I've heard that magnaflow increases HP anywhere from 3-23Hp is that true?? I just installed it on my L yesterday. Right now, I only have a K&N AF and magnaflow? Do you guys think im pushing 400HP or not even close?? Thanks for your responses!

 

It's a 2003 L

 

350-360rwhp in the cool weather.

 

Mufflers do not increase hp. They just sound that way!

 

even if it's listed at 380rwhp? is that a bunch of BS or what then??

 

I believe the 380 is at the flywheel.....which really doesn't matter.

Most people on this board will tell you it's the HP at the wheels that matters.

I have the magnaflows too and love how they sound. Didn't really notice much difference in performance though. I'm running the same set-up you have, and run high 13's.
Hope this helps bud..

 

1. Magnaflow will add ZERO horsepower.
2. Advertised STOCK lightning power is measured at the flywheel, not the tires.
3. By adding the K&N and the Exhaust, you've added ZERO power to your truck.

what you want to do is increase the flow of air through the engine. that is how power is created. Get rid of the stock exhaust manifold, stock headers and you will flow more air.
Port the heads and you will flow more air.

you have to "attack" the bottleneck areas of the engine. Unfortunately, the stock air box and the muffler, is not one of them, until you start making substantially more hp than the stock.

 

Cat-back system will result in "zero" rwhp gains. But is sure does sound kewl. I ran the single maggy for over a year and loved it. I recently switched to the dual magnaflow and ....ahhhhh....much better

 

AND YOU KNOW THAT B!TCH IS LOUD!!

(Rob...need to borrow this....WOOOHOOOO)...thanks

 

I thought the K&N increases the air flow in the engine..and how much does it cost for long tube headers, and getting rid of the stock exhaust manifold and porting the heads?? thanks

 

The biggest restriction in the exhaust system is the four catalytic converters. Replacing them with two high flow converters will help. Don't bother with the heads yet. Get yourself a bigger crank pulley.

 

Not true. If your muffler is restrictive as well as your intake, and you reduce the restriction, you will increase power. Not a great deal, but an increase none the less. If you squeeze the ends of your tail pipes until they are barely open with a full exhaust system upgrade, your truck will barely run. Yes, mufflers in general can be the "cork" in any vehicle. personally I have to say that the cat-backs in general are not the best hp per dollar values out there, they are more of a sound and bling mod more than anything else. BTW, I picked up 8 rwhp with the maggy cat-back and modified stock air box with a panel K&N. Not huge , but an increase. The way that the owner of Kooks headers put it to me was: In order to optimize any exhaust system, is not to go with big headers, but with a small (port size) primary tube header and have it get bigger as it works its way to the tail pipe. As he discribed , like a trumpet. Makes complete sense to me.

 

You will find the search button quite helpful on this subject. If you want more (and more importantly reliable) power, you can take the proven route. Pulley, chip or tuner like Predator, High flow filter (which you have). Change the plugs to a cooler plug and you'll have a 12 second lightning (or close to it).

I ran a PSP air filter, Accufab TB, 4lb lower, Denso IT22 plugs, 170* T-stat, Maggy cat back and JLP tuned Predator and made just shy of 420 at the wheels. Had the tune checked on a dyno to make sure A/F's were safe and had a nice safe reliable beast that surprised more than one Vette owner.

Good luck.

 

manufacturers quote the motor or flywheel hp. you lose about 18-20% of your power from the motor to what is laid down at the rear wheels. if i remember correctly, somewhere around 11% of that is lost in the transmission and the rest is the wheels, tires, gearset, driveshaft, etc...

 

03BadAzz, you are apparently not following my previously posted suggestions for you:

"1. Read.
2. Critically evaluate the source. Lots of pure idiots roaming these boards.
3. Read more.
4. Ask.
5. Do."

As a matter of fact, the fact that you did not understand that the 380HP was at the flywheel suggests that you have not even mastered step 1.

Why bother answering these questions, guys? They do not even rise to the level of Lightning 101.