Seems Like I Have I Lost Some Torque And Throttle Response - Nnbs

[jerstilly]

I have a 2010 Silverado 5.3. About 2000 km's ago I put on a MBRP dual side exit exhaust(3.0 in, dual 2.5" out), as well as a K&N drop in air filter. Ever since both of these mods it seems as if I have lost some throttle response along with low end torque. could this be possible? and why?

 

Would I gain more low end going with a Borla which is 2.75" in, dual 2.25" out, a 2.75" single OR with a corsa 3" single.

 

 

Thanks for your help.

[Stevens03]

Yes... VERY possible. You may have gained in the higher RPM range, but lost the low end. A smaller diameter exhaust pipe would help after the muffler. The 5.3L is very susceptible to loss of low end torque when putting higher flow exhausts on.

[jerstilly]

i also just found out that the intermediate pipe from the cat to the muffler is increased from 2.75 to 3.0", plus being 2.5" dual back, instead of available 2.75" in 2.25" dual out from borla.

 

 

Yes... VERY possible. You may have gained in the higher RPM range, but lost the low end. A smaller diameter exhaust pipe would help after the muffler. The 5.3L is very susceptible to loss of low end torque when putting higher flow exhausts on.

[shagadelic]

Yes! and you probably did. You created more flow and lost back pressure.

 

 

Alot of folks just bolt on an exhaust without doing the proper math associated with it. That's why those aftermarket full exhaust systems are so expensive...your not paying for the metal, your paying for the engineering and mathematics associated with the design.

 

Most people think my exhaust will be "bada$$!" and that's all that matters....well it's not that easy.

Specially when you start messing with the factory pipes and Y-pipes.

 

A simple muffler swap not so much, but it does affect it a little.

 

That's why people touting "strait thru!, strait thru!, you get better flow!" isn't always the best plan.

 

Sometime you want those internal baffles that some manufactures use (i.e flowmaster) vs strait through designs.

 

I'm a big Borla fan, i think they make the sweetest sounding exhaust note on the market, but they flow very well, so you need to be careful. It's not always as easy as making a custom exhaust with whatever dia. pipes you want, slap it together on viola!

 

You may end up running like a raped ape at the highend of your powerband, but at a big cost to the low end power.

[MightyMouse]

I disagree, decreased back pressure does not equal decreased torque. Back pressure decreases the efficiency of the engine and results in less horsepower. Your "butt dyno" is deceiving you.

[nbscanuck]

It is dyno proven, too much flow, hurts torque. If you need pulling power, don't put on headers and free flowing exhaust. If you want to rev high, let it breathe.

[Big Whiskey]

Yes... VERY possible. You may have gained in the higher RPM range, but lost the low end. A smaller diameter exhaust pipe would help after the muffler. The 5.3L is very susceptible to loss of low end torque when putting higher flow exhausts on.

 

I agree. I put dual straight pipes on my '06 and lost power on the low end. It would run like a wild hyena when it was at 6000 rpm though.

 

Stock 5.3's need some backpressure to retain what little low end torque they have. They're tuned for the stock exhaust system.

[GMstrong]

If your running a single i wouldn't go smaller then 3" if your duals then 2 1/4 is the smallest before it becomes restrictive.It all matters about the motor size and the HP.

[jerstilly]

If your running a single i wouldn't go smaller then 3" if your duals then 2 1/4 is the smallest before it becomes restrictive.It all matters about the motor size and the HP.

 

So do you think if I went with the borla exhaust I could get some bottom end back, its is 2 7/8 in, dual 2 1/4 out vs. what I have now 3" in, dual 2.5" out.

[GMstrong]

thats the setup im going with the same setu but i got the CherryBomb extreme.Dont get the borla get the flo-pro vforce 3" inlet 2 1/2" dual outlet.i got that muffler on my 99 sierra excellent muffler.great flowing.no where near as good as the cherry bomb extreme though.