Next Test: E85 flex fuel vehicle via fuel trimming

[bling5tatus]

Have you thought of experimenting with a ffv sensor? the way megasquirt implemnts it should be pretty easy to implement on any system, provided you have an extra sensor input. I want to try and use one on my car with a factory ECU... we'll see how that works.

Hey can you link some more info on this, please?

 

[bastarddsm]

I don't have it. but if you do to megasquirts site and search flexfuel sensor you will find it.

however heres what i know: the FF sensor produces a square wave output from 50 - 150 hertz. It rises linearly with ethanol percentage. i might have this backwards but 50hz = 0% ethanol, 150hz = 100%ethanol. Also the pulse width changes with temperature, I do not know what that affects. That being said we could take that in to a freqency to voltage convertor and apply it to a unused sensor input. EGR position sensor is a posibility. Then with some creative coding apply a correction to our fuel maps and timing map based on that input.

From what I can tell megasquirt uses a linear relationship between ethanol% and global compensation for fuel and timing.

Personally I would like two maps, one 100% ethanol, and the other 100% 93oct, which then it would take some sort of a weighted average between the two, depending on ethanol%. I am unsure if this would work, but if it did i think it would be better as it's not just a global change between the two maps.

Any other opinions?

 

[bastarddsm]

Is it possible that we could give up out coolant temp sensor? and use it for this, I know it has timing control and fuel control.

 

[turboglenn]

Is it possible that we could give up out coolant temp sensor? and use it for this, I know it has timing control and fuel control.

That was my originial plan, except instead of a sensor i would have a switch to trick the AIR temp sensor, but there's only about 13% adjustability on my ECU in the air map so i would have to fool coolant and i could get +/- 50% but then i would have to manually trim the warmup when not on the main fuel it's setup for. I'll finde a way, but most easy ones seam to have downfalls so until then i'll keep thinking up stuff

 

[bastarddsm]

I want to try it but the damn flex fuel sensor is $300, and i don't know shit about coding in what ever kind of machine language the dsm uses.....now if it spoke perl or fortran, it'd be cake!

Untill then, i spose i'll just use a dual image eprom, and adj the FP and base timing to comprimise..

 

[turboglenn]

I want to try it but the damn flex fuel sensor is $300, and i don't know shit about coding in what ever kind of machine language the dsm uses.....now if it spoke perl or fortran, it'd be cake!

Untill then, i spose i'll just use a dual image eprom, and adj the FP and base timing to comprimise..

Yea, the sensors price is keeping it out of my mind for a while (plus needing an ECU that can utilize it) Things like this are what's making megasquirt more and more attractive to me, i'd just have to order pre built ones since i would be in too much of a rush to get it finished and in the car. But with the price of pump gas anymore i think i'm just going to run strictly E85 and if i go on a road trip wherre i may have to buy pump gas, i'lll just make sure to have my laptop so i can change maps. A dual image chip (or newer haltech with dual switchable maps) would make this a cake walk, but with my old ass ECU I'll just have to do it the primitive way and spend a few minutes loading fuel and spark tables when i change. Although i haven't given up hope on making it an FFV i am now trying to decide what map will be more important to have spot on and which one to have "good enough" to not only drive but be able to blast some WOT pulls.

PUmp gas is so expensive i would almost want that map to be perfect to not waste any fuel. But being that i run e85 all the time i almost need that map to be the perfect one so it doesn't frustrate me while daily driving ( i hate having "holes" in my maps or any big AFR fluctuations) Since the switchable method i come up with will only be able to make global changes tot he fuel and spark tables this has to be planned carefully. Since WOT areas need an average of 25% change and most cruising areas only see about 13-16% change (on my car anyway) I was thinking that i could do a leaner tune on e85 at WOT so that if i set it up to only pull 13% or so to get the cruising areas great then maybe teh WOT areas would be near 11:1 if i took out 13% from a e85 tune that was running at say 12:1 (i think i'm rambling trying to make sense) But hopefully you get what i'm saying.

I'm now starting to wonder about how good of a track car i could build with a FWD eclipse. I would still want to keep it street legal with only the dash and front interior, but am seriously considering fiberglass hatch, doors, lexan rear windows etc... with the new trans w/ LSD i can actually bog my launches at 4500 RPM in a FWD (rare for me before the TRE) But the problem i'm having is still dragging along too much weight for good acceleration. The faster i make the car the less i worry about comfort and noise levels because now that i'm on solid mounts the whole car shakes like mad anyway

No matter what i do i want to keep it a DD and keep AC in it (i have that already) I just am really wondering how much ET i could drop and how much better my 60' times would be if i started pulling weight out of the car?

Anyone know how much can be stripped out of a near stock 2g FWD rear end? Or where i can get a hatch in fiberglass (i know where to get carbon but i'm on a malt liquor budget )

 

[turboglenn]

WEll, i just ordered a new 255 HP pump and "mounting kit" (what ever that includes) So when it gets here i will again crank up the boost and see if i can support the fuel needs at 11:1 all the way up through 7500 RPM at 25PSI. I will have a new wastegate cap and spring to allow me to run more boost here soon as well so plan on seeing me testing the fuel system up to around 32 psi (the very max area my compressor can be any where near efficient at)

i will update as soon as i can...I HATE waiting on UPS ground, especially since i could have gotten USPS priority for the same cost if not cheaper, but it wasn't offered.... USPS blows UPS and fed-ex out of the water now days, they had to step up their parcel game since teh email world has hurt their letter revenue so badly

 

[gsxtasy]

Dropping the fuel pressure from 43 to 36 helped me get a little bit out of the danger zone of over 100% iDC. I'm now seeing 96% at most, but at least i know it's not just staying open the whole engine cycle.

Although lower pressure helped with IDC's i also should note that i'm only getting AFR's of 12.8 - 13:1 once i hit the top end where i am near 100% IDC.

Hey glenn, dropping fuel pressure would actually make your injectors smaller, which in turn, normally would raise IDC's. This leads me to believe your pump is suspect, and not flowing enough fuel to the rail, just as you thought. I'm sure your aware of that, but I thought i would clear it up for any new comers reading along.

lower base fuel pressure = your fuel pump is bigger(flows more); but injectors are smaller(flow less)
higher base fuel pressure = your injectors are bigger(flow more); but pump flows less volume(flows less)

Another thing to throw in there for anybody wondering, is how to figure out how big your injectors are at a given base fuel pressure.

Injector Flow Rate at Different Base Fuel Pressure
(Injector Size) x sqrt(new fuel pressure/stock fuel pressure)=new flow rate of injectors

ex: 880cc injectors at 50 base fuel pressure on a 2g: 880 x sqrt(50/43.5)=943.45cc

So, at 50 BFP, your 880's actually flow 943cc, but now your fuel pump won't put out as much volume.

New Global Correction
(450/new injetor flow rate )-1= global correction

ex: same as above: (450/943)-1 = -52% global correction

Hope all of that isn't too confusing, any questions just ask.

 

[turboglenn]

Good info Aaron, thanks

When my new 255hp gets here I might see how difficult it looks and if i have time or my friend doesn't want the one i'm pulling out, i think i might make a dual pump hangar (~425 bucks for one online is outrageous)

And if the fuel is fixed with the new pump, i'm ordering slicks and making a trip to KCIR and getting myself an 11 second timeslip!!!! you should come downa nd run your car as well, i'd love to see what she'd do in the 1/4!

Also, anyone local, PM me if you've got any basic simple mods stiff left over, i have a friend who just got a used 2g and were trying to get him a nice build on a budget if we can find some decent used stuff) I've given him all my left over old mods , BOV and such, hoping to get him an AFC, some 550's and a 16g or something similar

 

[JayRolla]

Good info Aaron, thanks

When my new 255hp gets here I might see how difficult it looks and if i have time or my friend doesn't want the one i'm pulling out, i think i might make a dual pump hangar (~425 bucks for one online is outrageous)

And if the fuel is fixed with the new pump, i'm ordering slicks and making a trip to KCIR and getting myself an 11 second timeslip!!!! you should come downa nd run your car as well, i'd love to see what she'd do in the 1/4!

Also, anyone local, PM me if you've got any basic simple mods stiff left over, i have a friend who just got a used 2g and were trying to get him a nice build on a budget if we can find some decent used stuff) I've given him all my left over old mods , BOV and such, hoping to get him an AFC, some 550's and a 16g or something similar

He might as well just get the safc and 950's. Then he could use the boost juice.

 

[turboglenn]

He might as well just get the safc and 950's. Then he could use the boost juice.

Believe me i've tried talking him into it already

He doesn't want to get anything too fancy or big. He just wants a well running 16g car. He doesn't want to "convert" to E85 mainly because he's not a tuner by any means and wants something that he completely understands.

At the very most he's looking for around 300-325 horses daily

 

[turboglenn]

He might as well just get the safc and 950's. Then he could use the boost juice.

Believe me I've tried talking him into it already

He doesn't want to get anything too fancy or big. He just wants a well running 16g car. He doesn't want to "convert" to E85 mainly because he's not a tuner by any means and wants something that he completely understands.

At the very most he's looking for around 300-325 horses daily..probably end up around 275 or so realistically and he'll be just fine with that.

 

[turboglenn]

DAMN DAMN DAMN!!!!!!!!!!!! MY new fuel pump (255hp) wont' be here until friday I HATE UPS!!

seven whole days to get something here from the east coast, rediculous!

Also just heard from the place i ordered my new wastegate cap from, they called to say "it turns out a new 38mm cap will fit your old 35mm wastegate" i proceeded to say "duh, i told you guys that when i ordered it, but you're the ones that ordered me the 'special retrofit cap' for my old wastegate" And they could only promise that it will be here before christmass, so i'm calling tooday to tell them if it's not in next week to cancel.

Well, good news, they are expecting it any day now ( or so i'm told) I hope to hell the new 255 keeps up with the alky needed for 30psi daily driving duties. I've got a set of slicks to go pick up this afternoon as well.

I do have one concern about the fuel system. The first time i ever changed the fuel filter i twisted the hardline and broke it, i repaired it with a compression coupler and although i remember the coupler being larger in ID than the fuel line, does anyone think this could be causing a restriction that's causing my lean condition?

 

[playitlouddsm]

I have a friend here in Lawrence, KS that has a safc that he is not using anymore and i'm sure he'd be willing to part with it. PM me if your buddy is interested.

 

[Black_Bullet]

Believe me i've tried talking him into it already

He doesn't want to get anything too fancy or big. He just wants a well running 16g car. He doesn't want to "convert" to E85 mainly because he's not a tuner by any means and wants something that he completely understands.

Understand is just a matter of learning... Tell him to read up on e85, get all his questions answered, and then he should feel comfortable running it. OR tell him he's an idiot and his car will always be slow.

I do have one concern about the fuel system. The first time i ever changed the fuel filter i twisted the hardline and broke it, i repaired it with a compression coupler and although i remember the coupler being larger in ID than the fuel line, does anyone think this could be causing a restriction that's causing my lean condition?

No unless it some how goes into a weird shape and makes it a smaller diameter than the fuel line.

 

[turboglenn]

I got my new wasteagte cap and 14.5 lb spring today! Finally after damn near 3 months of witing on it, it has arrived. Now i can continue playing with E85 up to the 30 psi range and really feel what my motor can do with this particular setup. The only thing left s to get some cam gears and some springs and retainers so i can have teh cams dialed in and the valves shuting properly to max out my setup!!!!

Then i can move on to appearance repair and modification ( but it needs some serious repair first!! )
New carpet, seat covers, center consle etc.. it's all coming this summer, then a paint job next spring. I can't believe i've finally finished with the motor/drivetrain aspect of things!!!! (except for the 20g i plan on switching to, but it's still about the same airflow as what i'll be at now but faster spooling)

 

[JayRolla]

I got my new wasteagte cap and 14.5 lb spring today! Finally after damn near 3 months of witing on it, it has arrived. Now i can continue playing with E85 up to the 30 psi range and really feel what my motor can do with this particular setup. The only thing left s to get some cam gears and some springs and retainers so i can have teh cams dialed in and the valves shuting properly to max out my setup!!!!

Then i can move on to appearance repair and modification ( but it needs some serious repair first!! )
New carpet, seat covers, center consle etc.. it's all coming this summer, then a paint job next spring. I can't believe i've finally finished with the motor/drivetrain aspect of things!!!! (except for the 20g i plan on switching to, but it's still about the same airflow as what i'll be at now but faster spooling)

Nice, now you need to get some dyno and track numbers. Im starting to feel the same about my car. Engine/drivetrain is now complete. Next will be a larger turbo, like a 35r or something with good spool and enough air to make some good power up in this high altitude.

Ohh and did you say a 20g will spool faster than your current turbo?? Thats the first time ive heard someone say fast spooling and 20g in the same sentence.

 

[turboglenn]

When comparing it to a garret 57 trim a 20g is considered a "faster spooling turbo" My Garrett is laggy, and the map shows it. Plus the T3 hotside and stage III turbine wheel aren't the most restrictive, but they sure don't help spool either. Right now i see 20 psi by around 4200 - 4500, I'm sure a 20g would hit faster than that ( i hope anyway ) But, i can't remember what the last 20g car i worked on spooled by either, it just seemed to hit a lot sooner than my turbo.

Got the new pump in today (255HP) and it turns out my old pump was really a 255, so I'm hoping my loss of fuel was just from the pump being 10 years old. As the only thing left to replace if it won't keep up now, is to run a -6 AN feed all the way from the tank. I've got a big aftermarket fuel filter and -6 line from it to the rail with -6 return to the aeromotive AFPR.

Also I'm loving having the ability to make higher boosts now.. I think the E85 did a good deep cleaning on my engine as even on pump now , i'm seeing a lot less detonation. Before to run 24 psi on pump i had to have at least an M10 nozzle flowing in my meth setup. Now I'm on the same timing numbers but only running a M7 and still was hitting 245 psi with very minimal knock where as before the 7 didn't get me past 20psi Either way, as soon as i finish this pump gas tune I'm going back to my sweet sweet corn juice and am going to see what 30psi does at the track and dyno. Now i can order slicks and send my built motor back into the machine shop to have the mains resized again and get some higher compression slugs to go on the eagle H beams..i'm just happy happy happy...BUT my car did get hail damaged in the tornados last night

 

[Black_Bullet]

TurboGlenn, I think a 30r would fit your setup nicely.
Speaking of getting new slugs, are you brave enough to go for 10:1 compression since you have e85 + meth

 

[turboglenn]

I'm not brve enough for that by any means, but i do plan on being at either 8.5 or 9:1

The pistons i have now are only 8:1 and have some miles on them at this point and i don't really care for the sluggish'ness of them as far as driving in city traffic. That's the only real reason i ave to even want a different ratio. I'm fine with the top end as it is now, it's just off boost areas are too poochy.

 

[Black_Bullet]

I'm not brve enough for that by any means, but i do plan on being at either 8.5 or 9:1

The pistons i have now are only 8:1 and have some miles on them at this point and i don't really care for the sluggish'ness of them as far as driving in city traffic. That's the only real reason i ave to even want a different ratio. I'm fine with the top end as it is now, it's just off boost areas are too poochy.

9.1 sounds good with a e85 car...

 

[turboglenn]

I should add that after some recent pump gas driving, I have decided to continue the "ghetto flex fuel vehicle" tests . I'm going to get this map perfect on 91 pump and then just short one of the temp sensors (IAT most likely) and try and use those correction maps to add the fuel and then just use meth and a lower boost when on pump gas and keep the same timing map for both tunes. Then i'll just have a volume compensation at the flick of a switch, i just hope that a global adjustment will handle it and not make the closed loop sway to far to keep the cruising AFR's in check.

I'll update as always.

 

[JeffGST]

Speaking of getting new slugs, are you brave enough to go for 10:1 compression since you have e85 + meth

10:1 is the new 8.5:1 when using Ethanol. You would have no problem at all using 10 or even 10.5 to 1 pistons when using E-85 on the street.

Meth injection is obsolete when using E-85.

 

[turboglenn]

The only reason i won't go that high is that i want to be able to run pump gas when E85 isn't readily available, and i still want to be able to hammer on it with my pump gas map without breaking anything...10:1 would be some scary ish on pump gas and 20psi

 

[Black_Bullet]

The only reason i won't go that high is that i want to be able to run pump gas when E85 isn't readily available, and i still want to be able to hammer on it with my pump gas map without breaking anything...10:1 would be some scary ish on pump gas and 20psi

This is what I would do....


10.1 with a nice timing map and afr on e85 and whatever boost you desire.

When you run pump gas, leave your same afr and timing map on that compression ratio
but have a 2nd boost control you slap in there set for low boost like ( 12-14 psi)
therefore you shouldnt have to change tunes with boost no higher than that,
and with that tune and boost that low you should still have decent power to beat most ricers on the road anyways.
And not to mention you have meth, just use the meth for pump gas and you may still be able to get some good boost out of it with that tune.
I can imagen going up to 10:1 compression offering an addition 20-25 whp every were in your power band.

I mean are you seriously going to be driving it for performance when your on pump gas w/ e85 steadily available... Id only imagen that youd put pump gas in the car if you had to do a really long cruise or if you werent near a e85 pump at the time so you just dropped it in to make it TO the e85 tank