I was wondering if anyone else has noticed that their Z is sometimes faster than other times?

Sometimes when i gun it it seems to launch after 4500 rpms and sometimes it doesn't. I have read some cars' (porsche cayman) ecu has different maps to accomodate various driving styles-which is also why they have the sport mode swith/button.

I am starting to suspect the Z has a similar set up? I haven't seen any information on the stock ecu and its behavior patterns.

When it seems to be in slow mode i can feel like the engine wants to work harder but is being held back.

I find a few moments of driving it like i stole it helps.

anyone else noticed this? and any way to keep it in fast mode without driving like a bat out of hell all the time?

 

good one!!!

 

yeah, Ive noticed it too, Ive just assumed it was due to temp. Ive noticed that if you floor it at low rpms itll have a hesitation, but if you floor it, then let up and floor it itll jump. Weird, but my sentra was the same.

Mike

 

If you mean by flooring it, letting off and immediately flooring it again, that doesn't make the car any faster. Its just you feeling the effect of physics. If you let off the throttle the car lurches forward from the engine slowing the car down, and when you apply the throttle again it just throws you back, because the car shifts its weight to the rear.

TK

 

i agree with what you said.. that and if you have a stick the drivetrain seems like it has to "catch up" for a quick second resulting in a little bit of shock.. I rather ease onto the gas then quickly get on it. (Ease on it fast)

 

People really think their ECU's do this?


Do the cars you have seen this on happen to have automatics where the gear changes are done via the ECU?
I personally have never seen differement modes on manual cars like that. On autos I have seen them. Like my BMW had it. It was auto so it just changed the rev points and shift points to my driving style at that particular time.

Other then that, I believe all that crap is a myth until proven otherwise.

 

Of course an ECU can do this. why would a program not be able to vary output based on input? computers have been doing this for awile. (AI in video games)

the porchse cayman has this feature-per their website and its for more than just stiffening the suspension and changing shift points.

Since i have a standard shift points are not a variable in my expierements. My controls are my car, right foot and shifting at 7000-7500 rpm.

The point of the thread is to see if any one else has observed a variation in performance and to develope a HYPOTHESIS/THEORY as to what causes this.

again it is a theory and i am asking other observent z owners for input.

What i have observed is a variation in power in my vehicle. This is fact. why is unknown.

The only myth is it happens magicly.

 

trust me. Your Z or any other manual car does not magically change due to driving conditions like you mention above.
Show me documented examples from the manufacturers and I will come closer to believing maybe. But I think its a wives tale.

Different ambient air temps is likely the major cause for what you see.
Its colder one day and the car prob feels like a rocket ship. Next days its really hot and you drove it for a while and it kinda feels like a pig because its feeding in hot air.

 

a change in air temperature would be the obvious influence. while that can affect performance it is not the cause of what i am expierencing.

i bought my car in october and its been nothing but cold. these differences are not noticed day to day. like i said, when i start racing around it improves. (a few sprints)

example from a manufacturer? easy. any reflash on your ecu designed to enhance performance. there is a thread on here where someone is working on it now. and the example i opened with. porsche.

I admit IDK a lot about engine management systems... but playing with air/fuel ratio and timing (all of which are controlled by a computer) affect how engines perform.

I appreciate the input though...

 

I know all of this that you are saying. I am stating the manufacturer is not making seperate maps on their stock ECU's to run any differently depending on how much you "romp " on it.
What tells the map to change?
It is very possible, just very unlikely for a stock ECU to do, unless it is doing something for a auto car changing shift points or something similar.

I think it is more your imagination then anything.

 

possibly. time to take her to the track.

 

What i was referring to was a sluggish feeling when you first "punch it" from cruising in a set gear at low rpms. If you do it twice real quick it doesn’t happen. Like in my Sentra the Z is the same way sometimes. Not all the time. I don’t think it is the ECU, but more TB and fuel flow. My other cars don’t do this, just the Nissans. However, ECU's these days do have play. They CAN adjust for efficiency due to driving styles. Don’t know about a Z but some can.

Mike

PS- it has been my experience that if you run a car hard, it will be faster, if you baby it, it will be "baby'er".

 

robertinmesa - I live in Chandler, I drive an '07 6MT as well. I have NOT experienced this.