Hey Guys,

I did a search and could not come up with a proper answer to this question. Is the RPD HP and Torque display accurate? My car is on a stock tune and I did a couple WOT pulls in first and second gear today and the highest reading I got was 175kW = 234.5HP is this normal? Are these values supposed to represent Crank HP or Wheel HP?

Thanks

 

I would think it's probably not that accurate since it's just calculated based on parameters it senses.

 

im sure it calculates it based on MAF readings..maybe timing and cam phasing too.

 

The RPD is pretty accurate, not spot on but pretty close.

 

But the question is is it displaying an approximate Wheel HP or Crank HP? Because 234HP is a good WHP but a low Crank HP.

 

I've wondered the same thing about the accuracy of the RDP as well. but, more specificly about lateral Gs. Recorded 1.17 Gs today in both directions, not jerky either smooth sweepers. Used to do 1.02 on the stock tires. sorry / thread jack

 

The numbers are supposed to represent at the crank. My RPD would always max at around 260 lb-ft torque and the HP would rise up to about the 260HP mark as RPM rose. This matches the GM's crank HP and torque ratings. It would be slightly off (either higher or lower) on some days as the ECU got used to that day's weather/temp.

On that note, I do not think that it is accurate with the new Trifecta Infiniboost line of tunes due to possible scaling being used.... At least when the tune is activated.

 

many parameters go in to the rpd reading....

i can get my RPD to display 263hp.........
dunno what that means.....cant wait till GMS1 .....and see like 290 or whatever it may be

 

mine is reading something like 320-330tq with tune and mod of course.

 

do you know this? or are you assuming..

 

Def not accurate. Said 280/350 on my car when I put down 322/391.

 

It works directly off the OBD II sysytem.....thats what the techs use for diagnosing...
\

\


can't be to far off I would say.....Im not a tech or anything

 

Mine is set to metric units rigth now ie. Kilo Watts so I'll switch it to Imperial (HP) and do some pulls to see if I can get it to hit 260HP 260TQ

 

yea, many parameters can be displayed by it, but how many of those parameters are actually calculated factors in whatever formula is used to calculate airflow?

The dashhawk and interceptors do the exact same thing as the RPD, and I know they both just pull MAF numbers to calculate HP, disregarding factors such as CR, ignition timing, and valve timing (though changes caused by valve timing might be able to be measured by the MAF)

 

fair enough.....

at the very least i would have paid that much just to have the digi speedo there.......it so nice

 

so if my rpd is reading about 320-330 ish tq, and 290-300 hp? i assume its flywheel horses. btw, i'm at 4300 ft altitude.

 

It is in no way accurate or close to it. I dyno'd 322/391 and it doesnt even read that on the RPD, not even close. So to say its reading flywheel is even FURTHER away!!!

 

I dont trust those readings at all. Most of the cars I have tuned with RPD's say 285-295 hp and I know they are making more than that at the wheels.

 

Yeah, that's part of why I was saying that once tuned, it's probably not dependable anymore. When I was stock and later in stock mode, it would stick to the 260/260 story. It may be higher or lower by a little bit, but you could tell what it was going for.

When tuned, my RPD would read like 280-320HP/310-340tq if I recall, depending on the day and I doubt it was making that at the crank. Weird how it changed so much too... probably some sorta scaling Vince did.

 

makes sense
i cant remember the product name.....but it can register your 60 ft 1/4 mile n stuff

whats the name and cost of this?

 

Side note, 1BadBlue was claiming the 363whp on his car. Which car actually made that number now??? Dyno?

 

He was also claiming 317 ft-lbf @ 6600 rpm, which is 398 hp at the wheels....

 

I just got the GMS1 Kit on my car, and I put it to the HP & TQ window on, and I could have swore... That I made about 280 HP and 320 TQ... Soooo.

 

Are you trying to say they spew BS at times? :p

 

I'm thinking the same