Thadeus13

After grinding through all the posts regarding which exhaust to go with, which muffler to choose and which choices NOT to go with, I'm still concerned about the effects of an aftermarket exhaust on the truck regarding the Active Fuel Management(AFM).

My Choice:
I was planning on going to the shop this weekend to price out a custom exhaust. Cat-back, Flowmaster 40/50 (not sure yet), with a dual outlet exiting with split rearangled behind the wheel.

My Concern:
I've read a bunch of posts about how good the exhausts sound, but only a handful of how crappy they sound when the engine turns down tofour cylinders. The latter posts are what scare me most, though. I was hoping someone could clear this up, once and for all, if there is such a thing, with all the changes these days.

Thanks!

jophilpott

I have a custom Magna flow exhaust installed on my Tahoe. The sound doesn't bother me at all. I can hear it, but its nothing that concerns me, my wife, or our 4 year old. On the freeway or with the radio on, its pretty much a moot point.

I can tell while driving, without even looking at the MPG banner that the engine has switched from 8-4cyl, or 4-8cyl. You can hear it a bit in the exhaust I think, but again it doesn't bother me.

I said this in a similar post to this. What I think sounds fine, or sounds like crap may not be the same as what you think sounds fine or sounds like crap. Its hard to answer a subjective questions, because the only answers you are going to get are other peoples opinions. If you can, locate another Tahoe driver in your area who has a custom exhaust and ask for a ride...that's really the only way you will ever know.

You can see what I have installed in my signature, I love it, awesome car, and up next will be some stereo upgrades. I'm considering selling my Evolution so I can instead get a customed tuned ECM.

73shark

I agree. I can just barely detect it and it's not objectionable IMO. As I've stated before, it kind of reminds me of a muffled Jake brake sound.

Thadeus13

How does it sound on the outside?

Also, should I be concerned about performance or extra engine wear and tear? Does exiting pipe diameter matter? Judging by what you guys mention in terms of sound, I'm more concerned about damaging the engine than anything else.

Thanks for your responses!

jophilpott

People have been putting exhausts on cars for years and I haven't heard of any mass engines exploding or anything, lol! If you are upping the exhaust from the standard size to 3" piping, I don't see how that is going to hurt the engine in any way...just allowing for the exhaust gas to escape a little easier.

Thadeus13

LOL! You bring up a good point. I'm just a worry wart I guess. It's this whole AFM that's messing with my head.

On a side note, I was driving around last night and I started noticing the exhaust sound when the engine turned down to 4 cyl. Let's just say that I'm not too concerned anymore about the sound, because at least now I have a general idea of what it would sound like. Not to mention it's only really on flat highway and coasting that it turns down.

So, I'm going to head over to the shop today to get a quote.

Thanks for all your help!

jophilpott

FWIW, if I recall correctly I paid about $400 ish, a little under I believe for a custom 3" with Magnaflow muffler at a shop here in Vancouver, Wa.

Thadeus13

I got a quote from the gentlemen that would be doing the work. It came to $500 with true duals, 2 40 Flowmasters and angled split rear. I trust the guy doing the work, as I've been to this shop before, but just to be sure I checked around with some of my friends who got their exhausts done and the prices match out for the area. I'll be heading back there next Saturday to get the work done.

Thanks for all the info!
-Thad

Big D

I think you are over thinking the 8 cyl to 4 cyl change in exhaust...I changed my exhaust to a Magnaflow and the change is barely noticeable...almost a non-issue. Also, ifone islooking for improvements in performance and or mileage from a "performance" exhaust i thinkone will bevery dissappointed... Research a little more and you will notice that a very sensible solution is the addition of a stainless steel muffler ( i think flowmaster is steel, thus, not rust proof) the removal of your resonator and the addition of a stainless steel tip....Changing to a larger diameter pipe (3") and adding dual exhaust will not necessarily increase performance...Actually, it could reduce it....Please measure your exhaust pipes and you will notice they are about 2.75" in diameter...The suggestion described above can be had for about $200.... a lot less than a $500 dollar "cat back".... The change in muffler should be considered only as a sound enhancement.... the original exhaustshould bewell engineered (except the sound is boring).

Thadeus13

I never looked at getting this exhaust for any sort of performance gain. It's all a matter of personal preference. I had duals on my previous '97 Tahoe and wanted to do the same for this one. As for the Flowmaster mufflers being alumnizied steel, yes that is true. However, I had the same mufflers with the previous application for 5 years and had no issues of rust or deterioration.

So it comes down to a matter of opinion for looks and sound.

To each his own.

-Thad