Hello,
Everyone can see my mods in my signature below. I currently drive only on 100 octane with the following general settings: 23 to 24psi max boost; ~11.9 to 12.0 max afr on my Zietronix wideband during WOT pulls, and 12 to 15 degrees max timing.

In EcuFlash, my Injector Scaling is set at 860. I use RC 1000cc injectors, have two in-line Walbro fuel pumps, an adjustable fuel pressure regulator, and an AMS fuel rail.

So, the big question: If I'm flat out of gas, pull up to an E85 pump and "fillerup" to the top, can't I just reset my injector scaling downward 33% to add the needed fuel?

860 - 33% = 576.2

So, type in 576 in my Injector Scaling table, flash it in, and drive away?? Shouldn't it drive fine? Next step (in my mind) would be to carefully log and adjust, of course, but if I'm not racing around, shouldn't I be fine until then?

 

Your gonna need 30% more fuel not 30% less I think your going to have to get 1200cc injectors

 

you need to add about 30% more fuel

 

GT40 on socalevo max out his 1000cc injectors at 25psi on his 2.4L gt35r setup.... So, watch your IDC's carefully

 

Smoggy,

You are right in that you lower your global for the added volume of e85. I run from around 914 scaling to a 640 (been a while but this is close)

The concern is your idc's will go up a relative amount due to the 30% added fuel requirement. Sounds like your Fuel pumps could push the right amount of fuel but your injectors might (will probably) max out with your setup. on initial fillup with e85 I sat there watching my afr's when they started to go lean from 91 map on e85 I knew it was time to flash the e85 map. the car ran poorly until the more pure e85 came on. be advised that your second tank of e85 will require slightly different scaling possibly due to the absence of the remaining gas left when starting off on e85 for the first time.

I would turn down the boost with your setup and watch IDC's my guess is you will prolly need at least 1200cc injectors with your setup. I'm only putting down around 350whp and my 1000's are right around 70% if it is linear that puts my 1000's maxing out at around 440 hp. I use FIC's and supposedly they are known to flow more than RC's and these numbers are just linear guesstimates.

Good Luck man

 

That will get you close enough for daily driving, but don't got WOT. Those RC1000s are not nearly large enough for your mods. My FIC 1050s scale to 680 on E85, and they run up to 70% IDC with just a stock turbo, TBE, 24 psi, 11.5:1 afr (pump gas conversion). 500 whp/300 whp = 1.67 which means that you'll need 1600 cc/min injectors to maintain 70% IDC with the same power levels as pump gas. If you aim for another 100 whp, you'll be hitting something like 85% IDC which is a very safe IDC. I think the next step down is 1200 cc/min, but that will be too small.

 

Smaller scaling adds fuel by the way You are right about the 1200 though

 

Im gettin 1000cc injectors for my stock turbo and like Mrfred said he'll prolly even need bigger then 1200cc injectors.

 

I agree that my injectors will be my limiting factor, no argument there. But I'm willing to bet that I'll be able to safely run around at 500whp (around where I'm at now on 100octane) and even a bit more. But I'll be VERY careful with logging while getting there.

I hate playing with my adjustable fuel pressure regulator, but I can get a little more out of my injectors if I go from 43psi (stock) to 50+. The only downside is that then I have to change it back to 43 when I reflash back to my 100octane unleaded tune. Not a huge deal, but the less tinkering, the better.

Also, I'm generally more aggresive at pushing injectors to their limits than many on this forum. I know how to spot when injectors are maxing out and will make sure there is a margin of safety. Many on this forum and others trust math formulas and estimates rather than the real limit of injectors. Over the years, I seen these estimates turn out to be consistently overly-conservative. I've seen stock injectored Evo 8s running safely for years with 370+whp/wtq while everyone screams that you need bigger injectors. I've seen a 3076 on an Evo making 495whp with Denso 660s. It was driven and flogged daily without issue for over a year, before the owner crashed it. My car my 584whp/527wtq with 880s and a single in tank walbro. I'm still on that same engine. There's 3 out of many examples I could use, but all of these would have magically shown that their idc was over 100%, but all ran fine over time.

Don't misread what I'm saying though. I'll be very safe while logging and dynoing. I just believe that there is more headroom in injectors than the conventional wisdom around here dictates.

 

Why not tune your pump map to 50 psi as well rather than move it back and forth? Just a thought for the future

PS I would not get on it until after you check trims for STFT by idling the 15 or so minutes it takes to get a reading and adjusting your global accordingly. Actually I drove around and kept it under 4k rpm's and watched the AFR's like a hawk

Good Luck man

 

Please do not give the wrong advice. You lower the injector scaling and this adds more fuel. Smoggrunner got it right the first time.

 

Keep in mind that the way Evoscan logs IDC is off by about 10% points. So when you are at 100% IDC, you still have about 10% to go. I have noticed that the AFR goes lean and cannot be richened up once IDCs hit 110% at the top end.

 

You will need to change the latencies of the injectors when you convert over.

 

I don't. All I change is injector scaling. My trims are perfect for both pump gas and E85.

smoggy: 500 whp will be pretty close to the limit of those RC1000 injectors. I think Lucas was running around 500 whp with 1000s for a while. The engine was jetted pretty lean though, I think around 12.5:1, and with a stock turbo, peak HP earlier in the rpms, so there is more time to inject fuel.

 

I read this somewhere else, but I can't understand why. Are you sure?