my mustang is SLOW!!

Discussion in 'SN95 4.6L Mustang Tech' started by chickensofttaco, Apr 17, 2012.


  1. chickensofttaco

    chickensofttaco New Member

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    whats up guys?! i just wanted to hear some input on this!! this is my second mustang. its a 99 4.6 5speed and she feels very slow! previously i owned a 94 with a built aod, 4.10's, i/h/e, 75mm tb, afr 164's, e-cam, ford racing lower im, trick flow upper im, 40lb reds, 195lb fuel pump, 3200 stall, and lots more. it was alot faster than this car! i know it was built up and i have beaten several 4.6's but after driving my best friends 02 5speed gt i really wanted to get one for the reliability, 5 speed, and look.. my buddy has accel coil packs, off road x, custom flowmaster single chambers, intake, underdrive pullys, and supposedly a canned tune. the problem is i raced him and he flat out smokes me... its absolutely no competition and he burns half through second when i can just barely chirp it! what's the big deal?! how does he beat me so bad?! he is my best buddy and i know his car inside and out theres no tricks or funny stuff going on here. he only has a couple things done and its that much faster? i have replaced all the plugs and cops. when im in my friends car it has power all through the rpms when mine seems to have a mid range band that it likes. the power straight flattens out at about 3500+rpms. my brothers 04 spec v puts up a fight from a roll! this is rediculous! i originally planned on doing mainly appearance mods to the car but i may have to do something about this first! how much can i gain with a off road x pipe and a tune? the only mods i have are a volant intake and borla catback.
  2. 95Vert383AOD

    95Vert383AOD Active Member

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    Check engine light on? When was its last tune up? Plugs/ Fuel/air filter?
  3. Nightfire

    Nightfire Mustang Master

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    I would focus on making sure the car is running correctly before throwing money at mods. I would change the fuel filter, clean the MAF, and clean the air filter (it probably needs it anyway). Then I would have a leakdown and compression test done. From your description, it sounds like the car is hurting (ie. mechanical issues).
  4. trinity_gt

    trinity_gt Advanced Member

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    Power dying off or flattening as the RPM climbs suggests an intake or exhaust restriction. NPI cars suffered this because of restrictive heads but PI engines, while still not great, were definitely better. So, stupid question: Is the engine in the car the original? Any chance someone swapped in an NPI mill? Don't laugh, it could happen: If someone hurt the original engine and wanted to put the car back together for a quick sell they might source a "4.6" and not know what they're getting...

    You might also have a catalytic converter problem (i.e. blocked). Rare, but it happens.

    If you can you should dyno the car to establish a baseline and to verify that something is actually wrong. Assuming it's a 5-speed you should see something like 220-230HP at the wheels.
  5. joshjwc9

    joshjwc9 Active Member

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    Make sure your brakes are not dragging..the fact that you still have stock gears will also make it feel slow..
  6. 007

    007 Founding Member

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    So stick it on a dynojet and see whats up. You can usually get 3 pulls for about 75 bucks.
  7. Night Shifter

    Night Shifter Well-Known Member

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    Few things from my perspective...

    First, everyone above me has posted excellent advice to be sure to do all of that first.

    What cop's did you put on the car when you changed them? If they are aftermarket, go back to oem. Like NightFire said, check your cats cause they can clog up and bog you down...change your O2 sensors when you get a chance and ill bet you notice a big difference right away..

    An off road mid pipe will help you more than you think...you wont gain 30hp from it but over a factory or aftermarket catted mid pipe you will get better performance.

    Now, the few mods your friend has is actually going to give him a big advantage over you..the main mod being the tune...the tune does more than you would think performance and drivability wise and with it, hes gonna beat you everytime..the sct tuner is a must have for our cars

    That being said, what tires do you both have? If he has a better tire than of course he will win.. i know you said he spins but so do i...even with my lower control arms my car likes to dance around BUT with my tires, the second it hooks im gone.. his pulleys are helping him eveb though everyone elso on here will dispute that.

    as for the nissan, its a much lighter car so thata why hes giving you the problem.

    If yoy want to be quicker without havibc to sacrafice drivability then the first things you should do are gears and the sct handheld tuner...you wont have any issues from you buddies after that.. then if you want more add a tb and plenum..you can even get fancier with an aluminum driveshaft and even fancier with an aluminum flywheel..id leave thkse for later mods though..

    Check the parts weve all mentioned, throw in some gears, an off road mid pipe, and a tune and call it a day
  8. Night Shifter

    Night Shifter Well-Known Member

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    Damn that was a long post..and thank my phone for the typos lol
  9. 007

    007 Founding Member

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    Pulleys do help. No idea why anyone would dispute that?
  10. fiveohwblow

    fiveohwblow Official Member

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    several dyno tests have proven maybe 5 rwhp with accessory belts completely removed. They do not provide the gains many believed for quite some time they did.
  11. Night Shifter

    Night Shifter Well-Known Member

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    Crap i didnt mean to start the debate lol

    Accelerationwise they work, as far as horsepower goes maybe 1-2hp gain will be seen..just to clarify in no way was the claim made that they made power lol

    Each car is different though..more or less hp may be made with pulleys depending on the car..

    /end debate before it goes crazy :p
  12. fiveohwblow

    fiveohwblow Official Member

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    BS!! :fuss:

    Fighting because fight!!! :crazy:

    :D
  13. Night Shifter

    Night Shifter Well-Known Member

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    Damn stangent mobile and not being able to use smileys

    *lots of random smileys inserted here to contribute to fight*

    :ninja:
  14. Mark Palmer

    Mark Palmer Banned

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    Great site. A lot of useful information here. I’m sending it to some friends!
    [​IMG]
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  15. chickensofttaco

    chickensofttaco New Member

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    thanks guys... does the sct tuner really net 25hp?! if so i am definitely getting one! i have huge 255 55 17 truck tires! i can barely spin them! my bud is spinning and passing me at the same time!!! i just got some 03 cobras that im gonna put some 40 285's on next week.. then i think a xpipe and tuner.. it is indeed throwing a code! "p0442 emission evap leak (small)" i replaced the cap and it still came back.. i also inspected the filler tube and all the lines and couldnt find the leak? i didnt think that would slow me down but could it?
  16. Nightfire

    Nightfire Mustang Master

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    I'd love a chicken soft taco right about now....
  17. chickensofttaco

    chickensofttaco New Member

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    well for starters i found out that the rubber coupling that holds my intake onto the throttle body was folded and clamped which was probably leaking alot of air after the maf.. i replaced the last 2 cops with some good used motorcrafts my buddy had laying around after replacing his with accels and it seems to run a little better now.. i have yet to drive it but i will try and update tonight to let you know how it goes.. also the IAT seems a little suspect.. the sensor goes into the nipple on the volant intake tube and kinda just sits there post maf.. i also believe its leaking from there as well.. is IAT orientation critical? what if it shifts where its not getting a good reading but is pretty close? the nipple kind of holds it out of the stream alittle.. i may need to divise a new way to fasten it to the tube to better suit my needs if so.. im gonna need to seal it somehow anyways..
  18. Night Shifter

    Night Shifter Well-Known Member

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    The orientation of the iat doesnt matter but if its not fully sealing then itll throw a code...that shouldnt affect driveability though..when i pulled all the wires into the fender on thecar passenger side i forgot to hook the iat back into the intake but all it did was just throw the check engine light
  19. Night Shifter

    Night Shifter Well-Known Member

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    Any pics of the car or the engine bay? Id like to see what this thing looks like...

    Damnit your screenname makes me want taco bell
  20. fiveohwblow

    fiveohwblow Official Member

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    Resist the bell!!!

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