TRD/ Magnuson 4.0 Supercharger Tips, Tricks, and Mods

Holy shit, dude! What happened? Counting in a good night sleep of 10 hours I hope

 

That was a macho stud.

 

seriously I hope it does not take 15 hours

 

Question: Do you know it was the removal of the cats that shifted the power band, or was it the diameter of the y-pipe and tubing lengths that made the change? I believe the tubing diameter after the header flange on the stock ypipe is about 2". Changing that to 2.5" could be a big change in the exhaust velocity and scavenging effect at all but the high end of the exhaust flow range.

I suspect that it isn't removal of cats, but the change in diameter or length of the pipes. The cats are only flowing 1/2 of the engine volume, easy so to speak. I don't think they are a restriction in and of themselves, especially since they open up where they have to flow through the honeycomb. And, I know that a properly sized muffler will have very little impact on torque and HP on the dyno for max numbers... but sometimes the extra backpressure exerted by some muffling or restriction is actually good for mid range performance. Exhaust sizing is important, and it isn't all about max flow. Velocity, and length are important. We don't have the ability to make a perfect tuned length however.

 

only thing that changed was the removal of the cats. I already had 2.25" into 3" at the Y collector.

 

I was wondering about the pipping on the Y pipe just after the header. Thats around 2" then? I had picked up a 2.25 and its way too big. I am either going to pick up another no weld (only because i plan to do more work later) or if cheap enough ill have a shop add it but looking for quick AFR add if I can.

 

@XPOTRPR

OK then, I may stand corrected.

*edit*
Is your statement true even for the part of the y-pipe before the cat, and truly the only think you did was cut out the cats and splice in a 2.25" connector tube instead? My question is if that 2" section after the flange should be kept for its velocity and scavenging, or if it is only the cat that is a problem.

I'm thinking that 2.25" ypipe to 3" merge is the ticket for a max effort build, dyno bragging rights. But high midrange torque, offroad, highway steep inclines at altitude, a 2" ypipe and 2.5" merge is going to develop torque lower down, and obviously make it suffer a bit on the high end. Exactly what RPM one is better than the other though, I have no clue.

*edit #2*
What diameter are the @Roostfactor ypipes?

 

nope. ive just never done exhaust. my mechanical knowledge is rather beginner level.

 

Don't let any razzing discourage you, it's all in good fun anyways. You still did it and that's more than a lot of people out there and things can get ugly sometimes as you know. I learned by wrecking shit and not being afraid to take shit apart (sometimes I am) and learning as I go and most people are the same.

 

correct! my feels arent hurt. i would reccomend a stud extractor. shitty vice grips and a hammer arent ideal. however it worked for the headers and thermostat install.

 

Could t have said it better myself. I alexia’s get hesitant and have questions but you can say you did it and now know what is done or wheee an issue may arise and if you do have issue you learn what not to do.

 

Stud removal was the worst part of my headers. A lift helped tons. I would raise or lower the truck to exactly the right height to get my arm up and in that engine bay. Beats working on your back every day of the week.

 

The double nut trick on the studs to get then out works wonders.

 

It’s pretty dang challenging though. No joke. I did it with wheels off up on Jack stands. Not excited about the prospect of swapping them out someday. I did the header studs with the engine out, so that was gloriously easy.

 

Can someone post the URD header install guide? Or Link? Wanna make sure I have a complete understanding.

 

You're from BC. It's the Mary Jane you guys like to smoke over there.

Edit: you're not from BC. But, you're just south of it.

 

This guy gets it!
True story that there is no perfect system for all rpms. Exhausts are tuned for the desired operating range, 2200-4600rpm is what my system is tuned for.

OEM is metric sizing and approx 1.75" I'd.
My 2.25" y has id of just over 2".
My 2" tubing would have 1.8" id. Very similar to stock but equal length and of the correct length for desired rpm range.

2.25"

Back pressure is never needed or desired.
Exhaust velocity is what's required for efficiency.
Exhaust velocity changes with rpm and boost.
You are exactly right in the fact that there is no perfect system because what is best for bottom/mid range will choke flow at high rpm.
The inverse is true for larger tubing, reduced velocity at lower rpm = minimal scavenging until the engine "comes on the pipe" with increased exhaust velocity.

This is the reason people get big ass exhaust systems installed then lose all low end power.

What I try to do is target the rpm range we normally use our trucks in.

 

@Torspd im confused with the O2 bungs on the URD LT headers. OEM manifold has one sensor before the first cat (which is believe is the one used by the ECU for fueling) and the other one (which I believe only measures cat efficiency) is actually on the y-pipe but before the secondary cats.
So then why are there 2 bungs on these LT headers? One at the collector (probably the one you’d wanna use for fueling feedback) and one on a single primary runner??

 

The one on the primary is so you can use your oem O2 sensor.

You need an O2 extension to route the oem O2 sensors down to the collectors.

This is where you want them installed.

 

Got it, thanks! I figured you’d want it to measure all cylinders but didn’t realize it’s simply to have options. So you plug one