Install BD Down Pipe?

[MTTwister]

I'm about to pull the CAT for cleaning, and I have a BD Down pipe in the box in the corner. My current downpipe doesn't feel all that bad - not like the twisted mangled pipes I seen from other's pics ( must have been a Wed. build). I'm really debating the necessity of swapping ( going through the pain of a one man down pipe install) when the original isn't really that crunched. Also the OEM has a few curves in it to reach the CAT, and I'm wondering how hard it's gonna be to make the BD pipe ( fairly straight run) fit in there, clearance wise.

Remember, my OEM down pipe is no where near as constricted as many have pulled out...

Any and all's experiences appreciated. Thanks

[More Power]

Of the ones I've seen, it is the downpipes installed on the LD 1500 series (with EGR) 6.5's that have the most deformed downpipes. The downpipes installed on HD 2500/3500 series 6.5 trucks I've seen were not bad enough to justify replacment.

I suspect the dented & restricted downpipes on the EGR engines were supposed to help with EGR flow (increase backpressure). There are some slight differences in the frames dimensions between the 1500 & 2500 trucks, which may play into it as well.

MP

[MTTwister]

Thanks MP - I'm also believing that it's not bad enough to justify the 'hassle'. May be a downpipe in the Ads soon.

[Billman]

You've already paid for it. Why not spend a little time(free) and install it?

Less resriction in exhaust is always better.

It's not that bad of a job...Even with no help.

[Kennedy]

Originally posted by MTTwister:
Thanks MP - I'm also believing that it's not bad enough to justify the 'hassle'. May be a downpipe in the Ads soon. I would suggest pulling it out, holding it in your hands, and THEN see if you still deem it "not bad" any more...

[FarmerDale]

I replaced the downpipe on a 3500 - it was pounded and twisted like the others I have seen. Definately worth the time, and it was a one-man job to do.

[Marty Lau]

Tom;

I have taken my down pipe off a couple of times for Turbo removal and trying to "clean" the soot trap. I never did get the pipes appart to the soot trap, down pipe no problem. Just jack up the front of truck pretty good and put it on jack stands. If you need help if your going to head up to Great Falls soon bring it with you and I'd help ya.

[MTTwister]

Thanks 16gaSxS - I'll bear the kind offer in mind. Wanna tackle it this weekend, while the weather's really nice.

[rlvelin]

MTTwister

If you decide the OE downpipe is "remain in there worthy" I may be interested in the BD if you decide not to hang onto it.

I also have removed the downpipe a time or two and it is not too bad but two sets of hands definetly helps. I won't be around this weekend but if you want I can give you a hand today or tommorrow, afternoon or evening. I have a torch, welder, and various other fabrication tools if the need arises.

[MTTwister]

Thanks Ryan - I f you want to come by and "fondle" my downpipe - I think you'll see what I mean by "not too bad". No crunches, just a couple of unimpressive 'dings'. Seems to have a more serpetine nature than the BD pipe, which is what's got me curious about the replacement, fitment, lining up and all.

[rlvelin]

If you want a hand give me a jingle 490-9279. It would be interesting to see an OE downpipe with just a few "unimpressive dings", mine looks like it lost a fight with an MRI haul truck. I've been considering filling it with water and freezing it. I had the unfortunate experience to know that will make round tube out of 2" thin wall square tube.

[MTTwister]

Ryan - I probabaly won't start on it until this weekend, and as I recall your out of town. Guess I'll pull the OEM pipe, and then see what I'm in for. If I get "stuck" I'll give you a call next week and check your schedule. Thanks for the offer! Enjoy the Day!

[MTTwister]

Update - Got the Cat out and pretty much gutted. Hard to get it totally sterile with 12" of curved pipe on each end. To get it out the down pipe and crossover had to come off. The OEM downpipe looked "ok" when I took it out Friday night. In the cold hard light of Sat morning- it was looking not so good. Not totally crushed as others I've seen. but I thought - What the Heck - and slid the BD up in there (probably a lot easier with out the crossover in place). Great fit, easy one-man install, thanks to bailing twine to hold it up while i worked on it. tongue.gif Only 'screw-up' I clamped the 3" splice piece down before total final fitment, and had a very minor alignment problem with the flange on the downpipe.

One thing to look for - while I was pulling the crossover, one bolt on each side was loose. (Also had to file and chase threads of 4 of 6 bolts :rolleyes: ) When you're changing oil next time - y'all might want to take a 15mm and extendions under there and check them.

Still need to test drive and check for 'clearance' issues, but there was plenty of room .

Sorry Ryan - I used it!

[Marty Lau]

Hey Tom good going, I think you will find the new down pipe a help in the long run. smile.gif

[MTTwister]

Hi 16 - Yeah, it was worth the effort - as long as I had all the other stuff out anyway. Test run up Homestake yesterday - 65mph - ran 6# boost and 800 deg - Think last time I was pushing more boost - but slightly faster run, too.

Would these mods actualy reduce boost - the need for more boost? ( Wouldn't think so )
I am only shooting for improved fuel mileage.