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Thread: How does my attached "drag race" GCF look?

  1. Default

    Good question. I think I did yes. This would have been back in March 2020, so I'm going off memory here, but I think I did. Does this mean I can or can not also use that brown wire for the shift light? Since it's just a shift light (not an integrated tach) I don't know if I would need a tach adapter or if I could simply just splice my shift light wire into the existing tach wire setup. Prior to having the HyperSpark, I just plugged the shift light wire into the "tach" port on the side of the Digital 6 box, and that was it.

  2. #112
    Join Date
    May 2019


    I'm going to try hooking up my tachometer again. Mine's an '86 Camaro, but I actually don't know what year the cluster is from. But I never had an accurate reading from my HyperSpark spark or the former MSD box.

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    OK cool! Glad to speak to another 3rd Gen F-Body owner on here. Nick Gargano is on here, and he has a 3rd Gen also with a SBC. He's been helping me with some tuning stuff over the past few weeks.

    Keep me informed if you get your tachometer hooked up and how it goes. I'm going to try to just run my shift light tach lead over to the brown wire from the Sniper harness. Hopefully it works seamless and plays nice with my OEM dash tachometer setup. I'd really like to have a working dash tachometer, as well as a working shift light.
    1987 IROC-Z Camaro. Street-Strip-Show-AutoX
    406 SBC, Dart SHP, Dart Pro1 heads, Holley Sniper EFI with HyperSpark. 700R-4 ProBuilt, Moser 12 bolt, UMI suspension with Konis, big brakes, lowered.

  4. #114
    Join Date
    Dec 2009

    Default (Holley Sniper EFI Tachometer Wiring Information)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS T/W 11R 205 heads, 232°-244° duration/.623" lift/114° LSA camshaft, 12:1 C/R, TFS R-Series FTI ported intake, BBK 80mm T/B, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, -6AN fuel system plumbing, Walbro 255 LPH pump, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, B&M Hammer shifter, FPP aluminum driveshaft, FPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 M/T Street Comp tires.

  5. Default

    Yup, thank you. I remember reading that post either after doing a search, or perhaps someone had suggested it to me. I also remember reading somewhere about possibly needing a tach filter, but that might have been related to my previous MSD magnetic setup. I think the simple answer here is that I should just connect my brown Sniper wire to both the OEM dash tachometer and also to the Summit shift light. If for some reason that does not work, I will revisit the issue.

    Thank you Danny. This forum is a great wealth of knowledge and experience and I truly appreciate all this help guys.

    So far I'm loving the HyperSpark and Sniper EFI combination. Having the laptop cable to watch what the engine is doing live is really awesome, I just hope that I can get smart enough to make the correct adjustments to the tune!

  6. Default

    I did not want to start a new thread for this topic, because simply, this question is a continuation of why I actually started this thread in the first place. All the stuff in the middle pages was sorting out an ignition issue, and with that fully resolved, I just wanted to post my current GCF here because I plan to go to the track this Friday night and it's possible this will be my last track session of the year.

    I've been at the track a few times since I started this thread and have run a bunch of passes in the 11.8x and 11.9x range at 115 MPH. I learned that I had previously been giving the engine too much timing when I had my ignition table at 36°, 37°, 38° during the summer racing events. I've determined that the engine likes 35° of WOT timing and a 12.5:1 Target AFR for torque peak, with a 12.7:1 Target AFR for HP peak. I had to lower an area in the VE table between 2,600-3,400 RPM, which is where the converter was flashing in first gear. I was getting a significant rich dip on all of the datalogs and the AFR was going down to 9.5 & 10, so I took a few % out of that area of the VE% Table, smoothed it, and I'll check it after I make my first pass. I haven't really tightened up the Closed Loop & Learn Limits just yet either.

    I'm still working on figuring out my proper shift points using math, datalogs, and timeslips, but that's a long topic that I won't bore you all with. I do believe that I'm shifting too soon and dropping too low in the torque curve of the next gear, so I raised the rev limiter from 6500 up to 6750 and I plan on shifting at 6,500 instead of my prior target shift at 6,200 RPM.

    GCF for Oct 23 <--- GCF File.

    Simply, I was just wondering if anyone had any criticism, comments, or notable problems with the attached GCF I plan to run at this upcoming Friday's Test-N-Tune. As always, any advice is very much appreciated!

  7. #117


    I'm surprised that it idles at 15:1 AFR. Maybe you have an exhaust leak? Other than that it looks fairly normal. 10° Cranking Timing seems low, but if it works for you, then okay. Your ignition timing table seems a little over complicated, but probably isn't a big deal. Have fun, pay attention to the Learn Table and spark plugs.

  8. Default

    Thanks. Yes, when I had it idling at a lower Target AFR I'd get a pretty potent fuel smell. I was told this is a "false lean" due to the cam profile. There are no exhaust leaks, for sure, I have checked and re-checked. It does idle good currently at 15:1 and the 10° Cranking Timing has been super reliable. Often, I start the car from standing outside the drivers door just reaching in and turning the key, knowing I don't need to worry about working the throttle or any cranking issues. I do have to get better at reading spark plugs. I know there's a LOT to learn and I seem to just know the basics (fuel ring, timing mark on strap, etc.).

    Today I took a few minutes and wired up the 2-Step rev limiter feature from the Sniper. Tested it with the car in park at a few different RPM levels and it's working. Not sure that I plan to use it tomorrow at the track though. The car is an automatic and I usually leave from a 920 RPM idle; but perhaps I'll try one pass leaving from 1,800 RPM on the rev limiter. The engine currently does not make enough vacuum to keep the brake booster working, and I usually begin to creep forward on the starting line at around 1,800 RPM.

    testing at 2,500 and then at 3,500

    testing only at 5,000

    edit: abc, yes a transbrake might be a winter upgrade.
    Last edited by IROCZman15; 10-22-2020 at 09:15 PM.

  9. #119


    Time for a transbrake.

  10. #120


    If it creeps at 1800, try 1600. Wacking the throttle blades to WOT at 920 RPM seems like you are asking for a bog. If you can wack it at 1600, logic says it'll be better. Just watch your red lights. I see you've already been in red light city.
    Good luck and please keep us posted. I read ALL of this thread. I'm glad you found and fixed the issue (MSD box).
    I was told a long time ago not to get hung up on a "number". In your head you might think the timing should be 36°, but if the engine likes 33° or 34°, set it there, forget the number in your head. Also for AFR. If the car is faster at 12.4, but your head says 12.8, leave it at 12.4. Give the engine what IT wants and not what you think it wants. Experiment and find out what IT wants & needs, then feed it that.

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