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Gen3 dyno question

Discussion in 'LSx Development and Modification' started by Gen3Jonesy, Apr 18, 2009.

  1. Gen3Jonesy

    Gen3Jonesy New Member

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    Hey guys!

    I've recently had a fair bit of work done on my VTII SS gen3...

    Heads
    Cam 224/234
    OTRCAI
    Highflow Cats
    Springs + Pushrods
    Extractors + Twin 3 inch system
    VX Manifold + 80mm throttle body
    Mafless tune + rev limiter up 500rpm
    3000rpm converter

    And a rebuilt t700 with stage 2 shift kit and cooling system going in tomorrow.

    Diff ratio's are still standard.

    Now with that all out of the way... Onto the question...

    On the dyno she made: (@ Wheels)
    271.5 kW @ 5502rpm
    1186.1 Nm @4191rpm

    BUT....

    My understanding of a dyno pull is that it should be done in 3rd gear, as close to 1-1 ratio as possible(I believe 3rd in the T700 is exactly 1-1?) ... The pulls that produced those figures were done in 2nd gear (1.63 - 1 ratio apparently)...
    How will this effect the numbers? Is it what you would call a *True* reading?
    Would I then be wrong to say "My car has 271.5kW @ the wheels"??

    I've an ever growing mistrust of my mechanic, even these figures aren't up to what was promised before the mighty dollar was handed over... I would appreciate any answers you guys may have...

    Cheers!
     
    Last edited: Apr 22, 2009
  2. johnvtls1

    johnvtls1 New Member

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    thats a decent figure for those mods. maybe 10kws to low. cams not all that big i guess. if ur that worried chuck it on another dyno. where did u get the work done BTW?
     
  3. delcowizzid

    delcowizzid on holiday

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    the T700 can be a pig for kicking down to second on the dyno and a lot are done in 2nd gear unless you have the 4L60e version you can make that stay in 3rd via ALDL.
     
  4. Gen3Jonesy

    Gen3Jonesy New Member

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    Yeah it is the 4L60e box, I dont know why on earth they would do it in second gear... This does change the power/torque figures right?

    At this stage I dont really want to release who did the work... Though I'm not too impressed with them I'm not going to dog them by name... Yet....

    Second and Fourth fried on the dyno, as I pretty much expected... But with the new tougher box installed we'll be giving it another few dyno runs and a bit of tune tweaking next week... I'll give them that chance before naming names... :)
     
  5. delcowizzid

    delcowizzid on holiday

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    they normally calibrate the dyno to suit what gear its in anyway depends what mode its on and what gear they tell it its in.
     
  6. Gen3Jonesy

    Gen3Jonesy New Member

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    Oh, and as for sticking it on another dyno...

    This tranny rebuild has literally DRAINED every last cent out of me... I wont be able to afford to pay for run's somewhere else for a while... And I think my partner will castrate me if I touch my bank account again anytime soon :whistling
     
  7. Gen3Jonesy

    Gen3Jonesy New Member

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    Cheers delco...

    I'm pretty much worried that they are "Fixing" the figures to try and reach a promised power figure that they cant actually reach... Could be just paranoid but I've been getting a VERY dodgie vibe from them ever since the car went on the dyno...

    Dunno if this is the "Mode" your talking about, but the dyno sheet says "Correction factor applied: SAEJ1349" on a Dynamic Test Systems dyno....
     
  8. SICK SS

    SICK SS 7L 427ci BABY

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    should have been in 1 to 1 gear like you said can you put the dyno sheet up for us to have a look at sounds dodge to me
     
  9. Vt_vic

    Vt_vic New Member

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    is it just me but 1100nm torque seems a bit much for this combo usually its like 650-700nm
     
  10. lsx427

    lsx427 New Member

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    Its just to hard to fake numbers on dynamic test systems-you will get caught out-

    i feel on the dynamic test systems the only way you could cheat would be to increase the ramp rate but the afr ratio will be way off-

    the name of the game is to get the afr's vs the temps vs the spark and so on and on, dial in spot on-so the operator is really hurting his education and his work if you ask me.

    i own a dynamic test systems and i am in melb if you want to put your mind to rest-

    i like to do everything in 1 to 1-sometimes its gets a bit tricky as other cars tend to kick down like some fords i done-

    the way around it is to slowly feed the pedal in and a reach a speed that the trans cant kick down.....

    with a auto on the dyno you need to get stuck in it asap or else it will cook the trans-

    i seen to many auto cars cook on the dyno due to the temps being threw the roof-

    wether a trans is good or bad-by running high temp's will destroy both-

    the dynamic systems reads low from what i had come here-

    5-10 rwkw dd
    5-15 rwkw mainline
    10-25 rwkw from a dynologic-

    never had a dyno pak to compare...........

    but numbers are numbers at the end of the day-

    ? for ya-does it go like you wanted it to go

    does it feel like its got 270-280 rwkw?

    I did a lot of research before buying this dyno vs the others on the market.

    If you have any more questions feel free to ask-

    Hope that helps.
     
  11. lsx427

    lsx427 New Member

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    yes-being in a lower gear will cause that-

    unless the engine has got some big cubes behind it,n20 or turbo/blower.. or some decent rpms and a big ass stick..... i find it pretty hard-

    their should be 5-10 rwkw more gain in it being in a 1.1 ratio gear.
     
  12. Gen3Jonesy

    Gen3Jonesy New Member

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    Cheers for the help there mate!

    It has definatly had an increase in power, I cannot question that :) The issue is that the package is sold in kW values and I want every last kW possibe for the (quite large) outlay... There are also a few other issues that have risen up since and I'm just feeling slightly stooged...

    Where in melbourne are you and what do you charge for a dyno run?
     
  13. GMMAD

    GMMAD New Member

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    for a head and cam combo that figure is a bit low
    and it is 271.5 kW @ 5502rpm that cam should be making peak power at near 7k
    and 1100nm is way to high should be around 700
    and yes dyno should be done in 3 gear
     
  14. vtssgrunt

    vtssgrunt New Member

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    dyno numbers

    the dts dyno reads slightly lower than most dyno's,partly due to the 4 rollers turning all the time,even when the wheels lift onto the front rollers.
    (It is more accurate than others,hey)
    This means the numbers dont change for the better as some dyno's do!
    Try contacting the workshop that did your dyno and engine work,as the dyno may have been done in 2nd gear because of the rpm versus speed .The dts dyno has a top speed of only 198kmh and in 3rd gear 1.0 :1 ratio it will max out with speed.This looks as to what has happened with you.
    If the car feels like a weapon and it is heaps faster then maybe it is 270kw wheels,it sounds like you are confused abit and be causious listening to too many forum experts.
    Try the normal approach an go back to the workshop,discuss your concerns and they will help,there the experts.Expecially if it has the power and parts used,it seems normal for a 5.7 with 250,ooo km ? with cam and heads to do this.
    As they say some dynos may have had 285kw wheels ?
    Also there was a post saying you can do 7000 rpm?,with a std vx manifold
    (i don't thinkso?
    all the best.
     
  15. GMMAD

    GMMAD New Member

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    the standard LS6 can handle 7000rpm
     
  16. Baldric

    Baldric The BOSS

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    i reckon yours can handle 7500 launches steve :D
     
  17. minux

    minux Infidel Bear

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    Why do people get caught up in ****ing dyno figures? Workshops are making shitloads of money off it because people like to brag about inaccurate dyno readings.

    Should be based on what the potential time it can do down the 1/4.
     
  18. Baldric

    Baldric The BOSS

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    because they are a good reference tool to get a average reading
     
  19. Gen3Jonesy

    Gen3Jonesy New Member

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    Anyone notice anything funny with this post by VTSSGRUNT?
    Seems there is at least one detail about the car in their post that was not included in any of my post's...
    Obviously this is the workshop in question posting :yeah:
    No surprise there, I'm well aware that they check/participate in forums... Wierd that it took so long though...

    And for the record the "Normal approach" has already been taken and the car is booked in. With any luck I'll pick the car up next week with the problems solved and this chapter can be closed. :thumbsup:

    Stay tuned for the next exciting installment...
     
  20. ScoHar

    ScoHar Jizz in my pants

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    Bahaha, interesting although it is good to hear both side of the story.
     

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