Jump to content

Exhaust Guru's need some help!

skallywag

By skallywag
in Engines & Drivetrain

Recommended Posts

harley_man Enthusiast

harley_man

Posted
Posted

Range is a company that makes a device that plugs into your computer and it disables the AFM mode(4 cylinder mode), they also make a device that keeps it in v4 mode longer.

Txjose Senior Enthusiast

Txjose

Posted
Posted

I felt a bit of a loss on low end with my headers and 3" single exhaust but man that top end wow.

 

07Softail is spot on. With that much flow you will suffer from an excessive loss in back pressure resulting in a loss of power. I would only do dual 3" if i were running a cam and a blower and even then i still think a single 3" would be better.

 

Hell i think the 6.2Ls are dumb from the factory with the 3.5" exhaust. Should be a 3" i bet they would make the same top end but more low end.

 

Sent from my Note 4 on Tapashit

Jon A Senior Enthusiast

Jon A

Posted
Posted

Well, with headers and a 4" single I gained a ton of low end on my 6.2. I guess I must be doing something wrong? :P

07Softail Senior Enthusiast

07Softail

Posted
Posted

Well, with headers and a 4" single I gained a ton of low end on my 6.2. I guess I must be doing something wrong? :P

How bout some numbers i'm curious?

 

RT

Badass69 Senior Enthusiast

Badass69

Posted
Posted

Jon A, on 23 Apr 2016 - 1:21 PM, said:Jon A, on 23 Apr 2016 - 1:21 PM, said:

 

Well, with headers and a 4" single I gained a ton of low end on my 6.2. I guess I must be doing something wrong? :P

No kidding lol. I am the stock 3.5" pipe size on my 6.2 and make right around 400 ft lbs to the tires with tune, intake tube and exhaust only..... and that's power starting at 350 ft lbs just over 2000 rpm... and peaking at 4100 rpm as they do stock. 3" pipe would not benefit me in any way, shape or form. Achieving proper scavenging is the goal.... and what I have is working just fine. When I went from the stock catback with it's necks and goofy valve to the free flowing MBRP it was a noticeable gain throughout the power band.... including right off idle. Makes sense getting rid of all the of the elements that just get in the way of proper gas flow.

 

And if I read one more "backpressure" comment about exhaust I am going to snap ( not really but it's really annoying). Your engine is not a steam generator where a measurable restriction of flow is desirable...... it's not! You want flow velocity and scavenging.... not measurable pressures! And no saying "backpressure" is not the same thing.... it's not even related lol.

Jon A Senior Enthusiast

Jon A

Posted
Posted

 

 

How bout some numbers i'm curious?

 

Sure:

 

BoltonsSAE.jpg

 

An increase of 36 lb-ft at only 2000 RPM and 40 lb-ft at 3000 RPM. The other significant "power adding" mod was a CAI which should have little to no effect at low RPM after tuning. I guess people can say if I had stuck a 3" exhaust behind the headers instead of the 4" one maybe I would have gained 50 or 60 lb-ft at 3000 RPM instead of only 40, but it's a pretty fantastical claim that I'd need to see to believe. They're ARH 1 3/4" longtubes, not Tri-Y's or anything odd that could dramatically change the torque curve like that.

 

In short, I added big-ass cat-back exhaust and headers and gained a bunch of torque EVERYWHERE!

 

That said, it is a 6.2, I don't think the 4" is going to show much difference either way on a stock 5.3 vs a 3", and dual 3" on a stock 5.3 is certainly more than needed. But the idea going bigger than a 3" single is going to cause large losses of torque on the low end is something lots of people say but nobody actually has a dyno showing such a result.

07Softail Senior Enthusiast

07Softail

Posted
Posted

Damn... That's Nice. These 5.3's run good but the cylinder heads need a lot to be desired and just don't flow as well as the LT-1 heads. I guess the 4" is suited for the 6.2 definitely not the 5.3. Good Show

 

RT

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • newdude
      Seems to be Missing a lot of Updates

      By newdude · Posted

      Based on what I can tell, yes.   As for updating it, its a mixed bag.  Updates do fix a lot of issues, but occasionally can create some oddities.  They do more good than harm though overall.     Here's what the most current one does and a  V171 Improvements Important: Improvements will vary by model, build configuration, system, and sales region. Not all vehicles have all features. OnStar and Wi-Fi may not work after remote start CarPlay may not automatically reconnect Part of the Driver Attention messaging screen may be in English even though the language is set to something else XM may not work After a dead 12V the radio may set to Arabic at each startup Bluetooth contacts might not be able to sync with the vehicle During an OTA the 12V battery may drain Customer might see a screen telling them to return to the dealer After changing the Wi-Fi SSID or password a device may not disconnect If a device is connected on the 2.4Ghz band, nothing will connect to the 5Ghz one, which could show as slow Wi-Fi speeds Customers might have noticed Wi-Fi dropping in certain areas and reconnecting later Customer might see the top of the screen blinking during Android Auto Android Auto may not connect CarPlay audio might momentarily cut out The "Add Phone" button may be grayed out The radio may not start up   V167 Most Notable Improvements:   Outside Air Temperature is incorrect. -You may see a popup message for Engine Shift. (Corvette Only) After changing the exhaust sound they get a popup that "mode change not applied", even though it was. -When changing volume, the volume bar is for Traffic instead of Audio. -(Corvette Only) Improvements to the placement of buttons and text. -If the customer receives the message "Apple CarPlay Could not connect", the cursor might move in the opposite direction than expected when using the control knob. -Android Auto automatically starts playing their music, even though they have turned that off in settings. -Intermittently they have a red OnStar LED with no OnStar function and/or no audio. -The minimum length of the Wi-Fi password was increased to 12 characters. -The popup message "Driver Attention Check, check your mirrors or Super Cruise will shut down" may not have come up on the display when it should have. -Startup animation added for 20th anniversary of the V-Series on Cadillacs. -The Navigation app received location improvements when going under long underpasses. -In the Navigation app there are filters for charging points that the vehicle cannot use.   V164 Most Notable Improvements Most notable improvements contained in this release may include: Apps Intermittently, an “SD Card Removed” message will pop up in the Navigation app. While in the audio app, the radio may stop working. Trailer Tire Pressure sensors may not be learned in the Trailer app. Not being able to return to the home screen while in the Camera app. After an ignition cycle, the radio might go to a black screen or stop working if using Sirius XM. Spotify icon truncated on Audio app.   SXM When changing power modes with the ignition switch, the HVAC pop up might appear. During startup, the radio will show the brand splash screen then go blank. Receiving a confirmation pop-up when changing drive modes. A “Return to Dealer” message may appear on the radio screen. SuperCruise setting toggle may not work. System After an ignition cycle, the radio might go black or stop working if using Sirius XM (SXM). Settings When performing a factory reset, the radio may stop working. After performing a factory reset, the radio may stop working when trying to switch users. When trying to go into the Language section quickly after startup, the radio may stop working. Projection Wireless CarPlay cannot be connected after unpairing another wireless Android Auto device. When the Android Auto screen comes up to connect wirelessly, the screen may freeze if the Cancel button is pressed. Removed the Apple CarPlay Cannot Connect screen when a device fails to pair during the autoconnect process. CarPlay information may not show up in the audio app. Near Field Communications (NFC) chime may be heard when NFC does not work. The Cannot Connect screen does not pop up after the first connection on wireless CarPlay fails. Apple CarPlay is now functional in Guam. Over the Air (OTA) When a software update is cancelled, the downloading logo may still be displayed. Energy When using the Energy app, the radio may stop working. When plugging in the vehicle, the display might show “Now” instead of “Charging Upon Plug In.” Instrument Cluster Voice recognition can be started while on an OnStar or phone call. When downloading contacts, there is a progress bar and circles on the Recents page of the cluster. The temperature on the cluster and the display may be different. After receiving and ending a call on the secondary paired phone, the cluster may get stuck on the phone menu. Bluetooth Intermittent Bluetooth connection loss.
    • AndrewF
      Front End Rattle

      By AndrewF · Posted

      Looking for help troubleshooting a metallic like front end rattle. Figured I’d see if anyone had thoughts before I schedule an appointment with the dealer.   The rattle is fairly loud and occurs primarily when the front driver side wheel hits a bump, even fairly minor road seams. Sometimes does it when the passenger hits a bump but I don’t believe when the rear hits. Rattle still occurs when foot is pressing brake peddle so I think that rules out the caliper rattle I’ve read about. I’ve also checked the running boards and they are tight.   Most noticeable at slow speeds.    Any insight is appreciated. 
    • KARNUT
      What did you do to your "other" car (aka musclecar) today

      By KARNUT · Posted

      We try to make cruise the coast. It’s where our favorite casino is. I only want to spectate. Never took a car. Always had one to take. I belonged to a club once. Even when I used to drag raced. It was during test and tune. Probably because I’m not a night owl, party person. 
    • RyanbabZ71
      What did you do to your "other" car (aka musclecar) today

      By RyanbabZ71 · Posted

      We had a pretty big cars and coffee in Indy this past weekend.  Pretty much anything and everything was there.  
    • Atlas
      What did you do to your "other" car (aka musclecar) today

      By Atlas · Posted

      Good looking Olds, and TRX!   I haven't been into car shows either. I'm probably not a convert but I did push myself this year to attend a few select events to challenge some assumptions and try to experience car-based social clubs in a different way. I joined up with the local Hagerty group for some cars/coffee events, group drives. A month ago I showed my '94 Camaro I rescued last fall at Radwood. Had a good time, but, there was some sitting around with the car and that's the part of shows I don't enjoy as much. I prefer to be a spectator, walk the show, grab a burger, go home.   Radwood was the only era-limited event, but where it had strict model year limitations, it made it up in variety. Having Jason Camissa there was also a hoot.   Where I see old 50's car shows, doo-wop and winga dinga music stuff fading out, same with "only" vintage muscle clubs, it seems to be the activity-based clubs/events which are gaining strong popularity. Places where all cars and interests come together.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...