Just got home from the 2005 Silver State Classic Challenge in Nevada. We finished 4th in the 130mph Class out of 12 cars (averaged 130.2294mph for 90 miles, 4.3 seconds too fast from the 130 mph target speed).

When going through the "top speed" trap, I expected that the car would shut off at 155mph (since I have heard many places that the stock ECU kicks in to spoil the fun at this speed). However, I was watching the digital speedo in the first gauge pod tick up, 153, 154, 155, 156, 157... Our GPS that we use (since it is more accurate than a normal speedometer) showed 159 and change.

I had to back down after that, but the limiter never kicked in.

So, my first question is, since I still have not re-flashed the stock ECU, why didn't the limiter kick in? Not that I am complaining, but I just found it very strange...

I was running stock size rear tires (Nexen 245/45R18, full tread, less than 1500 total miles on them), and slightly different size front tires (245/40R18). Air pressure was bumped up to about 39 psi front, 38 psi rear.

My second question is: How does the limiter sense speed? Via the rear wheels or the front wheels? Is it gear and engine rpm based, transmission rpm based or wheel rpm based?

Can any of you Z techno-geeks tell me what is going on?

Thanks.

 

I did the same thing. Once you get to 159 it feels like it can go more but it doesn't. I think the limiter is at 159 on 03 350Zs. I was cruising at 159 for awhile and it just wouldn't budge.