4" vs. 5"
03-02-2007, 02:30 PM
#16
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coonrod, If you on big mods I would run 5". I run 5" to keep egts down but I dont think it dropped egts 200.mine spools a little slow and it has alot of drone under a load (pulling a trailer). I have a 5" downpipe all they way straight piped. I like the deeper tone than 4", its not so raspy sounding. Its pretty deep and I like the looks of the big pipe also. thats my 2cents
03-02-2007, 06:43 PM
#23
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Lark ......you made me laugh. That was good.
Not planning on big mods just eventually a turbo.
Well I may go ahead get the 5" on the way. If I might see a drop in EGT's and definetly will hear a deeper tone.
And no, I am not to old... I like it loud, but not a loud drone.
Thanks for the reply's, keep them coming
Not planning on big mods just eventually a turbo.
Well I may go ahead get the 5" on the way. If I might see a drop in EGT's and definetly will hear a deeper tone.
And no, I am not to old... I like it loud, but not a loud drone.
Thanks for the reply's, keep them coming
03-02-2007, 07:58 PM
#24
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4" vs. 5"
I've struggled with this for a long time. My wife says she prefers the 4" because the 'drone' is not as obvious; but my girlfriend says she really can't tell the difference with 5". My wife swears it's not so much the size of the exhaust that makes the difference, but how I drive the vehicle. I tend to agree with her because when my girlfriend is riding along she says her ex-boyfriend had 5" and it did not give the same seat-of-the-pants feel that my 4" gives. Another plus for the 4" is she said there's less back-pressure than she's experienced with the 5" exhaust, which means she noticed higher levels of performance. After giving this a lot of thought, and discussing it with both parties, my wife thought the money would be better spent on stacked modules and my girlfriend voted for the upgraded injector pump that doesn't run dry after a hard launch.
I've struggled with this for a long time. My wife says she prefers the 4" because the 'drone' is not as obvious; but my girlfriend says she really can't tell the difference with 5". My wife swears it's not so much the size of the exhaust that makes the difference, but how I drive the vehicle. I tend to agree with her because when my girlfriend is riding along she says her ex-boyfriend had 5" and it did not give the same seat-of-the-pants feel that my 4" gives. Another plus for the 4" is she said there's less back-pressure than she's experienced with the 5" exhaust, which means she noticed higher levels of performance. After giving this a lot of thought, and discussing it with both parties, my wife thought the money would be better spent on stacked modules and my girlfriend voted for the upgraded injector pump that doesn't run dry after a hard launch.
03-03-2007, 01:16 PM
#25
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The smaller (4" instead of 5") exhaust on moderately BOMBed trucks helps keep flow velocity higher, evacuating the post-turbine tubing more quickly, thus increasing the pressure differential across the turbine, which improves it's efficiency and ability to perform work - turning the impeller.
Above a certain HP level - probably 600, definitely 700+, 5" exhaust should work better.
Above a certain HP level - probably 600, definitely 700+, 5" exhaust should work better.
03-03-2007, 08:24 PM
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The smaller (4" instead of 5") exhaust on moderately BOMBed trucks helps keep flow velocity higher, evacuating the post-turbine tubing more quickly, thus increasing the pressure differential across the turbine, which improves it's efficiency and ability to perform work - turning the impeller.
Above a certain HP level - probably 600, definitely 700+, 5" exhaust should work better.
Above a certain HP level - probably 600, definitely 700+, 5" exhaust should work better.
03-04-2007, 09:44 AM
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Shane
03-04-2007, 11:09 AM
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Does she like it better??
Does anyone have any infomation regarding the difference of using a 4" or 5" exhaust system on a heavy modified diesel? What are the pros and cons? Does the fact of reduced back pressure using the 5" reduce spool up? Does it help top end? Anyone have dyno results comparing the two? Trying to decide to leave things alone or go to 5"???
We all know chicks love the 5" compared to the 4", however, will my truck really like it more??? I just want to keep pleasing her to get the best performance from her..( the truck that is ).
Thanks,
We all know chicks love the 5" compared to the 4", however, will my truck really like it more??? I just want to keep pleasing her to get the best performance from her..( the truck that is ).
Thanks,