RAM RHO HO Downpipes with High Flow Cats +100hp!

D&Sadventure · Apr 22, 2026

DBallz said:
View attachment 29259

@DBallz Your probably a hell of a drummer too.
I say that because clearly he has rhythm and the ability to use two hands and a foot at the same time

RHOJohnnie · Apr 22, 2026

DBallz said:
Had to get a new batch of brackets due to an error at laser which pushed us back a few days. That being said they are coming together now.

Production set ready for O2 bungs and brackets then out the door.

View attachment 28742

Those welds are tits!

PinnacleBuilt · Apr 22, 2026

Stackin’ em up

Jramos44 · Apr 22, 2026

DBallz said:
Stackin’ em upView attachment 29276

Beautiful, cant wait to get mine on.

matt35hr · Apr 22, 2026

DBallz said:
Stackin’ em upView attachment 29276

mghtymous21 · Apr 24, 2026

How tough is the install?

PinnacleBuilt · Apr 24, 2026

mghtymous21 said:
How tough is the install?

Not too bad 4-5 hours with normal mechanics tools. If your toolbox sucks so will your install time....

Drivers side fender liner comes out.
Skid plates come off.
Front driveshaft comes out.
4 bolt from the front diff yoke and loosen the clamp on the t-case side and it pulls forward off the shaft.
If you dont have the appropriate extensions and swivel joints this part requires putting t-case in neutral to rotate the shaft to gain access to each bolt, back to the toolbox sucking reference.
Sway bar mounts un-bolt.

Then it's just unplugging and removing O2's and unbolting everything.
The bracket nuts are tucked up a ways, so again if you don't have a long handle ratchet this is gonna suck. I hit them from the top with the ol' makita power ratchet once I have them loosened.
Bottom one comes out first.
Then the top one comes out super easy as mucho clearance now exists. Oe ones are fairly large compared to the Fat Kitties.

New ones go in way easier as the occupy less space.

mghtymous21 · Apr 24, 2026

DBallz said:
Not too bad 4-5 hours with normal mechanics tools. If your toolbox sucks so will your install time....

Drivers side fender liner comes out.
Skid plates come off.
Front driveshaft comes out.
4 bolt from the front diff yoke and loosen the clamp on the t-case side and it pulls forward off the shaft.
If you dont have the appropriate extensions and swivel joints this part requires putting t-case in neutral to rotate the shaft to gain access to each bolt, back to the toolbox sucking reference.
Sway bar mounts un-bolt.

Then it's just unplugging and removing O2's and unbolting everything.
The bracket nuts are tucked up a ways, so again if you don't have a long handle ratchet this is gonna suck. I hit them from the top with the ol' makita power ratchet once I have them loosened.
Bottom one comes out first.
Then the top one comes out super easy as mucho clearance now exists. Oe ones are fairly large compared to the Fat Kitties.

New ones go in way easier as the occupy less space.

That was a much more in depth reply than I anticipated, thank you very much.

Probably gonna be out of my wheelhouse due to my limited circumstances. I'll start researching shops that can do the install for me. When I hit 3k miles I'll be doing intake (hot button topic, don't care, it's my $$$) and cat back. At 5k I'm about 95% sure I'll be doing these downpipes.

RB72 · Apr 27, 2026

Look what showed up today!

mghtymous21 · Apr 27, 2026

RB72 said:
Look what showed up today!

View attachment 29451

Hot damn! Those are sexy! So is there any concern with radiant heat coming off them? Do they need to be wrapped or get some type of heat shield?

PinnacleBuilt · Apr 27, 2026

mghtymous21 said:
Hot damn! Those are sexy! So is there any concern with radiant heat coming off them? Do they need to be wrapped or get some type of heat shield?

Nope

Scottie2Hottie · Apr 27, 2026

DBallz said:
Nope

That is a little surprising considering where they sit and the heat I still feel off the oem. @DBallz any issue with those who add a stainless formable heat shield that wraps around and tac welded together? Like Zircotec.

Jramos44 · Apr 27, 2026

Got my shipment notice today! Super excited but not for the install…

mghtymous21 · Apr 27, 2026

DBallz said:
Nope

Would the heat coming off these down pipes (external radiant) be within the same ranges as the stock ones that have all the heat shields?

PinnacleBuilt · Apr 28, 2026

Scottie2Hottie said:
That is a little surprising considering where they sit and the heat I still feel off the oem. @DBallz any issue with those who add a stainless formable heat shield that wraps around and tac welded together? Like Zircotec.

Keep in mind that the factory ones did have an issue with melting so these are designed with the intent to dissipate heat at a much faster rate than the factory cats. The reduction in back pressure plays the biggest part in lower egt's but I have no idea how much that will change with additional shielding or coating.

There really is quite a bit of room from an airflow perspective and it's going to come through the grille and hit the firewall and funnel right by the downpipes out of the bottom of the truck.

Where the downpipes exit the engine bay is going to create a natural low pressure area and pull air through and out and there is a ton more clearance on the Fat Cats vs the OE cats which will increase the cooling efficiency of the air flow.

The OE cats are wedged in there pretty good with very little clearance in a lot of places. I'm talking millimeters and with that Fat Cats in there those clearances open up to 1-2 inches.