Cats or Crossover (Whats more Restrictive?)

[Shandon]

I am considering....

I currently have Balengers hooked to my Corsa and 1 set of magnaflow cats. If I were to remove the Cats completely I think the volume would turn up a bit more? Maybe maybe not? So.. if I loose the Cats but added back the crossover to help with sound (tame it a bit) will I have accomplished nothing perfomance wise?

So to sum it up. Does one set of Cats create the same back pressure that the crossover does?

 

[Black Moon]

You really can't compare the two. I've never heard of a crossover creating back pressure. It only balances the two sides and eliminates the resonance. I'm curious to see what others say.

 

[RTTTTed]

The crossover decreases the backpressure and increases hp. Not sure or the V10 specifics though.

A few of my friends tested the crossovers on their street/race cars. Small block Chev in a Datsun pickup gained .4 sec. at the track when the crossover pipe was installed. Most people got .2sec when they added a crossover pipe. Since they work - I've never built an exhaust without a crossover. Gen 2s came with crossover and all aftermarket exhaust systems come with crossovers.

The X pipes increased Torque more than the H pipes in V8s.

Newer Vipers gain cabin heat and weight from the crossover pipes.

Cats cause a lot of cabin heat and some restriction to exhaust. Good high-flow cats will increase hp on n/a engines nearly as much as no cats, at least when they're new and not plugged or restricted. Are your cats Hi-flow or stock replacements?

Guys like Sean Roe tested all the hi-flows before they decided who was going to make theirs. Ask him how much difference there is for your particular set of cats.

Ted

 

[Shandon]

Yea I wasn't sure if there would necesssarily be more pressue by keeping the crossover. I just figured that the sooner the air gets out of the pipe the better (less mass of air to push out of a pipe) but if thats not the case hmm. Im thinking about trying some different combos. Does anyone know if the stock crossover was 3" or 2.5 after the muffler?

Yes my cats are Highflow from Belanger.

 

[RTTTTed]

The easiest way to think of a crossover is that cylinders don't fire at the same time so when the exhaust pulses get to the crossover they can go the path of least resistance because now there are 2 mufflers available for each pulse. Balancing the pulses and pressures from each side of the engine also mellows out the tone/frequency of the exhaust.

The crossovers are normally smaller than the standard tube size (2" X pipe on a 2 1/4" exhaust).

However, V8s fire 2 cylinders from each side in a row (even fire engine) and that's why V8s sound so great. The Viper V10 is an "odd fire" engine and fires 1 cylinder from each side of the engine, not two, at a time so it would make sense that the V10 would not get as great an improvement as the V8 does.

Exhaust is more about pulses, sonic waves and pressure fronts than volume actually. The pressure and sonic waves create suction behind them. Having seen the cutaway of the Corsa "muffler" was enlightening at VOI X. The Corsa tech I spoke to there said that Volume of exhaust also "mellows out" the exhaust sound. So I would expect a deeper tone with a crossover pipe. Jonb at Online Shopping - Home has tons of exhaust experience and even used systems at his shop. Call him for stuff and advice if you want really cool. He may suggest an X instead of a crossover?

Ted

 

[Shandon]

The crossover I refer to is in the Gen III and its merly pipe that runs from on muffler (after it) on the passanger side and exits on the drivers side. The pipes do not share anything other than they cross over under the cabin area. I know that going catless will gain some HP but may not be worth it for the numbness in the ears. I am interested to see if longer pipe with turns has any detrimental effects on HP.

 

[RTTTTed]

Turns probably don't make any significant difference. The pipes crossed over to improve the exhaust sound. I personally don't like the sidepipes. The Gen1s stopped many people from buying Vipers they sounded so terrible ("UPS truck sound" was how they were usually described in mags). The 08's are the first sidepipes I really like, but the rear exit exhaust sounds better because of the longer pipes.

Ted

 

[Racer Robbie]

I have some info regarding sound on our web site at:

http://www.members.aol.com/AtroRacingTeam/PRODUCTS/AtRoRacingsProductCatalog