03hoe5.3

Would the speed engineering 3" true dual exhaust be to much for a stock 5.3 with a cai, 1/3-4 longtubes and a black bear tune or would I be better off with just the y pipe and a dumped magnaflow. I'm not looking to make much more power with the duals I just don't want to lose any power with them. I mainly want them for the sound and later on if i decide to get a cam and also will the true duals fit a 2003 tahoe?

Jake75

iTrader: (2)

i have a texas speed y pipe with literally 4 miles on it ill sale for 120

FFDP

iTrader: (2)

You don't lose power, it just moves the power band.

Stock exhaust is already like 2.75in, going to the full 3in isn't going to matter much if you do the long tubes. A tune will be the best way to get all that useless horsepower to the ground.

03hoe5.3

Even the 3" true dual exhaust from speed engineering

FFDP

iTrader: (2)

I think that would be overkill for true duals but just going to a single 3in would be the better option. You could have it split after the muffler if you want dual tailpipes.

03hoe5.3

So if I decide to go 3" true dual I won't lose any power from the large diameter? I plan to put a cam in the tahoe later on down the road so I was trying to see if it would be ohk untill then I still plan to get it tuned. I just don't want t to go to big and it kill power untill I get a cam

Jaxon2580

I'm gonna put my .2 in i just got a true dual 2.5 inch exhaust yesterday and installed speed engineering 1 7/8 headers and I'll just be honest with the amount I spent and how much power I got it would've been better to have just gotten true dual 3 inch or even single 3 inch then a split after the muffler

25hdtankhauler

Pending on bolt on and internal mods x piping formulas very. Just bolt on you can keep stock x pipping with a higher flow muffler. That is if you haven't super charged are turboed the engine. High performance exhaust pulse can be greatly improved with headers and low back force piping system. Exhaust match to HP is critical. Moderate HP gains keep stock piping with headers. There are tube size formulas on the net... Check one out. I'm putting 1 5/8" tubes with a muffler upgrade on a 6.0 & keeping stock piping with bolt on mods.

tpartsman

This is a conversation that does not need to be had, this is old horsepower knowledge. Big pipes x or h pipe ho flow muffler short pipes.

_zebra

iTrader: (5)

you realize dual 2.5" has about 38% more volume than a single 3", right? and dual 3" is about 44% more volume than dual 2.5". all significantly different systems.

having done dual 3" on my TVS LS1 (when i was originally intending on swapping in a 402), it feels like i sacrificed a bit of bottom end for the current setup (probably more so from the 1 7/8" headers vs using 1 3/4"). granted, i still plan on porting my blower manifold & doing a healthy cam some time after this deployment which would still justify such a setup (mid 600s hp). i can only imagine what a basic 5.3 would feel like running that setup in a truck weighing 1500lb more.

but there's a huge difference between a 620hp built 454 and a stock-ish 325ci motor! that big block needs to move so much air that the dual 2.5" was choking it out. some simplified math (without factoring in the intake, heads/cam, volumetric efficiency, & whatnot) would say at 6000rpm, the 454 moves 788cfm while the 5.3 moves 564cfm. that's 72% of the 454's air evacuation requirement. given that dual 2.5" is just over 69% the volume of dual 3", logically, you should see about the same exhaust gas velocity & back pressure running a dual 2.5" on the 5.3 as they saw running dual 3" on the 454.

then you look at the engines themselves: their test motor is a high-compression big block with a huge carb, high-flow heads, a healthy cam, and 2" headers. when you proportionally scale that back to a 5.3 as i did above, you'd still need the high-performance bolt-ons to make it a good A-B comparison. considering it's still a pretty stock engine, the airflow requirements will be lower and still not really NEED to have an exhaust system that big... which means the power band will be shifted higher in the RPMs and have a little loss down low.