So I finally busted out my ol' palm pilot and reloaded my Digital Tuning OBDII pocketlogger software on it. I used to use it with my VR4, but haven't in a while. The VR4 has a whopping 6-7 sample per second rate, and much to my dismay I found that the s2000 has the exact same sample rate

Anyway, my car is a 2004 AP2 with an 00/01 ECU. Other mods are an AEM V1 intake, berk TP, and no resonator in the stock exhaust.

One thing I noticed is its time for some ball bearings in the coolant lines or a Hondata intake gasket. Despite outside temps being about 50, my intake temps were around 100 degrees when I was getting on it.

Time RPM Timing O2 TPS

0.50 4858 44.0 0.76 15.32
0.99 5010 37.0 0.84 15.32
1.48 5285 29.0 0.82 15.32 <--on the gas, TPS has low priority updating
2.13 5703 25.0 0.84 89.19
2.58 6010 24.0 0.84 89.19 <--lean condition probably starts here
3.09 6351 29.0 0.12 89.19 <--YIKES!
3.60 6708 30.0 0.82 89.19
4.11 7042 30.0 0.84 89.19
4.61 7382 30.0 0.82 89.19
5.22 7796 30.0 0.82 89.19
5.74 8117 28.0 0.86 89.19
6.23 8389 28.0 0.88 89.19
6.74 8601 24.0 0.90 89.19
7.24 7184 43.0 0.76 89.19 <--off the gas
7.75 6591 48.0 0.06 89.19
8.36 6449 48.0 0.00 5.5
8.81 6351 48.0 0.00 5.5

I know narrowband O2 sensors aren't accurate enough for tuning, but I wanted to se what kind of readings I was getting. Check out what happens after 6k right when VTEC kicks in! Man it gets lean. On a couple runs I did logging nothing but the O2 so that it would refresh relatively quickly, I saw dips down as low as .09v right after the VTEC transition, wowee!!

It does look like it richens up a lot after 8k, not sure how much since its a narrowband reading. Now that I've got my VAFC2 I'll probably hop it on a dyno, lower the VTEC to around 5500-5600, richen up that tranisition area and then lean out the 8000-8600rpm area.

What about those timing values? I'm not too familiar with S2000 timing yet, but I'm used to seeing mid 30's on my boosted 3000gt!

 

Try UTH forum... Maybee it has something to do with the Vtec kicking in? I see where the constant TPS voltage starts and low O2 reading comes in 6351 rpm and like you said it probably starts @ 6010.. I need to invest in a good scan tool one of these days.. Maybee something like the OTC Genysis.

 

well the sub forums are so illogically laid out here I debated for maybe 5 minutes about whether to post this under S2000 talk, UTH, or the JDM tuning forum......

 

How do those numbers translate into AFR? Just curious...

 

you cant really translate narrowband readings into AFR, thats why they're almost useless for tuning. Narrowband is really only good for telling you if you went rich or lean, but not by how much

For instance, .96V on a narrowband can be anywhere between 10.0 and 12.5 AFR (I dont think thats exactly right, but should give you an understanding of how useless narrowband is, haha)

 

It may be your test pipe leaning you out.

 

can someone translate that technobabble into english for us stupid people.

 

Oh well for sure the intake and test pipe lean the car out, its a map based system not MAF, so it can't compensate for changes in volumetric effeciency when WOT.

I'm just saying the A/F ratio is acceptable everywhere EXCEPT right after VTEC.

I'm going to get one of those Synchronic adjustable fuel pressure regulators to pump up the pressure until that lean spot is normal, and then I'll lean out the rest of the range using my VAFC2.

 

Don't bother with the fuel pressure regulator.

Just stick the car on a dyno and tune the VAFC2.

 

no, the AFPR is a good idea

I want to bump up the pressure so that WOT fueling becomes really rich. Then, when I bring the AFRs back down to optimal levels with the VAFC I should have gained another couple degrees of timing.

Richening up the VTEC transition will make me lose a degree or two of timing there, which I dont want.