man the stuff people will try and sell in the name of making power. you know there is no way to get a cheap bolt-on miracle piece of equipment to make your car better. I am old school and firmly believe cubic inches+cold air is the best way to go. supercharging and turbo are ok too as long as its done right.

backpressure may not be needed to run a N/A engine but it definatly helps. Im not saying the more backpressure the better but there is a certain amount of backpressure you need for your engine to run at its best. you need to look at the system (engine) as a whole and not just exhaust part of it. why do you think a free flowing exhaust on my 01 grand marquis lost low end TQ, granted it did gain top end HP but its a give and take system if you want something you have to give up something.

http://www.hotrod.com/techarticles/a.../photo_01.html

Check this link out. It gives a very good explanation of "backpressure".

http://www.uucmotorwerks.com/html_pr...torquemyth.htm

At the same time, the reverse pulses that allow more air to be sucked into the combustion chamber, thus causing the PCM to change the fuel curve, does provide more torque. The more you open the exhaust, the reverse pulses diminish. That'* why most go with and "H" pipe when going with dual exhaust.

Saying that backpressure is exhaust fumes reversing into the chamber is not actually true. It'* "pressure", not back flow. Very different things here. You can have pressure without flow. That being said, you can have flow one direction, and still have opposing pressure.

Use this to determine exhause flow:

Exhaust flow rate =

D (in3) x full load rpm x E x (7* x 460*)
C x 941,760

D = displacement in in3
E = 0.85 efficiency for naturally
aspirated engines
= 1.2 for engines with scavenging blower (supercharger)
= 1.4 for turbo-charged engines
T = exhaust temperature; if unknown,
use 900°F for diesel and 1,200°F for
gas engines
C = 1.0 (two-cycle engine)
or 2.0 (four-cycle engine)

Once you have that info, use this to determine backpressure:



The silencer is, of course, the muffler, and/or any resonators. By using these formulas, you'll see that on any given stock or lightly modded engine, the backflow rarely exceeds 1" Hg. So, there'* no problem.

The problem arises when you modify the exhaust without changing other functions, such as intake, valve duration, fuel/air ratio, etc.

That'* not what we do here, nor do we condone changing only one thing. We warn plenty of individuals not to open the exhaust, or produce more boost, without also changing the breathability of the engine in its entirety.

Just do a search, you'll see.

http://cgi.ebay.com/ebaymotors/Ponti...QQcmdZViewItem

does this look like a scam to anyone?

ALL EBAY CHIPS are scams UNLESS they come with a name brand attached. Jet, Superchips, DHP, INTENSE, ZZP, etc.

Ah... Here'* another one. The guys on spike TV (not sure of which show) claim that it works. Seems to me like another fake fuel saver to me.

http://www.fitchfuelcatalyst.com/pro...uto/index.html

Hmm, interesting product. Their review pages has a pretty good list of seemingly credible sources that used their product with positive results (few emissions, better mileage, some small power gains) http://www.fitchfuelcatalyst.com/products/reviews.cfm
I wonder what they are using as a catalyst, assuming the reviews I've read are true.

yeah i did see that show was wondering if its true and if they are going to test it

Thats called vaporlock. Verry bad.

thats more of a ease of maintenance thing. It never needs adjusting. Definitely an upgrade.