You never want backpressure. Now, what you do want is exhaust gas velocity. Larger piping sometimes loses the velocity and it might hurt you a little down low, but will make more power up top once the air is moving.

 

so the ls1 motor doesnt need backpressure in the exhaust you are saying?

Go back to engineering school brotha.

 

No, it doesn't, nor does any motor. Once again, you are confusing backpressure with velocity brotha.

 

No engine ever wants backpressure. Backpressure is NEVER good. Why would you ever want something that is fighting exhaust getting out and away from the engine? What you do want is exhaust gas velocity, and even if you have a huge (say dual 3" or single 4") exhaust you will still make enough high end power that in a 1/4 situation you should come out ahead vs smaller piping.

 

I know sound clpis wouldnt justify the sound of the magnaflow but I gaurantee you shouldnt be dissapointed if you get it. It will please your ears and will get you attention and thumbs up from others as well. Good luck with your choice though

 

Maybe I can help you in your decision in another week.

I currently have Hookers with their 3" Y and no cats going through a LoudMouth with a FlowMaster Bullet (absolutely NOTHING inside) in place of the Resonator . . . LOUDER THAN A HURRICANE!!! I honestly don't think I'd gain even half a pony through a cut-out with my current set-up

I'm gonna be installing a FAST intake with a 90 mm TB, Kooks 1 7/8" Headers with their 3" Y, and a Corsa Exhaust. I'll post the sound clip if someone can host it

I was worried about losing a few ponies going from my existing exhaust to the Corsa but I should make up for it with the bigger Headers and Intake

I'll be installing as soon as the Kooks arrive. Anyone wanna host the sound just PM me



Christopher's Onyx Black 2001 SLP T/A Firehawk M6 #89

Bilsteins, Chrome Rims, Deck Mat, Birth Certificate, Portfolio

PERFORMANCE: Jung's S3 Heads | TSP 231/237 | '03 Viper Tranny | Hooker LT's/3"Y with FlowMouth | Spec S3 Kevlar Clutch | SLP Hi-Flow Radiator | Meziere EWP 160* | LPE 3 1/2" Aluminum Driveshaft | Jantzer TB | De-screened MAF | TSP Clear Lid-K&N | ASP Crank Pulley | SLP Bellows | NGK Plugs-MSD'S | Harlan's Shiftlight | FRA | TBB | tuned by Me | Crane Valvetrain | Hotchkis SFC's & STB | Mac Rear-End Cover | Stock Hurst with UMI Short Stick | SLP Reverse Logic Module | New '04 LS1 engine at 48K mi | Brembo Slotted and Cross-drilled Rotors with Red Calipers.

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Brenda's 2001 Racing Red WS6 A4

SLP Loudmouth Exhaust, SLP Lid-K&N, Bilstein Shocks, Eibach Lowering Springs, UMI SFC'S/STB, Brembo Slotted/Cross Drilled Rotors with Red Calipers.

 

Gmmg!

 

i still get a kick out of the 'you have to have backpressure'. yes you must have something that restricts the flow of exhaust. the more the restriction, the better the power. this is something an 80 year old would tell you.

we need a sticky titled velocity not backpressure.

if an exhaust system is too small/big, the motor will have to do the work in getting the exhaust out. the correct size will help 'scavenge' the exhaust. what this means is the out going exhaust exhaust pulse from one cylinder will create a vacuum behind it. with this vacuum, it will 'suck out', or pull (scavenge) the next cylinders exhaust out.

the fun is determining what size is correct for your application. things like rpm usage, cubic inch size of motor, single or dual pipes, and power output are things to consider in selecting the proper size exhaust. pipe sizing starts at the header and progressively gets bigger at the point where more cylinders are feeding into the same pipe.

 

Another thing to keep in mind is that the volume of hte exhaust gas decreases as it gets further downstream. If you go with a smaller diameter pipe further downstream it can keep the exhaust gas velocity up.

 

you are correct. i just wasn't trying to get too technical in my first post. didn't want the brains with backpressure exploding with so much actual thinking of exhaust systems. the further the exhaust travels in a pipe, the more it cools off. heat dissipates through the pipes. also here's another tidbit of info. the cooler the exhaust, the slower it moves as well. the pipes need to be as hot as the exhaust itself to move the fastest. as the heat dissipates, it slows the pulse. this is where coatings help. ceramic coatings, thicker walled pipes, and so on will help keep the pipes hot and move the exhaust pulse quicker.