Hi I am nearing the end of gathering parts for my build and need input on injector sizing, motor is a darton sleeved 84x87 gsr build, 4piston gsr head and pro 2 cams and compression at 13.1:1. I'm running e85 and will occasionally be running nitrous (either a 75 or 125 shot when I do). I know with e85 fuel is increased and need help determining what cc injectors. Thanks in advance .

 

get some ID725cc or some Grams 750cc
both great injectors to work with.

 

Is 725cc enough or 1000cc on lower MDC? I'm new to e85 so, and all info I found confuses me even more or is all info on turbo cars.

 

725cc is more than enough as long as your fuel system is upgraded,the Grams or ID's work really nice with 60psi base fuel pressure.

 

i used ID1000's on my build with 60psi pressure as well. You can get the 725s, but i wanted some extra room to work with in case the setup gets more aggressive and/or Force Induction. FYI, they were at roughly 60% Duty cycle at 9000rpm with a motor making roughly 260whp.

 

That's what I was thinking my tuner said either one but if I went with 1000cc I have more room to play with if I upgrade my build even further down the road. So looks like id1000 it is, thanks guys.

 

ran ID725 and e85 on my race h23vtec. had plenty of room

 

I'm on ID1000 waiting for E85 to re-appear in the area. I'm continually increasing my base pressure. It's going to be 80PSI once I put on my new manifold. These Bosch injectors just get better as pressure increases, pump and regulators usually limit people to 70PSI though. Aeromotive gave me the go ahead for 80PSI on my Warren G so I'll see what kind of power I can scrape from it.

 

What are your power goals? You'd need to know that in order to be able to know what injector size will be best for your setup.

You can play with the numbers using our Injector Flow Calculator here: http://fuelinjectorclinic.com/flow-calculator

Using that, it shows that you can make up to 292 whp at 90% duty cycle (259 whp at 80%) on E85 using a 650cc injector: http://fuelinjectorclinic.com/d-b-h/IS115-0650H

You can make up to 348 whp at 90% duty cycle (309 whp at 80%) on E85 using a 775cc injector: http://fuelinjectorclinic.com/d-b-h/IS115-0775H

You could also go with our 900cc injector if you are looking for more headroom for the future and they will run nicely still since they are very stable, but I'm not sure you NEED that big of an injector now (unless I'm underestimating your HP potential, in which case I apologize!).

If you have other questions please feel free to give us a call at (561) 427-0082 and we'll be happy to talk to you about your setup to make sure you get the best injectors for YOU.

 

On just motor I sure be in 250-275 range and then 125 shot at times on top of that. I decided between fic 900cc or Id 1000cc. Do you have videos showing the spray pattern of your injectors? Or any info on the 900cc.? If you like I could PM my complete build sheet to you. Just let me know thanks.

 

You may know this already, but our 900cc injector is going to be directly comparable to what many other companies call a 1000, so the flow rate should be the same between the two options you listed. We just find on our flow bench under our testing conditions that this injector does not flow a true 1000cc, its closer to 900-920cc generally.

We actually do have a video about our Data Match Technology which shows various spray patterns of our injectors including the 900cc here: http://fuelinjectorclinic.com/data-match-technology

You can also learn a bit more about our Data Match Technology on that page, which is a very advanced form of injector matching not only by slope flow value but also by individual offset values as well... this data sheet that we provide with our injectors offers the most comprehensive injector data available in the industry.

Hopefully that helps, feel free to respond to this thread and we can talk more here, or you can give us a call to go over anything if you prefer.

 

That def was worth reading. What is price on your 900cc injectors for 00 civic si with gsr swap? Are they e85 compatible? And how is idle characteristics?

 

Glad you took the time to read it... a little education can be quite valuable .

All of our injectors are compatible with E85 so you will be in good shape there. These injectors should offer excellent idle and light throttle behavior which are often the more challenging areas for an injector to operate smoothly, and of course they will be on point at heavy/full throttle as well.
A set of four 900cc injectors is $409 and that includes pigtails at no additional charge.

 

I'd size injectors based on a 80% duty cycle. In all honesty modern injectors are extremely efficient and an injector being too large is really a thing of the past. When people ask what size injectors I run and I say 1000cc @ 70PSI base pressure eyes widen. I shrug my shoulders.

 

Sure, thats good advice. It makes sense to give yourself a comfortable amount of headroom, mainly to do a bit of future-proofing so if you make a bit more power in the future you can keep your same injectors. Buying a set of injectors that will put you around 80% duty cycle at your power level is usually a good way to go, but thats pretty flexible up or down really since our injectors do tune so nicely and will still operate smoothly even if they are bigger than necessary.
It all depends on what your realistic ~1 year plan is on whether its worth it to spend more money on larger injectors now or not.

 

I'm saying rather than the 90% duty cycle power levels you talked about. This is honestly ******* stupid, get some 1000cc or 900cc injectors and call it a day. It's not that hard. FIC is trying real hard to get you their business, you make judgement call on that. Me personally from experience can say that ID1000's and ID1300's perform flawlessly.

 

Haha come on now... you're the one recommending an upsell to a more expensive injector that can support over 400 whp on E85/NA. . I didn't disagree with you though, our 900cc will run very nicely even if its quite a bit larger than needed (its not my place to speak of others). Is it worth spending the extra money on though? That is up to the customer... we generally recommend that you look at your ~1 maybe 2 year plan and decide if you think you'll need more injector in that time frame.

I'm trying to educate the OP by answering his questions as factually as possible... we aim to educate first and have some great reference material on our site. If you think that my posts have been compelling then I'll take that as a compliment.


89si,
I had to correct my original post with HP quotes, I had accidentally quoted crank hp instead of wheel hp originally so I went back and fixed that. With that said I would recommend at least a 775cc injector for your setup with a comfortable amount of headroom, and of course the 900cc is also an option if you want even more room to grow.
I will also add the numbers at 80% IDC as well to that post just for your info, but of course you can play with the injector size calculator to crunch any numbers you want.

 

hes pretty much always a douchebag. dont worry about him.

 

SMH at Prelude owners. Tell Amber I said hi! Do it once, do it right. Why buy multiple sets of injectors for the same car when a larger one off the bat supports everything you might throw at it.

 

I'm pretty sure that's what FIC is speaking about. He simply said his 900cc injector should perform as well as other 1000cc injectors on the market. Why is that bad advice?