What are the most accurate dynos? Are most dynos reliable? What are the cost to get your car tested on a dyno?After reading some of this thread "my DYNO numbers....which most think are fake.." by scubasteve22, I became curious about dynos, and I didn't want to thread jack the guy.

 

Just to get the car on the dyno and get a printout shouldn't cost more than 100-200. To get tuned, you should expect 250-400. Dyno's are not a universal HP meter used for comparisions. They are a tuning device. Take "peoples claimed dyno numbers" with a grain of salt. Each dyno is different, and can be made to read high/low, corrected or uncorrected.

 

Holy crap, if you are paying $100-200 for a dyno you are getting ripped off.
Most are $75 for 3 pulls, or $100 for the hour and as many pulls as you want.

Most tuners charge $200 an hour to dyno AND tune at the same time.

BTW, Mustang (name of dyno too) is the most accurate and realistic dyno.
But most people will go to a Dynojet as it give higher numbers for bragging rights.

But like dragstrips, you just CAN NOT compare one dyno to another. You can only compare same dyno, same location under same conditions.

 

Dynojet is the most reliable (harder to "Hot Rod") but many believe they are to optimistic.

Mustang is generally considered more accurate if set per manufacturers specs but can easily be "hot rodded" to show higher numbers. There are instances of one Mustang Dyno Showing 255 rwhp and another in the same town showing 290 rwhp on the same stock S197 GT on the same day.

My belief is that the Dynojet is pretty much spot on. The issue is the drivetrain correction factor many use to compare to stock numbers. A Ford Powertrain Engineer stated that an S197 M5 uses 12.9% between the flywheel and tires and gains 5 bhp from 93 octane. 305 x .871 = 266 rwhp. That seems about average fora M5 S197.

Edited to Add: Once you start modifying the 12.9% goes out the window. Drivetrain loss is neither linear nor constant.
A 300 bhp car may lose 13% (39 hp) and a 500 bhp carmay lose 11% (55 hp) just as an example.

 

In my opinion, dynos are only good for giving an accurate reading of power increases when modifications are involved. If you go to a shop and pay for a base pull and you read 300rwhp and bring the carback after a set of headers and CAI and read 340rwhp then that 40rwhp is the only thing you can be certain of. The truth is that your car may have not even had 300rwhp to begin with. The only thing that will remain consistent it the 40rwhp that you gained after mods.

 

Very good point

 

take it to the track, imho dyno's don't mean much unless you go frequently.

 

dynos are good for tuning, but not for measuring your car's potenial. Even if you get an acurate HP reading, they dont take into consideration your rear end gears, weight, aero dynamics, transmission shifts ect. On a track it takes all that into consideration. And it alot cheaper & more fun.

 

As some of the others have said, dyno's are only good as a tuning device. If you use the same dyno for upgrades, you'll get realistic power increases. In my opinion, the only way to get an idea of the real power you have, use your trap speed in the 1/4 mile. Of course you need to know the weight of your car too but trap speed is a great indicator of REAL power.

 

ANother thing to keep in mind is that a dyno will read different from day to day. THe numbers should only be used as a rough estimate and never taken as gospel. IMO bragging about dyno numbers is kind of a ricer move. There was once an infamous 03 Cobra that put over 650 hp to the wheels, yet it could only manage a low 12, and that, my friends, is LAME.