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thomas
06-28-2005, 09:29 PM
sup fellas,
got some questions here about my dyno graph. id like to see what kinda input you guys have for me and my ride:

ATP Tuning: 5/22/04 (NCE meet)
*forgot what dyno they were running, so if someone remembers pls. post it*

total of 3 runs.

mods: WORKS P2 and K/N drop-in filter. No tuning.

Run #1:
Max Power -> 229.0
Max Torque -> 237.6
A/F -> starts 14.5 and begins to drop to <11 at about 3.8 rpms and remains consistent to end of run.

Run #2:
Max Power -> 226.4
Max Torque -> 233.6
A/F ->starts 14 and beings to drop to </= 10 at about 3.6 rpms and remains consistent to end of run.

Run #3:
Max Power -> 225.5
Max Torque -> 236.1
A/F -> starts 14 and follows almost exactly the same as Run #1

what i want to kno are are these numbers where they should be? specifically A/F...i read alot about them on these boards but havent really caught on to the techie stuff of it. running rich? or running too lean? where are the numbers suppose to be or are they accurate?

i kno the HP might look be a little low, but my car pulls hard all the way up to redline ~ 7600-7800. boost holds a steady 19 psi. not really into peak HP numbers anyway, but more interested in the air feul ratio and how its suppose to fluctuate under load/pressure of driving.


sorry guys but no scanner. :roll: i have the printout sitting in front of me. i kno, im useless...

thx guys.

SouthernCrane
06-28-2005, 09:48 PM
run #2 seems a little too rich up top, but the other two runs seem to be about normal....at least compared to my P2 on a mustang dyno at Gruppe-S. I think most (? not sure) try to tune for something close to 11.0-11.2 AFR at redline, and since the P2 we have is a mail in flash, those rich AFR numbers are for safety (conservative tune for everyone to use)? I'm not sure how the AFRs differ from using different dynos.....hopefully one of the gurus here can speak up for you.

here are my afr graphs:

http://forums.evolutionm.net/attachment.php?attachmentid=68695&stc=1


http://forums.evolutionm.net/attachment.php?attachmentid=68696&stc=1

thomas
06-28-2005, 09:53 PM
thx for your input and posting up your graph, B. :wink:

MitsuMan
06-28-2005, 09:54 PM
the ratio is air to fuel 14.7:1.0 is perfect ideal mixture to achieve complete burn of the fuel. :chatter: when you see the 11's and 10's it means your running richer than stoichiometric(14.7:1)

SouthernCrane
06-28-2005, 10:02 PM
thx for your input and posting up your graph, B. :wink:

NP, always glad to help/ease minds.....sorry for the whack @ss digital pics of the graphs, no scanner on hand.

earlyapex
06-28-2005, 10:54 PM
the ratio is air to fuel 14.7:1.0 is perfect ideal mixture to achieve complete burn of the fuel. :chatter: when you see the 11's and 10's it means your running richer than stoichiometric(14.7:1)

what the? Yes that is true for part throttle and cruise closed-loop when the 02 cycles, but you don't want to run anywhere CLOSE to 14.7 at open-loop WOT.

A good aim is under 12 for 91 octane, (more like under 11.5 to be safe).

Thomas, your AF looks good. What boost do you spike to at onset of boost? I believe that ATP uses a dynojet which reads higher than a mustang dyno.

Can you scan your dyno sheets with AFR curves so we know exactly what AFR's you where running and also your tq and HP curves, because like you said, who cares about peak numbers. :)

thomas
06-29-2005, 12:13 AM
^^^ ahhh, no scanner... :? thisll prolly be difficult to explain.

from what im looking at, curves look pretty good...HP stays pretty straight and consistent up 7800, TQ is more of a descending slant, but is also relatively straight. peak TQ is at 3600-3650 and then holds til 5000...after that you notice a gradual drop to the end of the run...

so an optimal AFR should be about 12-11.5? at what rpm? or should they be holding consistent until throttle releases?

does running rich mean that the numbers are low(<10)??? im a little confused on this. is that rite? if thats true, a higher number (>14.5) would mean running lean...

my boost spikes prolly up to 23 most of the time. then settles down and holds. that changes when i mash it in 5th gear, then boost spikes a little higher :P

sorry for the dumb dumb questions...

earlyapex
06-29-2005, 12:24 AM
lower number = rich.

You really want to be 11.5 and under on 91 octane. Anything above 11.5 is asking for it and living dangerously.

One thing worries me is Mike said that the ATP dyno shows weird AFR's because its a non-load based dyno.

Are you going to get a free dyno at gruppe-s on the dyno day? would be interesting to compare the AFR's between the 2 dynos. In fact, you would be a prime candidate for what they are trying to prove from this dyno day!

thomas
06-29-2005, 12:30 AM
thx for the lesson earlyapex...def clears some things up for me.

yea ima try to make it down there so that i have something to compare it to. dont kno what kinda difference it makes but ill be running a turboback this time. :wink:

weird AFR? i dont think so, looks pretty steady...i dont notice anything that is out of whack. no silly spikes or dips out of line. if im reading this correctly.

LEVIII
06-29-2005, 08:30 AM
AFR is just as it sounds Air to fuel ratio.

If you are running 10:1 you are running 10 parts air to 1 part fuel. Now you see why the lower the number the richer.

14.7 is stoich and is that because that is barametric (sp?) pressure. Although turbo cars especally on 91 octane should be nowhere near this. It is just a base that all cars go from.

GokuSSJ4
06-30-2005, 10:10 AM
lower number = rich.

You really want to be 11.5 and under on 91 octane. Anything above 11.5 is asking for it and living dangerously.

One thing worries me is Mike said that the ATP dyno shows weird AFR's because its a non-load based dyno.

Are you going to get a free dyno at gruppe-s on the dyno day? would be interesting to compare the AFR's between the 2 dynos. In fact, you would be a prime candidate for what they are trying to prove from this dyno day!
for a safe tune anywhere with in 11.2-11.5 should be fine @WOT , once the rpms get higher (for a nice road race tune) you want them to drop (running rich at the top end)
Dr. Gray usually tunes a bit rich (for safety reasons ) on the top end getting into the low 10's (near 6500rpms) you can run a consisten AFR near 11.2 all across to squeez every safe hp out of your set up, just keeping an eye on the egts (as long as they don't pass 900) should be more than enough.