TRD/ Magnuson 4.0 Supercharger Tips, Tricks, and Mods

Sleeper status

 

It’s been hot. Was in the 90’s all week with crazy humidity. It was 82 yesterday. A little better.

 

Same here, extended the harness, went up into glovebox from passenger firewall, ziptied to the crashbar, ran all the way across to the driver a pillar.

 

Perhaps a dumb or inconsequential question:

Does the entire exhaust system, from header to the end of the exhaust pipe, have to be the same diameter for maximized benefits?

A little more specifically, will having 3.0" diameter headers and y-pipe reduced to 2.5" mufflers/resonators have negative effects? In other words, everything up to the muffler/resonator itself would be 3.0", and everything after the muffler/resonator would be 2.5".

 

I say 3" from the Y pipe back

 

I'm similar. I have the TRD exhaust. Now I have the URD Y-Pipe. Soon to have headers and high-flow cats. I just didn't want to spend more money on another exhaust.

 

Significant loss of exhaust pulse velocity. Lowered torque. In the low end primarily.

 

That's why I bought a whole new tail pipe section. Money grows on trees up here

 

Stemming from what, exactly?

3" exhaust diameter?

Reduction of diameter from 3" to 2.5"?

 

Too large of a cross-sectional area right out of the headers.

 

Gotcha. Thank you as always, @Torspd!

 

Nice. And no bugs.

 

Yep. 60* out now too.

 

One of the reasons for the development of step headers was to slowly decrease the size of the tube as the exhaust gasses cool so as to keep the velocity of the exhaust pulses consistent. It is a science for sure

 

12º is a magical number.

 

There is no stupid question if you don't know the answer to the question!

Tube diameter is extremely important to the performance of the engine but that is only one parameter. The general rule of thumb is the closer you are to the engine the more critical the appropriate tube diameters and lengths are utilized.

Tube diameter and equal length near the engine is where it is most critical in order to maximize exhaust pulse wave tuning. In a nutshell what you are trying to achieve is an extremely low pressure pulse on each cylinder at exactly when that cylinders exhaust valve opens. This helps to pull or suck the exhaust out of the cylinder instead of the piston having to push it out saving power. It also helps to pull more intake charge into the cylinder during valve overlap. This is why equal length headers and y-pipe of a specific diameter and length make a dramatic difference in volumetric efficiency.

Exhaust diameter further back will have somewhat lesser effect but is still important. You don't want to put all the time, money, and effort in making the first half of the exhaust as efficient as possible and then bottleneck the rear. If you choke down the rear, the exhaust pressure will rise and negate some of the scavenging effect of the header and y-pipe.

As stated before, 3" is a good size for our trucks when boosted.

 

Is the collector on the URD Long Tubes 3"?

 

2.25"

 

2.25"

-edit-

@Torspd beat me to it.

 

The URD Y-pipe is 2.25 as well, so most people running URD headers or y-pipe have some 2.25 bottleneck somewhere in the line. That's where I wonder how a 3" catback system will help if you're already restricted somewhere upstream at 2.25. My DTSTs are 2.25 in to the URD y-pipe with 2.5 TRD catback. Will a 3" CB exhaust really make a difference?

I actually like the sound of my TRD CB with the hi-flow cats on the shorties.