what size fuel injectors are on your boosted efi engine??

8552 Views 34 Replies 8 Participants Last post by ap67et10, Jul 24, 2009

ap67et10

Discussion Starter · Jul 17, 2009

Im in the process of building my procharged efi deal for my boat. i have a really good idea what size injectors i am planning on running, but am curious to see what other people have done. what size injectors are you running? do you only have 8? what kind of low rpm/idle characteristics are you seeing? how much fuel pressure? and what kind of duty cycle at full boost? and what is the setup you have?

i'm just trying to get a better idea of, if it would be worth running smaller injectors and adding 2 in the plenum for full throttle, or if i should just go with all 8 fully capable of handling the power i am expecting.

thanks, AP

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Unchained

· #2 · Jul 18, 2009

I run eight 160# injectors @ 45 psi on E85.
Same injectors I started with 7 seasons ago.
Motor starts in 1/2 revolution and idles smooth.
Size the injectors larger than the most hp you would ever need to run.

I just tuned a FAST XFI Procharged engine in a 25 Daytona and he used eight 120# injectors for 10# boost on E85. Starts good and idles smooth at 850 rpm.

No need to used any staged injector setup.
Good deals on injectors on ebay or yellowbullet.com

steveo143

· #3 · Jul 18, 2009

Hey Mark, I am about to get an intake made for my deal. I thought you said in another thread that those 160's were at 100% duty cycle. I was planning on making the intake to accept 16 injectors. 622 cu. BBC, 2 Y2K 91's, Fast EFI, 16 160# injectors on E85, Lee intercooler. What do you think?

Outlaw

· #4 · Jul 18, 2009

Mark, is your fuel pressure at 45 all the time?
I mean your not boost referencing your regulator are you?

sorry for the jack
I've got 8 95 lb injectors BTW but have not ran it yet.

ap67et10

Discussion Starter · #5 · Jul 18, 2009

Unchained said:
I run eight 160# injectors @ 45 psi on E85.
Same injectors I started with 7 seasons ago.
Motor starts in 1/2 revolution and idles smooth.
Size the injectors larger than the most hp you would ever need to run.

I just tuned a FAST XFI Procharged engine in a 25 Daytona and he used eight 120# injectors for 10# boost on E85. Starts good and idles smooth at 850 rpm.

No need to used any staged injector setup.
Good deals on injectors on ebay or yellowbullet.com

man i wish i could get E85 out here!! I would be all over this if i could get this stuff. would work way better for how much static c/r ill be running. i'll probably have to downsize the pulleys because i'll end up making too much boost with the pulleys that came with my blower but i don't want to run straight race fuel. but E85 would make it all better!! oh well.

how much more do you factor in for the E85? I know it requires a considerable amount of fuel compared to regular gas. what injectors would you be running if you ran race gas?

how much boost are you running? and do you happen to know about how much power you are making....if you want to tell everyone.

Thats great info on the injectors, thanks..i'll be looking around as i will need to pic them up soon. what kind of injectors are you running?

AP

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Unchained

· #6 · Jul 18, 2009 (Edited)

ap67et10 said:
how much more do you factor in for the E85? I know it requires a considerable amount of fuel compared to regular gas. what injectors would you be running if you ran race gas?

how much boost are you running? and do you happen to know about how much power you are making....if you want to tell everyone.

Thats great info on the injectors, thanks..i'll be looking around as i will need to pic them up soon. what kind of injectors are you running?

AP

I've had boost control issues all year and haven't got it where I want it yet.
With 60 mm wastegates wide open I was able to get it down to a mere 27# from the 30# it first went to.

That's where the injectors went to 100% DC and it bent the prop. It's running closed loop so it just adds as much fuel as it can.
I hate to put out HP estimates because everyone gets their panties all bunched up over that but 100% DC on E85 is around 1900 hp and it was a lean mixture at that. Good thing I only did a 2 second blast the first time. The engine has held up real good for all the overboosting this year.

sphss
It's been on the rev limiter at 7800 rpm so many times I lost count.

E85 takes 28% - 30% more fuel than gas. It's $ 2.29 / gal here.

I run 45# base fuel pressure. Vaccum reduces that to 42# and boost adds pressure pound for pound.

The injectors I have are green on top and say fomoco on the side.

Steveo, it sounds like a good package but I can't understand using 16 injectors. What are you trying to achieve, 3000 hp ? Can the rest of the package take that ?
I can email you my FAST fuel maps for a 3 bar MAP sensor. It should be pretty close for eight 160# injectors.

Everyone always talks about how much HP they want to make and how fast they want to go but once you get there you find it's a scary parts breaker and dangerous to drive around in. I just want to level off at 15 - 20# boost and call it good enough.

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steveo143

· #7 · Jul 18, 2009

Thanks for the clarification Mark. I don't want to run more than 8 injectors if I don't have to. Would love to be able to use 8 160's @ around $500.00, the 220's are about double in price. I am aiming for 2500hp and the rest of the boat will be able to take it. I will gear the v-drive to keep max rpm around 6200.

twntrbo

· #8 · Jul 18, 2009

ap67et10 said:
Im in the process of building my procharged efi deal for my boat. i have a really good idea what size injectors i am planning on running, but am curious to see what other people have done. what size injectors are you running? do you only have 8? what kind of low rpm/idle characteristics are you seeing? how much fuel pressure? and what kind of duty cycle at full boost? and what is the setup you have?

i'm just trying to get a better idea of, if it would be worth running smaller injectors and adding 2 in the plenum for full throttle, or if i should just go with all 8 fully capable of handling the power i am expecting.

thanks, AP

I have a 540 with twin garrett 4788's with 2 spearco 1000 hp intercoolers side by side.Bosch 160 lb injectors,45 psi @ idle.
I calculated that @ 2000 hp i'll be @ 88% duty cycle using a middle of the road .057 for the BSFC.

We need some lots of pictures of your boat and motor.

ap67et10

Discussion Starter · #9 · Jul 18, 2009

twntrbo said:
I have a 540 with twin garrett 4788's with 2 spearco 1000 hp intercoolers side by side.Bosch 160 lb injectors,45 psi @ idle.
I calculated that @ 2000 hp i'll be @ 88% duty cycle using a middle of the road .057 for the BSFC.

We need some lots of pictures of your boat and motor.

what kind of fuel are you running? thats some major hp right there. let see some pics of the setup.

i'm in the process of putting the engine together now. should have the block, heads, and rotating assembly back from the balancer and machine shop. but its a 502 bbc, gen4 bowtie tall deck block, pro crank billet 4.0 crank, carrillo rods, je pistons. i have a set of heavily ported (will know the flow numbers this next week) 990's, holley efi intake with 4500 flange and holley 2000 cfm throttle. the real power comes from the F2 procharger i'll be tossin on it. right now its set to put about 14-16lbs of boost at 6000rpm with the engine, but that is what procharger told me. we'll see what it really does. I think it should be around 1100 hp. I was thinking i would run 95lb injectors, which should be plenty for my setup...at least from the number i have run.

AP

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twntrbo

· #10 · Jul 19, 2009

I guess i should clear up my previous post.I used 2000 hp for the calculation for the duty cycle %.I'm only running 9#'s of boost right now on pump gas and i don't have the fuel pump to get me their.Doesn't sound like much but with a light boat it's really quick.With my combo i make 100 hp for every # of boost,i'm guessing you could make 1200 to 1300 hp on pump gas easy with a 622 and 91mm ers.
Are you using the FAST system now?

s2k1

· #11 · Jul 20, 2009

ap67et10 said:
man i wish i could get E85 out here!! I would be all over this if i could get this stuff. AP

Where are you located?
We buy E85 from Pearson Fuels in San Diego area.

s2k1

· #12 · Jul 20, 2009

steveo143 said:
Thanks for the clarification Mark. I don't want to run more than 8 injectors if I don't have to. Would love to be able to use 8 160's @ around $500.00, the 220's are about double in price. I am aiming for 2500hp and the rest of the boat will be able to take it. I will gear the v-drive to keep max rpm around 6200.

You can also run higher base fuel pressure instead of going with a bigger injector. I run 160 lb injectors on boosted engines at 60 psi base all the time with no problems. You can obviously do this with other injectors too.

Unchained

· #13 · Jul 20, 2009

s2k1 said:
You can also run higher base fuel pressure instead of going with a bigger injector. I run 160 lb injectors on boosted engines at 60 psi base all the time with no problems. You can obviously do this with other injectors too.

Does the higher pressure compromise your idle quality any ?

ap67et10

Discussion Starter · #14 · Jul 20, 2009

s2k1 said:
Where are you located?
We buy E85 from Pearson Fuels in San Diego area.

I live in claremont, but I keep my boat up in the central california, fresno area. I searched for placed to get E85 and only found 1 place in LA area and 1 place in Tulare which is about an hour or so from fresno. Other than that, I can't find any other place to get this stuff. My engine i'm building will be going into my Sanger Mini Cruiser, so its not a super hot rod or anything, its a bigger mini cruiser that won't be setting any speed records, just hoping to catch some average lake hot rods off gaurd and have a little fun with a total sleeper. The majority of my boating will be cruising, skiing and an occasional hot lap (I'm known for driving like a grandma...I don't like my dad driving my boat because he has a lead foot). So if I can't get it easily I don't think its going to be worth it for me. I'd be better off running an alcohol or methonal injection on a race fuel blend. i can just get a 50gal drum or av or race fuel if i'm only mixing a 1/4 to 1/2 with pump gas. it will last me a good amount of time that way. i will probably also get some diff. pulleys to run lower boost for straight pump gas.

however its just slightly depressing to think that if we had it here, i could just pump E85 right into the tanks and run all the boost I want.

AP

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ap67et10

Discussion Starter · #15 · Jul 20, 2009

Unchained said:
Does the higher pressure compromise your idle quality any ?

I don't have any first hand experience of drastically changing the base fuel pressure, however i have been factoring that in with deciding my injector sizing. When i think about it, it doesn't seem like there would be any reason it would change idle quality. if anything I would think it would be better, but i have no experience with this and could be way off.

I do want to say that i read somewhere that (don't quote me on this) steve morris was doing some efi setups with inline aeromotive pumps running around 110-120 psi fuel pressure on some big power procharged deals. This is just something i thought i remember reading. maybe you guys might know if i'm off on this.

One other questions i want to run by you guys is: On my holley setup, i'm planning to run the rails that holley has, but with different connecting hose and regulator but; was inside fuel rail diameter an issue for any of you guys? do you know what your fuel rail inside diameter is? I was thinking mine should be good, but wasn't too sure, its 1/2 inch.

AP

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s2k1

· #16 · Jul 20, 2009

Unchained said:
Does the higher pressure compromise your idle quality any ?

No, idle is OK. But, I mainly use one brand of ECU, Autronic. They (Autronic) claim to be fantastic at controlling huge injectors on small engines. I have never done any back to back testing with another brand of ECU.

78DiMarco

· #17 · Jul 20, 2009

Injectors

I run 96# injectors with about 17-18 pounds of boost on a 509BBC twin turbo. It maps out fine after we tuned it on the water. On the dyno at 11 pounds it made about 1000hp.

Good luck with your project.

ap67et10

Discussion Starter · #18 · Jul 20, 2009

78DiMarco said:
I run 96# injectors with about 17-18 pounds of boost on a 509BBC twin turbo. It maps out fine after we tuned it on the water. On the dyno at 11 pounds it made about 1000hp.

Good luck with your project.

when you run 17-18 psi what kind of fuel are you running? what is your static c/r? that sounds like a nice setup. what fuel management setup are you running? this sounds real similar to what im expecting power wise.

AP

twntrbo

· #19 · Jul 20, 2009

78DiMarco said:
I run 96# injectors with about 17-18 pounds of boost on a 509BBC twin turbo. It maps out fine after we tuned it on the water. On the dyno at 11 pounds it made about 1000hp.

Good luck with your project.

sounds like a nice set up,what size turbos?

ap67et10

Discussion Starter · #20 · Jul 21, 2009

78DiMarco said:
I run 96# injectors with about 17-18 pounds of boost on a 509BBC twin turbo. It maps out fine after we tuned it on the water. On the dyno at 11 pounds it made about 1000hp.

Good luck with your project.

you must be running delfi injectors then right? I haven't found any others that are 96lb.

AP

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