I'll probably attempt the install of the Tymar 2 piece 3"-3.5"-4" Stainless downpipe soon on my 1997 F250 extended cab with the 7.3 Powerstroke. I've watched a few Youtube videos and they didn't exactly make it look easy. Any advice appreciated.

would a basic Harbor Freight body work hydraulic kit be a good idea. https://www.harborfreight.com/4-ton-...kit-62115.html

sees like a tool i'd use more in the future

 

That tool will definitely help. You're in for a world of fun depending on where that pipe goes up to 3.5 and then 4 inches.

 

Dremmel with those small metal wheels helps quite a bit in that tight area. I used it more than a Porta Power.

Protect eyes und ears.

Mine is Diamond Eye if matters. Removal of stock? Use Milwaukee 'The Torch' blades. Others are ****.

 

I did mine quite a few years ago. I recollect seeing descriptions of the job ranging from "what's the big deal" to quite a lot of metal-bashing. I suspect the spread of difficulty is due to assembly tolerances on the trucks. If your engine is mounted on frame to rear of tolerances, and body towards front of tolerances, space between engine and firewall will be tight, and you'll be doing some persuasion on the firewall. Tolerances the other way, more space between engine and firewall, and no sheet metal mods. Hmmm... and state of cab mounts may also have an influence.

I finally got my old downpipe out with good reciprosaw blades. Should have just started with those rather than messing with cutoff wheels. Be careful not to snag any wires.

I had to do quite a bit of persuasion on my firewall. If you have to move the weld flange on the the bottom of the firewall, several slits with a Dremel before bending sounds about right. I tried PortaPower without much luck; simple pressure didn't do the trick. I did get a HF unit, but quality of the HF tool wasn't the issue. On a subsequent job, the cylinder on my HF set blew an o-ring that I have yet to replace. What DID work well for me to dent or dimple the firewall and bend back the weld flange on the bottom was an air hammer with a blunt chisel. You can get actual "hammers" for air chisels, both steel and soft tipped, as well as specific panel shapers; I just flattened out a standard chisel with a grinder and was careful. I'm trying to remember if I also used a long-length blunt hand "chisel" (squished and ground pipe end) and hand hammer for spots I couldn't access with a short hammer/chisel on the air tool. But overall, I found some form of "beatering" to be more effective than pressure or leverage.

For tools, I would start with good reciprosaw blades to get the old downpipe out. Then test-fit to see if fitment will be "easy" or "hard". If "hard", I would go the hammer or panel shaper route rather than PortaPower just for effectiveness, and even the HF unit isn't exactly cheap. ToolTopia has multiple options for hammer chisels or body panels, or get a cheap chisel from just about anywhere and grind your own.

And a thought on results- I was impressed with the improvement in low-RPM throttle response that just the downpipe brought. The truck could now get out of its own way from a stop.

My $0.02. Your results will vary.

 

Paddler, do you mean something like this? Mine is only a 3" DP.

 

Chuckle... that's the first I recollect hearing of cutting the firewall, let alone seeing it. Yours was a particularly difficult clearance problem.

I was comparatively lucky... I only had to dent the firewall and turn under the weld flange at the bottom... no cutting of firewall. I'm pretty sure I did not need anywhere near the depth of dent that you needed.

But I also recollect some folks getting away with very little work on the firewall. It didn't seem like there was any consistency between who made the downpipes and difficulty, so I'm guessing it was the detailed tolerances of individual trucks. The OP might get lucky, or not. But Glenn, yours seems to take the cake for unlucky!

 

yeah, i'm not feeling lucky. I think my cab mounts are compromised and will make this even harder. such a shame. i've got it running pretty good, adjusted brakes and new wheels and tires and was looking forward to seeing if the downpipe and open exhaust are noticeable in the acceleration. but i may need to plan for a bigger project to get it installed.

 

I kid around that my truck was one of the last made on a line that they started making the Ranger. On the Mule that I still have it was a piece of cake compared to the OX. A porta power did the job on it.

 

I cannot recall, but something about the manual versus auto fitment is different too. Maybe someone that has done both can testify. Something about a reinforcement ear or flange.

Furthermore, a full exhaust is apparently good for around 20rwhp on these on a stock tune. I would assume without any boost leaks nor leaking uppipes. Downpipe is obviously largest restriction, then catalyst. I heard OE muffler was straight through, but my truck came with a chambered off brand ergo cannot confirm.

Are you removing the flap in the turbine outlet while in there?

Keep us posted with your saga!

 

I had a porta power, Sawzall, and die grinder with 3" cut off wheels. I recall cutting a chunk of the heat shield off, then going to town on the firewall. Wear eye protection like stated and have a good time

 

I had a nightmare of a time concerning my downpipe and uppipes. Still not done. But man, I can't believe you had to chop the firewall out. I was almost at that point it felt like.

You're going to want to make sire you have adequate room and add some insulation to that floor opening. Otherwise, you'll have noise and vibrations thatll drive you crazy

 

I did that job years ago and yes, I did add some insulation to the firewall. The vibration was before cutting it open, the DP was hitting the firewall even after trying to make room driving me nuts! My other OBS was bend the pinch weld back and porta power it, done.

 

Check my build thread for precut insulation and deadening install. Not hard just took a bit of time.

No club cab stuff available, but those guys said regular cab and extended cab kits can fashion a suitable kit when combined.