E85 general setup question

[Maxthepersonz]

Alright guys so this may be a question I already know the answer to but I just want to make sure. I'm currently running a 1G Talon TSI with a Wally 255 rewire, Aeromotive FPR, FIC 850cc injectors, DSM Link v3 full, will full supporting mods, built head, and a ported big 16g turbo, followed with full bolt ons, Speed Density etc. I want to run my car on E85 because quality 93 fuels don't seem to be as common as E85 around me..

Question is how big of injectors do I need if I am looking to get close to maxing out this turbo? I don't think the 850cc will cut it. Thanks in advanced for the awnsers. I'm thinking either 1250cc or 1000cc..

 

[ErikTande]

What's your injector duty at on gas?

 

[Maxthepersonz]

and if someone would recommend a specific set of injectors that would be great. I want to go overkill, in the future this car will get a new block and turbo with 600awhp goals.[DOUBLEPOST=1418244210][/DOUBLEPOST]If I remember it was right around 70ish percent. Which is why I will need new injectors for E85.

 

[bastarddsm]

Those 850's will get you plenty far.

 

[gofer]

You can stretch 850's to support a E3 16g on E85 by increasing your base fuel pressure.

850cc/m X 0.67 = 570cc/m (on E85)​

850's using the basic equation to figure flow on E85 become a 570cc injector with a base fuel pressure of 43.5psi. According to our sites "Injector & Fuel Pump Supported Airflow" tech article a 580cc injector (43.5psi base) can support roughly 42lbs/m @ 100% IDC. Save your money and use the injectors you have currently, kick base fuel pressure up to 55psi which will increase your injector flow rate on E85 from 570cc/m @ 43.5psi to 640cc/m @ 55psi base fuel pressure.

If you're set on getting new fuel injectors and never plan on upgrading your turbo a set of 1050cc injectors will be plenty for that setup.

 

[bastarddsm]

That seems like a low airflow amount. I was moving about 45lbs/min on 750's with 47lbs of bfp. I think I ran it a bit lean though (13:1), car ran 120mph weighing 3300, so it made decent power.

If your planning on going big I'd just run the 850's until you go big. Everyone says the big injectors don't affect driveability, but they do. It's simple math .

 

[gofer]

...I like staying conservative, especially if it isn't my DSM. ECMLink has a nice table in their Wiki section showing injector size with airflow running E85 and what you can/cannot get away with. Going off of the table, bastard, it seems that 47lbs/m is do-able with 850's. In my personal experience, I was running 950's and flowing 47lbs/m and seeing 100% IDC's (11.8:1 AFR's) so I increased bfp to 50psi to keep IDC's in the 95% range.

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[bastarddsm]

Yeah good point on being conservative. Either way I hate this "need to have 2100's for E85 on a 16g" attitude that is common. Allong with "if you go over 80% idc, your motor will blow up, and god will kill a kitten" too. .

As another point of reference, I went 107 on a china 16g and E85 with 450's. All it had was a shimmed up stock fpr to get 55-60psi bfp, and no other tuning methods. I think it could have gone faster with a real 16g, and a new fuel pump. Ran solid 13:1 AFR like that, and had the lc1 simulated nb output set to 15.5:1 and the fuel trims were almost perfect like that. Not ideal, but just showing what you can get away with.

 

[Maxthepersonz]

Thanks for all the input everyone.. Yeah I guess you can say it was more of a friend telling my "dude those 850cc won't cut it on E85" and he knows DSMs fairly well so I figured I'd need bigger. Looks like it's time to turn up the FPR and get a good tune.

I just didn't want to cut any corners and figured I'd make sure. I also am definitely planning on a bigger turbo but maybe not til a year or two down the road.

 

[Maxthepersonz]

I'm just not trying to do anything even a little bit sketchy, so If I needed bigger I'd go bigger.

 

[bastarddsm]

Run em. If you find a smoking deal on some bigger injectors go ahead. But you won't really need them untill you get a bigger turbo.