Thread: Dyno (rant) thread

This could be seen as a rant thread, but it could also be informational.

But one of the biggest mysteries of the world seems to be how to make a dyno read properly, and consistently.

1 inch is an inch. A mile is a mile. A horsepower is just like these other units of measurement. So why is it that there are so many dyno manufacturers trying to rewrite the unit of measurement?

I've seen dynos lay out numbers of over 100whp difference on a 500whp car. I've heard complaints from "heartbreakers" and dynos that label their readings as Flywheel hp, when really they are WHP numbers.

If a HP is a measure of moving 550lbs 1ft/sec, then what seems to be the complication with all these different numbers I see all the time.

Around here, we have a dynojet, a land and sea dynomite, a dynapack, and a mustang. And while some of them have fancy features and electronics, none have been as consistent in measure than the dynojet. A lot of it has to do with the setup of the dyno parameters, but operator error should not be an issue.

And while most look at the dyno as being just a tuning tool, I look at it as a calculating tool. All calculators should read the same, regardless of who makes it.

Meh. Dyno's are for bench racing. Go to a track.

Dynometer does not equate to a calculator, that is for sure.

i agree with you why cant there just be a single measurement. the main problem is all of the software is supposed to compensate for alt, baro, temp, time of dayect and on top of that theres different measurement groups too but all the different companys do it differently. its lame and complicated

have you noticed that hp numbers for new cars seem different? like how they used to be 280hp or 300 hp nice round numbers but now there 167 or 337 or 203? thats cause the automotive counsel has changed the way they measure the hp and now same engine as before but now with a completely different measurment system. its supposed to be more accurate but wtf do you they have to change it?!?!?!

I think it's quite stupid. You would think they would all use the same measurement. I think it's also partly operator error. If they set the software up incorrectly; it isn't going to work as intended.

Also, if you get "crank/flywheel" horsepower ratings from something other than an actual engine dyno.... I wouldn't trust it. It's merely guessing.

A dynomometer reading at the wheels should not have any other compensating factors other than weather. So why other dynos have parameters for tire deformation, wind resistance, etc etc... it is just pointless.

It also seems like the OEMs have their own ways of measuring hp. Which is probably why it was changed by SAE. I've seen cars underrated and overrated for their factory specs, and there is too much variance. RX8 doesn't make anywhere close to 238hp at the crank, and the SRT4 made more whp than the rated flywheel hp. Grrr.

Noone would believe for one second that you can run 10sec 1/4 times with a 3000lb car and only 300whp. That car would likely have to make over 550whp+.

Dynos suck.

Nothing more than a tool. I can say with 100% certainty that no automotive dyno is as accurate as an engine test stand with water brake.

The problem is solely the way the car is tested.

The reason they all read differently is because of the way they are designed to calculate the production of tq/hp.

Here is a good read on how a dyno jet compares to a Dyna Pack and WHY they will tend to read slightly different.

Dyno Tech

I agree. I've wondered this for soo long. How is it soo hard to standardize this equipment to an exact measurment.... ithe thought used to upset me as to why its so hard for them to do.. but in the past years I've just decided to give up wasting time thinking about it. I used to ask the same question as the op, a mile is a mile and a pound is a pound then why the fuck can't a whp be 1whp.

Anyways hopefully someday they dyno manufactures can come to some understanding and make a standardized unit of measure. Maybe someday lol

ive dynoed on a couple of different dynos myself,my tuner uses a dynapak and on his my n/a ve with nistune rt/ sr16 cams/vrs 3inch exhaust/asp budget header/3inch intake only put 161 hp to the wheels.when i took the car to some other dynos for fun runs,dynodynamics i put out 210whp and dynocom dyno i put out 206whp...to me i dont really care cuase its just a tool,i myself for tuning am sticking with the dynapak my tuner uses