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Discussion Starter #1
So here’s the deal. I currently have a 4” turbo back exhaust. The down pipe fits like S#!T. It beats against the spring shackle and the trans dipstick tube. It is driving me crazy. A friend of mine that works for Dynomax got me a stainless turbo back system but the down pipe is only 3.5” and it necks down to 3” at the “cat” flange. The other side of the flange is the omit pipe and it goes up to 4” and that’s how big it is the rest of the way back to the tail pipe and then it has a five inch tip. I am definitely going to fix it where it necks down to 3” but the question is how much am I going to lose going to a 3.5” downpipe from the 4”? Would it be worth getting a 4” downpipe from another vendor and if so, who makes one that fits half way decent? Or should I just through the 3.5” Dynomax downpipe on and go with it? Decisions decisions.
 

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Discussion Starter #2
Wow. Either this was a retarded question or you people dont like me that much. lol Ya know the forum name is suposed to be funny, not offensive lol
 

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Stroke it B!tch
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Unless your pushing crazy power your only gonna hurt yourself with 4in. Some people notice a low end power loss with 4in. I would do the 3.5 or just keep the stock boy there really no need to have a down pipe bigger than you exhaust housing of the turbo.
 

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I have a MBRP 4" turbo back and was told there is no benefit to a 4" down. Mine came with a 3.5" down, runs and sounds great.
 

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Discussion Starter #5
thanks guys
 

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This is a never ending debate it seems but the 4 diamond eye do I have fits terribly
 

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:whs: my diamond eye was a PINA to put in...4" and saw no real change...maybe a little lower egt's
 

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6Leaker
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I never noticed any loss in low end power, going from stock to 4" downpipe and 5" system, but I certainly wouldn't argue any benefits over a 3.5" downpipe.

Mine is from Magnaflow and I have never had an issue with the downpipe fitting except for where it comes to the transmission crossmember, it rubbed the first bolt for a little while after it was first installed.
 

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Discussion Starter #10
I'll be installing the Dynomax downpipe this week sometime. Its seem to be the general concesus that it wont effect anything enough to notice. And I can get rid of that piece of s#!t thats on the old girl at the moment. Thanks for all the help fellas.
 

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I would put that 3.5" on just to not have to deal with any of the fitment problems people have.

From what my mechanic and I can tell, the one that is on my truck (on there when purchased) is the Magnaflow one and has literally rubbed a hole in one of the Y-pipes causing a leak there. Ill probably grab the MBRP 3.5" to throw on there for the extra clearance.
 

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Discussion Starter #12
Rubbed through your uppies. Than sucks man. well gives you the excuse to go high po on replacement uppies. lol
 

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My Diamond Eye 4" turbo back downpipe was the same...fit like chit, and almost rubbed right through the expansion/flex joint on the passenger side up pipe...also hit the shackle bolt on the leaf spring...and lastly...the damn cheap clamps pintched the downpipe to the point of having no adjustment afterwards...
Finally fixed it by moving the exhaust to the far passenger side fender...lol



(Twin turbos)
 

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Rubbed through your uppies. Than sucks man. well gives you the excuse to go high po on replacement uppies. lol
Yep. What sucks the most about it is you can hear the exhaust coming out of the hole. And then, if you arent moving and have the heat on, the exhaust smell comes right in the cab.
 

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Discussion Starter #15
Sounds like the 4" pipe isn't worth the trouble. I think the 3.5" will do just fine lol
 
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