maxedout95

iTrader: (1)

I am looking into putting bigger injectors in my 95 Maxima SE. I was wondering if anyone ever did this themselves and if yes is it time consuming I know it would take about 3-5 hrs for a mechanic but for someone that just does it on a weekend how long? Can anyone give me some tips ?And what are the best injectors to get?

1MAX2NV

iTrader: (5)

You have to take the upper intake manifold out to get to the rear bank injectors. Why do you need bigger injectors? I hope you have a real need and not some usual rice boy reasons. ie.."My buddy said they increase 10hp on his civic". I hope you have a new ECU to go with bigger injectors. If not, good luck driving your car home from the shop. LOL

maxedout95

iTrader: (1)

That's why I want to get bigger injectors cuz Im gettin a ECU but what would happen if I just got the injectors I mean all it does it gets you better flow and basically will increase the fuel output when you push it right ?

DA-MAX

iTrader: (10)

he's trying to say that you'll have to have a custom fuel program made for your ECU....the injectors wiil be of no benefit if the computer cannot properly make them "flow"

maxedout95

iTrader: (1)

I thought that any improvement to your fuel system should help you with getting more fuel out and be better flowing ( by better flowing I mean when you floor it it will dump more fuel) and even with the stock ECU it should improve the flow you might use more fuel when you step on it but I don't think that it will hurt the system.

DA-MAX

iTrader: (10)

you're not listening...the injectors are controlled by the ECU, if you don't upgrade the ECU to flow for "bigger" injectors you just did a whole ****load of work for NO GAINS! in other words you have bigger injectors but your still flowing at OEM rates.....in lamen terms "IT NO WORKY RIGHT!"

maxedout95

iTrader: (1)

"It Worky rit" but all I am saying that if I put in bigger injectors now and a aftermarket ECU later it shouldn't be a problem running the bigger injectors for now k

DA-MAX

iTrader: (10)

thereoretically I'd say you won't have probs, but in actuallity(since I've never done this)...I won't say that I'm 100% on that either!!

maxedout95

iTrader: (1)

Hey listen do you know what are good injectors to put in I mean I know probably something like from a 300ZX but is that the only thing ?

Chunger

iTrader: (1)

Wow... are you putting out like 400hp or something? 200hp NOS?

It's a waste money... but it's your money

Jeff92se

iTrader: (82)

I predict that your car will run like shat w/ the bigger injectors IF you don't have the ecu to go with it.

1MAX2NV

iTrader: (5)

Your car will stall at WOT with bigger injectors. Why? The ECU has no clue that you have bigger injectors. ECU is hard coded with "ONE" injector size (the oem size). Injectors are either ON or OFF. They are like a switch. So your stock ECU will turn it on and off as if you didn't have the bigger injectors. With a modified ECU, the tuner hard coded it with the "NEW" injector size. Trust me. I know this for a fact. With bigger injectors, you car will become undrivable.

Turbo95Max

iTrader: (25)

first of all do you need larger injectors? plenty of supercharged guys still run the stock injector size. 94 and 95 300ZX TT injectors will fit the 95-99 Max. Not sure about other year of 3Z injectors.


DA-MAX, you got the right theory but i tink you are seeing it wrong. Bigger injector on the "OEM flow rate" will flow more fuel then stock injector on the same program.
The ECU controls amount of millisecond the injector opens for, now if you have a larger injector or higher fuel pressure, you get more fuel out in the amount of time the injector opens...make sense?

1MAX2NV

iTrader: (5)

ECU controls the ON and OFF of the injectors. It's like a switch.
Fuel pressure regulator controls the amount of flow. It's like a faucet ****.

njmaxseltd

iTrader: (19)

Is anybody taking into consideration the simple fact that you need more air along with more fuel in order for your car to run correctly? Bigger injectors require a modified ecu to shorten the open time to compensate for the more fuel the injector will flow in the open position. Hance you have no gains. If you use bigger injectors with the stock ecu, your going to run rich and possibly foul your plugs & trip the o2 sensor circuit and cause a CEL light. The cars ecu will try to adjust the air/fuel mixture but will not succeed.

The only way your going to see any gains is if you can get more of the correct combination of air & fuel into your combustion chambers.

theblue

question for maxedout95:

please tell us how you came to the conclusion that you need different injectors. I hope that you have a better reason than beacuse you are getting an off the shelf ECU upgrade

and explain why you want to do an ECU upgrade and injectors when you don't even have a y-pipe. what an expensive way to get less HP than the y-pipe for more money. Please show us that you are not completely insane.

theMax

How do you know this?

I'm not doubting, just curious how one goes about learning so much about a car??

Jeff92se

iTrader: (82)

!) He is 100% right

2) He's a nerd so that's how he knows

maxedout95

iTrader: (1)

Well for the air issue I have a pop-charger but I don't know how much that will help. The gaines I am looking for is too open up a more open fuel output but I know that the stock ECU will not give me more fuel right away but I just wanted to get the injectors first and then the ECU cuz its more work and I wanted to take my time with it. So that's why I don't think that bigger injectors will do damage to my car or make it stall cuz the stock ECU will still tell the system to spray the same amount of fuel and will get the same amount of air.

SuDZ

hehe Good reasons.

SuDZ

1MAX2NV

iTrader: (5)

Some one is in denial. STOCK ECU WILL NOT TELL THE SYSTEM TO SPRAY THE SAME AMOUNT OF FUEL. Injectors are either ON or OFF. The ECU doesn't go "let's see what size injectors this rice boy have on the car" and then make all these "NEW" calculation based on the injector size. LOL...I wish the ECU was that smart.

Turbo95Max

iTrader: (25)

because im ASE certified and Toyota T-TEN graduate. My job field and hobby is automotive. I am not that old at 22 but ive been doing this stuff since 16. From working in shops, sidejobs, skool, and workin with some good drag/road racers i learned alot, asking questions helps too..heeh

DA-MAX

iTrader: (10)

yeah I knew I had a basic idea to it, I asked this questions ages ago and got the "too much flow so you'll run rich" answer...so basically I guess its you'll get the flow, but it won't be beneficial just a rich mix...

maxedout95

iTrader: (1)

explain why you want to do an ECU upgrade and injectors when you don't even have a y-pipe. what an expensive way to get less HP than the y-pipe for more money. Please show us that you are not completely insane. [/B][/QUOTE]


I want to do an ECU upgrade cuz it will give you more HP then a y-pipe will ever do.

j_bryan

iTrader: (1)

so does this mean you're going to do an ECU upgrade with your new injectors? if so, who's programming the ECU to work with your new injectors??

DA-MAX

iTrader: (10)

maxedout95

iTrader: (1)

Yes I will do the upgrade with the ECU and I'll probably get it through JWT or wait till something better and less expensive comes out.

SLC I30t

iTrader: (1)

DING DING DING (back to your corners)
it looks like someone is becoming an example. I hate it when I'm on trying to defend my question like the last piece of meet at the carnivour convention...

Anyway I've been asking this and maybe this is the place to do it. Can he use an fuel/air managment system in this application? Would it benefit? if so how much?

Flame on
DING DING DING

Don in Texas

iTrader: (-2)

been doing this since 16? Jesus, now I really feel old. I've been doing it since 15, but that wasn't 7 years ago, it was 21 years ago.

Holy $hit I'm old....I'm going to bed.

Shadow

iTrader: (15)

Maybe you're just not getting what Tony is trying to explain. If you get bigger injectors and keep the factory ECU, your car will stall. The ECU is coded with the fact that stock injectors are 254cc/min (I think). You get bigger ones, like 370cc/min or so, the ECU will not recognize this. The ECU does not see that the injectors are bigger, it was set from the beginning with the idea that the injectors are 254 cc/min. The injectors pulse, when they are working. Open/close etc, over and over again depending on what the ECU tells it to. If you have 370 cc injectors, each opening is going to spray a lot more fuel into the engine than necessary and you will stall. It's as simple as that. The ECU cannot recognize the larger injectors because it has no way of doing so. You plug in larger injectors, it doesn't change anything the ECU senses. An aftermarket ECU custom programed for the larger injectors will recognize that the injectors need to not stay open as long to flow the same amount of fuel as the factory ones, so the drivability is ok.
And what I don't understand is why on earth do you want bigger injectors when they won't do anything. Yes, more fuel and more air equals more power. But all you have are a pop charger and muffler, that's not even close to reaching the limits of the factory injectors. There is one guy here w/ ~320 hp at the wheels (almost double what you have probably) and he's running the stock injectors. So why do you think that your car is so special it needs bigger injectors.
Finally, and ECU upgrade doesn't give more hp than a y-pipe. Look into it.

Don in Texas

iTrader: (-2)

Stock injectors are 239cc.

There would be no reason to increase the size of your injectors simple to do it, when the OEM injectors are good for ~275hp. Once you determine that your hp needs support beyond this, you should consider injectors (370cc, or 555cc). Given that, your ECU would have to be modifed to control the new injectors, otherwise the car wouldn't even start.

I think this has been covered several times on this thread, huh?

maxedout95

iTrader: (1)

Well I wanted to put in bigger injectors and aftermarket ECU to get more power without getting a supercharger cuz I think that doin engine mods without puting in a easy fix like a supercharger is more gratifing when you beat someone with a turbo or a SC just on engine alone so I am thinking of ways to do this.
And a y-pipe will not give you more than 5-10 HP if that.

Shadow

iTrader: (15)

The Y-Pipe provides more than 5-10 hp. You're on the right track with the ECU, but bigger injectors are unncessary. That's what everyone is trying to tell you. You make more power by freeing up the bottlenecks in the car, intake, exhaust, y-pipe, etc. But the fuel system isn't a bottleneck with just bolt ons. Put it this way, no matter how big of an injector you get, and even if you get an ECU to control it, you will not make any more power than if you just got the ECU. Just because you have the ability to add more fuel with bigger injectors doesn't mean that your car will use this fuel. It will use as much fuel as it needs to make power, no more. You could double your fuel system capacity, and it wouldn't make any more power.

maxedout95

iTrader: (1)

This is what I kinda was aming at that it will not hurt the engine or stall it cuz the excess fuel passes through the regulator and returns to the fuel tank through a fuel return line right. But with a bigger injector and an aftermarket ECU programmed for bigger injectors I should get major gains on the HP I think more then a y-pipe cuz I don't see how a y-pipe would give me more than 5-10 hp.

SLC I30t

iTrader: (1)

because-
1. you drop the pre cats(air flow constricting)
2. Mandrel bends(air flow constricting)
3. Weight loss (lighter on her feet)
4. even if your not faster it sure sounds like you are BRRRRRRRRRRRRRRRR-BRRRRRRRRRRRRRRR-BRRRRRRRRRRRRRRR-BRRRRRRRRRRR)engine noise...he he nevermind, these pain killers sure make funny on this side of the puter screen.

maxedout95

iTrader: (1)

I know about the two pre-cats in the y-pipe but still with the whole exhaust done from the y-pipe to the muffler it still will not give you that much power.

SLC I30t

iTrader: (1)

I guess the pre cats caused more constriction than the pipe back does???

Shadow

iTrader: (15)

Y-Pipes dyno at over 10 hp usually. Veetec just installed his Cattman Y-Pipe and gained 16 hp. The rest of the exhaust is worthless to modify, but the Y-pipe is very important.

maxedout95

iTrader: (1)

Sorry to be a pain but I don't see how a y-pipe could give you more HP than a aftermarket ECU and injectors I am expecting to gain between 20 to 30 HP with these mods and then maybe the fuel rail and fuel pump.

SuDZ

Then go ahead and prove everyone wrong. Have you taken any steps yet?

SuDZ