Alright, well i'm going to try and save a hundred bucks by hitting the dyno alone this summer, and I will be looking to tune the car myself.

Brief Overview of setup:
-10:1 SOHC VTEC
-I/H/E
-Exospeed Stage 2 Cam

Brief Overview of tuning materials:
-Apex'i VAFC 1
-OBX Cam Gear
-B&M FPR

Now, I would just like to get a quick play-by-play of how I should tune the car. I know ideally I want a 14.7:1 A/F ratio, but i've also heard that I want 13.5:1 and 14:1. I am wondering what you all think is the ratio that I should be looking for.

I just want to get a basic idea of what the hell I should be doing here. Do I tune the AFC before cam gears, how do I get 14.7 out of the AFC and FPR? How do I get max power from the cam gears? When do I perform the narrow throttle run?

Thanks in advance.

-Bauley

 

Looks like you got alot to learn before you hit the dyno. Do some searches and read up on tuning. Check out hondata's website. Also you are going to need a wideband O2 guage to do the tuning

 

14.7? wtf. i think you should pay a tuner your first time

 

timing, cam timing, VAFC 14.7:1 for lower RPM 13.5:1 upper RPM. check out importbuilders site and read on tuning a motor.

 

Alright...I read the importbuilders thing, now I have a much better idea. I wish there was one of those for VAFC's

 

first do a baseline pull, then level out ur AFR to about 13:1 ish. then dial in your cam timing, i would first advance the intake cam and see how it likes that, if it likes it go more, if not go back. then dial in your exhaust cam, usually you retard it to gain more power. then once the exhaust cam is dialed in, move ur intake cam back and forth 1 deg to see if you can gain any more power.

now, you wanna move your vtec point up or down depending on what cams you have and etc, see which one gives you the fattest midrange power.

after that set your timing by moving the dizzy back and forth and see what gives you the best curve, usually advancing it some nets better power. back off the timing a tiny bit if your engine starts to knock, or the power drops off.

then play with the AFR. I would start by leaning it out some and seeing where in the power band it likes it. then lean that part out more, etc. if it didn't like it, go back and add more fuel.

Now the sucky part about the VAFC is, you need to add fuel with the FPR, and take fuel out with the VAFC. this is because VAFCs suck at adding fuel but are very effective at pulling it. if you notice that you are having to pull ALOT of fuel with the VAFC (more than like 10-15%) then lower the fuel pressue a bit instead because when you pull too much fuel with the VAFC you start to screw up ur igintion timing.

basically its trial and error with educated guesses,

*edit*--- i just noticed you have a single cam, so scratch that part about dialing your intake and exhaust cams,

doing the cam timing for a sohc is much simplier, all you really need to do is move it around and see where it nets the fatest powerband. dont sacrifice tons of midrange power just to gain like 2hp up top,

other than that the rest of the steps i described are still the same

 

i say dyno tune it because if you dont really know much about it you can blow your engine. butt dyno is alright but you'll never really know what you're A/F will be. All that money you spent, you wouldnt want it to blow up know would you?

 

Thanks for the help guys

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1 2 NV &raquo;</TD></TR><TR><TD CLASS="quote">timing, cam timing, VAFC 14.7:1 for lower RPM 13.5:1 upper RPM. check out importbuilders site and read on tuning a motor.</TD></TR></TABLE>

that about sums it up. That's how I like to do things.

Make baseline pull, stock everything.

play with timing till you stop making power.

adjust the cam timing, then recheck your base timing.

turn up fuel a few psi over stock.

then fine tune with vafc

with the VAFC, I like to run it about 14.7:1 pre-high cam for better gas mileage. Now up top I don't believe there to be one specific number for the a/f. Most motors that I have seen like it anywhere from 12.5:-14:1(usually low to mid 13s though).

 

You're gonna need some more tuning tools in order to street-tune effectively (and safely). Like a wide-band O2 sensor, an accelerometer, a way to datalog, and some kind of knock detection setup.

Unless you're going to be tuning & retuning your car often as you make modifications to the car, it's cheaper to take it to a dyno & have a professional tune it.

 

well as long as the dyno has a wideband he can take fuel out with the narrow throttle settings of the vafc for part throttle tuning.

 

Now, about partial throttle tuning...how would I do that.

Do I give partial throttle (a number above the low throttle point) up to the vtec engagement point? Or what...

 

Part-throttle tuning with a VAFC is pointless. The ECU's in closed loop, so it will correct to the default stoich air/fuel settings no matter what the VAFC is telling it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Daemione &raquo;</TD></TR><TR><TD CLASS="quote">Part-throttle tuning with a VAFC is pointless. The ECU's in closed loop, so it will correct to the default stoich air/fuel settings no matter what the VAFC is telling it.</TD></TR></TABLE>

So just worry about hi-throttle tuning with V-AFC?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Daemione &raquo;</TD></TR><TR><TD CLASS="quote">Part-throttle tuning with a VAFC is pointless. The ECU's in closed loop, so it will correct to the default stoich air/fuel settings no matter what the VAFC is telling it.</TD></TR></TABLE>

well thats what I had always thought until...

When I was dynoing my car a few weeks ago, I noticed that no matter how much fuel I took out at 1000rpm, my car was still still running 12:1 a/f at idle. This was on wide throttle mind you. I decided to try tuning that with the narrow throttle settings. -14% and bam, about 14.5:1 via wideband. This had no affect on my full throttle a/f passes.

This is with a mugen chipped p28 ecu chipped by Locash racing. Like I said, I was always under the impression that it would have no affect, just like you said, but I did it myself, and saw it with my own eyes.

 

So you only used the narrow throttle settings to adjust idle A/F?

 

Nope I tuned the car with Wide throttle settings. After it was tuned I noticed it was still running rich at idle, so I took fuel out of the narrow settings and voila! A/F went where I wanted it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WAFFLES &raquo;</TD></TR><TR><TD CLASS="quote">Nope I tuned the car with Wide throttle settings. After it was tuned I noticed it was still running rich at idle, so I took fuel out of the narrow settings and voila! A/F went where I wanted it.</TD></TR></TABLE>

So you only adjusted the narrow throttle settings for idle? No changes to the narrow throttle high RPM section?

 

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

So you only adjusted the narrow throttle settings for idle? No changes to the narrow throttle high RPM section?</TD></TR></TABLE>

I just adjusted narrow throttle up to 5000rpm. I never cruise with rpm higher than that.