These cars are drive by wire no mechanical linkage from the pedal to the throttle body. It is all controlled bu the ECU. When the pedal is all the way down the throttle body will only open 80% from factory.

 

+1. Not mechanical from the accelerator, more like servo at the TB. It's even in the flier - drive by wire. When you step on the "gas" your really only requesting that the car go as fast as it's been programmed. This includes reducing power when it slips (part of VDC). This is one of several reasons that we are continually told that the ECU is "complicated."

 

May be you need hospital..i guest?

 

I know about the "drive by wire."

How far a throttle body CAN open is mechanical. If it's like the rest of the cars with throttle bodies, there should be a metal stop that the blade rests on at WOT. The only way to open more than that is to grind down the metal stop.

That's one of the mods that people who port throttle bodies. Typically the blade opens to about 95% from the factory. They grind and smooth the blade, and make it open to 98-99%. It's good for a couple hp.

You can't open 100% because the computer will error.


Do you have a source for the 80% open thing? I see no reason why Infiniti would do that. It would only hurt fuel economy and power...... for NO reason.

 

Who let Yoda on the forum

 

there is no stop, nissan has done this in every drive by wire car introduced recently. And it really sucked for those without ecu tuning available. i had the same thing in my sentra ser-specv and my altima 3.5se. I tuned the air/fuel with a simple safc2 piggy back device, adjust timing a few degrees through the consult system, then was stuck with the 80% max throttle opening. I actually pulled apart a bad throttle body and looked at it. its simply a servo and rebound spring, there are only two stops. they are at 0 degrees and 90 degrees from that point(which is 100% opening).

I actually believe its a trick from the manufacturer for model year bumps in horsepower. for instance the altima 3.5 went from 240 to 245 to 250 in three years time. and they were shown to be making marginally better horsepower in each consequtive model year on the dyno's in stock form.

but add in the reflash they made available and the power levels ended up the same. sorry for the book, but its relative to the discussion.

 

No, thank you for the book, it's definitely relative. I don't know why they do the 80% thing then. BUt, it probably helps the tuners get the 10whp or so they're getting out of our cars.

 

glad to help.

a few years ago, speculation was that it was done for increasing reliability and decreasing powertrain warranty claims. basically a money issue.

the decrease top end would keep the customer in the lower and mid range. and honestly, it did that in all of the nissan/infiniti vehicles i have owned. thats where all the power/grunt was.