Stock shortblock and superchargers

Discussion in 'SVT Tech Forum' started by MysticVobra, Aug 12, 2004.


  1. MysticVobra

    MysticVobra New Member

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    I was just wondering what the longest anyone has gone with a stock cobra 4.6 shortblock and a supercharger? I know alot of people say that the rods and pistons in these things are on borrowed time once you slap a blower on but it seems that the people who blow these things up are the ones who become greedy with boost. I am running an extremely conservative tune on my car and really don't drive it that hard cept for the couple times a year i go to the track. Do i have anything to worry about in the future keeping my boost at 8lbs? I am really just curious to hear everyone else's experiences and opinions.
     
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  2. MysticVobra

    MysticVobra New Member

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  3. ironmedic

    ironmedic New Member

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    it would be a good question to answer. i am going the SC route myself on a stock engine. i think 6-8 psi is a safe range to run on a stock motor. that is the range my friend recommended to me for my 5.0 so the same idea should apply for a 4.6 (even though it is a different engine).
     
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  4. BLK_ROUSH

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    Apparently not a lot of Vobras on the board. :shrug:
     
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  5. cold96snake

    cold96snake Active Member

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    I've heard 30-40,000 on a safe tune, but no experience w/it. I'm interested too. I'm debating whether I want to slap the kit you have on, or to keep it stock so I can sell it when the '06 (or is it '07) cobras come out.
     
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  6. 99SVTAddict

    99SVTAddict New Member

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    There is no answer, that's why people aren't posting here I think.
    Same cars, same boost, same tune....one could blow up, the other last 80K miles. There's just so many variables.

    So here's the bottom line: be prepared for the motor to go....eventually.
     
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  7. JBVobra

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    thats a tough question and there is no definitive answer. I ran a '98 cobra with a stock pulley s-trim and a 4" powerpipe for about 20K daily driven miles, over 3 years. I saw about 9psi, maybe 10 on a really cold night. Car made about 450/380 SAE. Two weeks before I sold it, I had a leakdown/comp test performed, and it was as good as new. Tune was right at 11.9 to 1 WOT.

    Most of the "answer" lies in the condition of the motor before you plop the blower under the hood. Was it a mid day Wednseday car or a late afternoon Friday car? Those two names on your block will have alot to do with how durable that hand built, 9.85 comp motor will be. A blower (even tuned conservately) will definitely "root out" the weak points of the build alot quicker than running NA. So, to make a long story short, how lucky do you feel? Even taking all precautions and running proper fuel and tuning components, thats what it boils down to.

    I kind of felt on borrowed time at three years, so I opted for a change.
     
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  8. stang976

    stang976 New Member

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    you should have no problems with 8#'s. once you start playing with smaller radius pulleys for more boost is when it catches up to you.
     
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  9. Jpjr

    Jpjr New Member

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    This is kind of a depressing thread. I just bought an '03 cobra, even with a supercharger I really can't believe the motor will konk out anytime after 20 or 30k miles. I would hope to get 80-100k at least.. am I dreaming? (I hope not for what I paid for the car.. a vette will last forever)..
     
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  10. 99SVTAddict

    99SVTAddict New Member

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    No, no, no, no, no.....you are fine man. Your car has a steel block, forged crank, rods, and pistons...it was meant to have a supercharger on it. Us pre 03 Cobra guys have an aluminum block with forged crank, but that's it....plus our compression is 9.85/1 vs. your 8.5/1. The 03+ Cobra's are a whole new beast....have fun with it.

    My car will be done this week....after I blew the motor I had the aluminum block machined by Diamond....then put in manley rods and Diamond pistons (same 9.85 compression), Cobra crank, ARP bolts, billet oil gears, P&P'd the heads....it is now made to handle boost. :flag:
     
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