Straight piped exhaust/state inspection

[CumminsPower98]

As some of you may have seen a few days ago I posted that I had just installed my new 4" Jardine exhaust in a straight pipe configuration. Well today I went down and got my state inspection so I could get my new registration stickers. They looked under my truck and said nice system and it sounds great but you must put a muffler on so we don't get in trouble if you are pulled over. That pretty much ruined my day right there. I then went to work and slapped the 4" straight through Magaflow muffler on that came with the exhaust kit. This is much too quiet for me and it takes all the fun out of driving. The turbo whine is only very slight now and it just dosn't have that big rig sound it had before.



Ok my questions are this: what can I do to make it a tad bit quieter and look like I have a muffler but yet still sound awesome. I would like to know what a good resonator would do for the system. Do you guys think this might do the trick? Or is there a better muffler that lets it be pretty loud still. I am leaning towards trying a 4" resonator. I read some place that Jardine sells these. Is that correct and has anyone tried this setup? Any thoughts on this would be greatly appreciated, as I really want my TRUCK back soon. :{



Thanks!

 

[LarryB]

Get your inspection and then swap back? I dunno, I'm lucky and have no inspections at all where I live.

 

[CumminsPower98]

Larry, I wish it was that simple but I go to this tire shop quite offten (flats from work and so on) and they know me so I feel they would be able to tell pretty easily that I had not done anything. Whatever I end up doing I will go to a different place for my next inspection I guess.

 

[LarryB]

Kinda like the unwritten rule of flight physicals. Never get one from your regular doctor.

 

[JIM S.]

walker muff

Look man! get a 4" straight though walker muffler from NAPA and put it on there... you know how mine sounds, megaflow's are really megaplug's! LOL just kidding:--) Jim

 

[bighammer]

Why not get a slightly smaller pipe to fit inside the muffler? It would be a "straight pipe" in a muffler wrapper

 

[CumminsPower98]

Good idea!

Good thinking bighammer. I had thought about that last night and now that you mentioned it too, I might just try it. One nice thing is that the muffler fits over the 4" pipe on both ends and is the same all the way through so I should be able to just shove a piece of 4" pipe in there. I can also cut it some to tune it and make it just a little bit quieter essentially making a really short muffler. I wouldn't mind if it was a tiny bit quieter anyway so off to the shop I go to make a "legal" straight pipe. LOL

 

[LarryB]

If it's too tight of a fit, just make a cut along the full length of the pipe going inside.

 

[CumminsPower98]

Well the muffler is flaired at the ends so I did have to cut the 4" pipe to fit inside. I cut it 2" short and centered it. I do not like it still. It does not have the deep sound I am looking for. It sounds more like a quieter version of a straight 3" or something. I would like to hear from someone with a 4" system and a 4" resonator only. I do have my good turbo sound back but the tone is just not to my liking yet. More thoughts out there???



Thanks for all the replies so far!

 

[Fireman Dave]

I went straight 4" from the stock resonator back. It sounds great. I also think the resonator may pass as a muffler to prying eyes. No inspection here, and I've never been pulled over in it, so I haven't tested this theory.

 

[HoleshotHolset]

What about you crazy sons/daughters of guns that have 4" downpipes going into 5" stacks with no mufflers?



I got pulled over last week (running a red light) and the policeman said: "Is this thing a diesel?"

I felt like saying: "No, it's a slant-6 with no GD oil in the crankcase!!!!" But I just said: "... yeah, it's a Cummins. "

He replies: "Oh... . so that's why it's loud?!"

I said: "Yeah, I guess so... it was like this when I bought it... "



Play dumb. And those gauges are just for towing... ...



Matt

 

[CumminsPower98]

Fireman dave, do you have any idea how the traight 4" compares to the 4" with a resonator?



Here is what I want: I want a deep/big sounding tone without a lot of bark and air turbulance sounds. I guess all I can do is to keep trying different setups until I get what I want and have it look leagal.

 

[LarryB]

FWIW

Could you get away with steping up to 6" pipe, go 2' and step back down to 4"? Might look like a muff and sound like you want. You only need two 4" to 6" adapters and 2 feet of 6" pipe.

 

[AggieJustin]

Texas regs?

So do any of you Texans out there know how the inspection regs here work with respect to straight pipe exhausts? I've heard conflicting stories on what will and won't pass inspection. And I haven't seen the regs lately.



My inspection is due in a month, so maybe I should just stay the way I am till I get the new sticker... then swap it and have a year to enjoy



Justin

 

[Fireman Dave]

Mark,



Wally19 did the same as me, but he went straight 4" to the turbo - no resonator. His is quite a bit louder, but it's also a SB, so a tad shorter. I think the resonator may help combat the dreaded drone, also. Mine is nice and deep, but not bad at all inside. It really snorts off the side of buildings, etc... I was glad it's not too noisy inside. It also sounds great at idle - you can really hear the turbo whine through the pipe. By the way, the whole job cost me only $100. That includes the 4" Walker tailpipe and a cool 5" chrome tip (that's meant for a motorhome).



Dave

 

[JIM S.]

Hey

I just rememberd that somewere I read that a turbo is a DOT approved muffleing device... ... anyone heard of this???? seems like I read it on here(TDR) HMMMMM!! Jim

 

[CumminsPower98]

Well thanks for all the replies! I think I am going to call up Jerry Jardine and see about getting a 4" resonator. I wouldn't mind getting rid of the 2200 rpm drone. If the resonator quiets the system a little but still flows well and keeps the deep sound and turbo whine then I'm a happy camper.

 

[HoleshotHolset]

Jim,

I heard something similar to what you said too.....

I know for a fact that turboes quiet things down a LOT... . afterall we are squeezing a lot of exhaust gasses through some odd passageways and this quiets things down quite a bit.



I've heard that the class-8 trucks can get away with straight-pipes as long as they don't go to CA... . but this might be folk rather than fact.



Matt

 

[BHaner]

USFS says....

A turbo is an acceptable spark suppressant device. Never known it was a muffler as well!

 

[Briar Hopper]

Twin turbos will quiet it down a bit. More expensive than a fake muffler, but faster.

I've never worried about mine that much, even running a shortie 4" that ends just shy of the bed front, and I live in a state that has more cops on the road than a hive full of bees.