Aftermarket exhaust for the 6.5 TD

[Dart]

Installed a BD diesel exhaust last week, in search of more power/fuel economy. In terms of power, I think it delivered. Better response, quicker revs, etc. Fuel economy, waiting to see.

In terms of fabrication, I certainly was not pleased on several accounts. I had the system installed in Phoenix at a BD dealer.

First, the ugly-ass 5" stainless tip looks absurd on a 4" pipe exiting out the back. It serves to do little more than act as a megaphone. And some of us do like things a bit quieter.

The angle of the pipe exiting behind the tire allowed less than 1/2" clearance to the body. The angled tip provided had to stick way out to keep soot off the sheetmetal and bumper.

After getting under the vehicle, I noticed why it was mounted so high. The shop installing it had to choose between travel on the rear axle, or clearing the spring shackle. Unfortunate for me, they chose axle travel, leaving me with about 1.5" inches of spring travel, before the exhaust hits it. Won't work with my 3,300+ pound camper. Too bad BD did not consider the bend on the pipe, as they left substantial unused space over the axle which would have allowed more travel.

The shop used partly the new hangars supplied with the kit, and the old ones, which got slag welded together. I will have to cut them loose to get more clearance for the springs.

I pounded off the stainless tip with a sledge hammer, as it fit on so tightly it was impossible to remove without either hammering on it or grinding it off. I used my grinder to remove the extension pipe after it passes over the axle. It was not slotted, and was impossible to remove without a grinder. I fitted a new short aluminized angled 4" pipe to the end, to divert soot away from the sheetmetal and bumper, and also to give more body clearance.

I will buy new pipe clamps and will fabricate new hangers, so that I can clear the springs when I have a load on. Unlike the ones on there now, mine will look like they came from an actual factory, designed and built with pride in what is done, rather than the cobbled together units on now.

In short, not the first class unit I expected, for expending about $1,000.00 including downpipe, muffler and pipe, shipping and install. :mad:

Were you happy with the exhaust brand you bought? In retrospect, I should have bought a downpipe from BD, and had the rest fabricated locally, at probably less than half the price.

No telling if the 3" front part of the system is enhanced, at all, by the 4" portion after the catalyst.

Dart

[ttpost]

wow thousand bucks for exhaust?? i am still learning about the exhaust system but couldnt your local muffler shop just make you one for less or is there something special about these exhaust systems???

are you getting new exhaust manifolds also?

i know i had 3" put on one of my rigs from the manifolds down for about 250. included a rhino muffler. is stainless necessary?

i have 175k miles on my truck with factory steel and it is still solid, just want to got with bigger exhaust and a "clean converter"

[S\W Off Road]

I am very happy with the 4"exhaust I got. Fit was great and easy to install. I didn't get no 5" megaphone. I sure as heck didn't pay no big bucks for it.

[matt-max]

two words.......

john kennedy


very pleased with the 3.5" on the tahoe

sound is awesome. turbo spool, growl, slight rumble

performance increased noticeably, especially response. not sure on mileage except that it did not get worse

cost was around $500 i think w/shipping.

matt

[cruzer]

I purchased the Banks Stinger kit. The install was very easy w/no mods and it used all the stk hanger locations. Its been on for about 4 yrs w/no problems. I purchased it b4 I knew about TDP. In retrospect I wish it was 3 1/2" instead
of 3". They say 3 1/2 optimal.

[Dave C]

I recently installed Kennedy's 3.5" exhaust. Working by myself it took me about 7 hours (I left the cat out). The only parts I didn't like (or use) were the stainless steel band clamps. They don't hold the two pipes securely enough which allows the exhaust to twist in places and hit the frame, etc. I used all bolt-on type clamps instead. With this and my Boost Master, my milage improved by about 8%. I suspect that the bigger exhaust accounted for most of this. :D

[MJEasly]

http://www.atpturbo.com/Merchant2/graphics/00000001/Catalog%20Images/Clamps/CLA-VBAND-225225.jpg

I wouldn't mind a SS exhaust system that used the above v-band clamps. They would allow me to quickly remove the cat (for off road use only of course).

[Fredeberle]

I agree with matt.
john kennedy smile.gif
installed without much trouble (even with having to have the CAT flange welded to downpipe)
Has to be trimmed to fit your truck ( one size for all? ) :( Ended up with 4 ft. tubing leftover.
stainless clamps worked well for me but hangers have to be redone a bit.
Looka and sounds great :D
Fred

[patrick m.]

(quote). wow thousand bucks for exhaust?? i am still learning about the exhaust system but couldnt your local muffler shop just make you one for less or is there something special about these exhaust systems??? [quote]

most muffler shops cant bend pipe over 3 inch, (we cant). The tools on the press only go to 3. larger tools are not availible for the exhaust press we have, or many others.
it takes a much larger machine (and more expensive) to do big pipe :(

which is why i dropped the dough for JK's exhaust rather than building my own, and as everyone else says, it all fit just right. ;)

[gwaidman]

WOW! 1K USD!! Thats rich man. I ordered a Heath kit, turbo back, and installed it myself for $350. BD is just down the road in Abbostsford from me, and wanted $650 plus for the cat back system plus $180 for the down pipe. I think most members are happy for the less than 500 buck Kennedy or Heath systems. At least you are happy with the power. Not to start anything, but the BD stuff does seem to be a little on the costly side.

[Wheat Whacker]

Wow a grand for an exhaust. I bought and installed a JK's 3.5" system a couple years ago and I couldn't be happier with the performance and was very easy to install. As a matter of fact much easier than I expected.

[JoeyD]

I have the BD 4 in exhaust as well. I didn't spend a grand, maybe 400 including the downpipe. The fit was crap and the hangers were crap. I have had it for 3 years and it's ready for the dumpster as it's rotting away.

[whatnot]

Originally posted by Dave C:
I recently installed Kennedy's 3.5" exhaust. Working by myself it took me about 7 hours (I left the cat out). The only parts I didn't like (or use) were the stainless steel band clamps. They don't hold the two pipes securely enough which allows the exhaust to twist in places and hit the frame, etc. I used all bolt-on type clamps instead. With this and my Boost Master, my milage improved by about 8%. I suspect that the bigger exhaust accounted for most of this. :D I would never use anything else if I could get the SS band clamps. If they didn't hold it tight then either they were the wrong size or you didn't tighten the bolts enough. An impact wrench works good and they don't break if you keep tightening them like a regular U-bolt will. If you use u-bolts,(and properly tighten them) the pipes will get crimped and won't ever come apart again so if you ever need to remove the exhaust system, you will probably have to cut it. I bought my kennedy kit used and the pipes were all in perfect condition. If it had been installed with u-bolt clamps, it would have been almost worthless.

[Scooby]

I too recently installed JK's 3.5 inch system on my truck. The ss band clamps are the same type used on big trucks, and will seal better than the old u-bolt style, without distorting the pipe. I put mine together using some antisieze on the pipes, (as I have done on big trucks in the past) and being sure to slip the pipes together as far as they will go. TIghten the clamps till the 'reaction blocks' as I have seen them called, touch, and it wont move. I did use some of my original hangers on JK's system, and welded them to the pipe. I had a little trouble getting the clearance I wanted on the downpipe, and the original hangers seemed to hold the pipe where I wanted it. I am very pleased with the system.

[G. Gearloose]

"this one time, at band clamp ..." ;)

[Scooby]

Originally posted by G. Gearloose:
"this one time, at band clamp ..." ;) BOOOOOOOOOOO---- HISS !!!!

LOL!!

[Polar Diesel]

the shop i had do my exhuast, ordered the fittings, downpipe, and welded them all. one stait pipe from down pipe to where it humps up over axle. ends up angling back like duramax. no restriction whatsoever.and looks great. sounds good too. cost about 450 all togther.

[turboGMC]

hey polar diesel- are you saying you have no bends after the dp until the axle? Not even tranny crossmember?

[Polar Diesel]

yup, it's angled to just to clear cross member. it's one unbent 8,or 9 or whatever feet of tubing. if i knew how to post pics i could show you.

[turboGMC]

if you email me the pics I will host them. Id like to see'em. mctwistit@msn

[Polar Diesel]

can do. I'll have to take some shots of course. i'll get back to ya on that.

[Polar Diesel]

you may have to paly with the contrast and brightness to see everything, but you can see where the weld is from DP to long piece, and the crossover pipe. hope these help!!

[Dieselboy]

JK's 3.5" system is a good one. We installed one on our 96 suburban. It sounds good, looks good, and fits well. Since there's some extra length left in a few sections, it makes a custom fit possible. I would recommend it to anybody.