Ok everyone, I know that this subject has been beaten to death by many, but my question is regarding using a MAP sensor to control an NA engine.

Can it be done?

By that I mean can it be done period. Not with the UTEC presently, but could the UTEC be altered to rely soly on a MAP sensor?

If not, could the HKS Fcon control the engine soley by MAP sensor or any other engine management for that matter?

From my understanding, the UTEC could control an NA car via MAP sensor but only past a certian throttle position if not just WOT. Therefore this would make idle and light driving hard. Plus I remember reading that the tuning resolution is not too great below 0psi on the UTEC.

Thanks!

 

I'm new to this myself, having just installed my UTEC today. I'll be using MAF pulldown until I am more comfortable with the system..

You have a good question. I of course am not willing to just try it, but I'm sure someone here can tell us if you can use :

Open Loop Fuelling = 1
Fuel Mode = 0
Load Indicator = 0

And then tune injector on-time...

My guess is that setting the fuel-mode to 0 and/or load indicator to 0 would disable the injector map and enable the MAF pulldown map.

But if that is the case then what does it mean when you use open-loop fuelling with fuel mode = MAF? Does this only enable the open fuelling parameters for setup so you can scale injectors and/or modify the rev limit (eg. if you were NA with larger injectors, such as a spec-2 or 3 NA w/ internals)?

As I understand it though, you cannot use MAP (Speed Density mode) with NA because the sensor will never see more than 5v (5psi) or something like that. So using MAP with NA does not allow you to tune beyond the 50% load site.

Someone please correct me if I am wrong about that.

But I still would like to know if you can use MAF and TPS% (instead of MAP and Speed Density) along with the open-fuelling parameter and injector on-time maps. The advantage being an NA UTEC tune which does not need to be concerned with MAF pulldown "tuning drift" caused by the ECU changing the base values upon which the UTEC is adjusting via offset of those baselines.

Again, I have no personal experience yet. Just research. So if anyone sees inaccuracies please feel free to correct this.

Hope some more light can be shed on this...

-Smoky

 

From what I have heard you can use the MAP sensor for NA. You would just have some normal driving issues, but at WOT you could tune the car which means that it is not very useful since no one drives at WOT all the time.

 

Did you ask MRC or Sharif? They are both experts at the Utec and could answer questions about it pretty quickly. Just a thought

 

IIRC a MAP sensor will do no good on a non-turbo car because you'll never reach a positive manifold pressure, just a neutral 0. the MAP sensor's main function is to be able to tune according to the boost level.

I don't know why you'd consider using a MAP on a n/a car anyways.......the stock MAF is plenty sufficient and allows for more precise tuning.

 

You can tune a N/A car in speed density mode, however it becomes a more overkill than just doing it as a MAF offset, not much to be gained by doing so..IMHO.

 

I thought the major advantage of using speed density mode is that the Nissan ECU is bypassed and the UTEC relies on it's own (hidden) base map, which eliminates the need to retune around the ECU's base map adjustments over time.

Is that not correct?

 

Well in the case of ITB's you have no real choice but to use a MAP from what I know unless you run them through a manifold.

 

Also, the reason stated above about how speed density mode allows the UTEC to fully take over is the main reason I would like to do it. Then I think that I may be able to get the ITB's to work with the stock ECU.

 

This is correct, however 99% of N/A customers rely on the old MAF offset method..The A/F ratio usualy does not change unless you add or remove mods, the big culprit on NA cars is timing maps.Even in maf offset the timing you set is the timing you will run. This is the big advantage of going utec over a piggyback unit that pulls or adds degres of timing to a stock ecu timing..