BOTTLE ROCKET

iTrader: (4)

Are there any style/brand injectors that are difficult to "dial in" on a modded motor. While searching, I keep seeing guys mention certain injectors are not in the table, adn thus, are hard to tune.
Any to stay away from?

CLRD4TO

iTrader: (4)

A better question to ask is, I need XX size injector, what brand should I go with? I had problems tuning my green tops when many people had no problems at all. In my searching I found that people where having identical problems with other injectors too. I suggest to find the size you need and search the hell out of it. Its tough getting answers to questions that have been answered before.

BOTTLE ROCKET

iTrader: (4)

I've easily read 100+ post on the subject and there doesn't seem to be a concrete answer. Some say simply use the size calculator (I have), then buy any brand you like, and tune away, others say only specific "types" are easy to tune, and others require extensive tuning time

other opinions......
NEVER buy used injectors
Never buy rebuilt injectors
Only buy stock style injector
The disc style are superior
Etc, etc.,,,,,,,,,,,,,,

SSpdDmon

iTrader: (10)

You need to take a step back and figure out what your particular application needs and then we can help answer your questions around which ones you should buy. If you're running a few bolt-ons or even a mild cam, then the answer may be a stock injector is fine. If you're running 10psi of boost, then you're going to need at least a 60# injector. There's a difference...

crainholio

iTrader: (2)

The engine & mods are not relevant to injector tuning.

The injectors are tuned in the Inj Flow Rate, Offset, Short Pulse Adder, and Short Pulse Limit tables/values. Doesn't matter whether they are going on a supercharged 7.0L or stock 5.7L, or anything in between...for a given set of injectors their values will be identical regardless of the engine platform.

The engine is tuned in the VE, PE, and spark tables.

Changing injector values to tune for a cam, intake, exhaust, etc. is the wrong approach.

Some injectors are easy to install because their table values have been established correctly, eg. Greg Banish's DVD.

BOTTLE ROCKET

iTrader: (4)

The engine is tuned DEAD ON for part throttle. Idle is great with no surging (except for the cam) I have the VE tables literally either 0 or +1, -1 in 90% of table, with the highest anywhere being +2. The MAF is spot on with a nice crisp off idle transition, with the MAF table matching actual flow. I have a little spark knock early in WOT, but need to get my injectors/AFR correct before pulling too much timing

You need to take a step back and figure out what your particular application needs and then we can help answer your questions around which ones you should buy. If you're running a few bolt-ons or even a mild cam, then the answer may be a stock injector is fine. If you're running 10psi of boost, then you're going to need at least a 60# injector. There's a difference...

I know exactly what flow I need for the car (wife's H/C bolt on) just need to decide which "42s" I need. Thinking of getting my stock ones rebuilt by a sponsor

SSpdDmon

iTrader: (10)

OK - so you need 42's. That's helpful. People who have tuned various 42's can now chime in with their experience.

ramairJP

iTrader: (3)

Tuning is a snap if you have injectors with all of the table information. For a 42lb size I would suggest the GM GTP injectors (P/N 0280155868). You can get versions of these from several of the vendors.

crainholio

iTrader: (2)

Agree w/ ramairJP, those injectors are thoroughly documented via the ASA configuration and getting the tables should be easy if you can find a copy of the binary that is readable by your tuning software. Just copy and paste the flow rate, offset, short pulse adder, and short pulse limit and you're done.

crainholio

iTrader: (2)

And just to give an example of what I'm talking about, I run a stock LS6 with only intake and exhaust modifications. With factory injectors, my Long Term Fuel Trims were in the -9% to -2% range consistently in all trim cells.

I recently swapped in Ford red injectors, used Greg Banish's injector data with minor math to calculate the odd-numbered columns, and my fuel trims are in the -5% to -0.8% range now. No changes to any tables other than flow rate, offset, short pulse adder, and short pulse limit. Accurate injector flow data is critical, and without it you're in for major headaches.

ramairJP

iTrader: (3)

Thanks man. And X2 to what you said. I also swapped stock 26.6 lb injectors for a set of matched GTP injectors (listed as 36lb, but roughly 42 @ 58 psi). After entering all of the new data my VE and MAF tables never even needed a touchup.