Ford Powerstroke Diesel Forum banner

Turbo back vs. Cat Back

5K views 24 replies 10 participants last post by  WVRidgeRunner 
#1 ·
Next on my to do list after intake is exhaust, I was looking at diamond eyes. What are some pros and cons of turbo back and cat back systems. Also straight pipe or muffler?

Any advice on tips or is it more of an appearance thing?
 
#2 ·
If you don't live anywere that its gonna be a emission inspection issue Id say go for a turbo back set up. You might as well get the cat outta there and free up the exhaust as much as possible.
Im running (on a 6.0) diamond eye's 5" turbo back straight pipe set up. Was very easy to install and its not as loud as you would think. On a gasser it would drive you out of the truck.But in the 6.0 is pure mechanical music.
 
#5 ·
Call your local dmv or visit your friendly smog guy to find your inspection rules. They should be able to tell you what you need based on your vin and underhood markings
 
#6 ·
am I the only person who's never seen a 7.3 with a cat :dunno:

when you bought it did you have to get it inspected for emissions, I would guess not being in Wisconsin. If not get a turbo back kit.
 
#7 ·
I forget who told me but someone on here said autos did not come with a cat therefore they won't be required for inspection but SOME manuals did. That's for for thought, I cannot say wether it is fact or not.
 
#11 ·
turbo back diamond eye.

cheap, easy install, and mine is holding up good. my dads too

i have to smog my truck and they had no issue with turbo back system, but my truck did not come with a cat.

if you dont need to smog your truck and it has a cat, just put 4 inch turbo back on and save the cat just in case.

the downpipe is pretty restrictive on these, but not as bad as an OBS downpipe lol

as far as muffler vs no muffler, very little restriction getting a system with a muffler.
it does cut down on noise.

my truck is straight piped my dad has muffler on his, but his still sounds deep and you can still hear more turbo whistle than stock.
 
#13 ·
i had to smog mine its a 99.
98 and up required for smog, they have obd2 plug in is why.

if you do not have a cat from the factory, you can do turbo back straight pipe.
my truck was not equipped with a cat from the factory so i passed smog with straight pipe.
 
#15 ·
all 6.0's came with cats if im not mistaken. so you would need it to pass smog.
 
#17 ·
In California, yes. Just like with a gas engine ALL smog items MUST be on the vehicle for it to pass. The only difference is some diesels are inspection only and do not require an emissions test, my suggestion is unless you are 100% sure which you're in wait until you have to do a test then go from there, could save you a huge pain in the a$$ having to trek to find the pieces so you can go pay for a second inspection.
 
#18 ·
ok that all sounds like sense to me...well ive heard about all the problems that EGR coolers can have and what they can do to your engine and so i dont want the EGR to go bad and screw up my truck....should i just replace the EGR with an aftermarket one in stead of putting an EGR delete on just to be safe with the smog laws??
 
#19 ·
i would replace it with an upgraded unit, but that technically isnt smog legal either :rofl:

but they wont know the difference between egr coolers.
 
#20 ·
HAHAHAHAHAHA!!!!......dang these smog laws suck:mad:
ok i get it...you own a diesel truck in California so what did you do to get good performance and to keep the engine in good condition but also pass smog??...im looking to you man...your about the only one that understands what im trying to get at because these other guys that live out in the middle of America dont have these laws:rofl:
 
#21 ·
The biggest thing with CA smog is looks if you're just an inspection like my 02 is. If you have anything newer (6.0 and beyond) then you will most likely have to do a running test.
As far as any chips or programmers, as long as there is a stock setting you should be fine, for anything else, is has to look legit and/or have a CARB (California air resources board I think) certification. Your EGR change shouldn't be a big deal because it will look clean but a delete probably won't pass if the inspector knows what to look for, a lot of them don't as even still slogging diesels is relatively new.
One option you have is to take you truck in for a pre inspection, most smog joints will run your truck on the manual setting to see where it sits before doing a certified one which gets sent to Sacramento (DMV). This is usually a little cheaper and will save you from possibly having a gross polluter (not good!)
The other option you have (and as a state official I cannot recommend this) is a "hot" smog. DO NOT GO TO A SMOG SHOP AND REQUEST THIS! But that being said, if you know a guy who knows a guy it is doable.
The final option is your local laws, different areas have different smog regulations. Of the three counties around me there are 3 different ways of doing things. My county is a dyno county, another is a stationary rpm county (1500 and 2500 rpms) and the third is a no smog at all county (only during sales).

Check your local ordinances and talk to people in your area who have diesels and see what they have done. Look for that punk kid in his 20s and talk to him (he will most likely be able to tell you exactly what daddy paid for) (not all of them were daddy paid for! I don't want to offend anyone!), he's the one with the painted undercarriage, 20 inch tip, fully blacked out windows, and this time of year, has mud all over it from every weekend of going out to the local off road park. Also look for the firemen (I'm one of these), we are usually pretty well identified with a sticker or license plate, most if us know what we can get away with or know a guy who knows a guy.
 
#22 ·
ok thats cool...well i wanna get a lot of performance and open up the whole exhaust as much as i can but i guess i still have to follow the law but yeh....ill try to ask a few guys around here and find out whats up....i expect i could find a few guys that know a few guys....ive done that before:rofl:.....i just live in the east bay area and i dont know much as to the diesel smog laws and so ill find out....ive seen a few of those hard core guys in there 20's around here and so ill chat it up with one of those guys....hey man thanks for your help though...:thumb:....
 
#23 ·
I scored a 4" turbo back insynerator exhaust on amazon for under $300 to the door, it has a "muffler" that more or less is for looks. It's straight thru inside. In WV we don't do smog, but every now and then the inspectors get cranky if you don't have anything that looks like a muffler.
 
#24 ·
you can get diamond eye system for 250...hope you didnt pay much more than that!

and you dont need a muffler, unless your nosie ordinance is strict.
 
#25 ·
Mine was stainless from the turbo to the tip. Couldn't find a Diamond eye at that price in stainless, plus have to pass DOT inspection, so have to at least give the impression that there's a muffler :)
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top