The ATTESA-ETS (Pro) System

     Since I’m writing about the Skyline and GTR, I’ll start off the tech section explaining the ATTESA-ETS system that Nissan uses.

ATTESA-ETS stands for “Advanced Total Traction Engineering System for All-Electronic Torque Split”.  

Yeah.  Feel free to reread that if you need to.

     Let’s start by breaking that down into 2 seperate parts; the ATTES, and A-ETS. 

     So first, we have the Advanced Total Traction Engineering System.  It’s basically a complicated way (too complicated i think) to say that the car has a computerized traction system to keep the car from skidding.

     As for the All-Electronic Torque Split; it means the system can distribute the engine’s torque between the front and rear wheels for an AWD machine.

     That’s the basic understanding of the system.  It uses a computer to keep the car from sliding by distributing torque between the front and rear axles.

     Now onto the technical parts.  We’ll start with 2 facts;

1) When a car is cornering; the outside wheels obviously need to rotate more than the inside wheels to carry a car around a turn.

2) A RWD car usually has its rear wheels lose grip before its front ones especially in a high power machine.

     So when implementing an AWD system, Nissan thought “How do we get rid of the constant understeer in AWD machines?”.  Easy.  Make it rear-wheel biased, meaning it sends more torque to the rear than the front, thus ridding the car of AWD understeer.  Then they thought “RWD cars usually oversteer (lose rear grip before front), how do we get rid of that?”  Have a computer (16 bit microprocessor) figure out WHEN (G sensors recieve info at 100 times per second of all 3 axis) the rear wheels start to slip, and then proportion more of the torque to the front to “pull” (at a maximum of a 50:50 split) the car around a corner instead of forcing the driver to ease up on the throttle to counter the oversteer.  And BAM we have the basics of ATTESA-ETS.   So that’s for the 2nd fact.  But what about the first one?

     Well that brings us to the ATTESA-ETS Pro, first installed on the R33 Skyline GTR in 1995.  Since an outside wheel has to rotate more times than the inside wheels to carry a car around a corner, the Pro system could also proportionate the torque split between the left and right wheels, thus resulting in an independant torque splitting system.  If one wheel started to slip, the system would compromise by splitting torque to the other 3 to help pull/push the car foward.

     So if you were to drive an RWD, and it started to lose traction in the rear, you’d let up on the throttle to settle the car.  In an R33 Skyline?  Keep your foot on that petal and let the computer carry you the fastest the way possible.

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