boosted k20

whats up. well i just got my car dyno'd and tuned a little bit. we increased the fuel pressure, played around with the timing and the SAFC. I have a 97 LS integra with I/H/E, MSD 6A and blaster 2 coil, CROWER stage 2 403 cams,springs/retainers, skunk 2 cam gears and an SAFC.
Baseline was 130 whp and 109 ft-lbs of torque. after tuning we got 138 HP and 115 ft-lbs of torque. the car looked like it was running rich a bit. at low rpms it was run n an air fuel ration of about 14 but after 4500 it was around 12-12.5:1 a/f ratio.

whats the optimal setting for the air fuel ratio? 13.5?

We set fuel pressure to 40 psi with no vacuum, timing set at 18 degrees, cam gears at 0,0 and some changes to the AFC which netted us at 138 whp.
i tried adjusting the exhaust cam gear to -2 degrees but we lost HP. so i put it back to stock settings. i didnt even change the intake cam gear.

im gonna build up the block soon with high compression pistons(either PR3s or P30's pistons), so once thats done i'll get another dyno pull in and retune it. i need to know what air/fuel ratio i should shoot for

LowFlyin'

I have my H22A4 set between 13.5-14.0 ...don't know if that is optimal, I think it is a little on the safe side.

Honda_Tengoku

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LowFlyin’ &raquo;</TD></TR><TR><TD CLASS="quote">I have my H22A4 set between 13.5-14.0 ...don't know if that is optimal, I think it is a little on the safe side.</TD></TR></TABLE>

safe side are u nuts? no more than 13.5 AFR in the high cam at WOT!! generally people run 13.2-13.5 AFR. shoot for about 13.3 and 13.4 on the high cam and u are good to go!

boosted k20

thanks. i'll do that then.

1 2 NV

try anywhere from 13.5 to 13.0. i had a spike of 13.8:1 during my 1/4 mile passes this ur lookin at the video footage. every car is different. 13.0-13.8 is a solid # to shoot for.

GsR-Freak

hud? i thought the setting of FPR and a/f ratios for every setup of a car is alway different right?

i know pressure of FPR is different, but i could be wrong about a/f ratios. I think it should be the same for all setu[

1 2 NV

nope some motors like it richer 13.0+/- and some like it slightly leaner 13.6+/-. ur talkin minimal amounts of difference. but anywhere in that range is good.

0VtecKiDD

my motor ran best at 14:1 , its not too dangerous. ive seen some motors make power at 14.5:1.

WAFFLES

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VtecKiDD &raquo;</TD></TR><TR><TD CLASS="quote">my motor ran best at 14:1 , its not too dangerous. ive seen some motors make power at 14.5:1.</TD></TR></TABLE>

Exactly. MOST, I say most because it's pretty common, motors like it anywhere from 13.0-13.8:1. A little richer or leaner than that works. I usually tune for 13.2-13.8:1 just to keep it safe.

CHEETAH

iTrader: (2)

FWIW aim for 12.9 -13.0 at peak TQ, lean it out afterwards to as much as 13.5 at peak HP, and play safe with 13.3's after that.

With all the engine management technology in this day and age, its pretty easy to do that, AEM, Motech, Speedpro, DFI, Hondata ??? all have an a/f table chart (or Target), setup it up with the a/f's, close loop it, read the initial inj pulse (modified) at each band in (hopefully) a datalog file, take off the closed loop, hard input the inj pulse that you datalogged, hopefully not too many correction factors to the inj pulse, and fine tune from there.

There are also software aroudn the internet which you can apply a high-sampled datalog output to produce an effective TQ and HP graph which is a great measure to fine tune with if you don;t have a g-tech or dyno.

I know I went overboard with the response but figured it might be useful for you. If I'm confusing everyone then jsut post what you're confused about and I'll try ot clarify.


Greg

boosted k20

thanks alot fella's. i'll shoot for an a/f ratio of 13:1!

WAFFLES

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

I know I went overboard with the response but figured it might be useful for you. If I'm confusing everyone then jsut post what you're confused about and I'll try ot clarify.


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

So Greg, am I supposed to take the Red pill, or the Blue pill?

StyleTEG

You really can't say "Make sure its at XX A/F here, and XX A/F here."

Every engine is going to make power at different A/F, so each engine needs to be tuned on a dyno. In general you make most of your power playing with ignition timming anyways, changing the A/F just keeps you safe and makes sure you are not running into lean spots.

boosted k20

then i need me some hondata to tune the ignition timing. hmmmmmmmmm, if i have some cash ill get hondata. they make a program for nonvtec's right?

HXMan

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted k20 &raquo;</TD></TR><TR><TD CLASS="quote">then i need me some hondata to tune the ignition timing. hmmmmmmmmm, if i have some cash ill get hondata. they make a program for nonvtec's right?</TD></TR></TABLE>

Yea...you just need a non vtec OBD1 ecu.

GsR-Freak

aight since we all have the decent number of a/f for all motor...what about the a/f ratios for smog emission check, i know the leaner the better, but what is the limits? thanx

WAFFLES

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GsR-Freak &raquo;</TD></TR><TR><TD CLASS="quote">aight since we all have the decent number of a/f for all motor...what about the a/f ratios for smog emission check, i know the leaner the better, but what is the limits? thanx</TD></TR></TABLE>

most OEM ECUs run 14.7:1-15:1 on part throttle apps, mid 13:1s in the WOT maps with around 12.5:1 up top in the WOT maps.

Usually 14.7:1 will get you the best gas mileage.

boosted hybrid

Running the engine at 14.7:1 will only get you the most balance levels of NOx, HC, etc. Its purely emissions based to run the engine at stoich, OEM's do this for numerous reasons, but emissions being the largest factor.

You can easily tune an engine at very lean conditions in partial throttle with increased ignition timing to allow for good gas mileage. Typically i tune n/a engines around 16~16.5:1 a/f, and run around 50-52 degrees ignition advance in partial throttle. The increased ignition advance allows for compensation of the lean a/f, as well as initiating the flamefront for a quicker burn on the lean fuel mixture. By doing this I have found there is no loss in drivability, power production (as measured in part throttle on my dynapack dyno, maybe 3-5 ft-lbs of torque loss), and zero knock as read from the spark plugs during the part throttle operation. The knock level is tamed since the timing and fuel are past the maximum brake fuel/timing points. On basic bolt-on, and mild cam engines i have had reports from customers getting 35-40mpg! With more aggressively built engines, more aggressive cams, etc reports of 30-35mpg.

Back to the original question of what a/f is good for n/a tuning, i have found anywhere in the range of 12.8~14:1 to be sufficient. What i typically do with n/a cars is run them at various target a/f's under wot on the dyno. So from 12:5:1, 13:1, 13.5:1 and 14:1. I measure the torque production from each a/f. I compare each torque curve at the various a/f levels, and see where the engine likes to make peak torque. At resonance points, and different areas in the rpm band the engine typically likes different a/f values. I have been able to pick up 3-5 ft-lbs of torque in various parts of the rpm band by doing this.