Why your Dyno numbers mean Nothing.

[Rdrcr]

We, as modders, need to understand how a new part may perform on our car. We use the data and experience from others to tell us if the expense is worth it. There are some that have been able to do back to back dynoing on before and after individual parts go on, but more times than not, it's a grouping of parts. That doesn't necessarily make dynos inaccurate. They show in real time, what an engine is doing. It's up to those who use this info to make decisions on our own next purchase. I would rather live in a world that all the dyno numbers were out there, accurate or not, rather than a world without any posts with dyno numbers. I can make my own decision about my next purchase based on the varying dyno numbers on a particular part or grouping of parts far better than "seat of the pants feel" or 1/4 mile times.

I include 1/4 mile times because it only tells max effort. I drive my car on the street, so I like to see the torque curve to tell me whether it would be a turd without winding the piss out of it (which is where my opinion lies on comp cams).

I say keep the dyno numbers coming, just post them with the dyno graphs. That's where their real use is!

Agreed.

Dyno's aren't gospel, but, they're a good tool if used properly. More info the better. Keep them #'s coming.

Mike

 

[BV600]

Just to show
I made 515whp on a mustang dyno
then 558 on a dynojet was like wtf?
went to track and trapped 130mph in an auto.

 

[mastwolf]

I use it as a tool as well, but with that said.

When some one posts dyno numbers first thing I look for, is type of dyno, location and correction factor. If you can take those into account, you have a pretty good idea of what to compare said dyno numbers to.


Chris

 

[helli217]

I use it as a tool as well, but with that said.

When some one posts dyno numbers first thing I look for, is type of dyno, location and correction factor. If you can take those into account, you have a pretty good idea of what to compare said dyno numbers to.


Chris

They can absolutely be a great tool, especially when A/F is graphed. Seeing the curve tells a tale, regardless of dyno.

Also, from one dyno to another, if there is a 25% difference, the gains will also show a 25% difference (for the same vehicle, same mods). This is why the details you stated are crucial, because many look for gains only, thinking that gains will be the same no matter what from dyno to dyno. it's a machine, that uses a computer, and therefore a formula to compute and display the output. If the baseline is a certain % off of another particular dyno, so will be the gains.

 

[CodyK7]

Different people are into different things.

 

[mastwolf]

I think the title is a little misleading. Before and After numbers on same dyno are always a plus, but a lot of data can be had from a dyno sheet....as long as all things are considered and taken into account.

I see people getting wiser..asking correction factor...and locations and what Correction was used.


Chris

 

[JohnRichard]

I was sold that a long time but what really convinced me, my car dynoed 486 on a Mustang Dyno with a DA of 4400. I asked the operator if the factor was correct, like three times, the reply, my dyno always shows low numbers so those are correct...
A CJ Boss, monoblade, 1 7/8 long tubes catless H and AED tune... I know AED works magic, but really, 486?

That makes a nice base line to work from, but I will never see that dyno again so it really doesn't matter what that sheet reads.

To be honest I look at the torque curve and HP peak location.

 

[zinc03svt]

Weight of vehicle plus the trap speed give to me the best indication of actual horsepower. ET's show how well you can hook up and drive that power...

 

[D.T.R]

Dyno numbers don't mean much, they it just gives you a ball park. It is however the best tool there is for tuning cars. You can't be doing pulls on the streets for 2, 4, however many hours... while fine tuning a map for the car.
If you really want to see what the car is doing, hit the track. Simple.

 

[pufferfish]

You can't tell my HP from 1/4 mile info any better than 1/4 mile times from dyno numbers. It's all crap. But, in a world where I want to give myself the best possible educated guess as to how a go-fast part will work, I will choose subjective dyno sheets over subjective 1/4 mile times and vehicle weight ANY day.

That said, I have to call out the canned response of "ET is more accurate than dyno numbers". Anyone who says that is full of shit. I guarantee I can get into anyone's car and run the 1/4 mile and get a different mph than they will. I can add or take away 3 mph (depending on the driver setting the benchmark). Does that make me gain or lose hp in their car? Hell no. Wish people would stop repeating this BS. It's actually MORE subjective than dyno graphs....at least dynos take the human element out of the equation! Sorry if I offend anyone. Just sick and tired of hearing this rebuttal Avery time someone mentions "dyno numbers".

 

[Voltwings]

60-100 :rockon: thats how i like to compare, most cars can do it in a single gear, so you just let it rip. Start at 40-50 depending on how your gearing works, punch it, then see where you hit 60 - 100 in your datalog and there you have it. Put foot down and go, doesnt get "much" more simple than that. Obviously altitude and weather conditions nonwithstanding, but its such a short distance that you're less effected by externalities.

 

[pufferfish]

How do you factor rear gears into this method? 3.31's would give a different time 60-100 than 4.10's would.

Here's the real answer....have all the dynos calibrated! Picture an electric driven pair of wheels strapped to the rollers. The electric motor delivers a predetermined amount of power that is calibrated through amperage control to deliver say 300ftlbs. Then, the dyno software is adjusted to match the known torque output. Boom! Calibrated! And then every dyno can be interchangeable and the data would be less skewed. Of course, weather is still a factor, but if DA can account for weather differences in 1/4 mile times, this could be adapted for dyno calculations. How about it dyno operators? Want to put your egos aside and stop fluffing your numbers for science and the greater good of your customers?

 

[Voltwings]

You know i didnt think about that lol, coming from the Ms3 we didnt have different gear ratios so it never mattered... Anyone with a CJ intake and 3.73's happen to have a 60-100? Mine with 3.31's was a 4.45. Remember, 3rd gear only.

 

[beefcake]

shops manipulate them all the time. I've seen cars that put down over 1000 on one dyno, not make 900 on another....

I see people spouting off numbers all the time that are not even in the realistic realm of possibility

 

[BMR Tech]

You can't tell my HP from 1/4 mile info any better than 1/4 mile times from dyno numbers. It's all crap. But, in a world where I want to give myself the best possible educated guess as to how a go-fast part will work, I will choose subjective dyno sheets over subjective 1/4 mile times and vehicle weight ANY day.

That said, I have to call out the canned response of "ET is more accurate than dyno numbers". Anyone who says that is full of shit. I guarantee I can get into anyone's car and run the 1/4 mile and get a different mph than they will. I can add or take away 3 mph (depending on the driver setting the benchmark). Does that make me gain or lose hp in their car? Hell no. Wish people would stop repeating this BS. It's actually MORE subjective than dyno graphs....at least dynos take the human element out of the equation! Sorry if I offend anyone. Just sick and tired of hearing this rebuttal Avery time someone mentions "dyno numbers".

ABSOLUTELY ON THE MONEY - ^ this post right here!

I can make a car run the same ET, but vary MPH by 2-4.....simply by shift point manipulation/changes.

 

[Bdubbs]

shops manipulate them all the time. I've seen cars that put down over 1000 on one dyno, not make 900 on another....

I see people spouting off numbers all the time that are not even in the realistic realm of possibility

THIS. I'm not sure if the dyno I go to reads lower than a lot of others? It seems guys on here all hit 600rwhp with a tvs, whipple, or kenne bell with the same boost,17-18psi to be exact. I told the shop I'd like to be around 600rwhp, and they simply said I'd likely fall short. They were right! They said most all aftermarket blowers on the 03/04 cobras they dyno with same boost all make very very close numbers.

They seem to have a very good idea what cars will make around after knowing all the customers mods before they even dyno them.

 

['14 Shelby]

Voltwings: agreed. Too many posers posting as an extension of their dicks.

Wait you mean having a badazz car with the highest HP # is NOT a dick extension? :cuss:

 

[vortecd]

You can't tell my HP from 1/4 mile info any better than 1/4 mile times from dyno numbers. It's all crap. But, in a world where I want to give myself the best possible educated guess as to how a go-fast part will work, I will choose subjective dyno sheets over subjective 1/4 mile times and vehicle weight ANY day.

That said, I have to call out the canned response of "ET is more accurate than dyno numbers". Anyone who says that is full of shit. I guarantee I can get into anyone's car and run the 1/4 mile and get a different mph than they will. I can add or take away 3 mph (depending on the driver setting the benchmark). Does that make me gain or lose hp in their car? Hell no. Wish people would stop repeating this BS. It's actually MORE subjective than dyno graphs....at least dynos take the human element out of the equation! Sorry if I offend anyone. Just sick and tired of hearing this rebuttal Avery time someone mentions "dyno numbers".

Some people just can't drive a stick but not every car is a stick. With traction an auto should run about the same time no matter who is driving.

Now a little dyno shootout (same day and dyno) can be fun

My goal with my '13 was to run 10's, not make X amount of HP

 

[BMR Tech]

With traction an auto should run about the same time no matter who is driving.

This is true, however, judging power from the ET/trap speed, still isn't really valid. Plenty of automatic cars run different ET/MPH through the traps, with the same power output. You can manipulate shift points and vary your MPH, with an auto or a manual trans.

My goal with my '13 was to run 10's, not make X amount of HP

I would say my goals are to make the most power possible, and run the best ET/MPH possible. When you get into heads up racing, searching for every last hp possible is typical....and applying it to the track, is the most important aspect of it all.

It still takes XXX amount of power to run XXX ET/MPH. When it's all said and done, if two similar cars, make a difference of 50rwhp....the 50rwhp car will/should be quicker and faster. That is not always true, but in the hands of the same person, it is. Hence the reason the power output (knowing it) is so important for most racers.

 

[Rusnak_322]

So i see a lot of threads in here where people talk about Dyno numbers, but i don't think they truly understand the point or purpose. Sure every once in a while the sharp witted person makes the comment that the weather was different, the altitude is different, correction factor... There are things i feel most of us know.
However, tell me you haven't seen the "Thats all you made? I made 4xx with just an intake, x-pipe and bama tune!" comments once or twice. ^^ That statement literally means nothing.

A dyno is simply a means of tracking gains. If your bone stock 5.0 makes 300 whp on your baseline, and 380 when you're done modding, you have made 80 whp over stock. If your bone stock 5.0 makes 400 whp on your baseline and 480 when you're done modding, guess what... you have still made 80 whp over stock. The gains in both situations are exactly the same, the starting and ending numbers are useful for nothing other than tracking gains... or bragging rights i guess.
Yes, obviously there is a ball park every car should more or less fall into, but in the end its still superficial. This is why simply going in to a random shop and just getting a dyno and saying "i made XXX horsepower," doesn't really mean anything to anyone... Congratulations, but how much is that really? Or as they like to say "What does your dyno sheet trap?"

If the car making 380 whp in the above scenario raced the 480 whp car, who would win? Well, based on dyno sheets alone, the 480 whp car obviously. Well, considering these are both 5.0's that have made 80 whp over stock, we can actually assume the race would be pretty close. This is typically where your "driver mod," "sandbagging," and all matter of other comments come into play, because people just don't really understand a dynos operation i feel.

Below is a semi-satirical video made by AMS which touches on the subject of dyno manipulation. Not to say a shop will willingly manipulate their numbers, but to show how variances across the board can lead to different numbers, on top of other variables.

https://www.youtube.com/watch?v=sDwjfZvmPHg

If you start out with 300 Hp and finish with 380, you did better the the guy who started out with 400 hp and ended with 480. You both made an additional 80 hp on your respected dynos, but the guy starting with 300 had a larger increase in the percentage of power from baseline.