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Dyno Variances

djvoodoo

By djvoodoo,
in Engines & Forced Induction

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juggernaut1 Proficient

juggernaut1

Posted
Posted (edited)

Whilst not directly on topic - post 17 of the following link shows the different hp figures obtained using different shootout modes with the same car on the same day ( I knew turbo 4 cylinders were handicapped in shoot 4F :P ).

Notably, the second last dyno shows the effect on hp when the temp probe is placed near a heat source.

http://www.fordxr6turbo.com/forum/topic/59178-power-differences-between-shootout-modes/?hl=dyno

Edited by juggernaut1
juggernaut1 Proficient

juggernaut1

Posted
Posted (edited)

Take 2

Shoot4

http://i198.photobucket.com/albums/aa292/The_Boganxr6t/DSCF0007-1.jpg

Shoot 4F

http://i198.photobucket.com/albums/aa292/The_Boganxr6t/DSCF0006-1.jpg

Shoot 6

http://i198.photobucket.com/albums/aa292/The_Boganxr6t/DSCF0005.jpg

Shoot 6F

http://i198.photobucket.com/albums/aa292/The_Boganxr6t/DSCF0004-2.jpg

Shoot 8

http://i198.photobucket.com/albums/aa292/The_Boganxr6t/DSCF0003.jpg

Shoot 8F

http://i198.photobucket.com/albums/aa292/The_Boganxr6t/DSCF0002-2.jpg

Shoot 6F - Hot intake probe

http://i198.photobucket.com/albums/aa292/The_Boganxr6t/DSCF0009-1.jpg

No Shootout Mode

http://i198.photobucket.com/albums/aa292/The_Boganxr6t/DSCF0008-1.jpg

Edited by juggernaut1
scotty nm35 Grand Master

scotty nm35

Posted
Posted

1/4 mile/ MPH for finding out how much usable power you have, as stated before dyno for tuning.

Is that still a reliable indication of power, even if my slug auto won't get off the line due to the stock stally stator?

33GTRV Mentor

33GTRV

Posted
Posted

Good friend of mine stopped posting outright power figures on his wall in his cell due to people not liking them reading lower than other shops, and I mean considerably lower, but like the big sign above his dyno reads, dynos lie, tracks don't . I'm yet to see a car that didn't run the mph on the strip that the dyno power figure suggested.

Jazzadub Enthusiast

Jazzadub

Posted
Posted

Power delivery. What you lost in peak power you may have gained everywhere else

Could be that. I don't have a dyno graph of the supposed 330wkw run on 98, but I do have a dyno graph of a 320wkw run on E85 (not the 260kw 98 run).
So less power on E85 than it supposedly had on 98, but its surely going to be faster.
I think there must have been some tweaking done of the ramp rate to achieve the 330wkw figure for 98.
This is the dyno graph of the E85 run, does it looks fast? It sure feels fast!
post-115803-0-24003800-1404958875_thumb.png

Feels faster or is faster?

Fair point, I've never been to the track so don't have any rock hard evidence.

Lets just say it definitely doesn't feel like it has had 70kw ripped from it!

XGTRX Veteran

XGTRX

Posted
Posted

Dynos are tuning tools. The absolute power and torque measurements are irrelevant unless being used for a comparison to a change being done to compare to a previous measurement on the same dyno but even then changes in the driveline can make it hard to compare.It is used solely for tuning to assess and optimize engine parameters by a skilled operator.

Example is my clubby that with a flash tune and diff gears measured 270rwkw and did 107mph.I installed cams with head work, hi stall and retune and measured 274rwkw and ran 112mph. Based on mph should be about 40rwkw difference. And based on mph it should be about the 285rwkw mark give or take. Moral of the story the tuner used the dyno to optimise the setup and mph told me how much power it really had. Hope this helps.

XKLABA Grand Master

XKLABA

Posted
Posted

You can strap a car down to tight and lose power as well :(

Unfortunately there are many things that will effect dyno reads including tyre pressure

As others have said a dyno is just a tool used for tuning and a vague indication of power, that said a dyno isn't going to shop 100hp on a 1000hp car and vise versa, if you think the operator is fudging figures for what ever reason and not just a low reading dyno, I would be going else where

Mph is the best indication of power v weight and ET is an idication of setup

I always take my car to the 1/4 mile track after I do something to it ( power wise ) to see real life gains for both MPH and ET

An example for MPH, I not long ago had my 34 tuned and right after that I went to the strip, knowing it would run a 10 I rolled off the line and shifted to second then nailed it for the first 4 runs to get an idea of mph and ran consistent 131-132mph ranging from 11.6-12.5 et, last pass full noise from start 10.8@132mph so the start doesn't make much if any difference on mph unless your still turning tyres half track :P

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