Why Don't People Question This?

final5-0 · Jul 20, 2008

I found some time to cruise the various Stang boards this afternoon

I was happy to see many threads with dyno results

I did find it interesting to see very few people asked about

Was it a DynoJet or Mustang Dyno

Was the pull done with a Standard or SAE Calibration

It seemed like whatever numbers were stated
or
Whatever kind of sheet was posted

People were throwing them all in the same category

as if they'd all be on an apples to apples comparison

Anybody besides me ever notice that

Grady

DDSTANG94 · Jul 20, 2008

i do, and i dont think many people are aware of the significant differences there can be in certain dyno's and certain corrections...

Perfect example, I just had my bike dyno tuned on a factory pro tunning dyno....for anyone that no there modo is "TRUE horsepower" they call it that becase they dont have 5 correction factors like the dyno jets..the dyno jets read much higher that your actualy putting out...the tuner said to get the numbers i would have seen on the dyno jet i would have to multiply it by 1.15.. Factory Pro: Producers of the EC997 Low Inertia Eddy Current Dynamometer Series and Quality MC performance products read theres very good stuff in here

go to the true horsepower scale!!!

blksn955.o · Jul 20, 2008

Go to the track and street IMHO.

A dyno is nice to compare mods, A/F changes, and get a baseline to see were you stand. But who cares if you got a sheet that says 500hp and you can only run 13's...the real world is the street/strip.

I say street not for racing but drivability. It just takes longer/more people to deal with on the street or at the track than just your car on a dyno and those running it.

That said the dyno is a great tool but I think people get too "into" the numbers.

final5-0 · Jul 20, 2008

I certainly do see what you are saying here

One problem I got with using 1/4 mile results is .............
Driver skill ... or lack of it ... has SO MUCH to do with the outcome

Another problem with going to the track is ........

How well the car is setup to be effective at laying down a respectable
sixty foot which we all know is a MUST for the most efficient et

Neither of those issues come into play when you dyno

Of course ... dyno results are not without their draw backs as well

There are those shops who purposely do things to inflate results

Peeps can do tricks such as do their pull with no Serp Belt and
conveniently forget to say so which will elevate their results

anyway ........

I have an opinion DynoJet pulls with SAE calibration are a way to
keep different locations, weather, altitude, etc on a fairly even
basis to compare combos.

I have noticed fewer and fewer dyno pulls are done these days
under those conditions and I guess I can understand as the
Standard method of calibration seems to usually produce
results higher than SAE.

I welcome any thoughts or discussion or reasons why I might
be out there in left field on this subject

I just thought it might be interesting to share what I've noticed
and hoped to spark a discussion from my fellow SN friends

I certainly don't have all the knowledge about this subject

I've always found it interesting to compare the various combos
one can find on these boards

I usually do focus on those done on a DynoJet and try to make
sure the same calibration is used on both combos when I do
up one of my comparisons.

Almost forgot

Yes ... I too think one can get caught up in ... Just The Numbers

I do focus on the SHAPE of the hp & tq curves W A Y more than
just the peak numbers

Grady

Pokageek · Jul 20, 2008

Thanks for posting Grady. Yo uand I agree and disagree on some things and thats ok. But I think you are right. Plus you have shops that inflate numbers I am sure. One shop that doesnt do that is SGS lol. I like the fact that they are telling me how it is. My car was not putting out a lot of power and they didnt hide it.

I dont understand the diff between sae and std but I can do a search on it. I am sure theres also lots of peeps that do stupid tricks. BUT for example in my cobra thread. Mike said something about a cobra that put out X rwhp. When I factored that the car weighs (or should weigh) roughly 3700# I can estimate that his dyno numbers were prolly correct becuase the guys times were .5 tenths slower than they would be in my car being 94/95 is much lighter.

SO my point is the only way you can really trust a dyno result is if you know:

1. The shop.
2. Calibration used.
3. The QM result including the driver skill and gearset.

Even then its a bit of a crapshoot but closer.. All these dyno numbers randomly posted....I call BS. We prolly should pay little attention or add a disclosure..+ or MINUS 50 rwhp, lol.

The O.G. · Jul 20, 2008

there should be one standard imo

guessing what a car would do in a cold/hot ,high and low elavations etc?
correction factor ?i ..ts still a guess but it is a bit fair

i have wondered how cars were dynoed with an auto compared to a stick?
my 5spd is done in fourth gear..when do the autos get floored?
which is more consitent with each other?

anyone do their own driving while on the dyno?

dynometers are expensive $

blksn955.o · Jul 20, 2008

Autos get dynoed in the 1:1 gear as well...a non O/D auto like a th350/th400 and a C4 would be the 3rd gear. An AOD/7r40 would be the 3rd gear as well but with O/D turned off to keep the car from going into that gear.

If you know the 2nd/3rd gear ratio's you "can" recalibrate the dyno for those gears to keep wheel speed down...it would be easier to just do the 1:1 as so many cars have so many diff. gearsets.

tstang21 · Jul 20, 2008

i totally agree on what you are basically saying. when its comes to dynos, people get to much into the numbers. ive plenty of cars making 500rwhp, but on the street/strip, they get blown out by cars making 250rwhp lets say. its comes to tuning and driver skill. to me, numbers dont mean nothing. its in the SOTP feel and how the car drives :Track:

Black95GTS · Jul 21, 2008

I totally agree with Grady. The first thing I look for is "correction factor." Then there is also "smoothing."

In terms of the actual dyno... I think unless its an engine dyno, you don't have an accurate picture of what the motor can do. Chassis dynos, in my opinion, are useful for tuning but not so much for determining the actual output of the engine. Or how fast the car will go.

Adam

final5-0 · Jul 21, 2008

tstang21 said:
i totally agree on what you are basically saying. when its comes to dynos, people get to much into the numbers.

Yes ... Yes ... Yes ...

We have a winner ... Give this man a Chicken Dinner

ive plenty of cars making 500rwhp, but on the street/strip, they get blown out by cars making 250rwhp lets say. its comes to tuning and driver skill.

A certain percentage of this kinda thing is always gonna be present when
you compare different cars.

High HP STREET CARS usually aren't setup all that great to do the 1320 thing

Its easy to see why a car with CONSIDERABLY LESS HP and can hook
good enough to sixty foot reasonably well could make one look bad

to me, numbers dont mean nothing. its in the SOTP feel and how the car drives :Track:

You are so right when it comes to most cars that are driven on the street

Its all about the shape of the curves :Word:

How quick the tq curve jumps up
and
How long before it starts to drop

Grady

Zero Signal · Jul 22, 2008

Butt dyno is king in my book.

rj95svt · Jul 22, 2008

Everyone loves numbers!! but not enough people know enough about these dyno's to know that there is more than one correction factor and that dyno's are not all the same.

gcomfx.com · Jul 22, 2008

Easy answer Grady....

I don't question them, because I don't care about them. I know the system is flawed. Give me track numbers any day. Sure they throw in driver ability, but you know what. At the end of the day, if I were to pull up next to them on a deserted road. Driver ability is VERY important. :wink:

Why Don't People Question This?

final5-0

Mustang Master

DDSTANG94

New Member

blksn955.o

final5-0

Mustang Master

Pokageek

Active Member

The O.G.

Member

blksn955.o

tstang21

Member

Black95GTS

Active Member

final5-0

Mustang Master

Zero Signal

Active Member

rj95svt

Member

gcomfx.com

Similar threads

Why Don't People Question This?

Mustang Master

New Member

Mustang Master

Active Member

Member

Member

Active Member

Mustang Master

Active Member

Member

Similar threads

Privacy & Transparency

Privacy & Transparency