K & N Exhaust

Colorado Z · May 25, 2001

Does anybody have a K & N Catback system installed on their truck? The specs say that their catback system will give an average increase of 22 hp (compared to the usual 10-15hp of most systems), same torque (30 ft lbs) as Gibson. I just haven't heard too much about this system, mostly Borla, Gibson, Flowmaster, etc. I'm looking to replace my dual in/single out stock exhaust with something for a little more rumble and power. Don't know yet if I'll switch to dual in/dual out, or get something like this K&N where it's dual in/single out. What do you think? Does it make a difference?

Shaners · May 26, 2001

I haven't heard of anyone with the K&N system either. I'd sure like to hear one though.

I put the Borla system on my last truck and really liked it, but for now I'm going to stick with the stock system on this truck.

LT · May 30, 2001

I have heard of it but in context of high performance vehicles. I'm sure that they would see a market for the truck world as well.

LT

Colorado Z · May 31, 2001

Would I be better off with a dual in/dual out system, or a dual in/single out? What difference does it make, if any? I currently have the stock dual in/single out with two cats.

Shaners · May 31, 2001

If you go with the single out, you can go to a larger pipe (3" or so). If you go to dual out, then you need to keep your exhaust pipes at no larger than 2-2 1/4". If you go to large on your exhaust your truck will fall on it's face out of the hole. This is because the lack of back pressure will rob you of low-end torque. You will notice a bigger gain from the midrange up (3-5K rpm) with a larger pipe though.

The biggest problem with going bigger is that in everyday driving we don't see those kind of rpm's that benefit from the larger diameter pipe.

In my opinion, I would leave everything stock size and put on a good high quality system or muffler. Companies like K&N and Borla and PV have engineered this to an exact science and they build very good systems that we benefit from (pricey though).

The Vortec heads require back-pressure to be efficient, and GM has designed their stock exhaust around this fact. Generally speaking the louder the exhaust, the less back-pressure, and the loss of torque on the bottom end is more noticable.

Colorado Z · May 31, 2001

Thanks Shaner, that was a load of good information that I didn't know. But, does it make a difference if I go with 1 3" pipe with one muffler, or two 2 1/4" pipes with two mufflers. Is there any difference in hp and sound between the two set-ups? Thanks again.

Shaners · June 1, 2001

Both systems would be OK... If you want the "duals" look then I would recommend a 2-in 2-out muffler. This is for 2 reasons... (1) it would be cheaper than buying 2 seperate mufflers and (2) it eliminates you from having to put in an "H" pipe. It is not a good idea to run 2 pipes that don't come together somewhere in the system to equalize the back pressure on the motor.

I had the Borla on my last truck and the system connected at the "y" pipe and ran a single in dual out muffler. It was a 3" in and dual 2 1/4" out muffler.