Exhaust, Best for towing - Diesel Forum

willief350 · 07-01-2009, 12:25 PM

So im getting new gauges in today, Pyrometer, Boost and Trans Temp. I have been reading quite a bit on intake solutions and Trans Cooler upgrades, but exhuast is a hazy subject. Is there a clear ideas as to 3.5 or 4" downpipe? Should I DIY it, buy it, weld or bolt on? I need some direction. I have a boat that I am pulling up to PA from MD. mostly open highway with steady inclines. I would appreciate the help.

-Willie

SmokeyWren · 07-01-2009, 05:38 PM

Quote:

Originally Posted by willief350

Is there a clear ideas as to 3.5 or 4" downpipe?

The only difference between a 3.5" and a 4" downpipe is about a half inch.

No difference in performance for normal truck duties such as towing a boat or trailer with something like a 60-tow tune, or a total of around 300 horses.

The outlet from the turbo is 3", so whether you expand it to 3.5" or 4" doesn't really matter until you get up over about 400 horses.

So for your exhaust, the least-expensive fix is to replace the muffler with a Walker BTM (big truck muffler). Or if you can stand the racket and don't mind being illegal in most jurisdictions, then a straight pipe to replace the muffler. Next up the cost chart is an aluminized steel performance exhaust system. Another notch up will get you my "ugly" stainless exhaust system. And top of the line is the shimy chrome-like stainless exhaust system. All three performance exhaust systems will perform the same. The steel will rust after a while. The shiny stainless will impress your grease monkey in the grease pit at Wal-Mart. The ugly 409 stainless is my choice. It will last forever, even though it will have some ugly surface rust, and nobody but me and my grease monkey will ever see it.

If you're trying to build a turbo-back exhaust system piece by piece, you'll probably spend more money than by simply buying an off-the-shelf kit by MBRP or Magnaflow or Banks. Whether the downpipe expands from 3" to 3.5" or 4" doesn't matter - buy the one that's cheapest and matches the rest of your exhaust system.

Quote:

Should I DIY it, buy it, weld or bolt on?

I would buy the turbo-back kit, then DIY. If you don't weld, then take it to a muffler shop and pay them to complete the installation by welding the connections up tight.

All the pros bolt it on with muffler clamps, then they weld up the connections. Some amatuers might do one or the other, but the pros do both.

SO DIY with muffler clamps, but then finish the job by welding it on right.

Last I heard, if you call the folks at the following link they will sell you a 4" turbo-back stainless performance exhaust system for less than $300.
Performance Truck Products - Home
But his best price is only by phone. So call him and tell him you're a member of TheDieselStop and he'll take care of you.

**DSTRBD** · 07-02-2009, 10:59 PM

For towing with stock or mildly modified engines, we suggest sticking with a 3.5" down-pipe. It will give you quicker spool up and better low end power. Here is a link to our budget kits. Let me know if I can help with anything.

Thanks Smokey!!!

Exhaust Systems | 99-03 7.3L Power Stroke | Ford Power Stroke | Diesel Power | Performance Truck Products

westvandude · 07-03-2009, 01:09 AM

Nate's the guy....buy from HIM!!! Best deal anywhere.

Yes, 409 is actually better than the shiny stuff. It also takes heat cycles better than the shiny stuff - which can lead to stress fractures. I don't care about impressing the grease monkey under the truck (that's me anyway!). It's the last system you'll every buy.

There is a slight drone with the 4" turbo-back magnaflow system when towing heavy in the 60-65mph range as you build boost for slight inclines in O/D and locked up. It's not bothersome though.

Fitment was on the tight side by the front passenger side spring rear shackle but easily fixable. If you can handle a sawzall cut off saw, some sockets/ratchets you can change your whole exhaust. Best if a friend helps to hold the downpipe on the turbo while you align things below. Work front to back and keep everything loose. Then go again front to back tightening along the way checking for clearances. If you're really slow it's an hour or two. Can be done faster.

SS317 · 07-04-2009, 08:35 AM

I agree with what was said above. I have the MBRP kit and love what it did for my truck. In fact, it was the first mod I ever really did to the beast.

Don't be afraid of doing it yourself, it's really easy. It took me longer to remove the old exhaust than it did to install the new one. Get a saws all and have fun cutting the old one off.