Topic profile page for Backpressure.
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Topic "Backpressure" was discussed 0 times on 0 sites in last 3 months
Started 1 week, 4 days ago (2009-12-28 10:15:00)
by JimAllen
I recently installed an ISSPRO backpressure gauge (tapped into the left manifold) for grins and have been noting my backpressure. My truck is a '05 F-150HD 4x4 (I call the payload package trucks "F-150HD"... bear with my affectation, huh). The truck just turned 20K miles, has all the factory cats but a Dynomax 3-inch catback, running a Gryphon tuner, generally on Level ...
Started 1 week, 4 days ago (2009-12-28 07:32:00)
by mini_me
I read en hear a lot of people mentioning backpressure (or the lack thereof) and it's effect on performance. Now I can understand the need for backpressure on a 2 stroke engine but for some reason I can't get the picture clear on a (modern fuel injected) 4 stroke engine like our Rotax engines. To me on a modern engine I would say no backpressure at all is the best. Somebody ...
Started 2 weeks, 1 day ago (2009-12-24 01:29:00)
by jamie72
lots of backpressure new head studs and liberator perfmce.egr del.! now 10# boost at idle and 50# backpressure under throtle. and only 20# boost..please help!!!!
Started 3 weeks ago (2009-12-18 06:06:00)
by jeryruse
The reason that exhaust valves burn is because the engine is burning lean. Normal engines will tolerate lean burning for a little bit, but not for sustained periods of time. The reason why the engine is burning lean to begin with is that the reduction in backpressure is causing more air to be drawn into the combustion chamber than before. Earlier cars with ...
Started 3 weeks, 3 days ago (2009-12-15 15:54:00)
by msharptx
I am tying in a spring-operated pressure relief valve into a vent piping system, which imposes a backpressure greater than 10% (of the set pressure) on the relief valve. From my experience, when the backpressure is greater than 10%, you are required to run the calculations of the specific relief valve to see if it is suitable for the amount of backpressure. I ran the calculations, and it is ...
Started 1 month, 1 week ago (2009-11-29 22:29:00)
by RedEIKO0713
Been reading alot on backpressure as I have a pile of aluminum sitting around and was considering making a full system myself but am kind of... confused. Over and over i have read that backpressure being necessary is really a myth from people not properly tuning the AF ratio to get a chemically correct mixture to burn the right way, instead leaning out and thus overheating (notoriously valves) ...
Started 1 month, 2 weeks ago (2009-11-19 08:00:00)
by specv44
Would removing the muffler (the last 24" of the exhaust), replacing it with straight pipe and welding the tip back on, change the backpressure in the exhaust? GM is now "looking into" the muffler delete on the hhr. They are saying that it changed the backpressure on the exhaust/motor and that may be why it is misfiring. Problem for them is, is that it was misfiring before we deleted the muffler, ...
Started 2 months ago (2009-11-04 19:01:00)
by BladeMechanical
BackPressure OK, so I went wheeling a few weeks back, it kind of got nasty there for a while, not that I'm complaining, a little grind here a little bump there some three wheel motion and I finaly made it through. After my outing my Jeep's fuel efficiency when out the door, it started making kind of a roaring sound at start-...
Started 2 months, 1 week ago (2009-10-29 13:17:00)
by sflash868
I was thinking about removing my cat with a custom made midpipe. Has anyone tried this? I know some motors actually loose HP when you reduce backpressure but I'm not sure on the LR motor. Thoughts? Ideally, I want to dyno the truck with and without the pipe for curiosity sake.
Started 2 months, 3 weeks ago (2009-10-14 16:34:00)
by Brad SXT
So I know alot of people have been saying the SRT8 exhaust will not produce the backpressure needed for low end torque. I understand this, and I also understand that I need all the low end torque I can get. My question is, if I install a ported throttle body and headers, will this help shift the powerband back where it belongs? Or, would I still be better off with an R/T exhaust?
Started 6 days, 12 hours ago (2010-01-02 09:52:00)
by fastest430
NIB-2 they list for 69.99 ea. By Dynatech,vortex insert cones Stainless steel inserts install near the exit of the collector or muffler outlet to provide a large friction area to reflect and dissipate sound.No significant backpressure has been introduced,so the engine is still able to use the scavenge ability to create horsepower and torque. SELL $100.oo ,thats over a $40 saving!
Started 5 days, 8 hours ago (2010-01-03 13:20:00)
by Crazy Craven
My EXUP Servo stopped working the other day, I rode the bike still but knew the loss of power was there (bike was very different in low end) and I also believe that the EXUP valve is to give backpressure to low end RPM's right? Please correct me if I'm wrong, that's all I can figure looking at how it works. Secondly, last night I was riding home (my engine light is always on, code 17 & 18 ...
Started 1 week, 1 day ago (2009-12-31 12:46:00)
by SubiGT
Quote: Originally Posted by subaru_terrence hahah but it is true. Not to mention it is illegal , and what about the backpressure due to the exhaust leak? so is speeding, my full length DP, re-flashing the factory ECU, etc......... no preaching
Started 5 days, 20 hours ago (2010-01-03 01:28:00)
by Brettus
Quote: Originally Posted by MazdaManiac You are still not looking at what is causing the net decrease in flow. OK - I'm with you now . The decrease in flow is caused because the wastegate actuator is designed to adjust pressure . Reduce the flow capabilities of the motor and the wastgate still provides the ...
Started 1 week, 1 day ago (2009-12-31 11:26:00)
by Diver
Quote: Originally Posted by The Ace Οσο για το backpressure, λιγότερο είναι καλύτερο, ΑΛΛΑ μέχρι ενός σημείου. Από εκεί και πέρα τα κέρδη στις υψηλές στροφές είναι minimal, ενώ οι απώλειες στις χαμηλομεσαίες αλλά και στην καμπύλη ροπής είναι ΠΟΛΥ σοβαρές, λόγω ελλειπούς πλήρωσης των θαλάμων (τα εξερχόμενα καυσαέρια παρασέρνουν και το ...
Started 1 week ago (2010-01-01 11:49:00)
by mde's04titan
Quote: Originally Posted by sleepertrk Some of you guys are just plain silly. I swear if one guy says don't buy something you all jump on the bandwagon. Flowmaster mufflers have been around for a long time and there is a reason for that, they work. I have nothing against Magnaflow but the way some of you guys are so anti-Flowmaster its...
Started 1 week, 1 day ago (2009-12-31 09:36:00)
by Velocifero
Quote: Originally Posted by nvmsp open question. Does anyone know if apexr1 already has a cat that I could bolt up to the catless downpipe they make, the 3in. one.? I just wanted to know without calling them and lookn for their number. Cause I want to put on the 3in again but it needs a cat, high-flow or not it needs a cat for some...
Started 1 week, 1 day ago (2009-12-31 04:35:00)
by 1BADSS/SC
Quote: Originally Posted by BYT*SS*TURBO I agree. If you compare a K04 to a twin scroll K04 tho, you will find the twin will spool harder faster and hold out longer. Another quote from elsewhere: We have found the twin-scroll systems have higher backpressure at low rpm (which is good for turbo spool-up) and lower backpressure ...
Started 1 day, 10 hours ago (2010-01-07 11:54:00)
by need_a_VR6
Quote, originally posted by codesniper1313 » Can anyone explain the need for backpressure on a NA engine then? Back pressure isn't needed at all. If you could keep the exhaust under constant vacuum, it would be advantageous from a power point of view. This is obviously not possible other then under test conditions. What you do want is the pressure pulses that the back of the ...
Started 4 days, 2 hours ago (2010-01-04 19:35:00)
by 911st
Quote: Originally Posted by copbait73 Dave, you are correct, but more to the point. High compressor efficiency, high CAC efficiency equate to lower intake manifold temperature. All things being equal lower intake manifold temperature gives you denser charge at a fixed firing pressure therefore more knock margin. Firing pressure and ...
