dankl

iTrader: (1)

I was thinking about upgrading from my stock injectors soon. My mechanic stocks the 60# injectors and says they would be fine in my set-up. I know I don't need injectors of this magnitude, but since they have them right there in the shop, it would be nice and easy for me to buy them and have them thrown in. My question is, are these injectors overkill for my set-up? I may go with some N2O down the road. Is there such a thing as too much injector? Please, any opinions would be greatly appreciated. Thanks in advance to all who reply.

djfargot

iTrader: (2)

im no expert, but from what ive heard as long as you have some way to control them they will be fine. might be more difficult to tune but i think youll be ok.

dankl

iTrader: (1)

That is what I thought also. As long as they are tuned correctly, there should be no issues. Plus, I'll have room in case I decide to rip some more horses out it. Thanks for the response. Anyone else have any knowledge on this?

odd boy

How many HP is ur car? is there any future upgrade plan? If yes, to how many hp.

dankl

iTrader: (1)

Puttin down around 430 RWHP. I know the 60# are bigger than I need, but they had them lying around and now I'll have plenty of room if I want to get more horses.

ZL1Killa

iTrader: (17)

one, how much power are you making / going to be making in the near future?

two, if you don't have a high , or higher than stock by a good bit idle airflow you will run rich at idle and technically these injectors are too much for your car.

you will not be able to control these injectors unless you also add in a fuel pressure regulator, which even then at your power level will probably still cause you to idle rich.

grab you some 42# injectors or some 50# injectors. I believe that is the limit to what you would want to run as the 42# injectors from racetronix that I have at my current power level of 423HP and 431TQ boosted at 5psi yielded a 65% duty cycle, and you do not want to run higher than 85% duty cycle (but can)

check out my sticky in the fuel and injection thread, www.rceng.com go to their technical sizing page.

PM me if you need any more help. I have been through and around and over this boat over and over.... people continuously jump on the 60# bandwagon, install the injectors, tune the correct IFR and such and then complain and complain about a rich idle.

I'm warning you, don't do it. you won't like it. www.racetronix.com or even www.rceng.com both of them sell injectors, even flow matched injectors

dankl

iTrader: (1)

Thanks for the reply. They are in the car already though. Do you think these are holding me back on power? I was told as long as they are tuned in correctly, they would be fine. I can't tell if they are affecting my power output or not. I think they are only at around the 50% duty cycle, or somewhere in that range.

ZL1Killa

iTrader: (17)

they woin't hold you back on power, your idle will be rich and there probably isn't a damn thing you can do about it. However, your part throttle and WOT will be fine.

it isn't just about tuning. those injectors are probaly in the 40% - 50% range...if that, because if they are the mototron injectors those 60# injectors you just bought, if they are rated at 43.5psi..... our cars run at 58psi fuel rail pressure. which means those injectors are actually BIGGER.

60# @43.5psi = 69.3# @ 58psi

dankl

iTrader: (1)

So, the only issue with having these injectors in my set-up is a rich idle? What issue might this rich idle result in, if any?

I knew these were too much for my set-up. Kinda a weird situation. Brought the car in to have my fuel pump replaced, which had crapped out on me after a week or so of putting it in (255 LPH). So the mechanic replaced it for me. While doing this, I had him throw on my 92/92 combo. He mentioned having the 60# injectors at the shop. I told him they were too much for my set-up, but he said those are what they put in just about all their higher horsepower cars. I never actually gave him the go ahead on these. Showed up after work to get my car, and they had put them in. I figured I would let it go, as I was thinking about injectors anyways. But now that you (ZL1 Killer) say I'll have issues, I am a little upset about it.

gametech

iTrader: (1)

Those Mototron 60's are the easiest large injector I have seen to tune. As long as your charging system is up to task, you should be able to get them to idle just fine. However, I have seen cars that don't charge well at idle have issues with them. It seems low voltage and accurate short pulse width control don't play well together.

ZL1Killa

iTrader: (17)

charge well? charging system? are you talking about the battery

they are the easiest to tune on cars that it is necessary to HAVE them.

take a stock trans am...hell , lets say it is a 2001, with headers and new intake. put some 60#ers on it. tune it. I will guarantee 100% that you will have a rich idle no matter what you do.

gametech

iTrader: (1)

No, I was referring to the alternator. Because these injectors are right on the borderline of stock 5.7L idle tuneability, proper voltage is necessary to open and close the injectors within a small enough pulsewidth to avoid overfueling. However, they ARE tuneable. I understand the point you are trying to make about needlessly using too-large injectors, and I agree with that. However, to say that Siemens/Mototron 60# injectors cannot be tuned to idle at stoich on a stock LS1 is just not correct. Myself, and I'm sure many others have done just that.

HUNTER02SS

iTrader: (24)

I have 60lb. injectors in my car, although it is turbo charged,just cruising around or normal driving it was no problem. Red light to red light was no problem either and my car without boost is only 400rwhp! I say put them in and don't look back! That is one part you won't have to worry about upgrading later.

dankl

iTrader: (1)

Looked into the injectors with HPTuners. They are showing enough of a signal at idle to not give me any issues. Apparently, the issues arise when the signal gets too low at idle. I could be wrong, but this is what I saw and was told by my mechanic.

AFASTYZFR1

iTrader: (55)

my 60's dont give me a problem at idle

ZL1Killa

iTrader: (17)

I would like them to post in here and post up details. If someone has done this, which is believeable, and its probably coming from one or several of the experts up here, I would like others to know and to be able to tune their 60# injectors on a stock ls1 if they want to, and I mean STOCK internals, cam, etc. bolt ons sure, turbo sure... what i'm mainly talking about is stock idle airflow values no adjustin tb etc.



is it a stock cammed and internal ls1 346?


guys I believe its do-able, so a higher output alternator or better than stock alternator is required to produce the extra bit of juice to get these to run at real low?

ZL1Killa

iTrader: (17)

you have a cam and a FPR...and I don't know how much the other things you have done have affected your idle airflow amount


I'm no expert on this, but I just want some expert advice or tricks of the trade for those people that have bought 60# injectors so they can find ways/methods they can try to get back to stoich at idle

i'm wanting to talk about slapping 60# injectors on a stock off the showroom floor or VERY slightly modded (bolt ons) car. I always see people posting up here wanting help tuning injectors and injector help and people always putting large injectors on their cars and wondering about this and that problem (such as rich idle) and so I help them because no one else does (sometimes others do and have)

no one has come out and talked about this issue and i know between this past year that at least 8 people have PM'd me or asked me about injectors and 60#ers and i just tell them to stay away as most of those people won't make more than 550RWHP, so they are fine on smaller injectors.

I want to go into the details of getting 60# injectors to work on a STOCK or VERY slightly modded ls1 powered car.

So far we have:
-the charging system of the car.
-and you can add a FPR

gametech

iTrader: (1)

When my 60# injectors showed up before the turbo kit on my 5.7L gto, I installed them on the 100% bone stock motor. I had to play around with the short pulse limit, short pulse adder, and minimum injector pulse width tables. These often get overlooked, as people just plug in IFR vs KPA numbers in the main flow rate table, then wonder why they idle rich. I have to admit, however, that I did raise my idle speed to 800rpm before I changed those tables. The reason I made a big deal of the voltage is that on my friend's 434 SBC, he could not get 60's to idle at all when his alternator barely maintained 12.5V at idle. He replaced it with a different one that charged at a steady rate over 13.5, and he now has the 60's idleing no problem. As someone stated in your other thread, however, some other brands of injector are more difficult to tune for their size.

ZL1Killa

iTrader: (17)

this is noted and I saved it so I can refer to what to modify later to try and help people. I knew those other tables needed to be messed with , I played with them some on my car when I had 60# injectors, guess i didn't do it enough

thank you gametech!!

speeddemon651

iTrader: (8)

60#'s are a good way to go and will leave room down the road