E85 calibration for emissions testing

[rkreigh]

need to get a chip burned for E85 in VA

would like to try passing emissions with the 390 using E85

car will need to be tested with an exh gas analyzer to make sure it can get clearner than 48 HC (which E85 should help)

Marc or Corey can likely do this but don't have the exh gas analyzer and I don't want the expense of driving the car there anyway

any thoughts??

maybe Tony's corvette with help from them doing a "mail order tune"

my car has cams, no secondaries, and was running around 140 HC last test.

let me know if you all have any ideas. tony's has a GREAT dyno, but maybe not the exh gas analyzer.

hoping to only do this ONCE. thanks!

[XfireZ51]

Ron,

What part of the test exactly does the car fail? Do you have a plot of the HC and pardon me for asking but what cams are we talking about? E85?

[rkreigh]

I've got the Stage II LPE cams. 440 lift, 234 duration. something like that

I don't have much info as the emissions tests were done long ago and the VA just gives you the readings at the various MPH

I think it was the worst at idle at around 140 HC on a 48 HC standard.

[XfireZ51]

I've got the Stage II LPE cams. 440 lift, 234 duration. something like that

I don't have much info as the emissions tests were done long ago and the VA just gives you the readings at the various MPH

I think it was the worst at idle at around 140 HC on a 48 HC standard.

I can imagine it was probably idle and on decel.

[rkreigh]

anyone have tips for doing an E85 calibration?

just needs to run the car up to 30 mph or so, no secondaries so I can use both injectors.

need a tuner in VA who can work with me an ideally has an exh gas analyzer so I can validate that it will blow clean enough

might be able to work with Marc or Corey mail order and do several tries to get it right.

I do have EASE so I can collect the data.

thanks!

[Marc Haibeck]

Hi Ron,

All that should be needed is to flow about twice as much fuel compared to E10. I think that the oxygen sensors would still switch at 14.7:1 so they would need to be shut off and run open loop.

I would be concerned about the effect that the E85 would have on the fuel system hardware if exposed to it for over a week.

[rkreigh]

Hi Ron,

All that should be needed is to flow about twice as much fuel compared to E10. I think that the oxygen sensors would still switch at 14.7:1 so they would need to be shut off and run open loop.

I would be concerned about the effect that the E85 would have on the fuel system hardware if exposed to it for over a week.

thanks Marc,

the plan would be to warm up the car, drain the gas, switch the memcal, , put a few gallons of e85 in it, run it through the test, , an then come home and immediately drain it out. so the exposure wouldn't be too long. a couple of hours tops.

an open loop calibration would be just fine.

I'll probably try some fresh cats (as I have them) to see how close I can come as you advised. but with the tough 48 HC standard, my bet is that it won't pass at idle.

this would be plan B. very interested in E85 though for a turbo ZR-1

yes, the entire fuel system would need to be upgraded, but the power possibilities are there. problem is the "hassle" associated with storing a car for any period with e85 it would have to be driven very frequently or drained when not in use.

thanks for any tips or advice

[XfireZ51]

thanks Marc,

the plan would be to warm up the car, drain the gas, switch the memcal, , put a few gallons of e85 in it, run it through the test, , an then come home and immediately drain it out. so the exposure wouldn't be too long. a couple of hours tops.

an open loop calibration would be just fine.

I'll probably try some fresh cats (as I have them) to see how close I can come as you advised. but with the tough 48 HC standard, my bet is that it won't pass at idle.

this would be plan B. very interested in E85 though for a turbo ZR-1

yes, the entire fuel system would need to be upgraded, but the power possibilities are there. problem is the "hassle" associated with storing a car for any period with e85 it would have to be driven very frequently or drained when not in use.

thanks for any tips or advice


Even in O/L, wouldn't you need more than a couple of hours to get the tune right using a WB calibrated for E85?

[VetteVet]

Hi Ron,

All that should be needed is to flow about twice as much fuel compared to E10. I think that the oxygen sensors would still switch at 14.7:1 so they would need to be shut off and run open loop.

I would be concerned about the effect that the E85 would have on the fuel system hardware if exposed to it for over a week.

Marc,

Couldn't the target AFR values be adjusted to account for the E85? I would think that running in closed loop is going to be his best shot at passing.

Maybe I'm missing something. If so, I'm sure you and/or Dom will set me straight.

Jep

[Marc Haibeck]

Jep,

As I understand it, the OE switching oxygen sensors switch at a ratio of oxygen in the exhaust verses the 20.8% in the air. That represents stoichiometric combustion of gasoline. The ratio is very different for stoichiometric combustion of ethanol, so a switching sensor calibrated for gasoline would not work correctly with ethanol.

[XfireZ51]

Jep,

As I understand it, the OE switching oxygen sensors switch at a ratio of oxygen in the exhaust verses the 20.8% in the air. That represents stoichiometric combustion of gasoline. The ratio is very different for stoichiometric combustion of ethanol, so a switching sensor calibrated for gasoline would not work correctly with ethanol.

Marc,

Yes you are correct. I think E85 stoic is around 9:1 while stock NB O2 is calibrated for gasoline with a switching point optimized for 14.7:1. It is possible to adjust the O2 switch point but I suspect not to the extent needed to accommodate E85. Same for the WB. As I presented at the last Gathering, I play w these values to account for the E10 w a stoic of 14.3:1 and for dealing w the increased overlap of bigger cams. I might read up on how this is being done on the C6. I imagine O2 sensors from flex fuel vehicles may be alternatives.

[XfireZ51]

Ron,

In some quick reading, it seems that it may not be all that difficult to go to an E85 tune relatively speaking. The O2 issue really isn't one w changes to the calibration. Some disagreement regarding corrosive effect of higher alcohol content but fuel pump and injector mods would be necessary for increased fuel flow. Corresponding cal adjustments for same as well as SA changes to take advantage of cooler fuel. The Flex Fuel vehicles have a sensor in the tank to measure alcohol content directly and use the correct values already in the stock calibration to optimize for fuel used.
Bin switching or flashing would be a good feature to have when implementing this for our cars. I'll work on getting a bit more detail. Live and learn.

[USAFPILOT]

I am interested in this as well. I failed emissions for NO2 on gas, but with a can of denatured alcohol in the tank the NO2 came way way under but my HC's came right up to the limit. Was able to squeak under on the second pass on my second test by 1 HC. I am using the stock tune, but the car now has SW Headers, High Flow Cats and a B&B 3" exhaust with X Pipe.

[rkreigh]

running on both injectors full time with both pumps running will provide more than enough fuel to do 25 mph which is all the car needs to do for the emissions dyno.

I "spiked the gas" with lamp fuel a few years ago and got the car down to 98 HC on a 99 standard, but that was also before the secondary flaps were removed.

my cats are definitely older and putting some BIG and fresh cats on the car is worthwhile to see how clean I can get the car "as is"

Tony's corvette shop certainly has the dyno and probably an exhaust gas analyzer, and hopefully working with Marc and sending the data captures back and forth we could get this done. I know Tony has a tuner also so they may be willing to have a go at it.

probably will be a bit pricey but worth it!

[Hib Halverson]

Oxygen sensors sense lambda and 1.0 lambda is stoichiometric combustion for any carbon-based fuel be it pure ethanol or gasoline.

If you're going to try to cal for E85, know that...

1) Stoich for E85 is is around 9.8 but can vary because pump E85 often varies between 70 and 85% ethanol. So, you're going to need to calibrate for a lot more fuel flow, even at part throttle.

2) E85 is corrosive to metal parts of fuel systems not originally designed for it. Also, it may attack rubber and plastic fuel system parts.

If the car is close on passing the IM240 type test, I'd put some known good stock cats on it, then go get the cats really hot just before you test. If your car cools well, drive around the block several times at medium rpm in first gear then pull right into the test bay. Or if the test station is close to the expressway, drive in fourth gear at highway speeds for five minutes then go test.

[rkreigh]

Oxygen sensors sense lambda and 1.0 lambda is stoichiometric combustion for any carbon-based fuel be it pure ethanol or gasoline.

If you're going to try to cal for E85, know that...

1) Stoich for E85 is is around 9.8 but can vary because pump E85 often varies between 70 and 85% ethanol. So, you're going to need to calibrate for a lot more fuel flow, even at part throttle.

2) E85 is corrosive to metal parts of fuel systems not originally designed for it. Also, it may attack rubber and plastic fuel system parts.

If the car is close on passing the IM240 type test, I'd put some known good stock cats on it, then go get the cats really hot just before you test. If your car cools well, drive around the block several times at medium rpm in first gear then pull right into the test bay. Or if the test station is close to the expressway, drive in fourth gear at highway speeds for five minutes then go test.

I'll likely blend my own E85 to control it better. I'll likely try some fresh cats out but with the cams, no secondaries, headers, ect... I doubt I'll get the 390 to blow cleaner than 48 HC at idle.

hoping the E85 (or pure alchy for that matter) would be an alternative

if the car could be calibrated to run on it without breaking the bank I'm not too worried about the limited exposure the fuel system would have.

I'd only have it in there long enough to get through the dyno/sniff test

I'd warm it up on gas, drain it, swap fuel & memcal, and drain it out an hour later.

I'm only a block from the emissions test so it wouldn't even have to run that great as long as it can run clean, go 25 or 30 mph, to get by the dyno test.

any advice on folks in Northern VA that might be able to help out with this.

Tony's Corvettes is the only folks that might take this on, but I'm sure they would need some remote help from a better tuner.

I don't have secondaries in the car either.

[XfireZ51]

Part of the issue with idle is the overlap on the cams. This messes with the O2 sensors or should I assume you are running Open Loop?

[rkreigh]

Part of the issue with idle is the overlap on the cams. This messes with the O2 sensors or should I assume you are running Open Loop?


no doubt the overlap is a tough issue. it's running closed loop.

I had a LPE open loop chip previously, but that was before mark tuned it and removed the secondaries.

the cams are very streetable but not good at all for emissions, and I'm sure pulling the secondaries didn't help the situation either. but I sure love the way the car drives without them. throttle response is right now with the light flywheel and ti rods, and no secondaries to snap open.

I'll talk more to marc about this and see if he's interested. I think it could have some performance applications down the road for a high compression lt5 with a fully updated fuel system (pumps, lines, injectors, tune)

there is some power to be had with e85, especially with turbos!!

[XfireZ51]

no doubt the overlap is a tough issue. it's running closed loop.

I had a LPE open loop chip previously, but that was before mark tuned it and removed the secondaries.

the cams are very streetable but not good at all for emissions, and I'm sure pulling the secondaries didn't help the situation either. but I sure love the way the car drives without them. throttle response is right now with the light flywheel and ti rods, and no secondaries to snap open.

I'll talk more to marc about this and see if he's interested. I think it could have some performance applications down the road for a high compression lt5 with a fully updated fuel system (pumps, lines, injectors, tune)

there is some power to be had with e85, especially with turbos!!

So if you are running C/L then the O2 sensors are detecting a false lean.
The ECM is commanding extra fuel. Unless you adjust the O2 sensor window for idle, it will continue to do that. Also, the proportional gains need to be reduced. A cammed motor is more unstable and the values used for a stock motor tend to exaggerate the instability. That's why you find cammed motors surging and why most will use Open Loop.
My motor has secondaries removed and using Pete's cams on the intake side only. Running C/L.

[Corbusa]

Guys excuse my ignorance , I do not understand how the emissions work . My question is . If all that is needed is to pass the test once a year could some one just rig up some sort of Fresh air injection right into the exhaust where the testing is being done? ( a 30 galon air tank that kicks on at a certain rpm?) would that throw off the readings and show cleaner air? or a spark plug in each exhaust pipe wired to a coil to burn any extra fuel ? sorry for the dumb questions .

[rkreigh]

Guys excuse my ignorance , I do not understand how the emissions work . My question is . If all that is needed is to pass the test once a year could some one just rig up some sort of Fresh air injection right into the exhaust where the testing is being done? ( a 30 galon air tank that kicks on at a certain rpm?) would that throw off the readings and show cleaner air? or a spark plug in each exhaust pipe wired to a coil to burn any extra fuel ? sorry for the dumb questions .

because of the duration of the test a 30 gal air tank wouldn't flow enough volume and you'd like need a pretty big air pump to put enough into the exh to clean it up and fool the testing.

a good running stock LT5 usually just needs to have the injectors working right, fresh plugs, air cleaner and good cats to pass

many times a "spirited run" will clear out the carbon deposits from cars that don't see enough time at wide open throttle and the LT5 tends to "carbon up" from lugging around at low rpms. spiking the gas with a little alchy and emissions test products can help too.

try running some BG or techtron through a tank of gas prior to doing the test and change over to fresh oil as it does help if you are close but not passing.

[mike100]

The emissions guys aren't going to fall for the oki-doke/diluted with air trick. If your gas sample is over 5% O2 in Cali- that's a fail just for that.

Like if the muffler is full of holes or you thought you'd be slick and hold the probe 3 feet behind the tail pipe or something.