E85 Tuning Gurus - Please Help

So I have been tuning for a few years now and I think I understand the ins and outs of tuning pretty well. I have read up on E85, but it has thrown me a little for a loop when it comes to Maf g/sec vs Fueling.

My mods:

Vf43

Standard Stage 2 gear

X02 FMIC

DW740s

AVO fuel pump

AEM CAI

Using a very solid 93 octane tune, I converted to E85 last weekend. I multiplied my injector scaler (740 cc) by 0.70 and the car started up instantly and is running pretty well. After a few minutes, as expected, my fuel trims went wonky.

- They were at -15% at idle and my WOT runs were way rich from 2500-4500 RPM, 9.8-10.1 AFR vs my 12:1 target.

- At about 5,000-5,500 RPM - redline my injectors just ran out of fuel (I think) in which case they started to go lean (11.7-11.9 afr vs my 11.1 target).

Luckly E85 is pretty knock resistant and that lean mixture is fine. I have added timing (no additional boost yet) and made about 30 more HP on airboys sheet, but I want to address the rich condition at the midrange RPM before doing anything else..

So I am at a cross roads, I think the next step is either increase the injector scaler or rescale the maf. What should I do?!

Some logs:

romraiderlog_20110322_220011.csv

romraiderlog_20110322_230416.csv

You think you ran out of fuel, you did, IDC was at 112%!

So turn down the boost up top or get bigger injectors.

As far going too rich everywhere else, maybe multiply it by a bit less then 30%.

^ I wasn't sure if the 112% was a result of my injector scaler being about 518cc/min and my ECU "thinking" it was out of fuel or if i really was! I still have not wrapped my head around it frankly. If the ECU thinks the size of the injectors is 518 cc's wouldn;t my IDC show 100%+ even though there is more capacity?

Can't turn down the boost much more..major creep in the cold. Should be fine for the summer months.

EDIT: oops...meant 518 cc

I would do the following in this order:

1) Get bigger injectors - otherwise you are limiting your power and you don't want to constantly worry about lean conditions up top. I wouldn't waste any time tweaking the tune because you'll just need to do a lot of it over once you upgrade injectors. 850's are probably enough.

2) Re-scale the MAF - maybe it's close but since you're making more power you are seeing new parts of the MAF scale. As you scale the new MAFv's, also re-scale the mid-range.

3) Get back to the tune. Post logs here. I'm sure there are several people that would offer to help but right now any tune would be a "band-aid" working around funky MAF scaling and limiting injectors.

1) Get bigger injectors - otherwise you are limiting your power and you don't want to constantly worry about lean conditions up top. I wouldn't waste any time tweaking the tune because you'll just need to do a lot of it over once you upgrade injectors. 850's are probably enough.

Yes, but I would get ID880s.......... er ID1000s They tune nicer then DW850s.

2) Re-scale the MAF - maybe it's close but since you're making more power you are seeing new parts of the MAF scale. As you scale the new MAFv's, also re-scale the mid-range.

I doubt he is hitting higher voltage. He has already run his turbo all out in the cold. If you were tuning on E10 before, then E85 is not as far off as it normally would be. (not much difference, but a bit)

3) Get back to the tune. Post logs here. I'm sure there are several people that would offer to help but right now any tune would be a "band-aid" working around funky MAF scaling and limiting injectors.

I wonder if latency wasn't quite 100% before, the MAF was scaled around it, and now it shows farther off in the low V range (like 1.2-1.4 volts or so)?

I gotta save up for the injectors...will look into the IDs. In the mean time, I will play with the scaler in an attempt to get it close to the midrange targets. High end is ok at 11.7, besides I only drive on the weekends, and rarely without logging it. so monitoring it will not be a problem.

I am hitting slightly higher MafV on other E85 logs... 4.66v max vs 4.60v on pump. Airboys sheet is showing a 30 whp jump in power despite the slightly warmer temps.

I used the stock latency numbers with the DWs. The rest was basic maf scaling...I used RR maf tool for the closed loop stuff and open loop fueling spreadsheet that is posted on RR forums for the rest. Using airboys sheet I graphed target vs actual afr and it was always very close.

Thanks for all the knowledge guys.

The rest was basic maf scaling...I used RR maf tool for the closed loop stuff and open loop fueling spreadsheet that is posted on RR forums for the rest. Using airboys sheet I graphed target vs actual afr and it was always very close.

I don't know if the RR tool is that great. I'd use a different method. There are several. But you are on the right track... I want my observed WB02 values to be the same as what my map is calling for.. bottom line. I start with a flat AFR (like 0.80 lambda) and adjust my scaling from there.

I wonder if witchhunter can just mod your existing injectors, clean 'em, and give you flow sheets. But LBGT had a disaster with modded injectors so don't know I'd recommend that.. and supposedly PE850's are the devil but they've been fine for me [insert injector debate here]. I wouldn't look for PE850's though because I really think there are a couple variants of them.. and mine are obviously fine but there might be a legitimate problem with some of them(?) That's what the interweb sez anyhow.

^ I wasn't sure if the 112% was a result of my injector scaler being about 518cc/min and my ECU "thinking" it was out of fuel or if i really was! I still have not wrapped my head around it frankly. If the ECU thinks the size of the injectors is 518 cc's wouldn;t my IDC show 100%+ even though there is more capacity?

Nope... Injector duty cycle is the ratio between the injector pulse width and the time between ignition events.

Bigger injectors reduce IDC by reducing the pulse width.

So I leaned out the midrange successfully...now my stock clutch said see ya later at around 4,000rpm in 3rd! Looks like I will be swapping injectors and a clutch.

:lol: Typical E85 stuff.

Yeah E85 is pretty effective at doing that

Any reason you don't want to go with an ACT setup for the clutch?

We've had some trouble dealing with Witch Hunter in the past.. and they say they aren't going to mod Subaru injectors anymore.

ID1000's or Deatschwerks have worked better overall.

No specific reason for choosing CM over ACT. I had run a CM clutch on my turbod civic a loooong time ago and I was happy. Based on the reviews I have read on the FX300, I get a clutch with very close to stock clutch stiffness (some say it is less stiff than stock) and drivability with a ton more holding power.

I am leaning towards DW850s right now, price is right.

No specific reason for choosing CM over ACT. I had run a CM clutch on my turbod civic a loooong time ago and I was happy. Based on the reviews I have read on the FX300, I get a clutch with very close to stock clutch stiffness (some say it is less stiff than stock) and drivability with a ton more holding power.

 

I am leaning towards DW850s right now, price is right.

As for clutch, I would (and did) have gone with the ACT also. Proven performer... don't know much about this other one.

As for injectors, I'd probably go with the same.

I have the fx300 in my car now and really like it. I have driven cars with both and my preference is the fx300 but you can't go wrong with either. I haven't heard anyone having any of the drivetrain noises with the cm as well which is a big plus.

Dave

I am leaning towards DW850s right now, price is right.

I have three times now had some sort of fueling inconsistency with the DW850s in side-feed format. It is not the injectors fault, but rather some combo of the injectors and fuel rail. I think there is some sort of resonance, it causes things to go lean. NSFW had the problem with some other brand injector which was also about 850 cc/min and our side-feed rails.

On one 04 STI we put in Perrin fuel rails, and the problem went away, and fueling was then very consistent. In fact, very very consistent.

But by the time you get new rails, you may as well have just gotten the ID1000s.

Search a bit before you buy. I just like to recommend what I know works well with less possibility of problems.

I have the fx300 in my car now and really like it. I have driven cars with both and my preference is the fx300 but you can't go wrong with either. I haven't heard anyone having any of the drivetrain noises with the cm as well which is a big plus.

I didn't know you had that setup, Dave. I'll consider the fx300 next time around. 22k on my ACT right now...

It seems like there is really a hole in the market for medium-big reliable sidefeeds with a good reputation. I'll give you my PE870 (errr PE850 ) E85 latencies and scalar if you go that route... you'd get a bit more headroom vs. other 850's... but I'll warn you that the only LGT aftermarket part with a worse reputation is the SPT intake.

Quick update:

Had the FX300/WRX FW/TSK3/Group N Tranny bushings installed. So far really, really happy with the drivability/feel of this setup. Still breaking it in, but my initial thoughts are that clutch wieght is actually softer/lighter than stock and engagement is clearly meatier (not an on/off feeling). With the stock clutch I would get some chattering when starting from a stop on a hill. With this clutch, it is all very, very smooth...not sure if it is a result of the bushing or the clutch/flywheel. I have no odd noises or any drivability problems, NVH is exactly as stock IMO. Any recomendations on break in? I am pretty much babying it, no WOT, no quick takeoffs from a stop, no high RPM downshifting.

Also, cheaped out and got the DW 850 (sorry LBGT!), waiting to break in the clutch before installing and tuning them.