Hi, I am wondering if I just replace the stock injectors with bigger injectors on a stock engine, will I get some increase in performance or it will be the same ?

 

well... you'll have to add a $500 computer to control the new squirters... and I doubt the gains will be anything your looking for... They help so much on and S/C'd engine because it allows you to add more boost. Wouldn't be more than 20hp on a N/A car... if that. You can only add so much fuel... it will just run rich.

 

As I understand it, the normal injector duty cycle on the 5vze is around 80% for most of em in NA mode. That strikes me as being high, I'd say do it, but only moderately up the size, and get an AF meter before you do it. The more instrumentation the better too. I'd also do something to increase the intake flow and exhuast flow first...

 

NO. And the larger you go the worse your vehicle will drive.

 

If you send your injectors off to be flow tested and balanced, then you will get better performance and maybe little better fuel economy.

 

Power is all about getting more AIR in. More FUEL will bog it down.

 

I did the elbow mod, the ISR mod, and the O gasket mod which should give the engine plenty of air to breathe in. I am just wondering if installing bigger injectors (from Supra) will help to give even more increase in power in NA engine ? I try not to spend too much on mods and I am not looking into the big boost in power like the S/C and URD Kit as they are both expensive. I try to do mods that are affordable but at the same time, it gives a good boost but not a really huge boost found only on the S/C.

 

The stock setup can only burn so much fuel and with the few breathing mods you have it's not enough air coming in still to warrant more fuel. Unless you SC your truck then it's a waste of money.

 

fs8459, I thought you were selling your 4Runner.

 

I was at one time, but I decided to keep it for now

 

Yeup.

Fred, it's true that you've opened up holes in your intake system so that the truck can get as much as as it needs, but it's not _needing_ any more than what it's now getting. The vacuum created at the intake stroke is now being satisfied by the deckplate. To get any more air into it you have to force it in, and that's where the S/C comes into play.


True, unless it has more air to mix with.

 

I have to agree...the main reason for the larger injectors with a S/C is to prevent lean....this does not exist on a typical NA 3.4L engine. Unless you are somehow adding a significant amount of air to the engine (supercharger, NOS, etc), you will not see any improvement worthy of the cost.

....now it's time to save your pennies for the bigger mods.