 2023 i4 M50 11.48 @ 121.56mph, 3.43 0-60 (dragy)
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02-04-2009, 11:16 PM	#6
rcracer_tx Banned 55 Rep 2,013 Posts Drives: BSM 135i Join Date: Apr 2008 Location: Texas iTrader: (0)	A JB3 will take care of that problem
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