4" down pipe?
#16
05-20-2018, 09:44 AM
#17
05-20-2018, 10:09 AM
That was 15 years ago, so no I don't. Lots of things have changed with the 6.0 since then. I beta tested a LOT of parts and a LOT of tunes to help get the 6.0 performance stuff to where it is now. Granny truck is tired (and retired) and all she does is haul grandkids now.
#18
05-20-2018, 03:31 PM
On the down side....
the 4 inch offers no benefit, the 3.5 helps with back pressure on the turbo which is necessary and performs better. Stock is 3 inch with a resonator for my 2003. If you want the 4 inch down to fit, you may have to hammer back the pinch welds on the cab to keep it from rubbing.
the 4 inch offers no benefit, the 3.5 helps with back pressure on the turbo which is necessary and performs better. Stock is 3 inch with a resonator for my 2003. If you want the 4 inch down to fit, you may have to hammer back the pinch welds on the cab to keep it from rubbing.
#19
05-20-2018, 04:52 PM
#21
05-20-2018, 07:50 PM
Be it only short term, the 4" will offer a lower temp, not much, so you gain lower EGT for a short but turbo lag is the trade off on the lower end over a 3.5 which improves turbo spool up. I and several others, spent time on the DYNO when nothing was really available in the early days, the final decision is what makes you happy. My truck puzzled plenty of people at the time but I have an 03, which in turn seems to be the best year for me. I have probes before and after the turbo to see how it performed, you would be hard pressed to find anyone else who monitors the back side of a turbo.
#22
05-20-2018, 07:58 PM
#23
05-20-2018, 08:00 PM
#24
05-20-2018, 08:18 PM
#25
05-21-2018, 11:46 AM
Well, drove to work this morning 1hr at hwy speeds.
There was no obvious performance gains or loss that I could tell. I really did it to hopefully lower egt.
Im not really happy with it because of the extra noise. Not sure because it's up against the firewall or it's just the way a 4"down pipe sounds. I'll give it a few days and see what happens. I may reinstall the oem down pipe and go 4" from there.
There was no obvious performance gains or loss that I could tell. I really did it to hopefully lower egt.
Im not really happy with it because of the extra noise. Not sure because it's up against the firewall or it's just the way a 4"down pipe sounds. I'll give it a few days and see what happens. I may reinstall the oem down pipe and go 4" from there.
#26
05-21-2018, 11:56 AM
#27
05-21-2018, 01:57 PM
Hotshot
Currently in a similar conundrum myself, after years of driving a 7.3 I'm really enjoying how quiet my 6.0 is and don't want to increase the in-cab noise. Currently my truck has a stock exhaust but looking into options, main duties will be some daily driving and occasional towing of 5-6k. I'm thinking 3.5" down pipe to 4" with some sort of a good quality muffler at this point, anyone with insight that would suggest I'm leaning the wrong way?
#28
05-21-2018, 03:17 PM
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There is no audible sound difference between the 3.5 and 4.0 downtube. If you are hearing any type of additional sound, its probably the installation that is to blame. The slightly larger size is not significant but will help slightly with your EGT. That's really all there is to it.
If your installing a new exhaust system, by all means go with the 4" downpipe.
If your installing a new exhaust system, by all means go with the 4" downpipe.
#29
05-21-2018, 03:54 PM
There is no audible sound difference between the 3.5 and 4.0 downtube. If you are hearing any type of additional sound, its probably the installation that is to blame. The slightly larger size is not significant but will help slightly with your EGT. That's really all there is to it.
If your installing a new exhaust system, by all means go with the 4" downpipe.
If your installing a new exhaust system, by all means go with the 4" downpipe.