Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

Results 1 to 12 of 12

Thread: 95 Deville 4.9L... Dual exhaust?

  1. #1
    dommi.b is offline Cadillac Owners Member
    Automobile(s): 1995 Deville Base 4.9L
    Join Date
    Sep 2012
    Location
    Elmhurst, IL
    Posts
    15

    95 Deville 4.9L... Dual exhaust?

    Okay, I have been wanting to get some more power out of this car since I bought it... but never have been too sure on where I wanted too start. Now I know I want to start with the exhaust system, but I'm concerned that if I just start cutting off catalytic converters and throwing on a whole new pipe for the duel exhaust if I'm actually going to lose power/or cause some sort of problem because certain cars need the back pressure to function properly... So some advice or opinions on what I should do would be much appreciated. Thanks. :3


  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    MoistCabbage's Avatar
    MoistCabbage is offline Cadillac Owners 10000+ Posts
    Automobile(s): 2001 Seville STS, 1990 Seville (RIP), 1972 Sedan Deville
    Join Date
    Sep 2010
    Location
    East Boston MA.
    Age
    29
    Posts
    26,323
    Unfortunately, a freer flowing exhaust system won't get you much more than 1 or 2 extra HP at best. It'll sound nice, but that's about it.

    There aren't any performance upgrades available for these cars, 4.X or Northstar. Many of us would like some bolt on power, but it just doesn't exist.

    The cheapest way to add power to a base '95 Deville, is to sell it and buy a Concours.

  4. #3
    drewsdeville is offline Cadillac Owners Master
    Automobile(s): 2011 Crown Vic LX, 2009 Chevy Malibu 2LT
    Join Date
    Oct 2004
    Location
    Oak Creek, WI
    Posts
    5,607

    Re: 95 Deville 4.9L... Dual exhaust?

    The weakest link, by far, is the small valve heads. If you can't get the engine to breathe, the exhaust is moot.

    That said, when it comes to an engine with little/no aftermarket support, you have two options - get to know your local machinist very well and make it breathe naturally, or jam the air down it's throat with some forced induction.

    The 4.9 has been turbocharged a number of times, especially within the Fiero community. They've netted some ok results for (relatively) little cash. You might want to head over there for some tips.

  5. #4
    basscatt's Avatar
    basscatt is offline Cadillac Owners 10000+ Posts
    Automobile(s): 2003 DHS - two-2002 DHS's, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
    Join Date
    Feb 2004
    Location
    Minnesota
    Age
    65
    Posts
    15,689

    Re: 95 Deville 4.9L... Dual exhaust?



    you have simply chosen the wrong car to try to modify -
    there simply isn't any aftermarket support -
    and without spending tons of money -
    the only way to get any decent increase in power is to add NITROUS -
    but that will destroy the engine and trans very quickly -

    enjoy your '95 Deville for what it IS -
    and don't blame it for what it IS NOT -

  6. #5
    dommi.b is offline Cadillac Owners Member
    Automobile(s): 1995 Deville Base 4.9L
    Join Date
    Sep 2012
    Location
    Elmhurst, IL
    Posts
    15

    Re: 95 Deville 4.9L... Dual exhaust?

    Well darn... and here I was all excited to make this old guy finally powerful enough to beat my buddies turbo-diesel Pick-up... Guess not!! Thank's for the info guys.

  7. #6
    Join Date
    Jul 2011
    Age
    33
    Posts
    196

    Re: 95 Deville 4.9L... Dual exhaust?

    Quote Originally Posted by drewsdeville View Post
    The weakest link, by far, is the small valve heads. If you can't get the engine to breathe, the exhaust is moot.

    That said, when it comes to an engine with little/no aftermarket support, you have two options - get to know your local machinist very well and make it breathe naturally, or jam the air down it's throat with some forced induction.

    The 4.9 has been turbocharged a number of times, especially within the Fiero community. They've netted some ok results for (relatively) little cash. You might want to head over there for some tips.
    VERY well put! OP, here is your answer.

  8. #7
    Darth Mobius is offline Cadillac Owners Member
    Automobile(s): 1995 Deville Concours
    Join Date
    Sep 2010
    Age
    32
    Posts
    74

    Re: 95 Deville 4.9L... Dual exhaust?

    GM makes a motor called the LS4, it will be expensive, but it is a front wheel drive motor/tranny combo, and it will fit in the engine bay with motor-mount modification. I am also looking into this for my car, far into the future.

    If you really want to improve the car for racing, internet research is your best friend. That is how I found the LS4. Also, next year GM is launching a new line of motors that look to be vastly superior in terms of engine power and efficiency. I would also suggest looking into it when they announce the new platform, as there probably will be a front-front layout car in the mix. If not, there is always the LS4.

    I also looked into a custom dual-exhaust setup, but because of the way the fuel tank is situated, you won't get a true-dual exhaust setup, so a little wider single pipe and a magnaflow can will make it sound beefier while at the same time not costing you $800 or so. (Prices may vary by location, but the shop here wanted $850 for a cat-back dual with high flow cat.)

  9. #8
    MoistCabbage's Avatar
    MoistCabbage is offline Cadillac Owners 10000+ Posts
    Automobile(s): 2001 Seville STS, 1990 Seville (RIP), 1972 Sedan Deville
    Join Date
    Sep 2010
    Location
    East Boston MA.
    Age
    29
    Posts
    26,323
    Bolting an engine in is the easy part, getting it to work with all of the vehicles systems is the hard part. Your current PCM certainly isn't going to control a different engine/transmission combo.

    A freer flowing exhaust system will sound nice, but won't give you more than a few extra HP at WOT, at redline.

  10. #9
    VEGASELDO91 is offline Cadillac Owners Fanatic
    Automobile(s): 1991 ELDORADO (R.I.P.); 1995 Sedan Deville
    Join Date
    Nov 2009
    Posts
    341

    Re: 95 Deville 4.9L... Dual exhaust?

    I've been thinking about having dual outlets installed on my Sedan Deville, but want to keep the quiet sound this time around. I had them on the Eldorado with a 80 series muffler (i think) and it sounded nice IMO. Being I look at this car as a big luxury cruiser, I think the dual outlets will look nice, but prefer to keep the muffler quiet this time around! Don't get me wrong I've watched a youtube vid or two of Devilles with upgraded mufflers and dual outlets and liked it very much! I got compliments on how cool the Eldo sounded frequently, I just think the sound was better for that car. Good luck with your plans, I really hope you find what you are looking for, it would really be cool!!

  11. #10
    Darth Mobius is offline Cadillac Owners Member
    Automobile(s): 1995 Deville Concours
    Join Date
    Sep 2010
    Age
    32
    Posts
    74

    Re: 95 Deville 4.9L... Dual exhaust?

    You want to add 50 horsepower in an hour? http://www.performancechipsdirect.com/Cadillac/DeVille/

    Chip your car!

    Sorry I forgot about that, but my friend found that website about a year ago, and I had forgotten I had bookmarked it.



    Dommi B, I owe you huge, by the way. Looking at the installation for that chip I just posted a link for, I saw what an IAT was, and where it was located, and realized that when I got my friend to put the new motor in, he NEVER INSTALLED MINE! I think you just fixed my freaking idle problem.
    Last edited by Darth Mobius; 09-21-12 at 03:06 AM.

  12. #11
    MoistCabbage's Avatar
    MoistCabbage is offline Cadillac Owners 10000+ Posts
    Automobile(s): 2001 Seville STS, 1990 Seville (RIP), 1972 Sedan Deville
    Join Date
    Sep 2010
    Location
    East Boston MA.
    Age
    29
    Posts
    26,323
    All those "performance" chips do is alter the signal from the IAT, making the PCM "think" the intake charge is colder than it actually is. As a result, the air/fuel mixture is richened, causing idle/drivability problems, and DECREASING fuel economy and performance.

    Don't you think that if it were possible to add 50 HP, with a simple fuel ratio change, that GM would have done it from the factory....?

  13. #12
    basscatt's Avatar
    basscatt is offline Cadillac Owners 10000+ Posts
    Automobile(s): 2003 DHS - two-2002 DHS's, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
    Join Date
    Feb 2004
    Location
    Minnesota
    Age
    65
    Posts
    15,689

    Re: 95 Deville 4.9L... Dual exhaust?

    I totally agree with MC about the performance chips -
    they simply don't work -
    and the ONLY way those companies get away with advertising is the "fine print"

    UP TO are the 2 magic words that allow these guys to stay in business -

    UP TO a 4 MPG increase - and UP TO a 50 HP increase -

    if you get LESS THAN a 4 MPG INCREASE - the advertising is true -
    in fact - you WILL get LESS MPG - because of the nature of the chip -
    the chip simply tells the computer the air going into the motor is really cold -
    so the computer adjusts for a richer air/fuel mixture - which burns MORE fuel -

    and if you get LESS than a 50 HP INCREASE - the advertising is true -
    here too - you will NOT get ANY increase in HP -

    use your common sense when it comes to any of this stuff -
    don't you think Cadillac would KILL for the ability to legally advertise
    30 MPG highway rather than 26 -

    and 325HP rather than 275HP on the "Y" motor cars -
    and 350HP rather than 300HP on the "9" motor cars -

    and be able to do this all for a few cents worth of resistors -
    OF COURSE THEY WOULD - IF THEY COULD -


Bookmarks

Cadillac Posting Rules

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Read about Lincoln | Buick | Kia Forte Forum