kell211

does anyone have experience with how much difference the "weight entered" and "hp at 50" numbers have on the hp and tq. numbers a mustang dyno puts out?

my reason for asking is i had gone to a dynojet (which i know reads much higher) and the car did 370 hp. on 16.5psi. then went to a mustang dyno and did a baseline pull with no changes other than 1.5 more psi (18psi) it made 295. I know the mustang puts out lower, but that's way lower.

The guy who had it said they just got new software and it hadn't been calibrated yet. I was just wondering if it was the lack of calibration or the fact the new software said my del sol weighed 2850 lbs. and took 15 hp. for 50mph?

Adi Radoncic

15hp at 50 is way too much, I would say it should be around 12.20mph tops

PeakBoost

we generally run those cars ~10hp @ 50mph and weight at ~2600.
the mustang dynos have been tested as reading .9595 accurate, where the dynojet was something like 1.245 accurate.
we tested our mustang dyno back to back against a dynojet locally on the same day with the same car, zero changes made. the car was an EG civic h22, w/ PeakBoost turbosystem on 8 psi. took this car to a weigh station and certified 2548lbs.
our mustang dyno- 226whp
2 hours later on the dynojet we made 312whp...

the changes to the weight of the vehicle on the mustang dyno will usually show minor increases in whp, but will effect the load scenario.

a mustang dyno can be "tricked" in the cal. files to read like a dynojet, but we are unsure if we want to do this or not...

my best suggestion, if youre "disappointed" with your numbers would be to take the car to a dynojet dyno day, make a few zero change passes and see what comes of it.
the biggest thing to remember is that a mustang dyno is a much better tuning tool than a dynojet, and thats all that really matters. also, trap speeds will tell all

now time to go tune a big block, twin t70 sand car
this one should max our dyno out

ken

Boostfed

I dunno Ken, I do like the Dynojet better myself. We have dynoed cars from one Dynojet to another with minimal differences and also from a Dynojet to a Dyno Dynamics again iwth MINIMAL differences. All these dynos don't require any input of vehicle weight, why should it? The motor is going to make what it makes IMO, the weight of the vehicle shopudln't matter other than weight/load. All my experiences witha Local Mustang Dyno which is now gone is that people would make 200whp and 750 ft-lb torque on a Honda hehehe. Maybe it was the dyno operators BUT they had it for awhile. hehe I prefer a Dynojet myself and yes the #s are higher than most Mustang Dynos, at one point people were saying 15% diff BUT now people come out with higher Mustang Dyno #s then Dynojet #s too, WEIRD!!!!! A dyno is a tuning tool anyways BUT so many look for that BIG #, what matters is the TIME SLIP in the end but this is coming from the BIGGEST DYNO QUEEN OF THEM ALL!

kell211

I'm not really concerned with the numbers i posted. That was the base pull. I was still able to pull conciderably more than that on the mustang dyno.

I'm curious more because I'm trying to figure out if anything had changed or happened to the motor between the dynojet, which was back in the spring, and the mustang. If it had read 15% or so less than the dynojet, I wouldn't have wondered. The 25% discrepency makes me wonder.

So, could there be that big of a discrepency between the two??

tony1

The problem is that there are alot of parameters that must be set on a Mustang dyno. It can read high or low, depending on how it's setup, and that is good and bad. A dyno that is 100% accurate is the goal, but when you give the user control of the accuracy then it all goes out the window. Not saying that dynojet is more or less accurate, but at least accurate to most other dynojets.

PeakBoost

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostfed.com &raquo;</TD></TR><TR><TD CLASS="quote"> A dyno is a tuning tool anyways BUT so many look for that BIG #, what matters is the TIME SLIP in the end but this is coming from the BIGGEST DYNO QUEEN OF THEM ALL! </TD></TR></TABLE>

100% agreement terry

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Not saying that dynojet is more or less accurate, but at least accurate to most other dynojets.</TD></TR></TABLE>

see, this is why i am questioning setting the parameters of our mustang to match the #'s the local dynojets(which read almost identical from what we've seen).

#'s help only to show positive or negative gains from changes being made, with a baseline run or in realtime.

but we all know that everyone loves the big #'s

kell211

thanks for the opinions, the car felt the same going in, compressions still the same, etc. Made a good amount of power over the baseline pull by the time I left.

So, as long as the setting in the mustang dyno can cause such a discrepancy, I'm not going to worry my pretty little head about it.

For future reference, what types of dyno's put out accurate numbers and stay consistant from one dyno of that brand to the next??

sewell94

I've seen a difference of over 200hp between a Dynodynamics and a DynoJet. I know my buddy uses 12% as the correction factor on his DynoDynamic dyno to make it spit out dynojet numbers. Dynos are computers so they are only as good as the guy at the keyboard. Its real easy to fudge numbers. i know one guy who has his set up very overly optimistic. Customers love to see huge numbers, and where does everyone want to dyno, his place, becasue they have a better chance of walking out happier. I have a dynomite dyno. It has so many variables, Standard, Sae corrected, Din corrected, wheel hp, flywheel hp, etc etc. Theres about 20 different corrections built into mine, i have never heard of half of them let alone what the difference is(not that i don't know the difference between Sae etc etc). I leave me settings alone, i don't swap them out to make customers happy, kills the whole point of being able to compare your car to someone 2000 miles away. I know on mine that I can do 10 runs and they will all be right with each other within less than 1% difference. Mine was calibrated at 1000lbs to be off bye 1.14lbs. Thats pretty dam accurate if you ask me. Well why do i use the correction factor?? I use that because that what is everyone seems to compare. Dynojet is the gold standard. Thats all the mag guys used for along time. Its hard to tell a mustang guy that you didn't make 300hp, and see the tears come running down his face Do i think that the dynojet is optimistic, Hell yes i do, but i make sure i tell my customers what numbers they are seeing from my dyno, and i make sure to explain it to them. The biggest thing is that u use the same dyno to make your comarisons on your hp gains, and that dyno operator is using the same settings all the time. Theres alot of dynos now, but not alot of good dyno operators.

B18CXr

I use the HP@50 numbers listed on the Mustang Dyno website under the "download" section.......

http://www.mustangdyne.com/downloads.htm

see:

""Vehicle Test Data""