The Central Hub for DSM Community and Information

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. This is where the DSM platform history is documented and archived. Log in to help us in our mission, and to remove most ads from the browsing experience.

Had my first taste of E-85.....

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

turbodsm18

15+ Year Contributor
675
4
Jan 26, 2005
816/417, Missouri
Ok, So tonight me and my roomate went out to tune his car....Well, we got anxious and threw some E-85 in the bi***...It was a mix of about 2 gallons of 91 octane and about 6 gallons e85. ( The car is now gonna be strictly e85)

I will start out by saying, the car pulls freaking hard at 24 psi on a Turbonetics 50 trim......But heres what we are confused on...

I cant post a log because his laptop runs linux and his wireless card is not work so he cant send the log to me.

But.

The car is seeing a peak timing of 15.xx degrees at about 7K rpms. At 24 psi the IDC are showing 76% (he bought the injectors used and he was told they were 780cc injectors). The car is seeing no knock whatsoever.

Heres a problem....The Aem gauge shows about 12.8:1 AFR and Link is showing about 10.5:1 AFR

I believe the global fuel setting is right at 342 and the dead time is right at 315....


So my questions are: Should we read from the Aem gauge or from Link...(by the way, we are old school and I believe he is still on V1)?

What should we be seeing for peak timing on 24 psi.....(this is still on a bone stock(internally) 7 bolt)?

What AFR should we tune for on E-85.....(ive been reading to tune for about 12:1)?

All help is appreciated...

-Kevin-
 
Is it a legit copy of dsmlink?

What do you mean the global is 342?

2g Stock timing map will put you right around that 17* timing.

Trust your wideband, AFR reading in DSMlink is just an estimate. Or are you logging the AEM and it says 10.5 in link?

You should aim for 11.5-12.0 for AFR's.
 
Is it a legit copy of dsmlink?

What do you mean the global is 342?

2g Stock timing map will put you right around that 17* timing.

Trust your wideband, AFR reading in DSMlink is just an estimate. Or are you logging the AEM and it says 10.5 in link?

You should aim for 11.5-12.0 for AFR's.

I beleive its logging the aem wideband but Im not 100% sure. My roomates in bed and I dont know how he has the car setup, I just help with the tune. I wasnt sure about the global, he told to type 342 but Im not sure what he meant.

I will have to ask him in the morning what he meant..
 
I beleive its logging the aem wideband but Im not 100% sure. My roomates in bed and I dont know how he has the car setup, I just help with the tune. I wasnt sure about the global, he told to type 342 but Im not sure what he meant.

I will have to ask him in the morning what he meant..

I'll bet it's not 342. ;)
 
You may need to try a different WB type in Link. I had to try 3 before I got remotely consistent readigs at idle.

Trust the gauge for now.
 
Did you retune after putting in the E-85, or is this still a pump gas tune? E-85 requires ~20% more fuel supply than pump gas.

The calculated A/F in Link is based on airflow, inj pulsewidth and specific gravity of the fuel, then it calculates what your AFR probably is. If you find the spec grav for E-85 and plug it in, the A/F ratio in DSMLink will show much leaner. (Unless it is logging the AEM...)

I am sure you probably are near 12.8:1 since the WB actually reads oxygen content of the exhaust gas.

He is probably going to run out of injector when you get the AFR in check. Try bumping up the base fuel pressure and resetting global to give some more headroom until new inj can be purchased.

His global is -42. (450/780)-1
 
Sounds like your trying to log the AEM WB in DSMLink as well & the reading aren't matching up? If so this actually seems to be pretty common issue with the AEM WB. Seems as though they have changed the output several times so there are a few different AEM WB's that you can select from the list in DSMLink & hopefully one will make the logged readings match the gauge display. I know others who have had to send their AEM WB back for replacement, as they were defective & others that have selected another completely different WB from the list & the readings seemed to work well (dynojetWB). Also verify you have a proper ground for the WB & may want to try grounding at the ecu ground as you may have a voltage difference between your current ground for the WB & the ecu ground. For now, you should probably trust the display.
 
I thought stoich was around 9.5? Is it OK to shoot for 12's because E85 burns better? 12's is for sure it for gasoline, but I wasn't under that impression for E85. Actually, I just read a magazine article that says that max power rich is 6.9:1 and lean is 8.4:1 and that stoich is 9.7:1. Seems like that number comes from people who are running it, so maybe I'm missing something...
 
Thanks guys, I get off work tonight at midnight and we are gonna take it out and get the tune down a little better. I will shoot for a 11.7:1 AFR right now(to be safe).....

What peak timing should I be shooting for, I know 18 is about right for pump, but what about E-85...?

Thanks again to everybody, I cant wait to switch my car over and see what I can pull out of the B16g..

Ill post some more results tonight when we are done..

-Kevin-
 
I remember hearing about 20-21..

I'm by no means an expert on E85 tuning, as we don't yet have it up here :cry: but through different posts I've skimmed through, that seems about right to me as well. I believe I've read of guys running as high as 24-25 deg without any issues (though don't think I'd try this without concrete info first). I know with just meth injection & pump I currently run 19deg without issues & as far as I know you can expect abit more out of E85.
 
FWIW, I shoot for 22* on pump with 9:1 CR. I am running about 10.8-11:1 AFR to get away with a little more timing.

E-85 is as knock resistant as 116 race gas although it is only about 106 octane. This is good info that I have ran across on the Link forums multiple times recently.

I don't know what you are talking about tkelly... our cars are rich as hell at ~ 9.5:1 from the factory which is hard to make power on. Maybe you are referring to Lambda readings which I am not familiar with.

Stoich is 14.7:1.
A decent pump tune is about 11:1 (+ or - a little.)
E-85 is at least 12:1 and from what I understand people get away with 12.5:1 depending on the timing you shoot for.
 
the 342 is probably injector dead time.. As for tkelly talking about richer aFR's i think he's talking about ethanol AFR's which 9:1 ethanol afr will read about 14:1 on a wideband set for gas.... 11:1 gas = 's about 6.7:1 on ethonol...tune for pump gas AFR's they just wont be actual, it will read 11:1 but the actual mix will be at 6:1 it's all good tune it.. i run 22-23* timing on e85 and around 11.7 - 12:1
 
the 342 is probably injector dead time.. As for tkelly talking about richer aFR's i think he's talking about ethanol AFR's which 9:1 ethanol afr will read about 14:1 on a wideband set for gas.... 11:1 gas = 's about 6.7:1 on ethonol...tune for pump gas AFR's they just wont be actual, it will read 11:1 but the actual mix will be at 6:1 it's all good tune it.. i run 22-23* timing on e85 and around 11.7 - 12:1

Agreed...
:thumb:
 
I'd be careful on the timing. Although e85 is capable of high timing maps, it is so un-likely to knock, that you can run extreme cylinder pressures, and blow a block before you would ever knew what happened. I like to keep it right around 20* I know you can get away with more, it's just a matter of how daring you are. :rocks:
 
A lot of people run safc's on 1g's with stock timing maps and peak around 21-22*. Its been done for years and people have done it way before actual timing control for our cars. I agree anything over 25-30psi and timing should be kept in check.

Im running 22* at 11.1-11.3 afr's.
 
If I had E85 Id do 11.9- 12.1 afr with 17 degs timing at peak torque increasing to 23degs by redline
on 25psi... Thats pretty much how I tune my 16g setup on race gas, so Id run the e85 the same way.

Too much timing is bad, but I dont think on a 50trim and smaller that you have to worry about that too much unless your pushing for 25 + degs of timing which would be too much.
I think 12.1 afr is good median on e85, fuel consumption is already worse, knock control is great, so get some more out of it by running leaner. Ive heard many ppl keep making great power by leaning out all the way up to 12.5ish, and after that there werent any negligable gains going farther.

Let us know your results and what you decied to do, and getting it to a dyno would be a smart move
so you can find out for yourself what makes more power and how the tune pans out... ; )
 
Good points on the timing. Our cars are a modern hemi-spherical head which doesn't require near as much ignition lead as older V8's to get a complete burn of the fuel in time to create peak cylinder pressure by the proper time (usually around 15 or so degrees ATDC). So adding more timing then the low 20's is only putting more pressure back against the rod on it's way up and stressing the cylinder head/gasket area. Old V8's were so in-efficient that when running race fuel at teh track it is not uncommon to see 30-35* advance just so they can get the mixture lit and doing it's thing in time to transfer and make proper use of the enrgy to the crankshaft.
 
Well, an update on the car....The car is now tuned for around 11.1 afr and a peak timing of about 16degrees...

I tried and tried to get him to run 11.7 afr and about 20* peak timing but he wont do it....We are pulling the tranny out soon for a new clutch, but after that I may be able to convince him to change the tune....

Thanks for all the input guys, I will update this thread at a later date.
 
Well, an update on the car....The car is now tuned for around 11.1 afr and a peak timing of about 16degrees...

I tried and tried to get him to run 11.7 afr and about 20* peak timing but he wont do it....We are pulling the tranny out soon for a new clutch, but after that I may be able to convince him to change the tune....

Thanks for all the input guys, I will update this thread at a later date.

:|

Then whats the point of getting e85 if hes not even reaping the benefits...
He's just putting a fuel to burn faster for no reason.
I run more timing than that on pump gas dude :tease:
 
E85 burns slower, you hAVE to run more timing to even use it efficiently, please tell your tuner to take advantage of the fuel you're using or do it yourself, but if he gave you that conservative of a tune on E85 i'd be asking for some money back. You probably raen't making any more power on it without the correct timing, you're jsut making the car safer at normal street levels.
 
Add Value - Be Respectful - No Trolling - No Misinformation - Participate Often!
Support Vendors who Support the DSM Community

Build Thread Updates

Latest Classifieds

Back
Top