vxturboxv

iTrader: (2)

I’d like to start running E85 in my FD. We don’t have 93 octane here in KS and the 91 is horrible. Had nothing but bad luck with it on my turbo cars. I’ve converted all my turbo toys to run it.

Got a basically bone stock FD. Will be installing a 450lph walbro intank pump. And an adjustable fuel pressure regulator. From personal experiance and what I’ve read you need roughly 30% more fuel for E85.
Heres my quick break down…

If the OEM injectors flow 550/850cc at the stock 38psi. A 30% increase in injector size would be 715/1105cc. The OEM injectors should flow slightly more than 30% at 65psi base pressure. With the stock 10psi of boost total pressure is still well within a safe range at 75psi total. And that should Maintain the overly rich stock ECM AFR ratios. Then if I wanted to run pump gas I could just drop the base pressure down to 38 again.

And before people flip about 75psi of pressure do some reading. Its not a problem for the stock injectors or the walbro 450 fuel pump. Factory steel lines can more than handle it. Friends running upwards of 95psi of fuel pressure in boost for years with no problems.

Any massive holes in my idea here I’m missing? I’d run some sort of top lube with the e85 as well. Suggestions?

Eventually the plan is to run 750cc injectors and 1200cc injectors to keep the close to factory split. Then run an apexi Fc ECU and max out the stock turbos on e85.

fendamonky

iTrader: (6)

I'm pretty positive the stock injectors CAN NOT flow enough to provide adequate amounts of E85, no matter how much you turn up the base pressure.

Not to mention the fact that as you increase the fuel pressure you're actually decreasing the total amount of fuel flow your pump can push.

So what you're suggesting looks like a lose/lose situation..

If you wanna run E85 than just get the right sized injectors and run your pump at a lower pressure.

vxturboxv

iTrader: (2)

No offense, but you sound like an ignorant person on this matter. It’s fact that the injectors will flow 30% more than stock at the pressures I stated. So if 30% extra fuel is whats needed they WILL flow enough. It’s simple math.

Yes, obviously the pumps volume will decrease with pressure. The 450 will more than provide enough fuel volume at 75 psi for 10lbs on a stock Rx7... As I said in my first post.

Here is the 450 flow chart

dguy

iTrader: (8)

No offense, but you sound like you've already made your decision and are just fishing for compliments. Personally I haven't heard if anybody has done any research on whether or not the stock side feeds are happy with e85 running through them for long periods of time. Do whatever you want, I don't know if you're really open to opinions on the matter.

-David Guy

vxturboxv

iTrader: (2)

Not true. I'm open to discuss any educated opinions with people that have had experience with the subject matter. That is the purpose of a technical forum right?

Not sure why someone with no knowledge or experience on the subject takes it upon themselves to post opinions and hearsay "BS" in my thread. I'm not interested in what someones heard or guess to be true of false.

And FWIW E85 won't hurt your OEM injectors...

RENESISFD

iTrader: (13)

If you are using a stock ECU it will not work. The relationship between fuel required at part throttle and full load is different; it is not a linear 30% increase across the fuel map. There will be horrible drivability issues when you tune it to run the AFR's needed to keep your engine from blowing at full load.

Programmable ECU and bored out secondaries is the safer, smarter decision if you want to just run stock boost levels.

Copeland

iTrader: (42)

This sounds like a terrible idea but in for entertainment.

vxturboxv

iTrader: (2)

What experiance do you have with the matter to claim it won't work?

Of course it’s not linear the OEM map and ECU isn’t linear either. If your cruise cell value is 5 it will be 30% richer than 5 at cruise. If this is a little on the fat side in closed loop, the ECU *should* be able to trim the map via the 02 sensor. If your WOT cell us 50.. It will be 30% richer than 50 with the added pressure. I don’t think it will be as difficult as you think, but I haven’t tried it on an FD so I'm not claiming I know.

I’ve done almost the same thing on my daily driver. I swapped my 440cc injectors on my daily out for 1000cc injectors. Adjusted my WOT AFR’s with fuel pressure alone. Stock Ecu, stock boost, stock timing. Cruised and idled in the 14's and WOT afr's were in the low 11's. The car ran great. (turbo talon). Adjusting the pressure to the injectors in no different than adding larger injectors. Engine doesn’t know the difference. The only difference being that you couldn’t drop the pressure back down to normal to run pump gas.

Pointless for me to argue the point now. The 60k original mile FD I was on the way to buy this weekend had low compression on the front rotor. So I won’t be an FD owner… guess I’ll never know.

fendamonky

iTrader: (6)

Probably for the best... I'm sure your mindset of "wanting to take the wrong tools for the job, but tweaking them enough to kinda work out" fits in fine in the FC/240/DSM crowd.. but we tend to frown on people wanting to cut corners because they'd rather just force the wrong things to work, as opposed to putting in the initial work to get the right things from the get-go.

vxturboxv

iTrader: (2)

Yup, you got me. Get you another Turbo magazine and troll on the forums a bit more… Buy what the vendors tell you to and jump on the band wagon with the rest of the monkeys.

I build and race all my own cars. Their performance speaks for itself.

fendamonky

iTrader: (6)

Yes, you live your life 10 seconds at a time, we get it..




Obviously you're a competent engine builder, in fact probably the ONLY person here who builds their own engines Too bad some low compression made you balk from your purchase. Approx $1,000 in rebuild bits (hard/soft seals) plus a week or two of work (assuming you clean and clearance everything in your spare time) to break the engine apart, clean, and re-stack it is def NOT worth it for an otherwise low(ish) mileage car


It's cool dude, you've got a HUGE e-peen, I'll acknowledge to your superiority I'll go ahead and step away from this thread, get your bitingly witty last word in and feel good about yourself knowing that you "won" the internets.

vxturboxv

iTrader: (2)

I wasn't intimidated by the engine needing rebuilt, just with the price the rotard was asking for it in it's current condition.

Never claimed I was the only person who worked on his own car either. I pointed out that it's likely YOU don't work on your own car since you can't even grasp the basic general knowledge of how a fuel system works.

Take your slow little riced out rx7 driving self out of my thread and go talk to some other magazine fanboy "tuners". Your ignorance isn't needed here.

Speed of light

iTrader: (8)

I'm glad to see someone thinking outside the box, regardless of practicality. For years, I've taken pride in successfully doing what couldn't be done--according to the nay sayers.

Narfle

iTrader: (16)

If bumping the base pressure made the injectors reliably output more fuel than they were intended for, we'd all be running stock injectors out to 20psi.

The correct answer to get a standalone, as well as prep the entire fueling system for e85.
This is how we modify our engines to run more/different fuel, reliably.

fendamonky

iTrader: (6)

I wouldn't bother trying to explain reason to 'ole Kleetus up there... He's got his mind set on what he "knows" and isn't likely to listen to anything else. Unless he just feels like hurling some ignorantly mis-informed insults in reply.. lol

gsxrjjordan

Bumping base pressure certainly increases flow, it's a band aid, but it works and you can tune around it.

Problem is, stoich with E85 is far different than stoich for gasoline, so yes you'll need a standalone and some tuning. Not to mention that if you don't tune for extra boost (and especially timing), you'll make far less power on E85 than pump gas.

Stock turbos, stock injectors, stock ECU = stay on pump gas.

vxturboxv

iTrader: (2)

If you have a capable fuel system to handle the extra pressure it is no different than adding larger injectors. If you want to call that a Band-Aid I suppose your entitled to your opinion. It is common place these days. We are pushing 80lb injectors on E85 to 96+psi and making over 1000hp with them on LS motors. This is also done through OEM rails and 3/8 steel hard lines. Just because it isn't common place in the mazda crowd doesn't mean it won't work or that it's a Band-Aid. I'm also not claiming after market larger injectors, huge supply lines and rails wont' do the same thing. It will cost you more however.


Huh? The sensor itself doesn't know the difference in the fuels. On your typical gas scaled WB02 gauge you shoot for the same AFR's running E85 that you do when running gas. 14.7 indicated on the gauge with either fuel will be stoich. The mixture in the CC is what's different. Same goes for the factory 02 sensor when it trims the cruise maps in closed loop.

dguy

iTrader: (8)

Forgot I had posted in this thread. I'm confused as to why you're opposed to doing the job properly. There are a few giant flaws in your logic:

First, the standard single wire O2 sensor is only used in closed loop, which is going to be (if I recall) at idle, below ~3400 rpm in steady state, and only in gears 1-4 not to mention how notoriously poor the actual readings are.

Second, proper transient throttle response on a rotary is key. Of the piston motors I've tuned I noticed I could be somewhat sloppy with high load transients however on a 13b not so, boom. You will NOT be able to trim these properly on E85 without at least a PFC.

Third, timing? You're not going to benefit from the awesome cooling aspect of E85 without more, your MBT will be WAY different.

Fourth, I was more concerned with the rubber orings on the side feeds. I'm pretty sure that Buna-N is what they're made from, Buna-N doesn't like E85. At all.

Fifth, a 13b is not a GN engine. As you well know GN and T-Type engines are freaks of nature in the 'badass from the factory' department.

I could go on and on. There are a bunch of things that you're not taking into account, and I'm flabbergasted as to why you wont just drop the 600 for a PFC (even though in my opinion they're pieces of ****, but at least you get enough control for what you're doing).