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Dyno Sheet and A/F curve from yesterday...REALLY wierd A/F

Old Aug 29, 2004 | 06:25 PM
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Default Dyno Sheet and A/F curve from yesterday...REALLY wierd A/F

So we had a dyno day here in SD yesterday. My mods are as follows, JWT POP charger, Apexi WS2 exhuast...(springs and sways dont matter here). Anyways I was looking at my A/F curve and it was REALLY weird. Attatching dyno sheets... any ideas?


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Old Aug 29, 2004 | 09:15 PM
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Default Re: Dyno Sheet and A/F curve from yesterday...REALLY wierd A/F

I would get a reflash every mod changes the af. My af on my dyno was at high 14s all the way down to low 13s. Technosqaure can fix that and make it run low 13s all the way through.

Thanks Glen
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Old Aug 29, 2004 | 10:18 PM
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thats not that bad never seen the curve before on any dyno sheet but its still running 17.5 which is on stock ecu my car pulls that before...i wouldn't worry too much, but i am also not a big critisizer when it comes to dyno sheets...just when you dyno your car again and again like month or 2 later go to the same shop you will most likely and probably get different numbers wherever else you go..

Ben
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Old Aug 30, 2004 | 05:45 AM
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Yeah i'm not too worried. Even though the max at the top of the sheet said 17.5 the A/F never actually broke 14 so I'm not TOO worried but the curve just looked REALLY odd. The massive climb at 3500 was really wierd.
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Old Aug 30, 2004 | 06:04 AM
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The curve is a little wavy, another thing to keep in mind is the maintenance practice of the shop with their dyno equipment.

When I went to dyno tune the Greddy TT the AF curve was all over the place with wild spikes and after spending an hour of trying to dump more fuel in and not making a difference in the curve, we found out the filter in the sensor machine was clogged hence the bad AF curve, we pulled the sensor out and it was still reading 14 AF.

So make sure you know what they do with their equipment don't assume anything.
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Old Aug 30, 2004 | 07:06 AM
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Thats the thing everyone elses A/F was pretty much normal. Mine just has that really extreme climb at around 3500
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Old Aug 30, 2004 | 07:23 AM
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At your mod level I was runing around 12.5 pretty much all the way across and it actually leaned out to around 13 when I installed the plenum and test pipes, so you might want to be careful if you add more mods. An ECU flash might be in order, if not now definelty if you do more mods. Although for th eprice of the flash it might be worth it to look into a AFC or emanage type piggyback.
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Old Aug 30, 2004 | 07:29 AM
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Originally posted by westpak
At your mod level I was runing around 12.5 pretty much all the way across and it actually leaned out to around 13 when I installed the plenum and test pipes, so you might want to be careful if you add more mods. An ECU flash might be in order, if not now definelty if you do more mods. Although for th eprice of the flash it might be worth it to look into a AFC or emanage type piggyback.
I've been thinking about adding a S-AFC to my setup but I do plan on going F/I so it may have to wait until then. The S-AFC is good but I wouldn't use that as my tuning device for F/I. The emanage could be but its not as easily changeable tuning wise as the S-AFC. I guess I could use the S-AFC for now and then just keep it for fine tuning later when I have whatever management i plan on using. Do you have one yourself. I'd like to know what kind of experience people have had with it. I know its an all around good unit but I've always been wary of devices that alter Maf signals to do their thing. Thanks again for the help.
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Old Aug 30, 2004 | 09:54 AM
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The AF curve doesn't strike me as being unusual. It's exactly what I would have expected from an '04. Ignore the spike in the every beginning. Also keep in mind, tail-pipe sniffer (what I believe is used here) ... is on the avg. .5-.8 higher than pre-cat measurement location.
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Old Aug 30, 2004 | 10:08 AM
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Actually my build date is 11/03 so I think I still have the 03 ECU. Its just the massive jump at 3500 that has me wondering. Shouldn't it steadily increase not jump up that high?
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Old Aug 30, 2004 | 10:29 AM
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Originally posted by MIAPLAYA
Actually my build date is 11/03 so I think I still have the 03 ECU. Its just the massive jump at 3500 that has me wondering. Shouldn't it steadily increase not jump up that high?
That's definitely an 04. Again, the jump at 3500 is normal ... I get the same thing. TS ECU or APEXi S-AFC can certainly get rid of that, however. But from AF stand point of view ... your number looks fine for NA use.
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Old Aug 30, 2004 | 10:39 AM
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Originally posted by THX723
That's definitely an 04. Again, the jump at 3500 is normal ... I get the same thing. TS ECU or APEXi S-AFC can certainly get rid of that, however. But from AF stand point of view ... your number looks fine for NA use.
Cool, glad to know its normal. Are sure on the ECU. I thought as long as your build date was in 03 you still had an 03 ECU
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Old Aug 30, 2004 | 10:59 AM
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Originally posted by MIAPLAYA
Cool, glad to know its normal. Are sure on the ECU. I thought as long as your build date was in 03 you still had an 03 ECU
Well, I was speaking in terms of your car's year classification rather than the ECU. But, to my understanding, anything post 10-03 production date (yours is) is indeed an 04 LEV2 ECU. Don't quote me on this ... it has been a while.
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Old Aug 30, 2004 | 11:40 AM
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Hmm I've been searching. What build date does the ECU switch?
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Old Aug 30, 2004 | 01:30 PM
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Whats a perfect AF all the way through for max power? Im gonna get the reflash, because right now im in the low 14s, and im gonna be installing JWT cams.

Thanks Glen
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Old Aug 31, 2004 | 02:43 PM
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Originally posted by Zmego1985
Whats a perfect AF all the way through for max power? Im gonna get the reflash, because right now im in the low 14s, and im gonna be installing JWT cams.

Thanks Glen
From what I have researched, the normal A/F under normal driving should be around 14.7. Under WOT you want to be in the low to mid 12's to get the best power. I have an eManage hooked up and I will finally be able to actually tune with it now since I got my Zeitronix wideband yesterday.

MIAPLAYA,

That spike is pretty weird, but nothing that can't be fixed. Get a TS flash, or a piggyback ECU and you'll be set.

-Chris
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