DomZ

After some reading and thinking myself, I have figured what could be a big help. First of all, my car sees WOT a lot, according to someone from AAM a way back, every 6 WOT runs and your ECU adjusts itself to feed you some more power, I feel this is true, hence my 1/4 time on a stock 5AT Z. Also, race gas helps, when mixed, not all at once. If you dump nothing but 110 or 103 in your car, all you will do is hurt it, you need some of that lower octane gas to burn quicker....I mixed 3 gallons of 93 with 1 gallon of 103 and by my 2nd or 3rd pass at the track, I was turning better times...

All this stuff about the fighting ECU emissions is fine, but you need to fight back. Switch it up a bit, make the ECU readjust itself. I'm going to put a tank of 91 in to throw the ECU out of wack then put 93/103 in next time I go to the track...

Also, after reading all of this, I ordered a laptop and I am ordering emanage today or tomorrow. I believe the whole key to producing more power is to trip the ECU up, make it adjust to crappy settings of 91, then push it back to 93 and it will recalibrate everything before the steady decline in power that everyone seems to be having... Also, don't baby your car, the ECU needs WOT to know that you are serious about wanting power, if your car spends 90% of its time at 25% throttle, the ECU will adjust itself for your granny driving...

This is all just speculation, let me know what you guys think

brendone

How do you know when you ECU goes into "Safe Mode"? I installed a pop charger, reset the ecu (battery disconnect) and got some mild "Butt Dyno" gains. When I installed my 1/4" Spacer the car turned into a hog. I reset the ECU again last night and it seems to be back to normal (but for how long) so after reading all this, I'm guessing the ECU's going into safe mode. I'm not getting a CEL light.

sentry65

iTrader: (11)

i'm not sure what using just 91 octane for the sake of variety will be good or not. Using a lower octane will just make the car knock more and pull power. What's the use in waiting for the ECU to adjust all the time?


I'm not sure when the ECU reaches safe mode - does anyone?

maybe it's when you throw a SES or CEL light?

illZ

Safe or Limp mode is most likely after a SES or CEL.

Just a guess.

sentry65

iTrader: (11)

here's some new info I didn't know from the Unichip thread:

posted by baileyrx:


interesting...

that motec system is sounding better all the time.....

Nano

iTrader: (1)

the second set of 02 sensors is not IN the engine but at the end of the headers

sentry65

iTrader: (11)

hmm so i wonder if we did the non-fouler mod on all 4 sensors then if that would take care of the emissions issue all together.....

Z BOY

iTrader: (41)

so there are 6 sensors? 2 in engine, 2 on headers, and 2 on cats?

the7ferret

no just 4, 2 on the headers, two on the cats..

ZU L8R

iTrader: (84)

That's what I thought as well. I remember seeing them there. Don't know if there's enought room to do the fouler mod there.

Sharif@Forged

iTrader: (92)

The eManage is more capable than the Unchip. The Unchip enriches fuel via MAF trickery, whereas the eManage when coupled with the injector harness included with the Greddy kit, enriches fuel via direct IPW increases. It actually taps the injector wires and adds pulse width directly. Give it a MAP sensor input ($25 cable if you have the e-01), and you have a VERY powerful tuning platform.

A lot of people are unfamiliar with how the eManage works, but once you scratch the surface, people are begining to realize that is the best piggyback on the market today, and the next best thing to a stand alone, IMHO.

Not perfect...but pretty darn close.

illZ

100% Agreed.

ReavTek

iTrader: (1)

What exactly would we need to get this working 100% in an NA Z? Do any of the fuel return kits on the market supply everything needed fuel wise or would separate components need to be purchased?

Q45tech

"I was assuming, if by pulling timing, the engine will draw less air into it since it won't be as powerful.

If it doesn't suck as much air in because it now has less suction power, it'll get the MAF to reduce it's voltage."

Scarey that one believes an engine sucks in air? The engine is not a vacuum pump. Rings don't seal that well.
Air flow into engine is the result of earth's atmospheric pressure trying to refill the void, the the heat expanded air creates when it expands out the exhaust valves!

At idle [with 20" HG] the atmospheric pressure inside the plenum is still [20/29.92=0.6684 x 14.7= 9.8 psi]..........less than atmospheric is a long way from a vacuum.

At WOT the total outside pressure restiction is around 25-27 " of water column......a little less than 1.0 psi........or 13.7 psi at intake valves after runner at the fuel injector nozzle space.

MAF voltage [actually intake air temperature new colocated sensor] is used to correct ignition advance BECAUSE gasoline has a temperat octane ratio [sensitivity] that need to be trimmed.....hotter the air the less advance the gasoline can stand [property of flame speed-how fast the gasoline burns [reacts chemically with oxygen].

Before the use of intake air temp sensor this guessimate was derived from coolant temp sensor which use to reduce advance 1 degree per 5F starting at 194F topping out with 5 degrees at 212F [coolant temp] at head out sensor. [same result but slightly less accurate than just measureing the intaske air temp]
Also AC control computer signaled ecu when AC was on and derived at signal from AC outside air temp sensor which added additional retard to equation.
Why summer performance was often worse than the calculate drop in air density with elevated temperatures. [1% per 11F]

Really all gasoline fault and its Reid vapor pressure for emissions in Summer......why 3.5 have a fuel temperature sensor to help fine tune injector opening time to compensate for the changes in fuel density. Gains heat from tank to injector tip and that is a function of opening time - duty cycle.

kcobean

iTrader: (2)

This is complete nonsense. The intake valves are CLOSED while the exhaust stroke is occuring (which would be the "air expanding out the exhaust valves" as you put it.) There is a SMALL amount of valve overlap, where intake and exhaust are open at the same time, but not with enough duration to account for the dynamics you are proposing. All of your math (to the 4th decimal place even!) sounds great, but the end result is that YES, the engine *sucks* air. On an N/A car, the vaccuum in the intake manifold is created by the fact that the intake valve(s) opens as the cylinder is dropping, much like pulling the plunger of a syringe. How is this not "sucking"?

Additionally, How do you figure that "the rings don't seal that well"? They seal well enough to support the pressure of combustion, therefore they must also seal well enough to support vaccuum. Your logic seems totally flawed to me.


Less than atmospheric, while it may not be *absolute* vaccuum, is still vaccuum, and it is generated in the intake manifold by the intake stroke of each cylinder's sucking air from the manifold into the piston chamber. The *reduction* of vaccuum is the result of atmospheric pressure trying to equalize the manifold at atmospheric pressure. To imply that this process alone is responsible for providing the intake charge into the cylinders is incorrect.

While I can't say for sure, I believe the purpose of the temperature sensing function of the MAF sensor is to help calculate air density (which is a variable used in determing A/F ratios). Maybe one of our F/I experts can chime in and clarify whether air temperature is used as a factor in determing timing or not, but it would seem that at the temperatures inside the cylinder during the compression/combusion strokes, any atmospheric variance would be fairly negligible as it relates to determing spark advance. I'm not saying you're wrong, I just wasn't aware of air temp as a timing calculation as a timing calculation variable.

illZ

Good posts!

Q45tech

I suggest you take a few post graduate level engine design courses.

"To imply that this process alone is responsible for providing the intake charge into the cylinders is incorrect."
If you study piston ring design you will see they work primarily because of the high pressure/temperature of combustion. The ability to compress to 200 psi in one [upward direction] is no where near the same as required to suck in a charge [slug of air].....

Why bother when you have the Earth's 14.7 psi supercharger.

"1. (Physics) A space entirely devoid of matter (called also, by way of distinction, absolute vacuum); hence, in a more general sense, a space, as the interior of a closed vessel, which has been exhausted to a high or the highest degree by an air pump or other artificial means" ....................unsure how you can call a 1 psi reduction in pressure a vacuum.

But you are on the right track using the term "equalizing pressure"......primarily a heat transfer function.

""The internal combustion engine is little more than an air pump." This phrase has been used many times to describe the action of the engine displacing air. When a piston travels down the bore during the intake cycle, it creates a pressure differential, or a low pressure area. The air outside rushes in to equalize the pressure, thus filling the cylinder.""

Q45tech

Might find this site interesting:

http://www.engr.colostate.edu/~allan...e1/page1f.html

Lots of java applets to describe the process.

350Z_LMS

I realise this is a pretty old thread, but here's my question: I have read all that's been said here, but could someone give me a definitive answer to whether the TurboXS UTEC system would actually be capable of working with the ECU eliminating ping on NA modded cars? Take for instance a pretty "standardly" modded Z with headers, cats and exhaust (in my case Strup, Crawford and NISMO) on the exhaust side and Motordyne MREV plus on the intake side. I currently have installed the cats and NISMO ONLY and have all the rest sitting at home waiting to be fitted (doh). From what has been said, I have a feeling that fitting all of the mods would actually produce less performance on my 2005 35th anniversary Z. So, here's the point I am trying to make: I realise I need to tune the ECU to account for all of these mods, but there is no mention here of the "new" UTEC. Will this item SAVE THE DAY FOR SURE? Can anyone confirm this?

Gators2001

iTrader: (12)

Well back then i dont think the UTEC was available.

The UTEC works alone; it doesnt work with the OEM ECU.
My understanding is that the UTEC tricks the OEM ECU by telling it everything is ok. YOU need to Tune/program the UTEC for your car, so you can make the best of your mods.