Another Exhaust question

[65-f100]

Ok - let me get some input from some of you on this idea. I know the biggest restrictions seem to be the downpipe, cat, and muffler. If I get a nice mandrel-bent downpipe (3") from one of the suppliers and have the rest of the system done locally in non-mandrel bent 4" - eliminating the cat and getting a nice flowing muffler - wouldn't this be as good as a mandrel bent 3.5"? Understand this is not a highly-modified truck and from what I've read - 4" seems to be overkill anyway. I can get this done by a good local shop - he just does not have a mandrel bender. I actually haven't been able to find ANY exhaust shop around that does. Please give me some input on this - it would be a good bit easier (and cheaper) than buying a full system and paying the shipping and then paying to have it installed (I hate exhaust work!)

[Spindrift]

I would go to a performance/speed shop instead of a regular muffler/brake shop. They might be able to recommend someone that could do it. I'd even try a commercial truck shop, or dealership. I would think the less turbulence, the better, and that's what mandrel bending provides. The extra effort it might take to find someone that can do the work will be well worth your time. There are certainly those folks who believe 4" is overkill, but I'm not one of them. If nothing else, 4" provides a deeper tone, which I like. IIRC, I paid about $75 - $100 more for the 4" material.

[65-f100]

I did check with the performance shops. One told me he didn't know of anyone in SC that did it which I found hard to believe. Anyway - I know mandrel bent is the best because it is tru diameter through the bends and reduces turbulence as you mentioned. However - is it truly going to make a noticable difference in my Suburban?

[Spindrift]

I replaced my entire system all at one time. I was amazed by the increase in performance. Talk about "seat-of-the-pants"...my pants left the seat. Can't honestly say if it would have been any different if I had installed a 3.5" system versus the 4" system I selected. I can tell you with absolute certainty, since I've heard a couple of 3.5" systems, that there is a deeper, more big rig like sound with the 4".

Someone correct me if I'm wrong. Doesn't the Suburban system have more bends than the pickumups of the same vintage? Certainly the DMax has less. If the Burb does have more bends, and assuming the flow rate is the same for the two pipe sizes, then turbulence will be less in the 4" pipe, which equals better perfomance. Heck, technically speaking, better performance regardless of it being a Suburban or not. So...yes, the 4" system is better. Is the increased performance and sound quality worth the additional dollars...you decide.

[ 09-29-2004, 01:12 PM: Message edited by: Spindrift ]

[Billman]

I like the increased flow of 4" over 3.5". Especially with the boost pressures I've been putting through it. Just don't like the noise.

When I first did the exhaust, it was a coin toss. Glad I went with 4".

Straights, 90's, & 45's can be bought from a truck dealer. Add a welder and you can do it cheap. Otherwise buy a kit or let a muffler shop do it.

I don't think you'll find anyone bending 4" on their premises. They will just piece it together. That's what the performance muffler shop did with mine.

But judging from your list of modifications, 3.5" sounds fine.

[markelectric]

I know from past experience a ford tailpipe, muffler of choice, a piece of straight pipe, and the downpipe make up a good exhaust system in a pickup truck. I have heard and read how the subs can be a nightmare even with the kits. Apparently the heater and AC lines are not all in the same place on our burbs. I would think a kit would be a real good start. If a kit is out of reach, the downpipe, ford tailpipe and muffler of choice would get you started. The small offsets between downpipe and muffler may pose a bit of restriction but not near that of the old downpipe.
Personally I am waiting for enough $$$ to get the kit for our sub. Then I will get it put on when the wife is not looking......

[john8662]

I don't know if I like the 4" systems on a suburban, they are short in comparison to the longer trucks (crews, excab long beds, etc.) I have the 4" system on my suburban, I didn't notice substantial seat-of-pants improvement, even with new injectors. My factory exhaust wasn't THAT bad from what I read from other users, just the crimp for the heater line clearance was small. The downpipe wasn't horrible like some that I had seen. My complaint is that it is TOO loud in town, not on the highway. I don't like the sound of exhaust rumble, I like the sound of diesel "ping" and the sound of the engine, not the exhaust sound like a gasser. Anyone know of a better muffler that will quieten down a 4" system? My advice, if I had to do it again, go with 3.5"

[Billman]

John

I don't like the noise either. I went with a Walker Flo-Thru design. It quieted down the exhaust nicely. A little big though... about 50 inches in total length.

[dslpwr]

John

I have 4" muffler I got from Bill Heath that is QUIET. Its about 40" long.

[john8662]

Billman, dslpwr.

Thanks for the help on a quiet muffler, I'll jump underneath and take a look at how much room I have for a muffler. Any idea on cost? At 4" do you feel there was any loss in flow? So far I am not impresed with the exhaust system in general, but I haven't pulled anything yet.

[Billman]

A quick search turned this up:

https://www.rockauto.com/dbphp/prt,9,21838

I think I paid about $75 from local parts house.

As far as losing power/flow, impossible to tell.

[moondoggie]

Good Day!

Does anyone know if/how you could build your own exhaust & then get it aluminized? I've had aluminized exhaust previously, & it lasted about forever.

This topic has been encouraging. I thought I was the only DP member that wanted a reasonably quiet truck.

It can't take much of a muffler to make these things quiet. My 95 pickup recently got 3" cat back with no muffler, & I can't hear the exhaust at all, which is just how I want it. (Yes, I had wanted to go with a 3" or larger system - maybe next time

[Spindrift]

Brian,

I saw this in 4 Wheeler Magazine:

[[Ray Zuelke from U.S Tire and Oil in Combined Locks, WI., the suppliers of our tubing, tell us that, "the aluminizing process is the result of aluminum alloy being kilned into the metal during the drawing process, and the seam is then re-aluminized after welding. Since this process is not a coating, it will not flake off when bent in the machine. As a result, the entire metallic structure contains the alloy and therefore lasts longer and looks better all throughout the life of the product while in use." This also means that the inside of the pipe will be protected from corrosion as well as the outside.]]

Those words, if the guy knows what he's talking about, seem to indicate that an aluminized coating may not be the best way to go.

[moondoggie]

Good Day!

Wow - thanks. :D It kinda figures