This has been posted before with no reponse, but I have got to believe somebody has tried out the summit racing cat back system. At $149.00 it seems to be a very good deal. Please, if anyone has any experience with this setup, let me know. Otherwise I am going to have to be the first to try it out!

 

This is funnier than hell. I was just on the crapper reading about Summit's setup and got on the puter to post this very question. I have a 4.6 and don't tow anything with it. I just want a good sound. 3" is pretty big though. Does this system create enough back pressure?

 

I don't understand the concern or desire to create back pressure.

Are we not relieving back pressure with these performance exhaust systems?

I know about resonant exhaust tuning and all that, but that's not a back pressure situation.

Some of the best improvements I've seen for late model pickups - at least up to 3-4 years ago is a freer flowing exhaust system.

One of the best exemplifications - is that a word? - was the Chevy with it's factory 'Y' that joined at right angles and created a lot of internal turbulence.
More than a few of those guys went to a Banks 'Y' pipe and had immediate improvements.

The stock late model Fords are quite a bit more free flowing than the slightly older Chevys, but there are still performance gains to be had.

C9

 

I know with my Harley no backpressure meant loss of power. Don't get me wront you want it to breath easy but not too easy. Backpressure=power to a certain degree.

Think of it like this. When you blow out birthday candles you put your lips together real close and blow hard. This creates pressure and causes a powerfull wind. If you tried to do it with your mouth open as wide as possible you wouldn't have jack for power (not to mention you'd spit all over the cake)

So as I see it easy flow is better but too much is not a good thing. The one thing with the Summit setup it that you still have 2.5" pipe before the 3" so you'll never get more than the initial 2.5" will allow.

 

my fear with this setup is that it is going to be obnoxios loud. I might buy the system and just use a different muffler. This is the wifes truck. She said yes the exhaust but no to the noise! But even if I buy it at 149 and then another muffler for 40, i am still in under 200...not bad

 

Klutch - I'm curious if you re-jetted your Harley?

We rode a lot of 4-stroke dirt bikes in the desert and found jetting changes were almost always required when making any kind of an exhaust change.

There was always a horsepower gain with a freer flowing exhaust system.
Especially so once properly jetted.

C9

 

Oh yes it was re-jetted. But there is such a thing as overdoing it with free flowing exhaust.

 

I am pretty sure that if you have a supercharger you need "some" backpressure, at least it helped in my SC. I had a free flowing exhaust.. but. it ran rough. Put the resonator back in and it ran fine...??? I think back pressure is important part of a supercharged engine

Scott

 

Klutch - I'm guessing you're speaking of an overly large exhaust pipe.
That does kill exhaust flow velocity, but if you are running the right diameter pipe a totally open system will still run stronger than one with a backpressure restriction.

Looking at some of the late model Harley's, I'd say the pipes on them are overly large, but they sure do look good.

Valve event timing enters into the equation as well.
And maybe I should have included that when speaking about the no backpressure bit.

Regardless, as a practical matter with the dirt bikes and drag racing cars, we always had an improvement any time we could get rid of back pressure.

C9

 

C9........let me know what your exhaust does for the Super Crew, performance improvement (or not) and the sound too..

I just added a fresh air kit from Airaid to my 2k chevy truck. The air kit for the Super Crew is on it's way.

You have my email addy I do believe.

 

Have you tried that summit exhaust yet? Any reviews?

 

back pressure is a must for N/A trucks but not for S/Cd trucks. Running overly large pipes will improve your HP in the topend, but your lowend will be a dog.
S/C trucks want the lowest restriction as possible since we want to dump the exhaust flow and heat ASAP. I believe the L has less than 4PSI (i think 2) of backpressure. I know a guy who has 1 just behind the cats and his truck runs hard.
The only problem for SC guys is that without backpressure, you'll need to go into boost for power when putting around...not a good thing. Guess many people just put on a bigger stall converter then.
As for the Summit Cat back, I'm sure it's a good product. Just about everything they sell is quality, and if it doesn't work, just send it back because they have GREAT customer service.
-Tom

 

Backpressure is an old wives tale. It's all about mantaining velocity.

So has anyone tried the Summit exhaust system? I posted this question about 6 months ago and never received a response. (And I too found it in the Summit catalog while on the crapper.)

 

99sc4x4---Did you order it?

 

no it is backordered