Page 1 of 3 123 LastLast
Results 1 to 20 of 43

Thread: The inaccuracy of HEP and distributor is causing you to lose power.

  1. #1
    turbo addict
    Join Date
    Dec 2005
    Location
    Mesa, AZ
    Posts
    7,351

    The inaccuracy of HEP and distributor may causing you to lose power.

    I always knew HEP and distributor is not accurate because whenever I use a timing gun to set base timing, the timing mark always jumps between 10 to 14 and never settle on 12.

    Now with MS, timing mark is where ever I set it in the software, every time.

    After my last dyno, I found I am able to run more ignition timing while boosting on E54 (MS tune) than E85 (LM tune)! Here are the timing tables for both tune.

    E85 tune on LM with Turbonator, HEP and distributor. We added timing until no more power gain and power started to drop, then we back off couple of degree.




    E54 tune on Microsquirt with 36-1 wheel welded on the crank pulley. Same tuners on the same dyno.




    What does it all mean?

    With MS, I'm making about the roughly 250 WHP at 12.5PSI, it took 15.5PSI on LM to get the same power.

    So, if you're looking for low boost and high HP, I'd say go aftermarket ECU and get rid of the HEP and distributor.
    Last edited by tryingbe; 04-05-2021 at 04:44 PM.

  2. #2
    Rhymes with tortoise. Turbo Mopar Staff cordes's Avatar
    Join Date
    Dec 2005
    Location
    Tuscola, IL
    Posts
    21,441

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    If that's the only change you made, then that is a huge difference indeed. Thanks for that into. It's something to consider given that some aftermarket systems really aren't that expensive for what you get. I'll be sticking with the stock electronics, but it is something to think about for sure.

  3. #3
    Moderator Turbo Mopar Staff Force Fed Mopar's Avatar
    Join Date
    Dec 2005
    Location
    Greenville/Spartanburg SC area
    Posts
    7,557

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    He changed turbos also, but both are T04 cold sides, just in different trims.
    Rob M.
    '89 Turbo GTC

    2.5 TIII stroker, 568 w/ OBX and 3.77 FD

  4. #4
    turbo addict
    Join Date
    Mar 2014
    Location
    Toronto Canada
    Posts
    1,772

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    I think you would find the timing inaccuracy is not the distributor and hep but rather the rubber belt driving the whole works

    ms is probably less to do with it than your crank trigger system

  5. #5
    turbo addict
    Join Date
    Dec 2005
    Location
    Mesa, AZ
    Posts
    7,351

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    Quote Originally Posted by Force Fed Mopar View Post
    He changed turbos also, but both are T04 cold sides, just in different trims.
    I had a more efficient T04E-50 trim compressor wheel with a bigger T04E housing and now I have a less efficient T04B-V trim compressor wheel and smaller T04B housing. So if anything, I should lose HP going form 50 trim to V trim, but that's not what happened.

    Quote Originally Posted by Dr. Johny Dodge View Post
    I think you would find the timing inaccuracy is not the distributor and hep but rather the rubber belt driving the whole works

    ms is probably less to do with it than your crank trigger system
    Probably, but since the 8 valve's LM/SMEC/SBEC is tie together with HEP sensor, 30 year old HEP wiring, timing belt flex, i-shaft, distributor, plastic weld, and etc, timing inaccuracy would remain as long as you keep using 8 valve's LM/SMEC/SBEC.

  6. #6
    Slugmobile & MeanMini Caretaker Turbo Mopar Contributor wheming's Avatar
    Join Date
    Nov 2010
    Location
    Raleigh Area, NC
    Posts
    4,809

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    Quote Originally Posted by tryingbe View Post

    Probably, but since the 8 valve's LM/SMEC/SBEC is tie together with HEP sensor, 30 year old HEP wiring, timing belt flex, i-shaft, distributor, plastic weld, and etc, timing inaccuracy would remain as long as you keep using 8 valve's LM/SMEC/SBEC.
    And all those inaccurate variations/tolerances get compounded at times, belt lash, gear lash, etc.
    I'm sure that is a big reason the stock timing check has the reading bouncing all around.
    It would be nice to remove that variable without having to go full standalone electronics.
    Wayne H.

    '91 Dodge Spirit ES 2.5L turbo 5spd
    '05 PT GT 2.4T HO autostick (RIP)
    '89 Plymouth Acclaim 2.5L turbo auto, "Slugmobile" yes, THE Slugmobile!
    '89 Dodge Caravan SE 2.5L turbo auto, "Mean Mini" yes, Gus' Mean Mini! (Current best 11.699 @ 114.43 mph! - Oct 15th, 2022 Cecil County Dragway, MD)
    MeanMini dragracing videos: https://www.youtube.com/playlist?lis...URZLB1RxGYF6vw
    and other cars, trucks and motorcycles
    https://www.youtube.com/user/SlugmobileMeanMini

  7. #7
    turbo addict
    Join Date
    Mar 2014
    Location
    Toronto Canada
    Posts
    1,772

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    lol due to the timing wandering around I've never actually used a timing light on a TM/TD in all these years as it's basically useless
    my azz tells me more about the timing than a timing light ever could & always has done

  8. #8
    Slugmobile & MeanMini Caretaker Turbo Mopar Contributor wheming's Avatar
    Join Date
    Nov 2010
    Location
    Raleigh Area, NC
    Posts
    4,809

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    As Rob Llyod has tried to explain over and over, that timing check/adjustment procedure is just setting the timing reference.
    So it is important to try and get it close.
    With the ability to change timing maps with flashable ecu's and MPTune, the reference might become less important that what the end result actual timing ends up being. But, the way to do it right is still to have the reference right so the actual numbers are meaningful.
    Wayne H.

    '91 Dodge Spirit ES 2.5L turbo 5spd
    '05 PT GT 2.4T HO autostick (RIP)
    '89 Plymouth Acclaim 2.5L turbo auto, "Slugmobile" yes, THE Slugmobile!
    '89 Dodge Caravan SE 2.5L turbo auto, "Mean Mini" yes, Gus' Mean Mini! (Current best 11.699 @ 114.43 mph! - Oct 15th, 2022 Cecil County Dragway, MD)
    MeanMini dragracing videos: https://www.youtube.com/playlist?lis...URZLB1RxGYF6vw
    and other cars, trucks and motorcycles
    https://www.youtube.com/user/SlugmobileMeanMini

  9. #9
    Supporting Member Turbo Mopar Contributor
    Join Date
    Feb 2015
    Location
    toronto
    Posts
    1,765

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    Quote Originally Posted by wheming View Post
    And all those inaccurate variations/tolerances get compounded at times, belt lash, gear lash, etc.
    I'm sure that is a big reason the stock timing check has the reading bouncing all around.
    It would be nice to remove that variable without having to go full standalone electronics.
    On the geek thread, I suggested we use sensors such as crank and cam and translate i.e. convert to HEP language. This may enable us to use the stock electronic but with superior crank and cam position. This could help keep the cost down for us big spenders
    Regards,
    Miles

    DD '87 Sundance T1, SLH with rear disks
    '87 CSX #432 2.5 CB TII, SLH

  10. #10
    turbo addict
    Join Date
    Mar 2014
    Location
    Toronto Canada
    Posts
    1,772

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    yep but ten min on a quoit road with a distributor wrench will, get base timing set way way better than a timing light ever could
    in a really light car like a L body you would be surprised how little distributor movement can actually be felt

    timing light tells you what the timing is
    service manual tells you what the engineers set it to usually
    the car tells you what it wants

    always listen to the car - it's the only one that ACTUALLY knows

  11. #11
    turbo addict
    Join Date
    Mar 2014
    Location
    Toronto Canada
    Posts
    1,772

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    on using crank & cam sensors , going distributorless , r/t motors and I shaft -oil pump failures ..
    I think one of the big reasons the R/T's have the oil pump drive failures is the distributor delation

    I've personally seen what bad gear engagement with an oil pump drive can do / cause , be caused by in other motors and it really fubar's the engine
    to long an oil pump or dist shaft and kiss the pump good bye with the motor
    so with the dist drive lug , shaft , housing and most importantly the distributor clamp holding the housing down on the block .. WHAT's keeping the oil pump drive gear from climbing and dropping off the gear driving it ???
    NOTHING .. now
    like runing a hand file over each gear tooth and wondering why they keep wearing away ...

  12. #12
    turbo addict
    Join Date
    Aug 2009
    Location
    Myrtle Beach, SC
    Posts
    2,133

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    Why couldn't you leave the distributor in if using a cam sensor on the head and crank sensor off the crank pulley?

  13. #13
    Supporting Member Turbo Mopar Contributor
    Join Date
    Feb 2015
    Location
    toronto
    Posts
    1,765

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    Quote Originally Posted by thedon809 View Post
    Why couldn't you leave the distributor in if using a cam sensor on the head and crank sensor off the crank pulley?
    Yes you could this would only replace the HEP function.
    Regards,
    Miles

    DD '87 Sundance T1, SLH with rear disks
    '87 CSX #432 2.5 CB TII, SLH

  14. #14
    turbo addict
    Join Date
    Aug 2009
    Location
    Myrtle Beach, SC
    Posts
    2,133

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    Quote Originally Posted by chromguy View Post
    Yes you could this would only replace the HEP function.
    Exactly. If someone's that worried I would just remove the cap and rotor and Fab a little flat plate to cover it. Could probably mount the coil pack to it as well.

  15. #15
    turbo addict
    Join Date
    Dec 2005
    Location
    Mesa, AZ
    Posts
    7,351

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    Quote Originally Posted by thedon809 View Post
    Exactly. If someone's that worried I would just remove the cap and rotor and Fab a little flat plate to cover it. Could probably mount the coil pack to it as well.
    Already done.


  16. #16
    Supporting Member Turbo Mopar Contributor
    Join Date
    Feb 2015
    Location
    toronto
    Posts
    1,765

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    Quote Originally Posted by tryingbe View Post
    Already done.
    Perfect timing for the picture!
    Regards,
    Miles

    DD '87 Sundance T1, SLH with rear disks
    '87 CSX #432 2.5 CB TII, SLH

  17. #17
    Slugmobile & MeanMini Caretaker Turbo Mopar Contributor wheming's Avatar
    Join Date
    Nov 2010
    Location
    Raleigh Area, NC
    Posts
    4,809

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    Quote Originally Posted by chromguy View Post
    Perfect timing for the picture!
    Now YOU made the pun!
    Wayne H.

    '91 Dodge Spirit ES 2.5L turbo 5spd
    '05 PT GT 2.4T HO autostick (RIP)
    '89 Plymouth Acclaim 2.5L turbo auto, "Slugmobile" yes, THE Slugmobile!
    '89 Dodge Caravan SE 2.5L turbo auto, "Mean Mini" yes, Gus' Mean Mini! (Current best 11.699 @ 114.43 mph! - Oct 15th, 2022 Cecil County Dragway, MD)
    MeanMini dragracing videos: https://www.youtube.com/playlist?lis...URZLB1RxGYF6vw
    and other cars, trucks and motorcycles
    https://www.youtube.com/user/SlugmobileMeanMini

  18. #18
    turbo addict
    Join Date
    Mar 2014
    Location
    Toronto Canada
    Posts
    1,772

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    to use the crank sensor and cam sensor then use the distributor to actually deliver the spark energy from the coil to the plugs .. total waste of time

    sure the sensors would give you great accuracy in signal timing to the ecu .. but to still use the bounc-ie jounc-ie belt/i-shaft/pump/dist drive , you still haven't improved actual spark timing accuracy to the cylinders
    (IF by keeping the dist the intent was to still use the cap/rotor and wires)

  19. #19
    Mitsu booster
    Join Date
    Dec 2016
    Location
    Rutherford county nc
    Posts
    44

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    Umm.. rethink that a moment.. the rotor and cap is a rotary switch essentially. It does not affect timing more than a few picoseconds as long as the rotor is pointed at the terminal within several degrees. However, the reason for getting rid of the cap and rotor would be higher spark energy and I don't think that waste spark setup will deliver as much as individual coil on plug setup.. if you're going to go all out, why not go all the way out? Plus that eliminates all plug wires except the coil boot. Just my thoughts.

  20. #20
    turbo addict
    Join Date
    Aug 2009
    Location
    Myrtle Beach, SC
    Posts
    2,133

    Re: The inaccuracy of HEP and distributor is causing you to lose power.

    Quote Originally Posted by A_ Kelley View Post
    Umm.. rethink that a moment.. the rotor and cap is a rotary switch essentially. It does not affect timing more than a few picoseconds as long as the rotor is pointed at the terminal within several degrees. However, the reason for getting rid of the cap and rotor would be higher spark energy and I don't think that waste spark setup will deliver as much as individual coil on plug setup.. if you're going to go all out, why not go all the way out? Plus that eliminates all plug wires except the coil boot. Just my thoughts.
    You would have to Fab up a mount for a COP setup.

Page 1 of 3 123 LastLast

Similar Threads

  1. lose head bolts?
    By 663csx-t in forum Engine - Block, Piston, Heads, Intakes
    Replies: 46
    Last Post: 09-12-2010, 04:19 AM
  2. Wow, don't lose your rocker shafts!
    By turbovanmanČ in forum 16v Factory Engines
    Replies: 1
    Last Post: 03-16-2008, 02:55 AM
  3. Lose your Shelby in an accident in MI?
    By J&H Ryan in forum Shelby Models - Whittier Factory Cars
    Replies: 20
    Last Post: 07-29-2007, 08:57 PM
  4. power lose light won't flash codes
    By MoparN75 in forum Electrical & Fuel System
    Replies: 3
    Last Post: 08-03-2006, 07:02 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •