Lingenfelter ZL1 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Annatar · 01-04-2018, 10:59 AM

Apologies in advance if this has already been asked, or if there is a better place to ask this (in which case please move).

A buddy of mine owns a stage 2 Lingenfelter ZL1. He has a manual toggle switch installed in the console for controlling the exhaust flaps.

He's concerned about engine damage (because he has the stage 2 done to the engine) if he drives the car hard with the exhaust flaps closed, and has asked me to research it for him.

Is there any possibility of engine damage when flooring it with closed exhaust flaps?

ZMEnow · 01-04-2018, 11:24 AM

Quote:

Originally Posted by Annatar

Apologies in advance if this has already been asked, or if there is a better place to ask this (in which case please move).

A buddy of mine owns a stage 2 Lingenfelter ZL1. He has a manual toggle switch installed in the console for controlling the exhaust flaps.

He's concerned about engine damage (because he has the stage 2 done to the engine) if he drives the car hard with the exhaust flaps closed, and has asked me to research it for him.

Is there any possibility of engine damage when flooring it with closed exhaust flaps?

It was already designed to open under WOT before putting a Mild to WIld switch on it so why would he go WOT with it closed? If it's because its to loud then take the ticket or don't do it.

He is running a 10% lower and 2.55 upper, plus a 629/656 cam, so you are adding tremendous boost with longer value duration and then plugging the exhaust and asking for a part of the CAT to come back in to the Heads because its open longer. Or maybe not

Annatar · 01-04-2018, 12:39 PM

He doesn't have a Mild2wild controller, that's why he's unsure.

The switch appears to be an on-off switch of some sort, rather than a simple F8 cut-off. We haven't yet reverse-engineered how it works or ran tests because the car is in the garage for the Winter.

gmorris · 01-04-2018, 02:32 PM

There is no danger to the engine t run with the flaps closed. Lots of people do it once catless to cut down the noise. Worst case is a slight addition to backpressure and miniscule power loss but likely not noticeable.

ZMEnow · 01-04-2018, 03:36 PM

Quote:

Originally Posted by gmorris

There is no danger to the engine t run with the flaps closed. Lots of people do it once catless to cut down the noise. Worst case is a slight addition to backpressure and miniscule power loss but likely not noticeable.

Lots of people do it once catless .. That's the Key.. Just sharing what GM warranty is seeing come back in..

crazydave · 01-04-2018, 04:34 PM

Quote:

Originally Posted by gmorris

There is no danger to the engine t run with the flaps closed. Lots of people do it once catless to cut down the noise. Worst case is a slight addition to backpressure and miniscule power loss but likely not noticeable.

I ran the 1/4 once with the flaps forced closed by accident. Cost me maybe a full .1 at the most. The increase to the back pressure is minimal.

gmorris · 01-04-2018, 04:46 PM

Quote:

Originally Posted by ZMEnow

Lots of people do it once catless .. That's the Key.. Just sharing what GM warranty is seeing come back in..

So you think the engine is going to suck the cats back up through the primary, through the valves and into the chamber? I'd love to see one example of that. Increased back pressure doesn't mean massive vacuum. I have run mine (600whp) with cats and flaps closed hundreds of times. Choosing to not have an obnoxious car doesn't mean that you aren't allowed to have a fast car lol.

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ZMEnow · 01-04-2018, 04:53 PM

Quote:

Originally Posted by gmorris

So you think the engine is going to suck the cats back up through the primary, through the valves and into the chamber? I'd love to see one example of that. Increased back pressure doesn't mean massive vacuum. I have run mine (600whp) with cats and flaps closed hundreds of times. Choosing to not have an obnoxious car doesn't mean that you aren't allowed to have a fast car lol.

Sent from my SM-G950W using Tapatalk

Yes I have been shown examples of the LSA sucking pieces of a failed cat back up. Until the CAT completely fails those pieces have nowhere to go but sit on the front side of the CAT.

gmorris · 01-04-2018, 04:57 PM

Quote:

Originally Posted by ZMEnow

Yes I have been shown examples of the LSA sucking pieces of a failed cat back up. Until the CAT completely fails those pieces have nowhere to go but sit on the front side of the CAT.

Ok, assuming that's possible, do you really think that whether the exhaus flaps were open or closed would have made any difference?

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ZMEnow · 01-04-2018, 07:10 PM

Quote:

Originally Posted by gmorris

Ok, assuming that's possible, do you really think that whether the exhaus flaps were open or closed would have made any difference?

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Yes or I wouldn't have posted it.

stratman2SSRS · 01-04-2018, 07:40 PM

Probably a good idea to call Lingenfelter and ask them what they think.
Its probably not a big deal.

ZO6 Bryan · 01-04-2018, 09:18 PM

Quote:

Originally Posted by ZMEnow

Yes I have been shown examples of the LSA sucking pieces of a failed cat back up. Until the CAT completely fails those pieces have nowhere to go but sit on the front side of the CAT.

Never happen.

gmorris · 01-05-2018, 08:20 AM

Quote:

Originally Posted by ZMEnow

Yes or I wouldn't have posted it.

That's what I'm afraid of...others might read it and believe it too.

ZMEnow · 01-05-2018, 08:34 AM

Quote:

Originally Posted by ZO6 Bryan

Never happen.

Certainly wouldn't intentually bring bs to this site. I got this from one of the of GM warranty claims approvers who is a trusted friend and significant racer.

01-04-2018, 10:59 AM	#1
Annatar Drives: ZL1 six speed manual Join Date: Jan 2018 Location: Middleearth Posts: 135	Lingenfelter ZL1 Apologies in advance if this has already been asked, or if there is a better place to ask this (in which case please move). A buddy of mine owns a stage 2 Lingenfelter ZL1. He has a manual toggle switch installed in the console for controlling the exhaust flaps. He's concerned about engine damage (because he has the stage 2 done to the engine) if he drives the car hard with the exhaust flaps closed, and has asked me to research it for him. Is there any possibility of engine damage when flooring it with closed exhaust flaps?

01-04-2018, 02:32 PM	#4
gmorris Drives: 2015 ZL1, Red Hot A6 Join Date: Aug 2016 Location: Calgary Alberta Posts: 40	There is no danger to the engine t run with the flaps closed. Lots of people do it once catless to cut down the noise. Worst case is a slight addition to backpressure and miniscule power loss but likely not noticeable. __________________ 2015 Red Hot ZL1, Rotofab, Kooks LT's, 10" lower, ID850's, JMS BAP, BTR stage 3 torque cam, meth injection, self tuned with HPtuners 1969 Chevelle, 418 LS3, Ridetech suspension

01-04-2018, 07:40 PM	#11
stratman2SSRS Drives: Lingenfelter Camaro Join Date: Apr 2009 Location: Ontario Posts: 2,160 View My Garage	Probably a good idea to call Lingenfelter and ask them what they think. Its probably not a big deal. __________________

01-04-2018, 12:39 PM	#3
Annatar Drives: ZL1 six speed manual Join Date: Jan 2018 Location: Middleearth Posts: 135	He doesn't have a Mild2wild controller, that's why he's unsure. The switch appears to be an on-off switch of some sort, rather than a simple F8 cut-off. We haven't yet reverse-engineered how it works or ran tests because the car is in the garage for the Winter.