so discovered something interesting today, did a log late at night nothing on the road, so I decided to see what shes got. I pegged the gauge past 160mph it goes a little past them stops. then I looked at the log and according to the log it goes to 158mph and that's where it stops, the rpms keep climbing but the speed recoded in hptuners stops at 158 and will go no higher. is there some why to make the ecu register more speed or do I just need a gps if I want to see how fast it will go.

 

That surprises me since HP Tuners will allow you to raise the speed limiter to 318, I would think it would read beyond 158

 

Hpt may but the ecu may not. Iv tried twice where I burried the needle rpm keep going up and speed goes up steady to 158 and stops there every time. Even though on the gauge the needle goes past 160. Gps will confirm as soon as I remember to use one lol

 

You could probably calculate basted on rpm. Not sure if that's accurate or not.

 

Does an rpd go over 158 if the speedometer does, but the ecu doesnt?

 

If the ecu can't see it the RPD won't be able to.

 

I happen to know for a fact that the RPD does go over 158

 

Well this is just odd. I shall gps compare and see

 

I'd try it out to see my results but I live in Ohio and there's no road straight enough to do that

 

I guess even if the ecu can't decode the speed signal past 158 doesn't mean the RPD isn't capable of continuing to figure it out.

 

 

I second that for 2010 models anyway
Mine said 160 and gps said 152

 

Well I just top speed tested it, didn't burry needle like usual due to slight incline I guess. Speedo said 260kph, I guess that's same place on speedo as 160mph, hptuners says 158 mph, gps said 167.7mph or 270kmh, so this cars ecu definitely doesn't read past 158mph

 

You must live south, I have tons of straight, smooth, open roads up this way.

 

Scanner maximum speed tops out at 158 mph

The new 2.25 scanner can read past 158mph it's just a software limitation of 2.24 scanner. Built Corvette guys going 200mph+ on a dyno had the same complaint.

 

Oh sweet. And there is an update? Or will it be in coming update

 

I got a flashing cel at 158 lol

 

You have to request the beta by emailing HPT support. The scanner was disabled in earlier versions of 2.25 but should now be functional

 

So how did my RPD read 165? Does that mean my car came with the software upgrade?

 

It weird how the rpd works if I put mph on the interceptors and the rpd. The interceptors are off by like 1mph to the rpd

 

The HPT software doesnt read about 158, not the car's ECU

 

Ahh, OK. Wasn't that what HPT was reading that one time ;-)

 

Yeah, I'll have to pull that log back up and see if it just stops at 158 and holds

 

apparently its hptuners software that doesn't read past that. so rpd should work fine.