CTD2001

Well this morning my buddy and i drove are trucks up to a place in Bangor Maine called Diesel Fuel Systems. They have a inground Mustang Dyno. This is the first time i have ever been on a mustang dyno, all other runs were on dynojet. Anyways my best pull was 485hp and 1087 ftlbs, which to me were disappointing, i thought that my hp would be over 500. I was happy with the torque reading, the Mach 6s really help me regain the torque i had lost with the addition of the sledpuller 66. The numbers above were with the overdrive on, all other pulls the guy made were with the overdrive off which seemed strange to me because i had always pulled with the overdrive on. I had to convince him to make a pull with the overdrive on. He said that a Mustang Dyno would read lower then a dynojet, but a guy around here made a 650hp pass on the mustang dyno and then made a 633hp pass on a dynojet which contridicts what the guy told me . So i dont know, i am kind of at a loss here, want to break over 500hp mark and i figured with the setup up i have now that would not have been a problem. Any of you dyno gurus out there with some insight, i would love to here from you because i know the power is there, it is just not showing on the dyno. The truck has tons more power with the mach 6s then it did with the Bully Dog stage 5 and the sledpuller. Thanks for your time and to listening to me rant.

RAT_03

Mustang dynos always read lower than a dyno jet. for example my 03mustang cobra put down 540rwhp 585rwtq (dyno jet) then 510rwhp 554rwtq (mustang dyno).
Im very sure you are in the 500horse range on dynojet

CTD2001

Thanks for the info, i would like to get it on a dyno jet, but the closest one is in Mass, more info would be great, what kind of numbers are guys seeing with setups that are like mine, thanks again

TxDiesel007

I hate dynos for that reason

I myself thought id have fuel for way over 400 rwhp, BUT there is always a factor to it, tire size, wind, air, humidity, and in my case, faulty parts that were stretched to the limit (and beyond) and lack of air. 111 degree shop temps didnt help much either.

Dynos will bring ya back to earth, as they did for me, and they also let u know what u can work on, I dynoed 347, and i know for sure with a good clutch i can get bout 390 for sure, i wouldnt doubt it, and if i push my plate forward, im certain i can hit the 400 mark i want, twins? might put me up in ur realm, but theres still a ways to go before i get there, in either case once i toss a clutch in there, ima redyno and see what it does, ive changed a few other things since then too Good luck and look at it this way, ur closer to ur goal than i am.... keep at it!

Rick

PourinDiesel

Forget dynoing on mustang units.
The numbers vary and are inconsistent and are always low compared to a dynojet.

CTD2001

Thanks for the support and Txdiesel007,
Pourindiesel it is funny that you mentioned that about mustang dynos, i just got off the phone with scott at Mass Diesel cause i had a couple of questions for him, he said that he does not believe in the Mustang Dyno numbers and that the only numbers that he goes by for tuning on his drag truck are dyno jets. I pulled the codes on my truck and i remembered that i did not have the map sensor plugged in on my truck, it was unplugged, could that have any effect on my numbers? The code that i had was P0236. Has anyone dynoed with the map plugged in and unplugged? Was there any significant difference in numbers? Thanks again for you help

Tiny

I would like to know the same thing. When I dyno'ed, my MAP sensor for the Comp was unplugged, and the stock harness was plugged in. Did I leave HP on the dyno. My bad for not completely checking everything beforehand, I know I am a dumb @#%.

BigBlue

One guy did a dyno with his map unplugged and plugged in and gained 10hp and about the same torque with it unplugged.

CTD2001

Thats interesting, I had mine uplugged and i was getting a p0236 code which was map sensor voltage to low, or something similar to that. I was told that it is not good to have a bad map sensor and that it should always be left plugged in.

DPS

First, this is going to make many upset with what I am about to say so I appologize in advance.


There are two types of Dyno machines. Load and inertia.

Lets say you take a JD tractor to the dealership for a dyno check on hp. They hook up the driveshaft to a water brake dyno and then acclerate the engine to full throttle, next the dyno operator starts applying a load to the dyno, as the load is increased the engine will reach max hp, then as the load continues to increase the rpm will now fall and at a certain point you will find the max torque point.. THis is how a diesel engine needs to be run to get a true and accurate reading of its potential. A diesel engine needs a load to make power, this is why when you talk about pumps or fuel systems there are terms like, Torque rise, gov. droop, gov. response and sensitivity. If you go to a local semi truck, industrial repair shop, or ag shop they all use a LOAD dyno to get true readings for a "working motor" which is what you would find in a work truck or a pulling truck where acceleration is slow, but peak pulling power is important.

Now the other side.

The inertia dyno uses a roller of a given mass along with computer to calculate hp based on how fast you can accelerate a given load. These work very well to show hp on a street motor, or a drag race moter because what you really need to measure in this application is how fast the moter will gain RPM not peak torque and HP. These types of dyno machines are very subject to manipulation with diesels because of turbo spool and fuelsystem response to the load affect how the dyno can read the acceleration.

A dyno jet is an inertia dyno, the mustang is a load dyno along with superflow. Certain combinations that work properly will show little difference between the two, A sledpulling combo that needs big rpm to light the charger will show poor numbers on a dyno jet, but will rock a mustangs world. A drag race setup that spools will max a dyno jet out, and will have trouble on a load dyno matching the inertia numbers.


If there needs to be more clarification just let me know or call me at 317 401 4843.

Josh

CTD2001

Very nice write up, thanks for the help in clearing up the difference between the two. Is it possible that a dyno operater could allter the settings on a mustang dyno to yeild lower or higher numbers then a truck could really make? The guy running the dyno said a 2000 dodge made 675hp on his mustang on straight motor with a silver bullet turbo, a Idustrail injection vp44 and a set of injectors and a DD clutch. Only thing the motor had was head studs, no head work or anything else. I found that to be a little fishy when he told me. What does everyone else think of that. Thanks again

DavidTD

Josh, I don't completely agree with this. Anytime you don't accelerate to generate HP you are including the supplied energy of the engines rotating mass as HP generated by the engine. Can we call this HP. Isn't it harder to stop a train after it's built it steam than to stop it while it's trying to reach that potential?

Turbo response is pretty simple and can be mathmatically calculated. 5.9 liter engines will not spool a turbo designed for a 14 liter engine without spinning some stupid RPM. This is what a Dyno Jet tells you. Even on a load dyno, BIG turbo's will loose the ability to maintain RPM as engine RPM falls.

HP IS by definition the rate work is done. The work is the mass movement, the rate is the time needed.

I do agree pullers need to know how their engines respond in a full rpm, load applied situation. This is what they do in competition. Every other form of use, the owner is going to want response, and rapid rpm gain. This is best tested in a inertia environment like you said.

I think you mislead when you said about inertia "These types of dyno machines are very subject to manipulation with diesels because of turbo spool and fuelsystem response to the load affect how the dyno can read the acceleration". The term "manipulation" should be changed to "tuning". You cannot manipulate a Dyno Jet. It gives you what you made and nothing else.

streetsmoker

Yes you can manipulate a Dyno Jet!!! Especially diesels. Just try to tell someone otherwise why you get 100hp less pulling in 3rd gear auto/4-5th gear manual vs. OD . The reason is becAUSE OUR ENGINES wind out without creating and maintaining peek boost and power when in direct drive on that famous inertia dyno. Or bringing your engine up to speed, power braking to spool the turbo, then recording the run. You did not tune a thing doing this, you fool the dyno into reading a more accurate interpretation of power for our application..

signature600

But you said more accurate...isn't that what we're shooting for??

IMHO, if you can't build the same boost on the dyno you do on the street, you didn't load it enough!! If the rollers weigh as much/more than the vehicles turning them, you get good loading. If the rollers are lighter, then you're not getting the same load you do on the street!

Now I know that's not entirely accurate, because of wind resistance on the barn doors we drive, but it's close. Turbo engines need a load to make power

Chris

CTD2001

Well this is some interesting stuff to read, i did not intend to start a dyno war, but i am hearing some great stuff here.