First time on a dyno...
 

Well my friend invited me to go to a dyno meet and convinced me to make a few runs. I just ordered a smarty jr.(very excited about) and will probably run the medium 70 hp tune. Not wanting to even try the 100 hp for fear of loving it and slipping the very stock TC. Was wondering if there are any things i need to check and/or advice? All fluids were just replaced over the past few weekends. Its a major noob question but only one way to learn...

I would just make sure its at operating temperature before they pound on it. I like to let my truck run before they dyno it but I dont rev it up a thousand times either just let it run for min beforehand is what I do. I would shut your O/D off it maybe easier on the converter

cool beans, any advice helps, read the smary jr adds lockup in 3rd, that cool?

If he shuts his O/D off, he won't put enough of a load on the engine to get decent numbers. It would be a waste of time.

Guessing cruise through the gears, and get agressive once it hits third and go WOT once the TC locks into OD??? kinda confusing, im sure i can talk to some peeps there but trying to get some info here so i dont look like a total idiot.

Its alot easier when the engine is out of the application. I get to see Cat engines on the dyno whenever i want. [guitar]

Umm..John at Floor It dynos all trucks in 3rd. That's how I got my numbers.

So how does a guy with an 05' that has no od lockout do it????

I to went to my first dyno deal this past weekend it was a lot of fun. The stick trucks no prob. stick it in 6th load the moter and go for it, but the guy operating the dyno was having issues with some of the autos. He would ease them up through the gears and whack the throttle to early and it would downshift, he'd let off and do it again, i quess finally untill he had enough wheel speed to where it would not come down a gear. I stopped on the way and got a good shot of injector cleaner for good measure.

yea, the downshift is what i was worried about, i was wondering if i put it in tow mode for my auto if that would keep it in the taller gear

I've had the same problem, I am going to install a "mystery switch" to lock up my tc.

AKRAM had very specific instructions I remember reading, I just do not remember which forum, I am sure if you did a search you could find it.

I also tried dragging my brakes to load the motor, all that acomplished was unlocking my tc.:(

Dyno runs are the perfect use of the LockUp switch being added to a truck. If you search around the forum you will find lots of info on how to install a lockup switch for different models of trucks.

Once the truck is in OD turn the switch on. It prevents the truck from down shifting and keeps the lockup on. You need to turn the switch back off before bringing truck to a stop or it will stall the truck.

I am thinking of adding this just for Dyno use...

I have a lockup switch on my truck but when they dyno it the keep the O/D off thats how I got my numbers also

Most people say you're supposed dyno an auto in 3rd because that's the 1:1 ratio. I think dyno'ing in 4th would be the one that's a waste of time because the numbers would all be skewed.

I thought you could get the '05 reflashed to get the O/D lockout function?

Dyno in direct 3rd for Mustang Dynos

Dyno in OD on Dynojets

Anyone know why there is a difference between the two? I know one is inertia and the other load, but wondering why they would use different gears?

Never been back to dealer.... can you blame me?

Guess I've been wasting my time... should I remove my numbers in my sig?


[laugh]

It would be interesting to see the difference, if any.

Don't feel bad. I've wasted plenty of time (and a little $) on dyno runs. Did you see the post where I got 405hp on one dyno and 570hp on another dyno a few weeks later (with all the same mods/programming)? I would definitely call that a waste. [laugh]

Ouch...

Well I've only been on a Dynojet and the first pull I did the operator wanted me to try to keep her in third... which I did by letting off throttle right as it shifted into OD. I think I hit 380hp... and one wasted pull...

And I don't understand the difference in Dyno's either. Why would a third gear pull differ from a OD one? My thought is that it would be actually harder to make a better number on an OD pull because if your engine isn't producing serious numbers, you won't accelerate as quickly as you would in 3rd gear... make sense? Gears multiply torque... that's all they do really. So first, second gear the torque multiplication is MUCH greater than 3rd at 1 to 1 and OD which is obviously less than 1 to 1.

I dont know much about dynos, but from what I understand mustangs are load dynos, so you should make your pull 3rd or 1:1. While on a dynojet you dont get the same load so you need a higher gear to help load the motor and make some boost.

I may be way off but thats what I have gathered

What's the 1:1 gear on the 6 speed then? Is it 6th?

5th gear is 1:1....I think that is correct, but saying that, this last weekend the dyno operator had us all run in 6th for manuals and 5th for 48RE's. He said something about loading up the Dyno? I'm still not sure which is which or why....[duhhh]

I wish there was a 5th gear in the 48re.... [coffee]

Lol...wouldn't that be awesome!

I've only dynoed on a Dyno Jet, it was fun, but a waste of time IMHO. Guys at high elevation love to use the correction factor too :)

If the Mustang Dyno is anything like the load dyno I use to dyno my tractors, I would love to try it. We hooked up the PTO on the tractor, went full throttle, and pulled the rpms down with the dyno. Then out came the tools, and a 3/4 turn of the screw later, the 8.3 Cummins was making 20 hp more. I had a blast.

That makes sense to run in 4th to help increase the load, but aren't the numbers then skewed because the gear ratio isn't 1:1. If running in 4th skews the numbers on a Mustang it seems like the same would happen on a Dynojet?

If the Dynojet is seeing lower HP due to the lack of load, and then people are running in 4th to help inflate the numbers back up, then that doesn't really tell you squat about the true power output. If that's the case you might as well estimate the numbers yourself. [laugh]

Thanks for the insight guys, got my smarty jr. today and have been playing a bit. Thing is something else...

With enough practice and patience you can calibrate your dyno to get you good accurate #'s and use 3rd (non OD) when on a dyno. Many shops do it simply not to break stuff. But just like anyone here knows how at 52mph where the converter simply lock you get instant more power and the turbo's really get a change to push with proper engine load.

4th gear gives you more true HP # simply because your engine has more load to work with, but things break too

I have dyno'd quite a bit. And, I have always had very good luck with Dynojets. My consistent experiences and numbers on several DJ's show to run the truck up to about 70+ in 4th gear/od............and then hammer it up to about 120mph. It won't shift down and you will get a good positive run.

..

Well, the dyno event was pretty fun. I went with a group of mustang and pontiac gtp guys so i was the guy smelling up the place. Couldnt get a good reading on the dynojet there in 3rd so we used OD. The guy there said he had had a few diesel guys there before(they left their mark on the ceiling thanks to stacks) and said most had to use higher gearing to get realistic numbers???
Ended up using the 100hp tune and got about 386hp with 707ft/lbs. Anyways love the smarty jr! Got almost 1.75 mpg better afterwards driving home for easter.
Happy Easter everyone!