Exhaust upgrade question

[DennisG01]

I will soon be doing an exhaust upgrade as the first step to more POWER! I am aware of Kennedy's 3.5" kit. However, a local garage told me about a 3" Flowmaster kit that they could get for me. When I asked them if they could get a larger kit, maybe 4", they said they could only get what was in the catalog and that if a larger kit would be better, it would be in the catalog. I have always been under the impression that a larger exhaust can only help. My assumption about the local garage is they just want to sell me what they can get (I guess I can't blame them for that). Anyways, is there any truth to what they are saying... or is there a point where going to a larger diameter pipe no longer shows any worthwhile gains? Does anyone out there have any other suggestions as to where to buy? Thanks! I am learning a lot from the DP website!

[cruzer]

I think Kennedy found that there was performance gains going from 3" to 3.5", but minimal, if any, gain going from 3.5" to 4". My banks system is 3" and there was a definite gain from stk. Kennedy told me to remove muffler and put in a straight pipe to get better flow. Banks sold as a kit and others may too. It came w/performance air filter and gauges,and you will want gauges in the future. Trust me. At the time I did not know about TDP. Knowing what I know now, the next one will be 3.5" or larger. Try the advertisers section.

[Dvldog 8793]

Howdy
Any good quality exhaust system that is MANDREL bent with nice smooth curves is going to be better than stock. even if it's the same size(3" I think?) I know there are members out there that have installed powerjoke exhaust systems on the GM trucks and had good luck with it. I have Kennedy's system and am VERY happy with it. The biggest thing I noticed was the DOWN pipe from the turbo. the factory one was pretty much deformed beyond looking like a pipe! If you get any kit at all make sure that you get a new down pipe and clamps. I would also save the money and don't bother with a muffler :D much less a soot trap! If you go to Kennedy's web site he has all kinds of pics and good ideas. I know there ALLOT of great suppliers out there (Heath, from what I hear) but John Kennedy is the only one I have experience with.
Hope this helps....
L8r
Conley

[freddys]

I have a Forbes 4" exhaust system and iam happy with it. I got it from this guy Here (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33630&item=2456041089) but i didn't buy it off of ebay I went right to him and was very happy at the transaction. take a look Here (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=005695) where we talked about the forbes 4" exhaust.

[Wheat Whacker]

A new system will make you happier I chose JK's 3.5" system and have been very happy with it. Easy to install with a great sound slightly cooler egt's and a couple of lbs. of boost gain as well.

[MTTwister]

Wheat Whacker You need to find the 'other ' bumper sticker -
"Old truckers never die, they just get a new PeterBilt".

Never seen one myself, but if I do, I'm gonna score it. smile.gif

[triggerman]

You can get a mandrel bent Flowmaster down pipe and crossover set and a 3 1/2" universal tail pipe kit from summit raceing pretty reasonable. What you put between these kits is up to you.

[DennisG01]

Thanks, everyone! Based on your replies, it sounds like a 3 1/2" will do. One last question, though: By law, do I have to have a muffler (I'm in PA if it matters), and does a muffler from Flowmaster or JK's kit have a major impact on performance? Also, is it ALOT louder without a muffler? I don't want it to be annoying.

[Dvldog 8793]

Howdy
The "muffler" that comes with the Kennedy kit is reversable. If install it forward the baffles work. If you install it backwards it works as a straight pipe. Mine is backwards. :D As to the law, I have no idea??? My truck is a 1ton and thus is classifed as commercial vehicle ;) So it comes under different laws. No emision controls or extra safety stuff ect...
The noise level? I think it sounds GREAT. My kids think it sounds GREAT. My wife says it's to loud and sounds like a semi. Well thats 4 to 1! Ain't democracy great! :D
Beauty is in the EAR of the listener! ;)
L8r
Conley

[DennisG01]

Conley,

Thanks for the info! How much louder than stock would you say it is (a lot, a little, etc)? Thanks again!

[GMCfourX4]

Dennis;
It only sounds a little louder than stock inside the truck, and is easily tuned out by the radio... The great thing is, you can roll down your window, and the thing sounds like a big block, or a KW or something..... and when you get sick of the noise (lets suppose, for the sake of argument, that someone actually WOULD...) you just roll up the window, and you can't really hear it anymore. Its a wonderful thing :D (that's with muffler, I haven't heard one, but I'm told that even without muffler, the turbo quiets it down enough that it isn't offensive)

-Chris

[Dvldog 8793]

howdy
Outside the truck it is VERY loud when you put your foot in it. :D I had a friend of mine drive it around the block and rod on it pretty hard. it made the hairs on the back of my neck stand up. :D Really a unique sound. I have added insulation under the carpet of my rig and my truck is also the longest truck you can get. Length acts as muffler. A blazer would no doubt be allot louder. I really enjoy driving into the city and finding some nice tight alleys and the roll down all the windows and leave her in first!
Response from my wife="Real mature!" tongue.gif
Oh Well. As GMC4x said in the truck with the windows up it really isn't that loud. I've never tried mine with the muffler turned the right direction.
L8r
Conley

[Wheat Whacker]

The sound with JK muffler turned backwards sounds great. It is not that much loader in the cab with the windows up but it does have a nice rumble. I now put down my windows when I get to town because it sounds so good echoing off the buildings and the turbo whine is wonderful music :D :D . At idle the difference is almost unoticable. Sorry don't know about the law in PA but with JK it is almost like not having one ;) .

[dslpwr]

If you do not like noise, look at Bill Heath exhaust.

I have JK exhaust with Bill Heath muffer. Its a longer muffer that is straigh through with 4 inch I.D.

I do not like a noisy truck