Tuning out Deceleration Exhaust Popping - Page 8 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Pollock · 04-11-2011, 12:09 PM

Quote:

Originally Posted by GRYGOOS

I thought it was bad to engine break during the engine break in period of an LS3, something about letting the piston rings seal first? Consequently I haven't heard this sound yet as I've yet to downshift to slow down. Can anyone confirm as the OP may be doing his engine a disservice.

I think the manual said to keep it below 4K.

Drago77 · 04-11-2011, 03:05 PM

Yup, normal.

Shu71 · 04-11-2011, 03:24 PM

Throw a leg over many Harley's and downshift to slow down and you will hear real popping (decel rumble). It can be caused by a lean condition which in the case of the Camaro with Active Fuel Management apparently comes from GM reducing the fuel supply in decel. Letting the engine slow by using the gears is not neccesariliy a bad thing during break in provided it isn't extreme. It forces the piston rings to bed more quickly. Very hard full throttle accelerations from low rpms is much harder during break in because the rings are much hotter already from the bedding process and you risk microwelding the rings to the lands and then it will never perform to it's fullest potential. From what you describe though it doesn't sound like you are 'beating' on it during your downshifts so I'd say you are fine. I like rumble on decel but no popping. Harsh popping could be from an exhaust leak too.

papabearcamaro · 04-11-2011, 03:40 PM

Yup,normal and sounds like crap. One of the first things done when my car was in the shop was get that annoying sound tuned out.

Pollock · 04-11-2011, 04:03 PM

Quote:

Originally Posted by Shu71

Throw a leg over many Harley's and downshift to slow down and you will hear real popping (decel rumble). It can be caused by a lean condition which in the case of the Camaro with Active Fuel Management apparently comes from GM reducing the fuel supply in decel. Letting the engine slow by using the gears is not neccesariliy a bad thing during break in provided it isn't extreme. It forces the piston rings to bed more quickly. Very hard full throttle accelerations from low rpms is much harder during break in because the rings are much hotter already from the bedding process and you risk microwelding the rings to the lands and then it will never perform to it's fullest potential. From what you describe though it doesn't sound like you are 'beating' on it during your downshifts so I'd say you are fine. I like rumble on decel but no popping. Harsh popping could be from an exhaust leak too.

I have floored my engine a few times. Eased into it in first gear... no dumping the clutch. I let off around 6200 rpm and did not shift to second. Went straight to forth. You think I could have hurt the rings a little?

I have built engines before. Run them for 20 minutes then hit the drag strip.

cab2g · 04-11-2011, 04:07 PM

I love the decel pop.

xXSilencerXx · 04-11-2011, 04:09 PM

I like the noise personally.

Shu71 · 04-11-2011, 04:20 PM

Pollock, There is no way to tell if it did damage or not. If you had a couple hundred miles on it, then I would think the rings were already bedded in and you are fine. I am of the process like you but many times race engines are not built as tight as new factory engines. I build my Sportster engine, heat cycled it three or four times, then on a 20 degree night took it up the road wide open throttle through the gears a couple of times. That engine now has 30000 hard miles on it and never has burned a drop of oil and has outstanding cylinder pressure even after a long period of running nitrous on it.

Synyster · 04-11-2011, 04:21 PM

Decel pop = Awesome.

Pollock · 04-11-2011, 06:01 PM

Quote:

Originally Posted by Shu71

Pollock, There is no way to tell if it did damage or not. If you had a couple hundred miles on it, then I would think the rings were already bedded in and you are fine. I am of the process like you but many times race engines are not built as tight as new factory engines. I build my Sportster engine, heat cycled it three or four times, then on a 20 degree night took it up the road wide open throttle through the gears a couple of times. That engine now has 30000 hard miles on it and never has burned a drop of oil and has outstanding cylinder pressure even after a long period of running nitrous on it.

You never know what the guys did to your car before you bought it either. I realize mine was new but it still had 17 miles on the car. They told me the service guys took it out and that I had to buy it to test drive it.

mulletman · 04-11-2011, 10:11 PM

Mine does the same thing. It scares me, but just a little bit.

Doc · 04-11-2011, 10:15 PM

It's the rear gunner picking off Mustangs and rice burners from the tail gunner position.

Bond · 04-11-2011, 10:27 PM

Quote:

Originally Posted by linkwpc

Its muscle car. Its doing what its supposed to do.

Word to that! Love that sound!!

GRYGUSS · 04-11-2011, 10:37 PM

Quote:

Originally Posted by GRYGOOS

I thought it was bad to engine break during the engine break in period of an LS3, something about letting the piston rings seal first? Consequently I haven't heard this sound yet as I've yet to downshift to slow down. Can anyone confirm as the OP may be doing his engine a disservice.

Sry man!!! There is only one GRYGUSS!!!!

04-11-2011, 03:05 PM	#100
Drago77 Treasure Coast Camaro 5 Drives: 19 2SS vert, Mosaic Blk, A10 Join Date: Feb 2009 Location: Stuart, Florida Posts: 4,562 View My Garage	Yup, normal. __________________ My build:http://www.camaro5.com/forums/showthread.php?t=132722 http://www.treasurecoastcamaro5.com

04-11-2011, 03:24 PM	#101
Shu71 Drives: 2011 Camaro RS M6 Join Date: Jan 2011 Location: Illinois Posts: 795	Throw a leg over many Harley's and downshift to slow down and you will hear real popping (decel rumble). It can be caused by a lean condition which in the case of the Camaro with Active Fuel Management apparently comes from GM reducing the fuel supply in decel. Letting the engine slow by using the gears is not neccesariliy a bad thing during break in provided it isn't extreme. It forces the piston rings to bed more quickly. Very hard full throttle accelerations from low rpms is much harder during break in because the rings are much hotter already from the bedding process and you risk microwelding the rings to the lands and then it will never perform to it's fullest potential. From what you describe though it doesn't sound like you are 'beating' on it during your downshifts so I'd say you are fine. I like rumble on decel but no popping. Harsh popping could be from an exhaust leak too. __________________

04-11-2011, 03:40 PM	#102
papabearcamaro Drives: 2012 Chevrolet Silverado 4x4 Z71 Join Date: Dec 2009 Location: WI. Posts: 1,744	Yup,normal and sounds like crap. One of the first things done when my car was in the shop was get that annoying sound tuned out. __________________ SOLD(Traded for 2012 Silverado Z71 4x4 and 2012 Sonic Hatch.)...2010 Camaro 1SS/RS/LS3,yellow with House of Kolor Tangerine Pearl rally stripes,manual trans.Hurst short throw shifter,4 pack rally gauges,Roto-Fab air intake,Kooks long tube headers with high-flow cats,Borla S-Type catback exhaust,Comp Cam,PRC ported heads,Maggie with 3.6 pulley and 1:1 cog drive,secondary fuel system with 65lb injectors,ADM digital A/F and Boost gauge,Pfadt trailing arms and subframe bushings.614.25rwhp/566.82rwtq on 8# of boost. 2012 Chevrolet Silverado 1500 EX.Cab 4X4 Z71.

04-11-2011, 04:07 PM	#104
cab2g love. my. car. Drives: 2011 2SS/RS Join Date: Jul 2009 Location: Chicago Posts: 3,372 View My Garage	I love the decel pop. __________________

04-11-2011, 04:09 PM	#105
xXSilencerXx Butter Bar! Drives: 2011 SS, 1998 Trans Am Join Date: Dec 2010 Location: Patrick AFB, FL Posts: 1,364	I like the noise personally. __________________ 2011 Camaro SS, White/Orange, LSR Short Throw, CAI 1998 Trans Am, Red, H/C/I, 3200 CircleD Stall, full suspension 2004 GSXR 1k, Matt Mladin Edition

04-11-2011, 04:20 PM	#106
Shu71 Drives: 2011 Camaro RS M6 Join Date: Jan 2011 Location: Illinois Posts: 795	Pollock, There is no way to tell if it did damage or not. If you had a couple hundred miles on it, then I would think the rings were already bedded in and you are fine. I am of the process like you but many times race engines are not built as tight as new factory engines. I build my Sportster engine, heat cycled it three or four times, then on a 20 degree night took it up the road wide open throttle through the gears a couple of times. That engine now has 30000 hard miles on it and never has burned a drop of oil and has outstanding cylinder pressure even after a long period of running nitrous on it. __________________

04-11-2011, 04:21 PM	#107
Synyster Drives: 2006 F150 Lariat Join Date: May 2010 Location: Florida Posts: 1,665	Decel pop = Awesome.

04-11-2011, 10:11 PM	#109
mulletman Drives: 2017 Camaro SS Join Date: Oct 2009 Location: southern Illinois trailer park Posts: 636	Mine does the same thing. It scares me, but just a little bit.

04-11-2011, 10:15 PM	#110
Doc Dances With Mustangs Drives: 2010 1SS/RS MT Join Date: May 2009 Location: USA Posts: 3,819 View My Garage	It's the rear gunner picking off Mustangs and rice burners from the tail gunner position. __________________ Blue Angel is here!! 1SS/RS LS3 M6 IBM

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