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How much change doe a Jacobs Ignition make

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Chaotical, Jun 4, 2001.

  1. Chaotical

    Chaotical Registered Member

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    SLC, UT
    I just bought my ignition
    Jacobs Mileage Master Ultra Team and have not put it on yet..

    I'm just wondering how much of a change did people notice on thier Jimmy/Blazer..
    MPG, HP, and so on... anyone got any imput I'll tell everyone how much I love or hate it in a bit after I test it...


    Chaotic Entertainment
    85 Jimmy 4" Lift, 3" body Lift soon to come, Dana 44, 14bff,
    37" SSR's
    Salt Lake City
     
  2. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    i can not say anything about the jacobs good or bad. i know that when i upgraded my ignition i noticed a lot of differance. i dont know if you are going from points to hei like me or not. i had a lot smoother idle and a bit better MPG. HP was a very small nottice but my motor had 180k on it. so on a bit newer motor you might notice a better all round performance. i am sure you will like it. and i am sure it will help at the pump.
    just my bit of mind. i doubt it will help.

    1974 Chevy Blazer Cheyanne. lots of plans for it....
    but it is on 33's now, with saggy old springs. i am in so cali if ya got any parts for me.
     
  3. CaptCrunch

    CaptCrunch 1/2 ton status

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    I have heard nothing but bad things about Jacobs.... from the bull-crap claims of their product to the even worse service when they tried to take the stuff back on their bogus warranty. I looked into them a while back and decided I was avoid them like the plauge. I went MSD offroad, msd Helicoil wires, Holley HP module, and MSD coil and have had excellent results. I also have buddies running Crane w/ good results.

    -Mikey
    1987 Chevy K5 Blazer- 350 TBI
    <A target="_blank" HREF=http://www.geocities.com/milnerlives_2000/blazer.htm>http://www.geocities.com/milnerlives_2000/blazer.htm</A>
     
  4. kumma

    kumma 1/2 ton status

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    From what i've heard you really cant beat the GM HEI ignition in stock situations. It shows it shortcoming at rpms over 5000. Aftermarket ignitions are better in higher rpm motors. As for the jacobs i cant comment. Just some info.
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

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    I concur. Replace plugs, wires, cap, rotor, and module if you want a thorough tuneup. IMO, wires and plugs are the necessity to be replaced, and rotor and module need to be inspected to make sure they are ok, but can be re-used. Module if your truck own't start.

    Don't expect any miraculous gains in MPG or performance from any aftermarket ignition components.

    Except fuel injection lol

    Dorian
    My tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
    No anti-theft measures on your truck? No pity when its stolen<P ID="edit"><FONT SIZE=-1>Edited by dyeager535 on 06/05/01 06:44 PM (server time).</FONT></P>
     
  6. 73Jimmy

    73Jimmy Registered Member

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    I got a Jacobs module, a set of Jacobs wires and an electronic point/condenser
    replacement. It made a big improvement on my 73 Jimmy. Starts like it is shot
    out of a gun, runs smooth, and went from about 10MPG to 13-14MPG.
    Best improvement I ever did.

    Most of the guys on the board like the MSD units but I have had no problems
    with my Jacobs.

    73Jimmy
     
  7. HarryH3

    HarryH3 1 ton status Author

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    If your current ignition system is totally clapped out, then any new ignition system will make it run much better. Most of the "tests" performed with the miracle ignition systems start with a dyno test of a vehicle that hasn't had a tune-up in 50,000 miles or more. New plugs, wires, cap and rotor, plus a new coil and module are installed then WOW! look at how much of an improvement there is! [​IMG]

    At the other end of the spectrum, a friend of mine was totally into drag racing his stock Corvette. He kept incredibly detailed records of every pass that he made down the strip. He also kept his car in excellent condition. He decided to give the Jacob's "Power Team" a try and see what it would do for his car. Laid out mucho bucks, installed everything and went to the track. No change. $400 worth of no improvement in performance or mileage. He took it all off and sent it back under the Jacobs "guarantee". You know, the one that says that YOU get to pay a 10 or 15% "restocking fee" if their stuff doesn't measure up. So with shipping and the restocking fee it ended up costing him over $50 to find out that he wasn't impressed. [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
    It's a great day to be alive...
     
  8. DzrtRat67

    DzrtRat67 Registered Member

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    For what it's worth, I put an MSD on my '77 Blazer. Seemed to run a bit smoother, not much difference in pedal. Did get another 1-2 mpg though. I say "did" because one night on my way home, I lost my coil...hei...all three of the primary wires going into it were fused together! Apparently, this is semi-common with these balls to the wall ignitions...my advice, try to upgrade coil to a hotter one as well...although, personally, I don't know of any. Maybe someone else here can help out with that.
    Good Luck..
    Rat
     
  9. dyeager535

    dyeager535 1 ton status Premium Member

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    Yep. I bet if I put no matter what aftermarket ignition stuff I put on my truck, I would NOT add 2-4MPG. It's just not going to happen.

    The ONLY "problem" with the HEI that I have read about is that the "saturation" of the coil takes too long, and with aftermarket components, (MSD etc) the saturation time is reduced, so at higher RPM's (which is where the problem is with stock HEI) the spark is not reduced. That is all that I remember from the article, not sure if that is even correct.

    I don't doubt that it will help on startup, but I'm not worried about something I do maybe 5 times a day. I'd much rather keep my XXX$ and spend it on gas, which is where all my money goes anyways!

    Dorian
    My tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
    No anti-theft measures on your truck? No pity when its stolen
     

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