De-bunk the Myths! - Page 9 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Performance, Brainstorming & Tuning Talk about modifications, or anything else associated with performance enhancements. Have a new idea for performance/reliability? Post it here. No idea is stupid! (please use Detailing and Appearance for cosmetic ideas)

Reply
 
 
 
Thread Tools Search this Thread
Old 03-01-2007, 04:26 PM   #81
Junior Member
Posts like a Ricer Type-R
 
Join Date: Mar 2005
Location: Memphis, TN
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
tunnel1975 is on a distinguished road
Default

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.
tunnel1975 is offline   Reply With Quote
Old 03-19-2007, 01:54 AM   #82
Ignorant User
Posts like a 4 Banger
 
Join Date: Mar 2007
Posts: 126
Thanks: 0
Thanked 0 Times in 0 Posts
Dirtracr95 is an unknown quantity at this point
Default

Quote:
Originally Posted by projectheavytouring

as for getting rid of myths.... this isn't a manufacturer specific thing... but this whole "you need backpressure to run an N/A engine" thing has got to be stopped. backpressure is BAD for an engine... what alot of ppl think of needing backpressure is actually exhuast velocity ... while backpressure may remain in an exhaust tuned for exhaust velocity, the idea is to get rid of as much backpressure as possible, while getting maximum exhaust velocity. just think about it for a second or two ... back pressure... this is exhaust getting forced BACK into the combustion chambers... not a good thing
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
Dirtracr95 is offline   Reply With Quote
Old 03-19-2007, 11:18 AM   #83
Senior Member
True Car Nut
 
Join Date: Aug 2003
Location: Salina, KS
Posts: 5,246
Thanks: 0
Thanked 0 Times in 0 Posts
TrueWildMan is on a distinguished road
Default

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 900F for diesel and 1,200F 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.
TrueWildMan is offline   Reply With Quote
Old 06-19-2007, 01:03 PM   #84
Member
Posts like a V-Tak
 
Join Date: Jun 2007
Posts: 30
Thanks: 0
Thanked 0 Times in 0 Posts
il67bp is on a distinguished road
Default

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

does this look like a scam to anyone?
il67bp is offline   Reply With Quote
Old 06-19-2007, 01:05 PM   #85
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

ALL EBAY CHIPS are scams UNLESS they come with a name brand attached. Jet, Superchips, DHP, INTENSE, ZZP, etc.
willwren is offline   Reply With Quote
Old 06-25-2007, 09:19 PM   #86
Junior Member
 
Join Date: Apr 2006
Location: Purgatory
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
Bonneville92V688 is on a distinguished road
Default

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
Bonneville92V688 is offline   Reply With Quote
Old 06-26-2007, 02:36 AM   #87
Senior Member
Posts like a Supercharger
 
Join Date: Oct 2006
Location: Sioux City, IA
Posts: 154
Thanks: 0
Thanked 0 Times in 0 Posts
sandness is on a distinguished road
Default

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.
sandness is offline   Reply With Quote
Old 10-21-2007, 01:13 PM   #88
Senior Member
Posts like a Camaro
 
Join Date: Oct 2006
Location: montreal canada NEBF07 ONBF07
Posts: 987
Thanks: 0
Thanked 0 Times in 0 Posts
firebuick is on a distinguished road
Default

Quote:
Posted: Mon Jun 25, 2007 7:19 pm Post subject:

--------------------------------------------------------------------------------

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.


yeah i did see that show was wondering if its true and if they are going to test it
firebuick is offline   Reply With Quote
Old 11-02-2007, 10:59 PM   #89
Junior Member
Posts like a Ricer Type-R
 
Join Date: Oct 2007
Location: Omaha, NE
Posts: 18
Thanks: 0
Thanked 0 Times in 0 Posts
86 electra is on a distinguished road
Default

Quote:
Originally Posted by dblack1
its supposed to vaporize the fuel b4 it gets to the injectors
Thats called vaporlock. Verry bad.
86 electra is offline   Reply With Quote
Old 11-02-2007, 11:02 PM   #90
Junior Member
Posts like a Ricer Type-R
 
Join Date: Oct 2007
Location: Omaha, NE
Posts: 18
Thanks: 0
Thanked 0 Times in 0 Posts
86 electra is on a distinguished road
Default

Quote:
Originally Posted by pitts64
HEI distributers on older pre 72 engines.
The points work just as good on the old engines.
HEI was need when they leaned out engines for emissions.
thats more of a ease of maintenance thing. It never needs adjusting. Definitely an upgrade.
86 electra is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Gaming audio myths Mike Computers-Phones-Tablets 5 08-26-2014 05:48 AM
8 Fuel Economy Myths Debunked YoungGunLs1 Lounge 1 03-04-2011 06:53 PM
Top 10 Beer Myths MOS95B Lounge 2 03-31-2007 08:47 PM
Colder t-stat myths DrJay Performance, Brainstorming & Tuning 49 07-29-2003 12:45 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 10:58 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.