180.3 whp 151.4 lbs/ft

For some reason, we couldnt tune the vtec crossover. When we tried to add any fuel it would just bog BIG TIME.. i didnt think to print out any of those plots, should have. But ya.. its either a) shitty gas or b) the vafc itself. possibly timing? i dunno. i talked with some ppl and they said they've seen that before.


As shad told me, its got more to squeeze out of it. I'll prolly go hondata after all is said and done.

thx again shad.

i'll write down all the vafc #'s tommorrow.

 

those arent bad numbers at all. check the wiring. does vtec engage at all?

 

nice numbers crate.....

 

So how easy was tuning the VAFC? Looks like pretty average numbers for a tuned VAFC, I/H/E. In any case 180hp with a Prelude is nice.

edit: Hey that's a nice lil A/F reading they give you.


[Modified by RY8127, 11:28 PM 3/7/2003]

 

i was shown how to do it prior, and i probably could have done the tuning myself. But i had my mechanic do it my first time and i watched... and learned quite a bit. From now on i'll definetly be tinkering with it myself. I'm gonna replace the plugs, cap/rotor, and run some octane booster and make some adjustements myself. Go and just pay for a couple pulls on the dyno and tune myself. Fairly straight foward actually.

 

Wow, my USDM motor put out approx the same max hp (1.2 hp lower) but you have a good 12lb/ft of torque on me. Essentially the same mods. Gotta love the additional compression.

edit: Though I was able to tune my A/F a bit better than yours. Did you try using the uncorrected fuel match part of the V-AFC? I'm not quite sure if it will help, but I'm not even 100% sure what this does..


[Modified by TimeRacer, 5:33 AM 3/8/2003]

 

no, didnt mess with those settings. I'm gonna read up more on that, replace my cap/rotor/plugs and run some octane booster and see what happens when i try it again.

ya, torque is cool. =]

 

Shad does really good work. I hear he is at Abacus full time now. hit me up sometime, im out on atlantic ave.

Doug


[Modified by shakes, 2:22 PM 3/8/2003]

 

im always out and about per say. i got the same exhuast as you =] im a silver 4th gen, stock looking sept lowered and gunmetal stock si rims. honk if ya see me. im always around the beach area... lunasea's, and block and such.

and ya, shads at abacus fulltime now.

 

nice numbers crate, but it appears as if you have quite a bit of tuing left, judging by your a/f, you are all over the place, especially near to vtec crossover where it spikes, ideally you'd like a nice flat a/f, i give you a thumbs up though 180hp to the wheels is nice

 

i understand what you are saying.... but from knowing the work of the guy who tuned his car. i would not worry for one second. Shad ran his civic hatch with an ITR engine @ 18 psi boost while at NOPI HIN. 11.04 1/4. and he runs that car on a reguliar basis with no problems. not at 18 psi of course but still. that guy is a tuning GOD!!!

Doug

 

Nice peak numbers, but you sure are running rich for an NA car in the majority of the RPM band. I run that rich with 9 psi on my JRSC. Next time try to get it leaner (other than that lean spike at your vtec engagement). There is more power to be had.

 

Nice. ...Hey, wait a minute. I've seen that same dyno somewhere before...
http://www.sr20deforum.com/showthrea...threadid=38210

Your lean spike at VTEC is pretty weird. Nice numbers though!

Andrew

 

nice numbers, but as said before your a/f ratio is all over the place. it should be a nice flat line after it is properly tuned. most tuners pick a number (like 13.5) and stick with it. if there are any fluxuations or spikes, thats what needs the attention and shouldnt be difficult to take care of.

peaec

 

try setting the vtec unmatch low>hi to -5% should give you a few more ftlbs b4 vtec comes in and make it smoother


and why were you adding fuel. you need to take some out. you are running 12.8:! afr, thats too rich for NA, take it to around 13.8. geez, who tuned that **** so ill know where NOT to go


[Modified by Furry, 3:29 AM 3/10/2003]

 

i agree on the leaning it out a tad more. but i also liked the idea of it being a tad "safer" per say.

i will definetly be wanting to play with that unmatch setting and see if i can smooth it out.

and that spike you see isnt that bad, one time when we tried to add some fuel to smooth the a/f out through that range, she just bogged hard. i am going to set the vtec in at 4900 again. and try your suggestion of the unmatched to -5%. I will see if it bogs like it was doing before.

 

those numbers are really good, i got that same spike at vtec.....gotta get it fixed

 

a tad "safer"?? your not getting dangerous with a basicly stock setup till around 15.5:1

the last car i did was a b20vtec and it wanted to run at 16:1 from 2000-3800, made mad tq, i backed it down to 14.8-15.0:1 cause its a daily driver and has a ls teg 5th and spends alot of time there. if it had been a race car then it would have stayed at 16:1. they way you have it, 12.5:1 is just making you have bad gas mileage when you are beatin on it

 

next time i dyno i'll be more willing to play with it less liberally. and i'll let ya know what happens =]

thx for the input.

 

Preludes are notoriously not detonation resistant due to the placement of the piston rings. They've very weak, but 15.5:1?? I thought stoich was around 14.4:1? Why would you want to run so lean?

 

what I/H/E are you running crate? those are sweet numbers and looks like you'll only get better with more tuning. you should give ngk zfr7-f11 (one step colder) plugs a try too next time you tune and advance the timing.

i can't wait to mine tuned.

 

Stoichometric is 14.7:1 Air to Fuel ratio. This is the ideal mix for gasoline combustion to release the most energy. Let me repeat, it is the ideal. However, here in the real world, within a combustion engine, we have to worry about things like detonation, engine temperatures, MTBE additives in our fuel. No gasoline engine runs at 14:7. If it did, it would not last very long.

Based on everything I've read about the H22A over the past 6 years, the limit for safety on this particular motor is right around 13.5:1. Some other N/A motors can be safe up to about 14.0:1, but the H22A is particularly sensitive to detonation. The H22A does not like to be run lean because its pistons have a very small ringland area. So for reliability the max target should be right at 13.5:1 on an H22A. That is not only where the safe cutoff is, but it is also where the H22A will make the most power.

Anything over 14.0:1 is too lean for any street motor.

Andrew


[Modified by aklucsarits, 9:20 AM 3/10/2003]

 

KGA - i had actually planned on it.

Aklucsarits - ya. my ultimate goal is to have it sit aroudn 13:1 really. i blew my old h23 motor.. most likely due to my autox's and having it sit arount 6k rpm's the entire track. So i'm overly causious with this one (the h23 was pretty ragged to beging with though). And that spike i have at vtec is why we added a touch of fuel, when i added +6% in that range, the spike fell down to about 14.5:1 and smooth out really nicely. but in doing so, at vtec the engine bogged BAD. and chugged.


[Modified by Crate, 2:24 PM 3/10/2003]

 

Yeah, that spike is really strange. What ECU are you running?

Andrew

 

jdm ecu.

hit me up on aim - crated0g