Was reading through a bunch of old posts last night trying to figure some things out for my exhaust system. Right now I have a 97 PSD with a K&N, TS chip, and am getting ready to do the exhaust. I have a Diamond Eye 3 inch down pipe in hand and was debating a Cat delete pipe then stock muffler this is the cheapest way to go around here. My other option is a 4 inch back from the down pipe.

My major concern is that it sounds like you have to beat the crud out of the firewall to install the Diamond Eye. Is this true or not? My local guy does not reccomend after market downpipes because of the constant rattle. Wife will not tollerate that!!!

Second I have a local guy whom I really trust and has done great things to all my other vehicles. He reccomends a 4 inch from the stock down pipe back with a straight 36 inch muffler from a Semi truck.

Wife and the kids ride in the truck all the time so louderto a certain extent (straight pipe) is not an option. Budget is limited and I need advice/ help from people who have been there done that.

 

You do need to clearance the firewall/floor for the dp install. You just need to cut the seam where they meet in a few places with a sawzall or something and if you have a portapower it works good to push it back for clearance. I just used a big bar and a block of wood and have had no issues at all with it rubbing/rattling. These trucks vary in the clearance so some take a little more making of room than others.

I just run a 3-4 inch dp and straight pipe the rest of the way so I'm not going to be much help in the muffler area. You will want it to exit in the stock location to keep the sound down more too. Mine exits in front of the rear tire, not quiet, but how I want it.

Others will help with a good muffler choice.

 

FWIW, my downpipe and NoKitty pipe arrived friday. I'm planning to go down the first option you posted. Not expecting any huge noise increase. Expecting a little work doing the firewall seam but not much. Have measured it and I guess our truck was put together with a bit more clearance than some.

Also, I would NOT expand the exhaust w/o eliminating the stock pipe...too many pictures around to show you why an aftermarket downpipe is used.

 

It looks like assembly tolerances determine whether you have a straight-forward downpipe install or a PITA. I wasn't as lucky as Makomark, so I have some thoughts on the PITA end.

For downpipe removal, sawzall and some good-quality, long metal-cutting blades. Spend a couple of bucks for Milwaukee or similar blades. Downpipe will be out of there quickly and safely.

Next, try to drop the top section of the downpipe in and connect to the turbo. If you have decent clearance, particulary around the back of the head, then you should be OK to just cut and bend the weld seam at the firewall/transmission tunnel. If you need to clearance the firewall, do it before bending the seam.

I did not have luck with portapower on the firewall. It's OK for bending the seam, but not much help higher up on the firewall. I had to move my firewall a decent amount for a 3" downpipe. I finally got it done with a little shorty air hammer and a short chisel that I blunted to use as a peen. The short hammer and chisel lets you get in around the turbo and head from on top, and alongside the transmission from the bottom. I used the hammer to peen the firewall... basically to stretch and dent it. You don't want anything remotely resembling a sharp chise. I used a little Kobalt-brand hammer from Lowe's; it's smaller than most I've seen. Little is better in this case.

Once you have enough clearance on the firewall, THEN you can bend the flange back. It's much harder to clearance the bottom of the firewall if bend the seam first.

If you get good clearance, you shouldn't have any new rattles.

 

YAY! another chance to show the "DON'T USE A TORCH" link!: Ford Diesel Power Forums - View Single Post - Exhaust removal gone horrible.
Use a sawzall

 

WOW WOW WOW!!! That hurts!!!

 

Yikes.

Now thats a REALLY bad day.

 

Eng bay looks pretty good LOL

 

Explain that to your insurance company

 

Finally got the DE hardware installed. Guess on amount of work was wrong. On ours, bending the seam would have been adequate but I couldn't get the top half installed without cutting out the seam for about an inch. Would up with almost 1/2" of clearance afterwards.

The pipecutters offered at the parts stores can't handle a 3.5" pipe so the Kat came off manually. (Sawall gave up the ghost after 5 minutes on the downpipe.) Knocking out the slug took a bit of effort too.

Only had two short trips since - turbo whine is most noticeable when the boost just starts up and is not noticeable by 8 psi. If the mileage improves, we'll be happy.

 

FWIW, I recommend using a porta power for pushing the firewall in. I have the 4 ton model and it works fine, but you need either a cheater bar on the handle or to stand on the handle like I did for extra leverage to REALLY push the firewall in. On both of them that I've done I can drop the top 1/2 of the down pipe right in without any rubbing or having to squeeze it through there, just slides right on down into place. I didn't want any annoying rattles or rubbing... mission accomplished.

 

I fit a 3"DP to 4" straight pipe without any firewall modification. No rubbin or anything either
Anyway. under the mods stickied thread I like this writeup on PSN:
How to: Downpipe Install - PowerStrokeNation

 

I didn't have to make a cut on the lower part of the down pipe, just cut the cobra head off the top and it should drop right out the bottom with no issues.
Also FWIW, I highly recommend an SS band clamp for AT LEAST clamping the 2 piece down pipe together. Those u-bolt clamps wrinkle the pipe when they are tight enough to keep it from coming apart, and getting the down pipe apart when you need to (not if... when!) is a major PIA. SS band clamps work great, don't wrinkle the pipe, and make disassembly painless. I have all the joints except 1 in my exhaut clamped with SS band clamps, well worth the extra $ spent. The only one I didn't use a band clamp on doubles as a hanger and there was no way to make the band clamp work in that spot. Just go to Napa and tell them you need a 3" SS band clamp, about $8 I think. The 4" ones were around $10.

 

I have the 3.5" DiamondEye DP to 4" exhaust, with factory cat, exiting through the DE 4" muffler at the stock location. I'm disabled and had a shop do my install, so I'm no help on how difficult the install is.

Turbo whistle is noticeable to a point but not annoying to family members. My gals have not said anything negative about the exhaust tone or sound level.

How did your install go?

 

I have the Diamond Eye 3" down pipe into 4" dual tail pipes, no cat or muffler. In cab noise is only slightly higher than with the cat and/or muffler installed, but it sounds awesome. I was in downtown Spokane yesterday with the windows down and listening to the exhaust bounce off all the buildings... it was fun!