Ok, so here's the deal. I've had my Yellow jacket speedo calibrator installed for the past 2 years without issue, but ever since I installed my comptech charger, the speedo has been acting strange. Here's what it does.

Under hard acceleration, sometimes the speedo will go to 0 MPH all of a sudden. It will stay at Zero untill you pull the plug on the yellow jacket and re-plug it in. This never ever happened before the charger install. Has any one had an issue with the car accelerating too fast for the module to compensate? I know that sounds crazy, but I can't figure out why it would have worked fine for 2 years prior, but now as soon as I install the charger, it starts messing up. Anyone have a high HP S2000 with the Yellow Jacket installed?

Here's some background on my car. The car is a Miata with MY02 F20 installed. The rear end is a Miata Torsen LSD with 4:10 gears. The rims are 14s so thats why I need the Yellow jacket module. The smaller tires (smaller then the S2000s) Changes the final drive ratio.

Any experience would be helpfull. Thanks Guys!

Nils-

 

Run a separate ground to the yellow jacket.

 

A stronger ground is needed, after about the same amount time with my YJ I had an issue with it too.

 

I'll give that a try. Thanks for the advice!

 

I had the exact same problem when I used to be geared and supercharged.

 

Did you end up fixing it? Or just put up with it until you took the charger off?

 

I just put up with it. I mounted the calibrator on my gauge pillar and simply unplugged it and plugged it back in whenever I had a problem.

 

Sorry to bring this back from the dead but I am also having this issue. I was wondering if you folks switched to non-resistor spark plugs (NGK 7173) because I have a hunch that these are what are causing the grounding issue. I had my yellow jacket in for some time with no issues until around the time that I installed the spark plugs. I will check it out tonight as we could have a discovery on our hands haha.

 

nice find if it proves to be correct...

 

No...I have the problem and still have OEM plugs.