What is the Utec's capabilities in terms of scaling down injectors, am I wrong to think that any size injector will work? I am planning for the future with the size of the injectors, I will go with a built longblock later this year, but until then I want my car to run perfect, so with that said: My ultimate horsepower goals are around 620-700 whp with built motor, I would imagine a minimum to achieve this would be 650cc injectors, but I was told the ecu would need to be reflashed, but isn't that what Utec is for?

Essentially, I am happy with my current hp, the return system is basically for reliability purposes, and the injectors are for the future, so what size would you guys recommend for the least about of headaches while tuning? I plan on tuning at the 9-10 psi range this time, I know I will get a few more horses and there will be no complaints, lol.

Thanks and all of the advice I receive will be greatly appreciated, so far most of my mods have come from the advice and precautions of you guys.

Craig

 

Injector scaling is a fine art with these systems. I have installed 3 sets of the idenical injectors into identically setup cars, and the idle will vary between perfect and pretty rough. I wish there was a definative answer to this question. Technically, the UTEC and EU can scale a 750cc injector, provided you lower your fuel pressure down to about 35-40psi differential pressure.

My advise, is to get the injector that will meet your current needs. If an idle bump is needed, you can do a Cipher increase, or TS idle increase.
Keep in mind, for your power goals, you will be running a pretty wild cam, so an idle increase is going to be a necessary, regardless of injector size.

 

We have scaled 750cc's so far on the utec, and ran fine.. The future software update will allow the UTEC to raise Idle.The Cypher software from my understanding can only bump idle up 100 rpm's or so.with cams, you may need more, which would require reflashing the ECM or waiting for future software updates. From my understanding the UTEC will work with up to 1000cc injectors, but we have yet to try it...
One of these packages may help you out..
https://my350z.com/forum/showthread.php?t=179753

 

I have most of these items, but the return system and injectors, good deals though. You and Sharif always come to my aid, lol, maybe one day I will be able to move up from my Novice level of understanding.

To address the wild cam, yes I will have a cam, but how high does the idle need to be, it is already at 950 rpm? And Sharif, when you say that the Utec will idle between perfect and pretty rough, is that periodically or permanently?

 

will idle rough if not tuned perfect at idle or low loads..

 

If you idle is already at 950rpm, you should be fine. We usually bump them up to 1000rpm and they idle perfectly without stalling. Sounds like you are good to go...even with 750cc injectors.

I assume you mis-typed on this. Idle stability has little to do with tuning, per se. The only UTEC variable you can change at idle or part throttle cruise, is injector scaling/MAF manipulation. And it usually takes a couple minutes of fiddling...once it done...you are stuck with whatever idle condition you have. I just didnt want people to think you can always fix a rough or low idle, just with tuning. Sometimes you can clean it up, and sometimes you can't.

 

you can also advance timing at idle too Sharif..

 

Not in the 0% load column. That's stock ECU territory. I havent tried setting up the UTEC to take control even under 0% load and vaccum conditions, as I'd rather have the stock ECU control that.

 

Try it...Youll love it..In fact in speed density set up, you can completely remove the MAF sensor if you wish..

 

How can you do that? what about when the engine is in vaccum? could you explain more.

Do you mean that you setup the utec to take over even under vaccum?

Thanks,
Az