Engine Pop question
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Cruiser
Joined: Dec 2010
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From: Abu Dhabi
Engine Pop question
Im planning to do some engine work and have been reading alot lately on the different options but the current setup im running causes a loud pop between shifts when going flat out.
Im running the vance and hines air cleaner and vance and hines big radius 2 into 1 with no tune so far.
When running against a rocker with the same set up but with a powercommander i left him in my dust. There was no comparison which is strange because the tune should improve the performance as far as i know.
What are your thoughts/suggestions on this? im thinking of replacing the vance and hines cleaner to the screaming eagle heavy breather and power commander and having it dynod.
Also, how bad is the pop for the engine because it turns alot of heads
Thanks
Im running the vance and hines air cleaner and vance and hines big radius 2 into 1 with no tune so far.
When running against a rocker with the same set up but with a powercommander i left him in my dust. There was no comparison which is strange because the tune should improve the performance as far as i know.
What are your thoughts/suggestions on this? im thinking of replacing the vance and hines cleaner to the screaming eagle heavy breather and power commander and having it dynod.
Also, how bad is the pop for the engine because it turns alot of heads
Thanks
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Joined: Oct 2009
Posts: 682
Likes: 1
From: In the World
Plus one on oct1949....
But...given your mods...and u r using factory ECM....more than likely cause is "afterfire" which happens in the exhaust and not "backfire" which happens on the intake side. Afterfire pop is annoying....but not damaging. Backfire will blow up an intake.
I bet this started when you took off the factory pipes...now you no longer have a cat and some sunburned mixture is getting ignited when flame blows past a closing exhaust valve. Also...happens more when engine is lean....high AFR...and when timing is advanced a bit too far. No doubt you are lean...factory ECM runs lean....and a stage 1 setup makes it even leaner....I suspect u may also have predetonation...which is bad thing. Some "turners" aka aftermarket ECMs...allow you to cut fuel supply while acceleration from when it starts (high rpm point) to when it quits (low rpm point). I have a zippers Thundermax with that capability...but I am certain other units do also.
I used to street race cars in my younger dumber years...sometimes less powerful cars are left in the dust ....even in a drag race...by the better...bolder driver....lots of the time.
But...given your mods...and u r using factory ECM....more than likely cause is "afterfire" which happens in the exhaust and not "backfire" which happens on the intake side. Afterfire pop is annoying....but not damaging. Backfire will blow up an intake.
I bet this started when you took off the factory pipes...now you no longer have a cat and some sunburned mixture is getting ignited when flame blows past a closing exhaust valve. Also...happens more when engine is lean....high AFR...and when timing is advanced a bit too far. No doubt you are lean...factory ECM runs lean....and a stage 1 setup makes it even leaner....I suspect u may also have predetonation...which is bad thing. Some "turners" aka aftermarket ECMs...allow you to cut fuel supply while acceleration from when it starts (high rpm point) to when it quits (low rpm point). I have a zippers Thundermax with that capability...but I am certain other units do also.
I used to street race cars in my younger dumber years...sometimes less powerful cars are left in the dust ....even in a drag race...by the better...bolder driver....lots of the time.
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Joined: Oct 2009
Posts: 682
Likes: 1
From: In the World
Please disregard my earlier post...this damn phone makes incorrect corrections....and mobile HD forum won't allow editing.
Given your mods...and u r using factory ECM....more than likely cause is "afterfire" which happens in the exhaust and not "backfire" which happens on the intake side. Afterfire pop is annoying....but not damaging. Backfire will blow up an intake.
I bet this started when you took off the factory pipes...now you no longer have a cat and some unburned mixture is getting ignited when flame blows past a closing exhaust valve. Also...happens more when engine is lean....high AFR...and when timing is advanced a bit too far. No doubt you are lean...factory ECM runs lean....and a stage 1 setup makes it even leaner....I suspect u may also have predetonation...which is bad thing. Some "turners" aka aftermarket ECMs...allow you to cut fuel supply while de-acceleration from when it starts (high rpm point) to when it quits (low rpm point). I have a zippers Thundermax with that capability...but I am certain other units do also.
I used to street race cars in my younger dumber years...sometimes less powerful cars are left in the dust ....even in a drag race...by the better...bolder driver....lots of the time.
Given your mods...and u r using factory ECM....more than likely cause is "afterfire" which happens in the exhaust and not "backfire" which happens on the intake side. Afterfire pop is annoying....but not damaging. Backfire will blow up an intake.
I bet this started when you took off the factory pipes...now you no longer have a cat and some unburned mixture is getting ignited when flame blows past a closing exhaust valve. Also...happens more when engine is lean....high AFR...and when timing is advanced a bit too far. No doubt you are lean...factory ECM runs lean....and a stage 1 setup makes it even leaner....I suspect u may also have predetonation...which is bad thing. Some "turners" aka aftermarket ECMs...allow you to cut fuel supply while de-acceleration from when it starts (high rpm point) to when it quits (low rpm point). I have a zippers Thundermax with that capability...but I am certain other units do also.
I used to street race cars in my younger dumber years...sometimes less powerful cars are left in the dust ....even in a drag race...by the better...bolder driver....lots of the time.
Elite HDF Member
Joined: Aug 2008
Posts: 4,133
Likes: 125
From: Japan
+1. Better mods or build cannot compensate for a lack of drag racing "skills".
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Joined: Oct 2009
Posts: 682
Likes: 1
From: In the World
Indeed brother...I learned that fact on some straight flat roads in Virginia many decades ago....
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