Thread: Dyno (rant) thread

In the past with my other cars, and my tuner (who uses a dynojet dyno BTW) I've always just considered a dyno as merely a tuning tool. Granted while its cool to lay down a huge number for nutswinging purposes, 1/4 mile times are where the truth lies.

inertia dynos are the most accurate due to how they work. I like the dynojet 248h. It is very simple and unless the drum changes mass it will measure the same all the time. the problem with more modern dynos is that they use a load cell which is very sensitive and I can bet they have never been calibrated since leaving the factory. I always check out a dyno prior to use. I will come will my own equipment to measure temp and RH. If the dyno uses a load cell I will ask to see the certificate of calibration. I also check the tail pipe sniffer for recent calibration. I ran a cal lab for 9 years so I am pretty picky when comes to measuring equipment.

It would be nice for them to get in sync..

imagine going to a gas station and all their "gallons" being different.

yeah, one time you fill up and it takes 8 gallons, and the next time you go it takes 12 at the station across the street.

dynojet 248c is the one we have around here. I love it. It doesn't matter what the weather is, or what time of year. I always get consistent results that are repeatable and comparable to all of my previous trips to the dyno.

It is by far the simplest, and most consistent dyno around, and I suppose that is the reason why they are the most popular. Some scrutinize them because their hp #s are too high, but every time I've seen a stock car run on the dyno the numbers come in line with the ~20% drivetrain loss.

A GTO is rated 400hp with the LS2 motor, and it puts down about 335whp on the dynojet. If any other dyno read lower, then it would show a drivetrain loss of well over 20% and that is unrealistic for a RWD. 17-22% seem about right for a RWD with drivetrain loss.

But if I bought a car rated 505hp like a ZO6, and it didn't even put down 400whp i would be pretty confused. Drivetrain loss % decreases as the power increases. If you strapped your brand new ZO6 to a dynapack or mustang and only made 360whp how accurate can that be?

But plain and simple, if I want bragging rights to compare numbers to anyone, anywhere, the dynojet is the dyno of choice for me. There is less to go wrong, and the weatherstation pretty much does all the calibration for you. The static high load it produces is constant. It doesn't change at all. If you can spin that 4000-5000lb roller to Xmph in Xtime then you make Xwhp. Simple, effective, genius. Perhaps not the best for tuning your car, and spending time in specific load cells, but by far the best at measuring whp numbers.

I can dyno here, then dyno in Washington, Florida etc, and the dyno #s always seem to be within 2% on uncorrected values.

my last dyno trip the dyno op didnt have something right because the first pass showed over 11,000 rpms and like 150whp then the second time it was reading 9500 rpms but really we were barely revving to 8k every time he adjusted it so the rpms would lower i would gain power but i didn't have very much cash to play around so we never got it just right.. they shouldn't of even charged me for the inaccurate runs.. kinda b's if ya ask me.. but it was some new guy an i kind of just showed up.. next time i will go to my regular guy to get some more accurate readings..

The fact is that if you are going to a dyno, you are going to tune your car. You want to make the most power that you can with a particular set up. Who cares if they read differently, if you attend the same dyno every time that you want to tune your car then it really shouldn't matter as long as it is set up the same every time. I personally wouldn't run all over town trying to find the dyno that made me the most horsepower when in reality that doesn't matter one bit, unless you're the type of person that likes to say that yours is bigger...catch my drift?

Stick with a dyno for whatever reason, close-by, they know they're shit, they're nice guys, w/e, but stick with one.

end of rant.

the dyno i went to is the one i always goto, just had a different op that time.. before the n1 cam swap i put down 171whp then when i installed my n1's an ssac an got 150whp that first run i about shit my pants.. then i noticed the rpm's reading at 11,500ish an notified the guy then he changed it a bit an it said 172whp but was still off then changed it again an it read 185whp but was still showing 1500ish more rpms then what we were really revving to.. i just wanted a base run to compare since i just went from stock 2.0ve cams to N1 cams and a ssac header then i ran out of time an never really got what i feel is an accurate reading..

in the 1/4 mile i run 14.3 at 99mph on bald crappy street tires, riding the clutch like a mad man all the way through first an part of second tryin to keep the tires from spinning. Before the cam swap i was doing 14.7 @ 94-95 mph.. My 60fts are terrible.. 2.4-2.6

anyway i agree dynos are just tools, but sometimes the operators mess up and things just don't come out right..

every dyno should read nearly the same, variations due to humidity/altitude, etc are acceptable, but a 100whp difference on a 500whp is just absurd!

yes, just stick to the same dyno to see your results to the different mods and tune your car...

If every dyno was calibrated correctly then only air temperature and altitude would have affect. The problem is some dyno’s are calibrated correctly and some operators don’t give a fcuk. The problem isn’t the machinery is the operators. For this very reason dynos/rolling roads should be used a tool to gauge bhp/lb-ft increase or decreases and the best way to do this is to stick to the same dyno/operator.

got to a horse ranch.....with lots of horses...tie them 1 to 10 at a time with some chains to the back of you car and have a tug o war....see how many it takes to be even.lol