Stock G8 GT mufflers cost 14rwhp at 500rwhp level
Here's a dyno overlay of the stock G8 GT mufflers vs running with no mufflers at all. 14rwhp loss. Now I need to find a free flowing axle-back that is still quiet. SLP Powerflo looks like the front runner as I hate drone as much as I hate back pressure.
2013 Corvette Grand Sport A6 Forged LME 416, Greg Good ported TFS 255 LS3 heads, EPS 222/242 .629/.604" 121LSA cam, ECS Novi 1500 supercharger running 11psi, ARH 1 7/8" headers, NPP exhaust, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwhp on race gas, w/stock street manners.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads, FAST 102, 231/231 114LSA cam. 506rwhp/442rwtq.
11.413 @ 121.29mph 1/4 mile, 168.7mph Texas Mile (all performance stats from 2010).
2014 GMC Yukon Denali XL 6.2L Air Raid MIT, VVT tuned to the max w/EFI Live.
2000 Pewter Ram Air Trans Am M6 heads/cam 508rwhp/445rwtq, 183.093mph Texas Mile
LS1,LS2,LS3,LS7 Custom Camshaft Specialist For custom camshaft help press here.
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Wow I wonder if pypes mufflers cost any loss. They flow pretty free.
2014 Harley Davidson Street Bob-Vance and Hines Short Shot staggered.
2013 F150 Ecoboost- Loaded and stock.
I doubt it you can see right through them.Wow I wonder if pypes mufflers cost any loss. They flow pretty free.
So much for the stock muffler not being restrictive...on a mild modded car probably 5-8 hp.
2009 G8 GT Stryker Blue Prem/Sport/Roof
Go: Rotofab, Corsa Exhaust, Kooks Mids, a little HPT secret sauce = 13.1@108 (traction where are you?)
Show: V8 Holden Badges, Clear Side Markers, GXP Rear Diffuser
Misc: AutoDim Mirror, Almost Factory Bluetooth
Previous Rides: 2004 GTP, 2004 GTO, 2002 TA (miss this one)
Great info. I always wondered what the difference was when I put them back on.
08 G8 GT: MagnaCharger TVS MP1900 10psi, LS9 cam, 72# injectors, Roto-Fab CAI, SLP Headers, Corsa Catback, etc.
My Garage
What about a Solo Cat-back with Kook's connectors?Originally Posted by Patrick G
2015 White Hot Chevy SS - Sunroof/Spare/Stick - BTR Stage 3 cam, headers, intake *Traded 11/11/2023*
2018 GMC Sierra Denali 1500 - 6.2L, Ultimate Pack *Turned in 4/13/2021*
2016 Jungle Green Metallic Chevy SS - Sunroof/Spare/Stick *Traded 2/1/18*
2011 Radiant Silver Metallic CTS-V Wagon - Corsa Axleback, AirAid Intake *Traded 7/7/16*
2008 Panther Black Metallic G8 GT * Sold 6/10/14*
Great find Patrick! Thank you for this. Now I have 2 good reasons to get rid of the stock axle backs...... A little more sound (with hopefully no drone), and pick up some RWHP
...
2009 White Hot G8 GT (stock)
* SOLD * 222/230 .597/.600 114+4 EPS Cam, Patrick G ECM/TCM Tune, Roto-Fab CAI, HSRK, Yank 3200 Torque Converter,
Transmission Cooler, Kooks 1 3/4" LT Headers, high flow cats, stock mufflers, Billet Prototypes Catch Can, UD Pulley,
Ported Intake Manifold, Spohn Trailing Arms
407 RWHP & 365 RWTQ
Best Time: 12.517 @ 115.02mph w/ 1.97 60' time - (on stock 18" AS Tires)
Since a motor is effectively an air pump, has the conductance (airflow) been determined for the OEM system? In other words, at what power level (assumes power sync correlates with airflow) does the OEM max out? Just because there is loss at 500RWHP does not mean there is statically significant loss at 350 or 400. From the data, looks like 415HP is where it consistency falls off. even at 500, 15 is a 3% loss... what is the repeatability run to run to run on dyno? Not trying to be smart guy, I have no experience with dyno data...just looking to learn.
Thanks
9.5 RPM (Red Passion Metallic)
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"If the women don't find you handsome, they should at least find you handy"-Red Green
It's ironic but Executor999 and I were just discussing mufflers and now this. Sure would be nice to have a good sounding muffler with performance to go with it.
jcmGT - We baseline Patrick's car before making any changes and the number are always the same. Once he finished his tuning with the head cam swap, we did several pulls with and with out the mufflers and they were consistent around 13-15rwhp difference.
Patrick if the parts come in I will have 2 custom axle back exhaust for you to try this weekend. One for race only and one free flowing, drone free for the street.
Definitely want to hear about the results!
2008 Pontiac G8 GT | PBM | Premium Package | Tuned by Patrick G | Wrenched by Enhanced Street Performance
AC Delco | ARP | ATI | BMR | Centric | GForce Engineering | GM | Holden | Kooks | Manton | Moog | Norris Motorsports | Patrick G | Pedders | Pirelli | PRC | RCR | Rotofab | Russell | Texas Speed | SuperPro | Xforce
'Charlie the GRRRR8' - Rest in Peace 11/14/2013
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