dyno day in 6 days, what to look for

Discussion in 'Dyno Performance' started by 94yellow50, Apr 27, 2015.

  1. 94yellow50

    94yellow50 Member

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    Finally taking my 94 to get dyno tuned this coming Saturday. Any tips on things to check or go over before it goes. Planning on swapping in new plugs, replacing dist. Cap n rotor, just replaced fuel filter, fresh oil in. Just looking for any tips from people who've previously done this. Also I'll let anyone make guesses too. 94, 10.5:1 306, trickflow 170 tw heads, steeda 19 cam, holley systemax 2 intake, long tubes, x pipex bassani mufflers, pro m I think 76 mm maf sensor, 70 mm tb, 24lb injectors, all accessories minus smog, t5, 4.10 gears (not that it will matter too much)
     
  2. 96blak54

    96blak54 Legend

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    Where is the dyno day located?
     
  3. Michael Plummer

    Michael Plummer Active Member

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    This should keep you busy:
    http://forums.corral.net/forums/superchargers/1334584-your-hp-tips.html

    Good luck and your 4.10 rear-end gears will hurt your dyno number (lower). Installing higher rear-end gears will not increase your horsepower. It will slightly decrease your horsepower and torque on a dyno test. But it will greatly increase your acceleration and allow your engine to operate at a higher rpm throughout your normal driving range. So you will be utilizing more of your engine’s horsepower and torque all the time.

    Now the why: Higher numerical rear end gear are less efficient than lower numerical rear end gears. A chassis dyno like a Dynojet measures RWHP & RWTQ by how quickly the drum accelerates to a given RPM and calculates the conversion. With the bigger gearing and all else the same, the drum will accelerate quicker but to a lower speed (RPM) and that's were the difference in rwhp comes from.

    I hope this helps
    Michael Plummer
     
  4. 96blak54

    96blak54 Legend

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    Nitrous hits on a Dynojet jump like +1000hp, so that backs up what Plummer stated.
     
  5. 94yellow50

    94yellow50 Member

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    I'll be going to dynotunemp up by Chicago suburbs. Amd yes I had read that the higher gear would read a lower number. But oh well I guess lol. Any idea on how far off that will throw the numbers? And is there any correction factor he can figure in to give the numbers closer?
     
  6. 94yellow50

    94yellow50 Member

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    Results are in. 303hp/ 305 tq. Advice from the tuner wad pull the spacer between upper n lower which is an inch. Said that will bump hp up because it'll shorten the runner. Said with a better cam I'd be 325 to 330 easy. Cam shut down around 5700. 24lb injectors were at 95% duty cycle so a good idea at some point would be at least 30s. Plus the 4.10 gives lower numbers. So all in all I'm happy. I said if it makes 300 I'm good. Any more is just extra. But now with the info it's leaving me wanting a custom cam n port the heads lol
     
  7. rw95gt

    rw95gt Member

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    Nice numbers. I bet its a blast around town. Any tuning or stock?

    Sent from my RM-877_nam_att_205 using Tapatalk
     
  8. 94yellow50

    94yellow50 Member

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    That was after adding fuel n timing. First baseline run he aborted at 4k because it was super lean the whole thing. Idle,cruising, and wot all needed more fuel. Ended up with 23 degrees on 93 octane. He told me if I wanted to mix in some 100 or higher I could go more timing but we tried 25 on the 93 n actually made less power.
     
  9. Michael Plummer

    Michael Plummer Active Member

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    You made good power and you left happy, congrats on a successful day.
     
  10. Michael Plummer

    Michael Plummer Active Member

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    * Advice from the tuner wad pull the spacer between upper n lower which is an inch. Said that will bump hp up because it'll shorten the runner.
    A) Mike Post is a good and smart tuner and you should listen to his advice. Personally, I never understood why people used spacers because they do nothing in terms of heat reduction.

    * Said with a better cam I'd be 325 to 330 easy. Cam shut down around 5700. 24lb injectors were at 95% duty cycle so a good idea at some point would be at least 30s.
    A) I agree with Post's advice and you should seek out Feezy74 on the Corral for your custom camshaft needs.

    * Plus the 4.10 gives lower numbers.
    A) A 3.73 or 3.55 rear end gear would be a better suited for your application. Post can always add more total timing in your operating range to make up for the reduction in acceleration if you install a lower rear end gear.
     
  11. 94yellow50

    94yellow50 Member

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    As far as the spacer goes that was an issue of hitting on the valve covers. And there was a 1 inch laying at my buddies so I used it. I'm gonna see if I can get It to clear without the use of the spacer, if not at least want to get a shorter one because the inch is way too much extra from what I need. As for the gear, I had a 3.73 up until a year ago, when I snapped an axle, now I wish I had just left it but I'll run the 4.10 for a while at least.
     
  12. whiplash473

    whiplash473 Moderator Staff SN95 Supporter

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    I'm planning on going there real soon. How was he to deal with? I've met him once and talked to him on the phone twice, the second time on the phone he was not friendly whatsoever, actually demeaning. But the other time and when I met him in person he seemed like a great guy. Maybe just caught him on an off day.
     
  13. 94yellow50

    94yellow50 Member

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    I thought he was pretty cool to work with. Explained what he was doing as he was changing things and why he was doing what he was doing. After a couple runs we had to pull plugs and gap them down lower, he asked if I do the work on the car, said yep built it myself. So he said well I can do it and charge you labor or I'll give you the tools a s even gloves and I pulled them out, ended up helping me to speed I up anyway and gapped them as I pulled and re installed them. No charge extra. We did a ride after to do drive ability test n he brought the laptop n data logged as we drove. Adjusted a few things while we were out. Even right when I pulled it up to pull into the shop he could tell just by the idle and sound it was lean, and it ended up being way lean when I first started.
     
  14. whiplash473

    whiplash473 Moderator Staff SN95 Supporter

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    Sounds good, I'll be setting up an appointment soon. Thanks for the input.