502 Mpi Problems???????
07-10-2002, 07:32 PM
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Location: beaumont tx
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07-11-2002, 07:04 PM
#15
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Tommy- Not to offend and I'm not saying your not going 8 MPH faster, but it sure the hell isn't from the Vortec MPI kit. To be fair, the $50.00 adjustable fuel pressure regulator [best part of that $1000.00 kit] might be helping your SM manifolds add an optimistic 25HP per engine. In a 31 Formula [nice boat BTW] 50hp would be almost unoticable... 2 -3 MPH? Maybe if your lucky. What could be in that kit to give you the 120hp minimum to push that boat 8 MPH faster? Let's start with the highly acclaimed "billit" flame arrestor with claimed 35% increase in airflow: It dosen't matter if it flows 200% if the throttle body and motor can't pass it. I have taken my stock flame arrestor off , ran the boat and no difference. Additonal HP : about 0....no, I'll give it 5hp because it really does look cool. Next up The MSD Ignition Amplifier: Never proven to make more HP, some say cleaner transoms, better idle & tip-in; probably so. Additional HP: about 0. Next [and my personal favorite] "The Reprogrammed ECM" this mysterious and miserably programmed black finned box, just waiting for some wizard to tap all the horsepower lurking inside. Let's see what this does: after spending $1500.00 in reprogramming [2 from the Grand Wizard himself] I concluded it doesn't do ****. Granted these were on modified engines, but your fuel/air ratios that come in the little black box are fine as is. But you say now I got a 5400rpm rev limit.....thats fine but since your stock valve springs are approaching their limit a 5000rpm's
continuous, what good does this do you? How about the more agressive spark curve? You might get a little better acceleration and almost nothing on top. Additional HP: about 5....No 0! Because for most boaters, this is a scam! Next and last "Maxfow fuel Optimizer": The 50.00 secret of this 1000.00 kit. It allows you to make other small changes to you motor such as exhaust manifolds, SMALL cam increase,etc...it increases the regulated fuel pressure tomatch the increased air flow of the modification. Changes must be kept conservative or you will quickly run into expensive road blocks i.e.: throttle body, manifold,etc. Additional HP: Depends.
Let's add this up.....roughly 0 horsepower [give or take 10 to compensate for my personal bias]Oops, almost forgot, we got 25HP each engine from the less resrictive manifolds.
Tommy, let's say I believe your 8 MPH gain [I think I might]. Heres my theory: 50HP total from the manifolds, 140# less weight in your bildge from the manifolds...your boat might really like the slight change in CG also. The days when you compared top speed the conditions were suitable/unsuitable for speed, other weight in boat, etc. Were props changed? Going from a bad prop for your boat to an excellent prop for your boat could mean an 8MPH swing in itself. I just don't think It came from the EFI kit.
Hope you still don't think I'm a smart**s. I really want to earn "the Boater's Consumer Ombudsman" award. Take care, Berg
continuous, what good does this do you? How about the more agressive spark curve? You might get a little better acceleration and almost nothing on top. Additional HP: about 5....No 0! Because for most boaters, this is a scam! Next and last "Maxfow fuel Optimizer": The 50.00 secret of this 1000.00 kit. It allows you to make other small changes to you motor such as exhaust manifolds, SMALL cam increase,etc...it increases the regulated fuel pressure tomatch the increased air flow of the modification. Changes must be kept conservative or you will quickly run into expensive road blocks i.e.: throttle body, manifold,etc. Additional HP: Depends.
Let's add this up.....roughly 0 horsepower [give or take 10 to compensate for my personal bias]Oops, almost forgot, we got 25HP each engine from the less resrictive manifolds.
Tommy, let's say I believe your 8 MPH gain [I think I might]. Heres my theory: 50HP total from the manifolds, 140# less weight in your bildge from the manifolds...your boat might really like the slight change in CG also. The days when you compared top speed the conditions were suitable/unsuitable for speed, other weight in boat, etc. Were props changed? Going from a bad prop for your boat to an excellent prop for your boat could mean an 8MPH swing in itself. I just don't think It came from the EFI kit.
Hope you still don't think I'm a smart**s. I really want to earn "the Boater's Consumer Ombudsman" award. Take care, Berg
