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I Feel I'm Making Low Power... Boss 302 Cobra... Should I Be Worried?

Discussion in 'Tuning À la carte' started by Rossim22, Jun 30, 2012.

  1. Rossim22

    Rossim22 New Member Established Member

    Mar 24, 2010
    Fort Myers, FL
    I was getting some work done to the car and had my 03 cobra tuned at the same place. Originally with a returnless system on my posi ported eaton at 17lbs I made 525/543. I was having an issue switching gears on wot runs where the car would hesitate, so I went with a return set-up. Same shop did the tuning and I dropped to 505/520. After ruining a piston, the current shop accused the previous engine builder. Stuck between a cobra and a hard place, they agreed to avoid a bad reputation and cover future labor and tuning, I was responsible for parts.

    I went with the boss 302 upgrade block from modmax and had them build a shortblock with 9.2cr (previously 9.1) able to withstand 1000hp. It was shipped to the current shop who just recently finished installing everything and tuning, this time I'm going with a 93 and E85 tune. I was expecting (hoping) for a 550/570 on 93 and maybe graze 600 on E85. The car put down 502whp and about 520wtq now at 15lbs (same pulley combo) at 11.4afr on 93 but then on E85 made 560/577. Is he just giving me a safe tune for driving around on pump? I'm using SCT

    Last edited: Jun 30, 2012
  2. 1QUICK10TH

    1QUICK10TH Just A GT Established Member

    Aug 7, 2007
    Tuckerton, NJ
    Your numbers seem a little low but not too bad. What's the timing?
  3. ttype69

    ttype69 New Member Established Member

    Jun 12, 2011
    Mentor, Ohio, United States
    Ill throw my 2 cents down hopefully some one will chime in to. From most of my investigations a eaton ported or not is usualy maxed at the 500 mark. Now i know there is an argument there but i did allot of research and found that 500 is about it . know your hitting 560 with it on e85 due to the cooler burn i suppose and thats what putting up the numbers .I would like to know your injector size also . my notes on this would be
    #1 your blower isn,t a so called monster so your just chokeing the motor. so now you have a bigger motor with a small blower witch isnt working well together 4.6 with small eaton is very responsive and performs well .
    #2 running dif fuels as in e 85 and 93 usualy you would want an injector change i can almost guess if you have 60's on and that with the eaton is only ever going to yeild 550 560 hp. when usuing e85 you will always need a bigger injector . but haveing only a eaton you wouldn't go bigger than 60's it just wont make that much air flow to use a bigger than 60 injector
    Basicaly it doesnt supprise me that you made the same power due to using the same blower and injectors.
    Oh also the switch gear hesitation is kinda normal due to the pprv. hopefully this has been deleted if so. your just shifting the car way high in the rpms and it realy doesnt like it. common on these cars i can give you allot of tips on how to fix this . i did see you switch to returnless would also like to know what set up that is .
    Anyways imo it would be very unlikely to hit the 600 rwhp with a eaton ported or not and if you did you would be haveing a nuclear melt down under the hood. Also just for argument sake to say 600 with a eaton people do it all the time or whatever i would just day good luck with that cause parts will fly.
  4. DSG2NV03

    DSG2NV03 MUST HAVE BOOST!!! Established Member

    May 6, 2004
    Jacksonville, FL
    I am going to have to agree with the above. Sounds like you have a nice breathing motor now being choked up with the Heaton. Timing?

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