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itsallgood
Member
Thinking of adding 4" exhaust to my Duramax to lower towing egts. Heard it doesn't make much of a difference @ elevation. tow between 6'-13k. Anyone have before & after results?
4" exhaust @ elevation
- Thread starter itsallgood
- Start date
No results on paper, but from every forum I've ever read from even with over 10K lbs you should expect to see a couple hundred degree drop from stock. Not a Dmax, but both my buddies Dodges dropped 150 degrees while just driving around town. Need to get guages on my Dmax cause I have a 4" Magnaflow setup. Pretty much like any other motor there are only benefits to creating less exhaust restrictions. Hope that helps tho.
racer
racer
exhaust
I have a 04.5 duramax. definately noticed a difference with the aftermarket exhaust and cat delete. noticed an even bigger egt diff with the diamond eye downpipe. more with the downpipe than the exhaust.
I have a 04.5 duramax. definately noticed a difference with the aftermarket exhaust and cat delete. noticed an even bigger egt diff with the diamond eye downpipe. more with the downpipe than the exhaust.
I know on my 7.3, just deleting the muffler and shortening up the exhaust, its still stock 3" dp but then 3.5 to 4 out the side, things were a LOT happier, boost rolls on smoother and about 100+ degree egt drop messing around empty, downpipe should be even better.
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itsallgood
Member
Sounds like you recommend doing the downpipe first? Did you notice it would spool up quicker? I have the Edge juice, PPE boost valve, airbox mod, & ported turbo inlet mod already & its still a dog off the line.
Had good results with 4" turbo back on my 01 and 03 Cummins.
Put a 4" MBRP system in my buddies 07 LBZ and it made a nice difference. The Duramax stock exhaust has some weird restrictive kinks in pipe right after the downpipe.
I would say its worth it.
I'm at 5000 ft elevation FYI.
Put a 4" MBRP system in my buddies 07 LBZ and it made a nice difference. The Duramax stock exhaust has some weird restrictive kinks in pipe right after the downpipe.
I would say its worth it.
I'm at 5000 ft elevation FYI.
Exhaust helps at any altitude.
If you are going to spend the money and time why wouldn't you do a 5" turbo back system?
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itsallgood
Member
Did you also do the turbo back or downpipe back? Whats a safe EGT to continuously tow @ .... 1200? Do the MBRP & Diamond eye sound about the same? Just want the lower egts not the added sound.
Just got on it on a on ramp & only saw 16psi @ 6'. Seems low, what kind of boost are you guys seeing @ elevation?
International and Cummins say 1200 EGT (pre turbo) can be sustained with no limits. Mack says 1250.
The "guidelines" that many follow are:
1200 or under, no worries
1300 for no more than 1 minute out of 5
1400 for no more than 30 seconds every 5 minutes
1500+ no more than 10 seconds every 10 minutes
Me personally, if I see more than 1300, it is time to back out...
The "guidelines" that many follow are:
1200 or under, no worries
1300 for no more than 1 minute out of 5
1400 for no more than 30 seconds every 5 minutes
1500+ no more than 10 seconds every 10 minutes
Me personally, if I see more than 1300, it is time to back out...
My limit was set at 1280, now I rarely see 1150. I was headed out of town and had a local throw on a downpipe back with a Hi-Flow muffler. It's not any louder, but now the turbo whistles.
I went four rather than five because my truck sees more dirt than pavement. I have already smashed my 4" tailpipe twice. It dropped my temps to where I wanted, no need for more.
I went four rather than five because my truck sees more dirt than pavement. I have already smashed my 4" tailpipe twice. It dropped my temps to where I wanted, no need for more.
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itsallgood
Member
To veer off topic a little I recently had an emissions test. I paid an extra 25.00 to have the guy turn up the edge to #3 & run it. Level 3 should add 75hp. It netted 30 more hp @ the wheels over stock @ 6k’. I’m running 35’s & the guy said that was good considering the larger tires.
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badass1000
Well-known member
Because 5" is too loud and sounds like ****. If you make over 500hp at the wheels and it makes a performance improvement over the 4" then sure. Go with 5".
I don't seem to notice it on duramax's, but I hear mostly dodges and some fords with 5" and it is really loud and ****y sounding. Even just driving around normaly it is too loud and crapy sounding.
I don't get every ones obsesion with smoking either. Smoking does not = hp. it means your truck is not tuned correctly. I know dodges don't have efi live so they can not tune them to run high hp and not smoke without a standalone, but come on. Yes their are some really fast trucks that smoke, but some of the fastest duramaxs I have ever seen don't smoke very much. I have seen duramax's run 9's and not blow much smoke and I have seen dodges smoke the whole track out and run 14's.
I was on the interstate today and their was a duramax getting on it in and out of trafic blowing smoke every where. (maybee he had some bad injectors) got up next to him and layed on it. watched him in the rear view droping back blowing smoke every where. My duramax blows a little smoke hear and their when I first punch it, but then it clears out and does not blow any black smoke. I know some intentionally tune their truck to blow alot of smoke. Yes it is cool some times, but you never know who it was you just smoked out and what they do, and can do to effect all the emisions crap we have to deal with on new diesel pickups.
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Rattlin_Ram
Active member
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Rattlin_Ram
Active member
The N20 and twins help that a lil bit...
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badass1000
Well-known member
I have seen a duramax on nitrous runing 12's I believe and he smoked the whole track out.
I am not up 100% on diesels. I drag race street legal motorcycles. I just have a bunch of boltons/minor mods and preditor on my lly.
Can you run a bunch of nitrous and not smoke? I believe so. Smoke is just excess fuel right?
It just pisses me off when something blows alot of smoke. It is like a 16 second honda with a open header to me. Or those damn JR dragsters. Loud as **** and slow.
Honda and JR dragster could have full exhaust and muffler and not really effect performance. Diesel truck could blow no smoke or little smoke and still run the same times if tuned correctly.
I don't mind if it is fast and loud. Your not going to put a exhaust and mufflers on a nitro car. I don't mind the smoke as much at the drag strip or tractor pulls. But it kind of pisses me off to see it on the street. I have watched dodges blow smoke all over the damn place just driving a normal pace. It is like a harly. makes a lot of noise (smoke), but goes no where.
Sorry for the rant.
I am not up 100% on diesels. I drag race street legal motorcycles. I just have a bunch of boltons/minor mods and preditor on my lly.
Can you run a bunch of nitrous and not smoke? I believe so. Smoke is just excess fuel right?
It just pisses me off when something blows alot of smoke. It is like a 16 second honda with a open header to me. Or those damn JR dragsters. Loud as **** and slow.
Honda and JR dragster could have full exhaust and muffler and not really effect performance. Diesel truck could blow no smoke or little smoke and still run the same times if tuned correctly.
I don't mind if it is fast and loud. Your not going to put a exhaust and mufflers on a nitro car. I don't mind the smoke as much at the drag strip or tractor pulls. But it kind of pisses me off to see it on the street. I have watched dodges blow smoke all over the damn place just driving a normal pace. It is like a harly. makes a lot of noise (smoke), but goes no where.
Sorry for the rant.
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