Very interesting read Spin, thank you. I wish I understood more about tuning (someday I will actually get the time to play around with HP Tuners that I bought 2 years ago). I hope that you guys continue to test and improve on this, it makes perfect sense logically to me that it should work.

Spin, I haven't made my annual donation yet this year to St. Judes, but I am going to do so when I get back in the country beginning of March. I will make the donation in your name. I always enjoy reading about the things you come up with and post and appreciate the time expense and energy you put out for the Corvette Communities benefit.

I know you are a big supporter of St. Judes so understand that my donations to them are a direct result of your efforts to us. Thanks Again.

 

Thanks

Are you military? (out of country)

 

Great info!!!

 

Hello Mr. Spin,

I think at the end of the day we are coming up with the same outcome, although with a different approach. First, let me tell ya, I am NOT one of those tuners who will keep his or her tuning methods close to the heart and thus totally block out other methodologies and/or processes. I pride myself in having an open mind which to me, is key if you must continue to learn.

I believe your approach is correct but it may not apply for all applications/combo. Case in point, my car, I initially took your approach and for some reason it did not work and that is why I went the other way…the scaling the injectors way. And yes, scaling the injectors does effect fueling globally as well.

Currently, I do not have any drivability issues; my L-trims at cruise are between -1.6 and -2.8 and WOT between -6 and -9 or so…I like fuel in my tunes. My on board A/F reads 12.3, the dyno tail pipe reads 12.4 which is exactly what I’m commanding on the PE (14.7/1.19=12.3). Once I have my PE set, I then adjust my MAF High Freq table to curve my fuel map to whatever the car likes.

My E85 end results on avg thus far is 597/548…will I make more by taking your stoich approach? Who knows but why not try it again…right? I’m not looking for any magical number but instead, I’m seeking for a way that is best all around and thus far my approach has enabled me to make great safe power with no issues whatsoever. But hey, I’ll give it another pass this evening on the dyno and see what happens…perhaps I did something wrong during my first attempt.

Thanks,
Carlos

 

OK I am trying to figure out where this math is coming from. In some post it's 14.1/12 another post it's 12.5/9 something then the last post 14.7/13 Where are these different denominators coming from or more to the point I am running gas pump E10 93 octane.

I have set my Stoich Value to 14.12 In the above example I divided 14.12 / 12 for a PE value of 1.17 and entered that into my EQ Ratio vs RPM table. This actually represented a roughly 10% less value across the cells from the stock values.

My car did not like that at all. Prior the only change I made was just the Stoich Value to 14.12 and the car ran so much better. With the additional change it didn't run worth crap. Did I enter the wrong value or into the wrong table?

PE is a new area for me. I understand the basics that the thread is relating but not too sure if this is an area I should be messing with. Still learning.

My power enrichment value is set at 1.3000

 

If you were running 100% gas with stoch @ 14.7 the 1.3 PE would command 11.3 a/f. That seems very rich to me for a NA engine when the concensus is it should be 12.5 to 13.0.

One possible reason it runs well at the 1.3 is your actual VE is better than your PCM thinks so when you command 11.3 the actual is closer to 12.5.

 

Not military, away on business.

 

Its not about being open minded.

Stoic is the stoic value of your fuel (9.76 for E85) and your injector flow rate is the size of your injectors. Inputting incorrect values for one or the other isnt being innovative.

Anyway, no one is saying its right or wrong. Your outcome is what you got. The point it that when you do things like this, eventually you input some value that has an unexpected effect on something you didnt foresee.

 

So if the Stoich is 14.12 and the PE is 1.1 the command afr should be around 12.8. Correct? Im just playing with numbers seeing if my math is right or if Im missing this entirely.

 

I see...and yes, I like keeping an open mind.

By the way, I've done a couple other cars the same way and both turned out great.

Like you said earlier, you have not tried it, so try it and then see what you think. There is more than one way to skin a cat; I believe I found another way...and it has worked thus far.

We're traveling to the same destination on the same hwy and roughly at the same speed, just on seperate lanes.

Well, the dyno crap is over, now lets see if I can improve on my previous 9.70's N/A ET's the next time out.

Thanks,
Carlos

 

Yes.

 

What formulas are your using to get to those numbers?

 

Divide 14.12 by 1.1 and you get 12.8.

 

E10 is pretty much the only pump gas available around here and at 93 Octane. Per the table above 14.12 / 12.5 = 1.12

I am sorta undrstanding this but still confused as to where in the PE table (HP Tuners) this value goes and is it one cell or all cells?

 

In my old tune all cells were the same value for stoich and for eq ratio vs rpm. The enrichment rate was a little different in my original tune as well. Im not sure if Im right though. Im learning as well too.

 

I don't suppose there is an executive summary of this thread...

 

Nice try. I had to read this about 4 times before I understood it.

The best summary I can do for ya is by adjusting your stoich value properly to the fuel you are using (adding more ethanol has the potential for more power by increasing the octane rating) you can make more power. Thats kinda the nuts and bolts of it. It is way more complicated than that but its what I got out of it.

 

Here are my results using E85 based on my tuning method outlined above. This is my personal 2006 Z06 with only the Widow cam, ARH no/cats, Vette-Air scoop, Killer Bee, FAST intake and 60lbs injectors.

We pulled it 40 times experimenting with plugs (heat ranges/gaps), fuel and spark trims also with IAT and ECT temps and ambient temps.

Here is the link below for the dyno runs:
http://www.theair-charger.com/e85fuel.html

Thanks,
Carlos

 

I'll see if I can dig it up. I think it was just changing the stoich value, calibrating the maf, richening up PE probably to a 1.225 ratio, and bumping timing. I'll check to see if I still have it. I think I was running around 29* of timing, tried for 31* but it wouldn't hold it safely in 3rd gear.

Andrew

 

I's like a copy as well if your don't mind.