hey honda-tech, i recently failed the very challenging IM240 emissions inspection and have 3 months to figure out a solution and was hoping people could offer some advice.

my build is an 82mm gsr block with usdm b16a pistons (are those pr3?), a b16 head w skunk 2 pro series valvetrain, skunk 2pro 1 cams and a stock gsr tranny .

is there anyway to tune this build to pass emissions inspection? im currently tuned with ectune in open loop :/ but have a neptune rtp waiting in the box that i am pretty ready to start playing with.

since i doubt there is anyway to make these cams pass emissions, what cams would be good given my build? im especially worried about the stiff valve springs on a stock cam. would it wear out the cam or the valves or just add to pumping losses?

i have b16 cams laying around that i am willing to sacrifice!

at this point i just want to pass emissions with flying colors and could care less about power.. i even considered finding a d series somewhere..

thanks for your input!

 

Well that part exactly did you fail? I thought the PRO 1 will retain a fairly stock Idle characteristic and be relatively good on emissions.

 

First step would probably be to enable closed loop.

We kind of need to have an idea of what parameters you were failed for.



Also, I am planning a similar build. Any idea what kind of power your setup makes?

 

Search my thread "passing emissions tricks" There is a TON of info in it. Yes me and another guy had some disagreements at first but the trick has to do with Methanol.

 

https://honda-tech.com/forums/showthread.php?t=3009516\
here is my thread. Read up and I bet you pass

 

alright, thanks for everyone's interest!

for the test results:
maximum allowable hydrocarbons is .5000 g/km and i had 1.1396 g/km
maximum allowable carbon monoxide is 9.3200 g/km and i had 10.4424 g/km
maximum allowable oxides of nitrogen is 1.2400 g/km and i had 1.7754 g/km
for the record, the test facility is under the impression that i am still running the d16z single cam ex motor. I'm not sure how the displacement change would effect the numbers, it shouldnt matter if its running well right?

from what ive read (mostly on here) people have a hard time getting these cams to idle because of all the overlap and duration, as well as people not degreeing them in properly or at all. i also read on here (https://honda-tech.com/forums/tech-misc-15/skunk2-stage-2-pro-1-cams-basic-smog-ca-2710377/) that the pro 1's primary lobes have the same lift as a gsr's vtec lobes! my setup made 121 tq and 182 hp on a mustang dyno, unfortunately i never got out to a track to put down some times.

for closed loop/tuning:
i got tuned w ectune at a performance shop so i can only datalog and can't adjust any parameters... i have been slowly setting up my car for tuning with neptune rtp though because i want to do it myself and give it all the attention it needs for a really smooth tune. for now though i don't want to waste any time learning to tune on some hard-*** pro 1s from scratch if there is barely any chance of them passing because i only have 3 months before my insurance extension is expired and unrenewable without passing emissions.

and thanks for the link 93egSleeper, i am off to do some reading!

 

Pro1s are not hard to tune nor do are they hard to make idle when degreed in properly. Hell, Pro2s are easy to tune IMO. When I say easy to tune, I mean that it is easy to make the engine run very smoothly at both part throttle and WOT.

I cannot comment on how difficult it is to make them pass an emissions test though as MO does not have emissions testing except for a few counties.

Enabling closed loop so that the ECU can target stoich will certainly help quite a bit in most cases. The 14.7:1 A/F target was chosen mostly because if offers the lowest emissions.

The results contained in the thread that was suggested to you might certainly be worth a try with your time crunch.

 

wow helpful thread 93egsleeper, those test results are hilarious! so a 1:1 methanol and high octane mix, i will definitely give it a shot! where did you buy your methanol? we have a very similar build except for my skunk2 pro 1s. do you think even with these beefy cams i stand a good chance at passing? if so i would totally dick around with tuning this setup to get it just right. i have a wideband installed and my afrs seem ok, they dont go below 12.3ish (wot) or above 19.7ish (decel). back to methanol research!

 

Put stock cams in?

Takes like 20 minutes.

 

Honestly if you ran the car down to about a 1.5-2 gallons of gas and put in a gallon to 1.5 gallons of Methanol you should be in the clear, and you wont need to worry about adjusting your tune. I drove about 15 miles on 2 gallons of gas and 2 gallons of methanol mixed without issues...yes it ran a little doggy and hotter but as long as you don't race there you're fine. Just hit the gas station right after and fill it up full. I am fortunate enough to have gotten the methanol for free from a family friend who races the outlaw brackets every weekend and had a barrel left over from the season that was going bad so he gave me 5 gallons. I would call around to some top end machine shops who build motors for the higher end domestics and ask where they have the meth at. They should be able to tell you. I would be willing to bet you pass easy since mine practically blew zeros all around.

 

I'd make sure you have degreed the cams properly and get a real good tune..

 

will the increased heat from running 1:1 meth and gas show up on the temp gauge? im not sure if they would care or not that i was running hot if i passed emissions. and sleeper are you tuned in closed loop, just out of curiosity? i think i am finally done with the questions!

 

No it's not a noticable increase in temperature to effect the temp gauge...the only reason I could tell was my cat got a little bit hotter and I could smell it burning off a bunch crap. I assume this is because it runs a little bit leaner, but not enough to be a hazard to the motor as long as you drive it accordingly. I am tuned in closed loop, crome pro gold.

 

In for results. I've got Pro 1s and I'd like to know if I have a snowball's chance in H3ll of passing CA emissions.

fm

 

alright, i just got some free time, ill try and go this week, probably thursday.
if this doesnt work i need to work on tuning it in closed loop which will involve switching from my ectune to neptune.

i have an a/f gauge installed, what kind of readings should i expect from 1:1 gas and methanol? so i dont freak out..

 

By a little leaner, you would mean 25%. I would probably retard the timing a bit and stay away from WOT. Fill the tank after the test with the highest octane you can find. We used to do this alot, but never 1-1.

 

I honestly can't say how much leaner I didn't have a wideband hooked up when I drove it in for testing. It wasn't bad enough to make the car non-responsive, just enough to make throttle responce power lag a little bit.

 

im, of course, worried about messing up my motor, what would happen in the worst case? get hot and melt and seize? what are the symptoms, pinging and temperature gauge and driving like crap? i havent heard pinging yet and not sure what it sounds like. i have seen the thread on here thats for making a cheap listening tool to hear detonation though, which i was planning on making for my eventual tuning ..

im starting to think i should finally try to tune it myself and get it in closed loop before the next test. after all, i was tuned in a houston, tx summer then moved to vancouver, bc which are pretty different climates. once i have a basic idea of what to change and what to look for i can try to make a seperate tune for my gas/methanol mix i guess. im tuned in ectune but i have everything ready for the switch to neptune, so at least ill have my old basemap for comparison. all advice and suggestions are welcome

thanks everyone for their input

and pr0honda, what ratio gas:methanol would you suggest?

 

so i bit the bullet and got it re-tuned. made similar power and the emissions were much lower: hc was .74 gm/km, CO was 2.19 gm/km, and NOx was 1.10 gm/km. everything passed except HC. then the tuner tried adjusting timing and adding methanol only to lower HC and raise NOx. In the end they replaced my crappy Magnaflow high flow cat with some other 3 way cat that is California legal so you know its the good.

the final numbers: HC was 0.03 g/km, CO was 0.14 gm/km, and NOx was 0.90 gm/km.

thanks everyone for the help.