You still haven't posted any specific facts to back this up. Please do so or refrain from making such bold statements.

 

https://www.evolutionm.net/forums/ev...-round-xx.html This is the DD vs. Dynojet comparison he was talking about. The statement isn't very bold at all. The bold statement would be to say it's not true, so how about defending your perspective WITH SPECIFICS FACTS.

 

How do you know it's not the Dynojet that's the most accurate, and the others aren't artifically low? Are engine dynos load or inertia based? The thing that's always bugged me about any dyno is that people throw a fixed percentage to account for drivetrain loss vs. flywheel power. I think that's extremely illogical.

For example, let's say you have a stock Civic. Let's say it's 100 flywheel horsepower. On a dyno it makes 90whp (FWD, relatively low drivetrain loss). So that's 10% loss. Now you build a turbo engine, re-dyno using the same exact clutch, flywheel, trans, axles, brakes, tires, basically everything that can contribute to "drivetrain loss". You put down 450 whp. At the same 10% drivetrain loss, that would mean it's making 500 crank hp. Here's the point. The stock setup lost 10hp to drivetrain loss, while the built setup lost 50hp. There's no logic there.

Someone needs to put two engines, one stock and one fully built, on engine dynos and then drop them in the same car back to back and see what the drivetrain loss really is. I'd bet that it's far from a fixed percentage of crank horsepower.

 

Just to clarify, are you disputing that DJ's read really high compared to DD's?

I hear you. And this has been debated a million times over. All I can say is some vaious spec engines have gone from engine dyno to DD in the UK and 24% rule has held very well. Also consider a normal stock Evo 9 makes about 220 atw on a DD which if you apply the 24% rule you get 289 hp which is spot on as well.

Now the 24% rule I would not describe as transmission losses, because many of the losses are throgh the tires. Now can 24% of 700 hp be "lost"? Is that physically possible? I'm not qualified to answer that question except to say the number has withstood some limited testing in the UK.

 

x2

Car came off the inertia dyno and set the stock turbo record first pass and red record second pass. No logging or set up, just adjusted tire pressure. Car idles and runs like stock Thanks to Crispeed and Mikes dynojet.... But besides all the debate, to me any dyno is just a tool.

 

I'm sorry but crcain arguing and or debating or whatever u choose to call it with Chris is just getting comical.

 

Some of the best engine tuners in the country are directly involved in professional racing series and I can guarantee you they did not tune on an inertia dyno.

 

i thought Crispeed tunes your car or is same guy?

[Sounds like the Chris that tunes my Cars.. Quite honestly without trying to stir **** he HATES the dynodynamics and mustang and i am going to say he is one of the best TUNERS in the country.. Not a dyno operator but an actual tuner.. My RS went right from the inertia dyno the 1st time and in 5 passes down the track ran 8's in street trim.. We didnt touch, log or adjust anything right off the trailer..]

 

In P.R are like 7 Dynojets that comes to my mind and 2 Mustang.i have ran all this dynojets with exact same accurate hp,a few hp up or down on a 430hp car with out correction since most dynos here are at sea level but humidity and temp are very high here and climbs the hp a lot if use the Sae correction factor.the Mustang there are one that reads higher than the Dynojet,the other read lower than the Dyno jets,to be presice 10% lower on all cars i have compare ,this 430hp nissan made a best of 390hp on the Mustang without touching the tune two days later at same temp and humidity,in PR this is very consistent,90humidity and temp of 85-90 f.what dyno i use?,the low reading Mustang,cause is a close friend,have a better and consistent reading Innovate wideband,in turn all dynojets i have use have diferent A/f readings,i know you can manipulate the Mustang reading by increasing the size of the Roll diameter,my friends is 50".if he inputs 52"to the software, hp can increase as high as 30hp on 300hp car,i hate cheaters.with the load i get a more consistent a/f reading ,egts,timing setup,builds more boost sooner like in the street and very accurate day to day measurement,when the Mustang is out of service,i do the all the tuning in the street and then go to the Dynojet to make my customer happy.

 

I don't really have time to sort through that entire thread. But that has nothing to do with this subject anyways. You are taking one dyno with a certain correction factor against another dyno with a possible unknown weather correction factor which can lead to all sorts of large differences. That test is great for those two dynos, but does not translate to all dynos in the entire world.

Once again, the adjustability of the dyno's is what makes them inaccurate for comparing across the country, or just across cities.

Dynojets CAN read really high compared to a number made on dyno dynamics, depending on the way that is is setup. Because you can get the dyno to read almost anything you want it to, this argument is a moot point.

I'm glad that you have a rule that works out numbers wise between two specific types of dynos that you have in use. My personal opinion is that 24% is a very high, unrealistic figure to compute for drivetrain loss. I would be interested to see what a GTR puts down on a DD, as their drivetrain losses have been specifically calclulated by the OEM. For reference a stock EVO 8 motor will put down between 230 and 245 whp on our dynojet

I'd appreciate some more information than that if you want to be a contributor to this discussion. Do they not use them for a specific reason? Do they tune the engine on an engine dyno first? What racing series are they involved in... ETC!


To clarify quickly. I am not saying any one dyno is better than another. I am just trying to have a discussion and understand why so many people are consistently bashing one dyno or another and putting out huge numbers on this dyno, or saying that another is a heartbreaker. It is obvious that a few people are deeply rooted in their feelings and do not wish to admit that something may be able to be improved upon on their equipment of choice. I am not arguing that load control is a bad thing, I am not arguing any point really. This thread is meant for informational purposes only. If you have some hard, raw data to support any point you wish to make, I would love to see it!

 

What? You really don't believe there could be a 24% loss of power through an all wheel drive drivetrain?? 24 may be a little high, but it has to be close to 20.

Are you saying a bone stock Evo 8 has put down 245 on your dyno also. Hell that engine was only rated for 271. That would only be a 9.6 % loss.

I am not going to argue if load bearing is better or not. It's personal preference to the tuner if anything. You mention "heartbreaker" which I most commonly hear Buschur's dyno referred to. Why does it bother you? Is it not true that his dyno reads significantly lower than yours? When comparing hp figures as car enthusiasts tend to do, there has to be that notation of what dyno was used. ie. Take a 430 hp Evo off of your dyno. Can it run high 10s? No. A 430 hp Evo off of Buschurs is good for high 10s though. Obviously both cars don't really make the same power. So now when two guys are talking about their 430 hp cars without saying what dyno you wouldn't really know how quick the car is.

 

+1, I am not trying to add fuel to the fire, but I have to take sides in the lower portion of your statement that I made bold. My dyno reads pretty damn close to buschur and cbrd. I don't know of any cars that can knock off high 10's with 430whp coming off of a dynojet that isn't a tin can weighing under 2000lbs.

 

Yes, I do believe that 24% is a bit high. 9.6 is also very low. I've always thought that 10-15% has been a more acceptable figure.

Also, the notion that there could be a 24% drivetrain loss or even a 15% drivetrain loss on a car making 600whp is a bit out of control. That means that a 600 whp car would be making 744whp @ 24% loss and 690 @ 15% loss.

You say HAS to be be close to 20 which I still think is very high, but I don't have any evidence to prove you otherwise, just like you don't have anything to support that claim.


Typically those dynos will read lower than ours. I don't have a problem with that. I definitely think that which dyno the car was on should be included. Let me know if I'm misinterpreting what you are saying here...


I'm not disagreeing with you at all. Drag times have alot to do with the driver however, which is good to keep in mind. Hell, if you put me in one of those car I will probably runs 12's because I can't drive anything that isn't a reverse manual vale body 3 speed. MPH will be effected by the run, but I like to refer to it more often to get a better guess of how fast the car is going.

 

Good to see some humor

 

For ****s and giggles, how does a SuperFlo come into play in all of this? Closer to a MD, DD, or DynoJet?

-E