Bad Bimr

Well I gotta throw it back at ya and say you obviously do not know what you are talking about. Drivetrain loss has nothing to do with a dyno. A chassis dyno could care less at how much drivetrain loss a car has. It just measures power at the rollers. I assume what you are trying to say is the difference between a different types of dynos.

dynojet dyno- most commonly used and claimed to output the highest numbers. Wheels spin rollers. NOT load bearing.
dyno dynamics and mustang dynos- lower numbers, load bearing dyno (good for tuning). wheels spin rollers.

Your statements are correct about the "load" and "intertia" dynos, however you are incorrect that this has anything to do with drivetrain loss. It is true that you can add drivetrain loss into some of these dyno programs. Now the the dyno will just estimate crank hp not rwhp. Adding a higher number means bigger numbers and bragging rights. Hell while you are at it throw another 50 hp in for safe measure.

Good info on dynos.

Bill

sleepyca31

You just reiterated what I said-I said specifically that saying 30 percent drivetrain loss on a dynamic is simply an easy way that I am sure he was trying to explain that basically a dynamic reads 10 percent lower than a jet. That is how the tuner explained it so was reitereating-I am smart enough to understand its not going to increase drivetrain loss which is obviously a fixed quantity-but say it how you want-10 percent lower is 10 percent lower. Saying 30 percent loss simply gives you a more comparble number to the dynojets-or you could say a 20 percent loss BUT tag on 10 percent for a dynamic.

So not sure what your "throwing back at me" but you simply stated what I stated and then didnt even read my post-

I could care less-that wasnt even the topic-and throwing in another 50 hp makes no sense-all I said was dynamic reads 10 percent lower than a jet. You also falsley stated there is only a 17 percent drivetrain loss??? Never heard of that my friend. 20 for a stick and 25 for an auto on a bimmer is pretty standard.

Anyway your welcome to your own opinion but not sure what your post had to do with my topic of this thread

Bad Bimr

A chassis dyno does not care about drivetraib loss. It does not matter. It cannot figure it out. It does nothing to the output of the numbers. Drivetrain loss in a car cannot be 20-25% when dynoed on a dynojetwhen and 30-35% when dyno'd on a dyno dynamics. You are confusing drivtrain loss for something else. Maybe it is the correction factor that you are referring to?

Like I said before different dynos give different nubers. You cannot compare one dyno output to another. The dyno dynamics dyno is regarded as "the heartbreaker" becasue it shows the lowest and truest numbers of most dynos. However it does not show the lowest numbers because of drivetrain loss percent.

As for drivetrain loss percent, nobody truly knows what it is however from thousands of dyno sessions it is believed that manual BMW's show ~17% not 20%. As I posted earlier for an automatic I estimate ~25%. Please research this topic by going to a few other BMW and other car forums that are more technical in nature and use their search button.

Bottom line is you should have done a baseline pull. Pull of your mods, do a pull, re-install and dyno again.

Bill

sleepyca31

I dont know bill-I guess you cannot read or choose not to read-I am not going to go back and forth-I guess you need translation into other words-call it what you want-you want to call it a "correction" factor to be happy-fine-the 30-35 percent loss can translate into a 1.428 correction factor-so forget I said 30 percent and just think of a dynodynamic using a 1.4ish correction factor for an auto. and 1.28ish for a dynojet.

Is that better? Nothing to do with drivetrain loss-its just a "correction factor" per each dyno.

Anyway I found 2 people with stock 330s who are going to dyno at the same place/dyno-and they have the exact same engine obviously and hp rating so I will keep ya posted of what they put down-I want to know as much as the next guy if mods are worth it in the end-I could care less, I am of the school of thought-studied economics-that sunk costs are lost-so my money is spent and doesnt matter to me-but I would like to save the next guy some dough if the mods I did were useless so encourage people in the area to run a stock test before they updated their software.

And yes I should have done a stock-I was naive about dynoes and the shop told me they couldnt dyno an auto-I believed them, then did some reading and learned myself about dynos and obviously this is not true-my fault yes.

Anyway take your own car to a dynamic and a jet-you can see for yourself the 10 percent difference

Bad Bimr

It is obvious you are young, naive and do not understand anything about dyno's. If you did understand you would not have posted for help or reading your dyno plot. I tried to help but you will not listen.

Bill

sleepyca31

Well when a dyno plot is completely fked up-yes I agree I had never seen one like that before-Never said I was a pro dyno sheet reader or dyno man-simply knew the diff between a jet and dynamic-dont gotta be an expert in every aspect of dynonameter technology to read for ten minutes about the topic-and how were of any help by telling me incorrect info regarding the dyno numbers-or giving your .02 about the numbers at all-that was not even my question. It is obvious you are old and hit your plateau of intelligence that was less than you had hoped for-sorry about that.

gsi

WOW, OK look there i still hope. first of all both these dynos are faulted, the dynodynamics is a much better and more accurate dyno than the dynojet, but both are useless for calculating flywheel HP. now this may help you... there is a dyno called a MAHA this is the industry standard dyno and in the professional automotive industry it is considered the worlds best and most accurate dynamomiter, also most expensive. this dyno has the ability to calculate (accurately) drive train loss, NOT a gess by who ever is the dyno operator. it dose this by using a cost down resistance calculation as well as obdII interface. this is also the same dyno that is used by BMW both in there R&D labs and in manufacturing assembly plant lanes, and YES this is a officially approved dyno by BMW (this means you will not void your warranty by running your BMW on this dyno). if you would like more info or a location where one can be located PM me. at this time i believe there are 5 in north America.