1600cc+ injectors excessive?

[cflaherty3]

I am in the market for some injectors and if I am running only race fuel and have no plans on running any kind of ethanol in the future are injectors over 1600cc just excessive? I see people like Tim running secondaries with a total of over 3000cc per cylinder it had me curious. I was looking into something like 2150s what do you think?

 

[evil tsi]

the bigger injector you run, you can run more timing/boost before seeing knock. so go big or go home

 

[Calan]

I am in the market for some injectors and if I am running only race fuel and have no plans on running any kind of ethanol in the future are injectors over 1600cc just excessive? I see people like Tim running secondaries with a total of over 3000cc per cylinder it had me curious. I was looking into something like 2150s what do you think?

What are you using to tune with, and why do you need bigger injectors?

the bigger injector you run, you can run more timing/boost before seeing knock. so go big or go home

Injectors have nothing to do with the amount of timing and boost you can run, unless they are the limiting factor in getting enough fuel to hit a target AFR.

And without a way to adjust the ECU for them, injectors that size will cause way more problems than they'll solve.

 

[cflaherty3]

I will be running an AEM ECU so there will be basically limitless tuning potential, I also am looking to be running a very large turbo either a HX52 or a Garrett GT4202R so I will need a significant amount of fuel but I want to know when a certain size just becomes a waste.

I'm in mid build so I have nothing posted on current setup but it will be a stroker with a very built head running rather large cams as well if this helps.

 

[Calan]

Depends on airflow; but if you run those turbos to their max potential, you'll probably need all the injector you can get...especially if you decide at some point to run ethanol.

Since it sounds like you're building a high-revving all-out race car (which would be the only reason for one of those turbos and a stand-alone system), you might as well go with 2150's...especially since they are known to be some of the most well-behaved large injectors out there.

No offense intended, but if you are asking this question I think you are in way over your head on building a race car.

 

[cflaherty3]

No offense intended, but if you are asking this question I think you are in way over your head on building a race car.

I really appreciate your input and constructive criticism and but I've learned a rather large amount because of people like you, but this doesn't quite make it over my head its close but that's whats making this fun and all the more rewarding when I finish it and can see this reaction from people when I put up a build thread.

 

[evil tsi]

What are you using to tune with, and why do you need bigger injectors?



Injectors have nothing to do with the amount of timing and boost you can run, unless they are the limiting factor in getting enough fuel to hit a target AFR.

And without a way to adjust the ECU for them, injectors that size will cause way more problems than they'll solve.

i beg to differ, the more fuel you have the longer the fuel burns before you see detonation. so the difference between 1600 and 2150s is pretty large. you are saying that no change in boost level from those two injectors, more timing could not be run? i disagree

 

[Calan]

I may be way off base here, but it sounds like you are kind of shotgunning this build, rather than choosing some definite power and application goals and then designing around that.

Do you have specific power goals? A detailed budget that includes cost for replacing the parts you are going to break regularly? Are you going to be tuning the car, or is a shop/team going to be doing it? Do you have a detailed parts list worked out yet?

Be sure to keep your profile updated, or post up your mod list as you finalize your decisions.

Good luck with it.

 

[cflaherty3]

Thanks! and yes I have quite the parts list racked up and no stone will be left unturned. I want a high 7 low 8 AWHP machine. There is no specific application I am building this car towards so I am doing everything possible to make it as rounded as possible in all areas, also giving me complete freedom for what ever I desire. The tuning like the machining will be left to the pros. I may sound careless in this build but there is a defined method to my madness.

 

[Calan]

i beg to differ, the more fuel you have the longer the fuel burns before you see detonation. so the difference between 1600 and 2150s is pretty large. you are saying that no change in boost level from those two injectors, more timing could not be run? i disagree

Assuming the engine mechanicals can handle the horsepower, the maximum boost and timing you can run at any given AFR is determined by:

a.) when MBT (Maximum Brake Torque) is reached, or
b.) the knock limit (which is basically a result of cylinder pressure and octane rating of the fuel)

The size of the injectors is only relevant in being able to hit the target AFR at a desired duty cycle. On a properly tuned car that is predictably hitting that targeted AFR, the size of the injectors is pretty much irrelevant, other than minor variations in how well they respond under low-load operating conditions.

On a factory (not modded) car, just dropping in injectors larger than stock with no other changes will richen the AFR, and probably allow more boost and/or timing to be run... but it's a bad idea without knowing what's really going on with the tune.

I want a high 7 low 8 AWHP machine.

Well... good luck with that. There's only been a handful of people that have hit low 8's or less in over 20 years of trying, and those cars are not "well rounded" in any sense of the word; and they have years of engineering and experience behind them. Get into the 10's first, and then work on 9's and 8's if you have tens of thousands of $$$ and lots of time on your hands.

 

[cflaherty3]

HAHA Sorry the way that was typed wasn't how I meant it to be perceived, I'm not looking for a 7 or 8 second car but a high 700 low 800 horse power car shit if it runs 10s I'll be happier than a kid with a litter of puppies.

Which don't get me wrong thats still going to be tough and luckily I have pulled a rather well paying job at such a young age so I have plenty of expendable cash (11.6k) invested already.

 

[Calan]

Ahhh... that's better then.

 

[cflaherty3]

I am inexperienced but not stupid and even though I make good money doesn't mean I'm looking to waste it. Once again thank you for the help and criticism!

 

[Calan]

Should be a good build, and sounds like you are taking the right approach. Keep us updated.

 

[twicks69]

I am in the market for some injectors and if I am running only race fuel and have no plans on running any kind of ethanol in the future are injectors over 1600cc just excessive? I see people like Tim running secondaries with a total of over 3000cc per cylinder it had me curious. I was looking into something like 2150s what do you think?

Craig, a Walbro 255HP in-tank fuel pump with a Walbro 255HP in-line fuel pump with M10x1.0mm to -6AN adaptor fittings and copper crush washers on a -6AN feed to in-line fuel filter with a 40 micron stainless filter Aeromotive ORB-10 fuel filter (P/N: 12335 - Aeromotive | 12335 - 40 Micron, ORB-10 Red Fuel Filter ) with ORB-10 to -6AN male adaptor fittings to -6AN line to your fuel rail, then -6AN line from the fuel rail to the AFPR, and sleeving the -6AN line from your AFPR onto the stock hardline return line with a Pro Clamp (P/N: 3277-6 https://www.pegasusautoracing.com/productselection.asp?Product=3277 ).

Use a set of 1350cc FIC BlueMAX fuel injectors if you are going to stick with c16/Q16/VP Import race fuels or any sort of lesser octane level. These injectors do fine with oxygenated race fuels.

This setup is dyno proven to make 835AWHP with ~88-90% duty cycles at 13.5V battery voltage.

If you want to make more down the road, either increase the base fuel pressure from 43psi up to 50psi-55psi range (this pump configuration can handle around 110psi of line pressure efficiently) to decrease your injector duty cycles, or increase fuel pump voltage with a Kenne-Bell Boost-A-Pump voltage amplifier, and a healthy alternator that can put out 13.2-14.4V battery voltage. You can always upgrade to a 150A or 200A Saturn alternator and wire its signal wire to the fuel pump power wire that runs to the fuel pump relay (SignalStat 192 relay) with 8ga power wire.

You don't need larger injectors unless you are going to be running different fuels like E85, E98, Methanol, etc.

The reason why I have so much injector on the car is to run E85, E98, and Q16/Import fuels. The super-large injectors (2000+cc) do not work well with oxygenated race fuels like Q16 or Import, so it would only allow me to run C16 or E85/E98 to get my power production.


As well, with the 1350cc injectors, you can still keep a nice fine resolution with AEM EMS of around 30uSec for mSec/Bit Fuel Trim Option, and will have plenty of room with raw fuel map values between 80-130 for the table with a hybrid boost comp map. Heck, you could easily do a 20uSec resolution if you wanted for finer resolution, but the 30uSec seems to work nicely for me with smooth stable idle on these injectors. The FIC BlueMAX 1650cc's are always an option, as I have a brand new spare set of them that I was going to use as primaries but had no time to get them on the dyno for some load testing. They idled actually better than the 1350cc's but I put them in right before the Shootout and didn't have time to tune them for load so I had a hickup that I never dealt with, so I pulled the injectors and put the 1350's back in to race the rest of the season.

The injector latency values I am using with the 1350cc BlueMax injectors are:

6V = 2550 uSec
7V = 2550 uSec
8V = 2190 uSec
9V = 1690 uSec
10V= 1380 uSec
11V= 1150 uSec
12V= 960 uSec
13V= 810 uSec
14V= 700 uSec
15V= 600 uSec
16V= 530 uSec

(This table is found under SETUP --> Injectors --> Primaries --> Battery Offset Primary Table --> Graph or Table, enter these parameters)

 

[cflaherty3]

This is exactly what I was hoping to get out of this! I have little to no availability to any variant of ethanol so for me to run that would be difficult. Now with this fuel system handle excessive boost? I would like to see boost somewhere in the low 40s psi on race days and such.

 

[SHEARER_TSI]

Not sure if this was mentioned yet but if you plan on running an oxygenated fuel you will NOT want fic blue max ( like 2150's) or ID 2000's because they can not be used with those types of fuels.

 

[twicks69]

Not sure if this was mentioned yet but if you plan on running an oxygenated fuel you will NOT want fic blue max ( like 2150's) or ID 2000's because they can not be used with those types of fuels.

Yup, see post #15.