3" vs 2.5" header & exhaust

Discussion in 'General Viper Discussion' started by alpha85, Nov 7, 2009.

  1. alpha85

    alpha85 VCA Member - South

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    Does anyone have any input on 1 7/8 headers w/3" cats and exhaust vs 1 3/4 headers w/2.5 cats and exhaust. I'm sure with full throttle 3" would be better but what about all around driving. Would 3" lose low end torque. I am looking at my next upgrade.
     
  2. RobZilla

    RobZilla Viper Owner

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    With as much tq these cars have you wont notice a low end loss with 3". Take the cats off for cooler sills. Best bet would be to do 3" headers and a catless cat back exhaust. If you feel cats are best for you and your set up, get some high flow cats.

    :usa:
     
  3. alpha85

    alpha85 VCA Member - South

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    What advantage would there be with no cats?
     
  4. RobZilla

    RobZilla Viper Owner

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    A slight hp gain, cooler side sills, and a viper sounding exhaust. The stock exhaust with headers and cats sounds like a sewing machine. Does not fit the viper persona at all.

    :usa:
     
  5. plumcrazy

    plumcrazy Viper Owner

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    knowing your final goals will also help in the decision
     
  6. Chuck 98 RT/10

    Chuck 98 RT/10 VCA Venom Member-Midsouth

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    What Plum said. What's the objective?

    More sound? Bigger is better.

    More performance? That's a little trickier. Bigger is better but only if the engine is designed for bigger. Specifically the camshaft.
     
  7. 99 R/T 10

    99 R/T 10 Enthusiast

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    Who makes 1 7/8" headers? Either way, go with a full 3" EXHAUST and no cats for better sound and cooler side sills.
     
  8. HHI VIPER

    HHI VIPER Viper Owner

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    I also read that no cats creates an exhaust smell inside the car??? :dunno: Does this apply to Gen I and Gen II? The Gen II exhaust runs out the back. I was thinking of running no cats with Corsa and stock manifolds on a Gen II (advise from Viper Days in Savannah GA) but I would not want to smell like a tailpipe when I got out! :D Any input??
     
  9. KNG SNKE

    KNG SNKE Viper Owner

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    Should be only minimal smell inside if any. I only have minimal but I believe I have an exhaust leak at one of my band clamps.
     
  10. JonB

    JonB Viper Owner

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    Your sig says 'enthusiast'........... is it a Ram SRT? I am truly amazed by all the good answers.........but I feel unable to answer accurately because you did not mention the Year-Model-Mods-Planned Mods ! Only HHI asked and qualified his reply. And Plum mentioned goals as well......

    THE YEAR MATTERS ! It all matters, and matters a LOT.
     
    Last edited: Nov 7, 2009
  11. cash84

    cash84 Viper Owner

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    I agree, they are also missing out the advangage that this club has to offer if he actually has a Viper.
     
  12. eucharistos

    eucharistos Viper Owner

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    hhi v

    even with rear exhaust, you will get exhaust smell inside the car, i think more in an rt than in a gts, though this is only conjecture based on my rt. ride around with the top on and rear glass out, or just top on and windows down and sniff :crazy2:

    the aerodynamics of the car causes this "reverse flow". ever notice how dusty your bumper gets just below the licences plate :omg: i think i remember jonb talking about squished bugs on the rear bumper after high speed runs :drive:

    if you are bothered by smell, hi flows, and even they smell noticeably more than stock cats
     
  13. alpha85

    alpha85 VCA Member - South

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    Mainly street some track. I would like to stay naturally aspirated.
     
  14. alpha85

    alpha85 VCA Member - South

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    Hennessey, B&B
     
  15. alpha85

    alpha85 VCA Member - South

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    Gen 3, Alum fly wheel, 355 gears
     
  16. alpha85

    alpha85 VCA Member - South

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    I have a exhaust smell with cats
     
  17. alpha85

    alpha85 VCA Member - South

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    I have a 05 Gen 3, Alum fly wheel,355 gears
     
  18. alpha85

    alpha85 VCA Member - South

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    Any suggestions?
     
  19. Dom426h

    Dom426h Viper Owner

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    ............
     
  20. Dom426h

    Dom426h Viper Owner

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    what are you referring to?
     
  21. alpha85

    alpha85 VCA Member - South

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    What do you mean?
     
  22. JoelW

    JoelW Viper Owner

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    So how do you like the 3.55 gears? Too short?
     
  23. RTTTTed

    RTTTTed Viper Owner

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    I know this thread is old but the info was never supplied so ...

    All 4 stroke engines work better (at all speeds and rpms) with headers and no exhaust, even a lawnmower. Mileage, torque and hp are all increased with headers and no exhaust.

    Viper headers are generally made in 1 5/8" and 1 3/4" tube sizes. There are burns collector headers, stepped headers (notmally the best choice for stock levels of perfomance) and "pickled" Belanger headers which are also excellent for stock power levels.

    For supercharged and Nitrous Oxide powerlevels the largest headers are the best. The pickled Belangers are an excellent header, but restrictive for power adders and the pickles can be torched out for better perfromance.

    Corsa exhaust uses sound cacnellation technology to "tune" and quiet the 'bad' sounds from the exhaust with no baffles or dimples or any other restriction to the exhaust flows in the 3" tubing.

    Your car smells of gas? Sounds like you Cats are plugged? Perhops your rear oxy sensors have triggered an extra rich condition to "protect" you Cats? What is your fuel mileage? My highly modified, lowered compression GTS gets 20mpg US.

    Ted
     
  24. RTTTTed

    RTTTTed Viper Owner

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    Back "in the day" a 340 engine came from the factory with No Cats and 2.5" exhaust. That was the largest size made. GM used 2.25" on most of their cars because it was much cheaper.

    488ci and Viper engines are basically a 360HP engine with racing heads built out of aluminium and much more refined. Obviously a 2.5" exhaust system is too restrictive. 2.5" exhaust was used for 275hp so 3" is a must for a HIGH PERFORMANCE engine.
     
  25. EFI-1

    EFI-1 Viper Owner

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    Good post Ted. I've read posts about slower times with the larger exhausts on these cars, but can't for the life of me, imagine that dual 3" is too much exhaust for a big 488...even a stock one.
     
  26. RTTTTed

    RTTTTed Viper Owner

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    Thanks,

    On a 2 stroke an exhaust is needed for performance. Remove any of the exhaust excepting muffler and the engine slows considerably. BUT ...

    On a 4 stroke engine pipe is needed to take the exhaust away from the head and valves. Headers use a collector to help scavenge/suck exhuast gases from other cylinders resulting an increase if power. Racing old style cars (70 440 Dusters etc.) as much as 10 car lengths (100hp) could be gained by removing stock type exhaust systems. Although I read that torque was decreased I certainly didn't notice any loss of power. An equalizer tube (x tube) between cylinder banks also increases performance on a V8 but that doesn't seem to help on the V10 engine and when used (Gen2) is for exhaust sound quality.

    Ted
     
  27. Bandit3

    Bandit3 Viper Owner

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    06 Coupe with no cats, and no smell, except when I fill up with race fuel, then it smells gooooooood!
     
  28. PhoenixGTS

    PhoenixGTS Viper Owner

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    Had a conversation with Lou Belanger yesterday (If you have not experienced this it is something you should do at least once before you die) and he swears up and down - and has for years - that Vipers are faster with a 2.5" exhaust after his headers rather than a 3". He also admits that the 2.5" over a 3" is much quieter (thus their GenIV cat-back systems being 2.5").
     
  29. Olddudesrule

    Olddudesrule Enthusiast

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    Just finished installing Belangers on my 2001. I already had R/T's and Corsas, all 3". The only 2.5" section that was replaced was the factory turnout which I replaced with the supplied Belanger 3" turnout. With the full 3" system, the only thing I've noticed so far (no dyno #'s) is a deeper tone at idle, louder at medium and WOT, and the "seat of the pants" feel that the motor winds up faster.
     
  30. Dietz

    Dietz Enthusiast

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    I bought the B&B 1 7/8 headers, took forever to get, and then cut out the cats and most of the corsa exhaust. The corsa exhaust tubes actually cracked around the welds. I went 3" pipe all the way out. The car opened up so much more power then with the cats, its like having a new car! The noise level isnt too bad when your in the car. When its just running it sounds awesome, but when Im going down the road people seem to freak out because its so loud when I pass them or just step on the gas. Im thinking I need to get rid of the back corsa and put in an X pipe.

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