1jz dyno

[harwewe1]

I went to the dyno today and got some mixed results. My car is set with a full 3" exhaust, SAFCII, HKS filter, 2jz pump and US 550's with a resistor. Arnount made the harness. The problem is this....from 2k to 45k the graph is smooth but at the 5k, 6k, is going rich. At 55k, 65k, and its trying to go lean. The graph looks like a wave past 4k. The boost is holding 14 perfect and yes I know this is on the edge. I think its got something to do with the computer pulling the timing out. What do ya'll think? Its a auto ECU- 5-speed car.

[drjonez]

time to work that SAFC....

[Trent]

Originally posted by drjonez
time to work that SAFC....

I agree there. That's what the AFC is for my man! Lean it out @ 5-6k and then richen it up at the higher levels if necessary. IIRC, between 5 and 6k is when the MKIV pump dumps to 12v so you would be going rich and then with that much boost, it might be leaning out a tiny bit up top.

[witeenigma]

that and i thought auto ECUs actually retard the engine cuz it's thinking it's shifting at certain points so it makes the AF look like a wave right?

[harwewe1]

Thats right, a wave. I've worked the SAFC for 1.5 hours on a dyno jet and it will not make the a/f curve flat past 4k. If its the auto ECU what do I need to do? Thanks for the info!!

[XTC Dynamic Supra]

stand alone

[MelloYello]

I've heard of several people running pig rich up top no matter what they adjust.

[joliroger4]

If you are really worried about the computer pulling timing, run a mix of xylene with some marvel mystery oil. If you have the same result, the computer isn't pulling any timing.

[adjuster]

Toulene is also a great additive, and you don't need the oil to keep everything running right.
I was just at the dyno yesterday, and becasue I'm a manual trans, I did not have any wave problem.
However, my car does run rich at the top, but is lean the rest of the time.
Added fuel to the lower and mid range, and it helped, but with more boost, I'm close to lean all over.
Added more fuel and now it runs great.
However, now my idle is totally screwed up. (Made no changes down there, something else must be FUBAR as crappy idle was never a problem for my car untill yesterday.)
I would think if your ECU is pulling timing, you could try and add timing at those points and smooth out your curve. (Does your piggyback have that capability?)

[harwewe1]

no it dosn't. Its a SAFCII. I guess I will either have to get a 5-speed ECU or a stand alone like a power FC or AEM. I have people close by that can tune the AEM but the power FC might be a problem. Any suggestions- oh yea, I'm about 3 months from getting a single setup (sp67)

[jza71]

I think we have the same problem, see my dyno sheet from stock to single t66. Im still trying to figure out what is going from 5.5k-7.2k rpm.

here is how it looks bone stock:
http://images.cardomain.com/member_images/10/web/358000-358999/358108_8_full.jpg

and here is how it looks with the T-66:
http://images.cardomain.com/member_images/10/web/358000-358999/358108_20_full.jpg

and here are a couple more :D
http://www.supraforums.com/forum/showthread.php?s=&threadid=138650&perpage=25&pagenumber=1