i dunno if their meter was wrong but i was running very lean. their wideband was hooked up to my cat so maybe it read too high. it is possible for a stock r with just bolt ons to lean out to 14.3-14.8 when vtec hit?? just curious this dyno i went to seemed very off..


Modified by danny98r at 7:02 AM 1/11/2005

 

mods are aem cai, t1r header, testpipe+ catback

 

anyone have any reply to this???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by danny98r &raquo;</TD></TR><TR><TD CLASS="quote">it is possible for a stock r with just bolt ons to lean out to 14.3-14.8 when vtec hit?? just curious this dyno i went to seemed very off..</TD></TR></TABLE>

Sounds reasonable with your mods. Search for dynos, some people logged A/F with the stock ECU. I remember it was lean, especially when mods are added. MAP type air meters can't notice when you start changing exhaust/headers/etc., since the pressure is the same even though the flow is higher. MAF can do this and is generally more mod friendly when in open loop conditions (WOT).

-Chris

(quit bumping danny)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote">

Sounds reasonable with your mods. Search for dynos, some people logged A/F with the stock ECU. </TD></TR></TABLE>

They are usually way rich...in fact everyone WB02 readout for stock motor I've seen has been safely on the rich side.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote"> MAP type air meters can't notice when you start changing exhaust/headers/etc., since the pressure is the same even though the flow is higher. MAF can do this and is generally more mod friendly when in open loop conditions (WOT).</TD></TR></TABLE>

-wrong, pressure will change as volume increase....the two are interelated

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by El Pollo Diablo &raquo;</TD></TR><TR><TD CLASS="quote">They are usually way rich...in fact everyone WB02 readout for stock motor I've seen has been safely on the rich side.
</TD></TR></TABLE>

I'll plead ignorance on this one. At high RPM, yeah, they're all rich, but at lower RPM (near VTEC engagement) I could have sworn I've seen stock motor ITR's with I/H/E with 14:1 Air-Fuel. His question was for A/F "when vtec hit".

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by El Pollo Diablo &raquo;</TD></TR><TR><TD CLASS="quote">-wrong, pressure will change as volume increase....the two are interelated</TD></TR></TABLE>

I'm going to disagree with this one for sure.

If you start with a 100% stock ITR, and floor it, you might get a measurement of -0.05 bar of vacuum. If you add a header and exhaust, you're increasing the flow, which would only move the MAP voltage down given the same restriction on the air filter/intake. So the ECU would reduce the fuel, if anything. There's no way for that pressure to go higher with higher flow on the exhaust side. If you replace the intake, the highest you can get the MAP to is 0.00 bar (relative pressure), and from there, where do you go?

MAF with a heated wire will measure flow based on the cooling effect of the air on the wire.

MAF:
http://www.kemparts.com/TechTalk/tt06.asp

Airflow discussion:
http://www.customefis.com/faqsite.html
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Custom Engineered Fuel Injection Systems &raquo;</TD></TR><TR><TD CLASS="quote">
The only advantage of using a MAF sensor over a MAP sensor is that since a MAF sensor directly measures the air entering the engine, the ECM does less calculating and the system is a little more tolerant of changes to the engines air intake system. In other words, you can install headers, a hotter cam, change heads, etc., and the system will automatically compensate since the air is measured directly. But this advantage quickly disappears since the MAF sensor itself is a major bottleneck to airflow on performance engines. More than likely, you will need a larger after-market expensive ($500) MAF sensor for any meaningful performance upgrades. So much for MAF sensors.
</TD></TR></TABLE>

 

My ITR has done I.H.E and vafc2.
i got my car tuned with the VAFC2.

then at a dyno day, i put the car on the dyno for a power run.
the dyno man said vtec kick in too early. (but it was already tuned)
he set it 300rpm higher.

the A/F ratio at vtec engagement leaned to 15.5:1 because of 300rpm difference
pretty scary if you asked me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by El Pollo Diablo &raquo;</TD></TR><TR><TD CLASS="quote">

They are usually way rich...in fact everyone WB02 readout for stock motor I've seen has been safely on the rich side.

</TD></TR></TABLE>

I can attest to this, if my memory is correct around 12.5-13 @ VTEC engagement and richer towards redline, i believe I was around 11 at max rpm.

 

does it seem like i am doing damage to the motor if its runnin that lean.

 

From what I have seen, these motors seem to work well in the 13.7-13.2 range. The fatter side more toward higher RPM at WOT. This is for a motor with right around 11:1-11.5:1 Cr... of course timing is important, dont forget that element guys. running like 28-25 total degrees from like 5800-9K is about optimal. tuning with header length to tune out mad dips helps, I dont fully understand it but I saw quite a bit on that 200whp stock block b16a project refrenced in the sig. That motor is/was basically a full 91oct 1.8L tune with a B16a bottom end with B18C bearings. To see what VTEC was meant to do... I mean it really opened my eyes to what these motors can do Funny thing is this car liked to idle at 12.7 It had amazing vaccum at idle at the time of breakin. Having a street engine that drives like a normal car under high cam, and then when you stab it... you can scare people