I've been reading a lot of arguing that the PROOF is in the dyno numbers. Air intake kits, for example, CLAIM to improve horsepower anywhere from 3%-12% depending on manufacturer -- oddly many of them look pretty much the same in their ad photos. So how can that be possible? Well, I just read a great article on measuring Hp by CAR&DRIVER magazine (address listed below) which determined that the same car could be run on different dyno equipment and come out with different results. That single statement means that a dyno chart is NOT PRODUCT FACT. Just like the diet industry -- these results may not be typical and your results may be completely different.

Wouldn't it be cool to plug a laptop into your car's CPU port and see for yourself the difference a mod made -- while you were driving? That would put an end to non-real-world dyno tests. It would allow you to see the results for yourself under "your" normal driving conditions. SURE the results would ALL be different. But it would be hundreds of people's results that we could see instead of just a hand full -- no more of the "he-who-screams-loudest-is-right" mentallity. What would be even cooler would be an Hp readout on your trip computer. It would be just like MPG and everyone would brag over their results.

Point is. Sorry guys. "Show me the numbers" holds no water with me anymore....the results are NOT carved in stone! If you can't simulate road AND wind then the dyno is pointless because the engine is not performing as it would ON THE ROAD in the real world. If you can't bring your car to my town and get identical results on my local dyno (and you evidently can't) ... then it's not worth arguing about. Life's short enugh. Let's stop the bickering over worthless numbers and .... let's DANCE! ..... .... joke (laughter add years to your life - negativity reduces it.) Don't you get tired of the negativity?


You can read this informative article at:
http://www.caranddriver.com/article....rticle_id=8020

OK. You can start yelling now -- let's see who's loudest?

 

This is nothing new. The purpose of a dyno in addition to seeing how much peak power the engine is putting out, is to track change from mod to mod. If you're using the same dyno on the same day and keep everything else constant it is a very effective tool in seeing how much hp that intake/exhaust/pulley/whatever added and where in the powerband the change took place.

 

All this bickering about dyno numbers is seriously dumbing down this forum. Sounds like a bunch of Honda owners :smile:

t.

 

I agree, this is nothing new. Dyno numbers look objective but the testing process itself is prone to bias and inaccuracies. For me, in order to get a grip on any dyno numbers I see I have to know where the numbers came from- who is doing the testing. Are they impartial or do they sell that product? Is there conflict of interest or are they doing independent testing.

Another way to look at any performance mod would be (besides the advertised dyno numbers):
Can I drive with greater enjoyment/ease or with greater safety?
Does it cause trouble or interact negatively with my other mods?
Does it affect the reliability of my MINI?
If I care about autocross or lap times- does it shave time off my run?
Is it a good value for the investment vs reported benefit?
Is it a performance mod or is it really an appearance mod?

 

i agree, while the dyno are useful tools, they are not all equal, and the results will show that, but instead they are very usefull for one to see the effects of mods and such.... the numbers themselves are almost irrelevant, curve shapes and changes are much more important, be it they shape or the peaks you can track the course of the changes and there affects to determine if they are worth while for you the driver of that particular car, once again power in certain areas dont always mean thats what the individual wants, some what nuthing but the peak number they can get while others what alot of low end grunt and could car less about the peak, and there are some that want a nice flat powerband, etc, etc, the result of a dyno are as useful to the individual as to their particular wants, and what it is going to take to acheive that, nuthing more, every dyno is going to mean something diffrent to each individual, one may say its an awesome dyno graph and other will say it is crap, its the nature of the beast.......

 

I've seen a car

...yes, the same car without any changes to the car

...run on the same dyno

...run on the same day within relatively close timeframe to each other

produce three different graphs of torque and HP!


I for one, will go out now and put the 5hp MCS duct tape mod onto my car.

 

Did it - but only adds HP in reverse.

 

According to the article, a dyno performed at a typical "dyno shop" will not be able to simulate real-life driving condition to produce an accurate hp reading. In Dinan's case, wind (air intake) is a major inhibiting factor effecting the numerical outcome of the dyno. Real life driving will supposedly return a higher hp due to higher wind velocity. Hence, it's difficult to determine the true performance benefit of aftermarket upgrades. On the other hand, when different products are dynoed under the same conditions, using the same car and the same dyno, the comparison of the results may be more valid. Unfortunately, dyno numbers is the only way for the consumers to learn about the product despite of their validity. :smile:

 

Yes, this is known and unfortunately many people don't realize it. There are also tricks that you can do to certain dynos to make it seem like you got more HP. It is a good estimator and it is a very useful tool when you are doing your own runs as a measurment device but for all practical purposes it's worthless. In fact I'm sure this has been mentioned before in past threads... I especially remember some heated Magnaflow discussions.

Really, the limiting factor in these cars is usually the nut behind the wheel. Now matter what the car is capable of, it's only as good as the driver driving it. I also agree that there is really no other way to measure what performance parts are capable of. Just realize that when a product says 10-15 hp... expect about 5. It sucks but that's why we have great online sites like this where people (usually) post good baseline runs and then a mod run. Unfortunately the butt dyno is also terribly inaccurate.

 

I've actually seen very few customer dynp tests of products showing before and after results. For lower-priced items, it may not make sense. But for >$500 items like exhausts, chips, etc. it would be great to see before and after dynos done by enthusiasts. Individual dyno runs can be misleading due to errors or maliciousness, or just random variability. A multitude of independent before and after dynos would be great for gauging the accuracy of vendor and manufacturer claims.

 

Thanks. I learn more by reading your discussions than I do by asking a stupid question. And FYI. I think I might try doing a dyno of a new exhaust system so I can see what all this is about. And do some road work to FEEL if there is a change.

So if the dyno can swing, do you think I can have a dyno made of my car at stock, and save that as a reference? Then when I add a mod, re-dyno? Or should it always go from stock to mod during the same dyno-day of testing?

 

>when different products are dynoed under the same conditions, using the same car and the same dyno, the comparison of the results may be more valid. Unfortunately, dyno numbers is the only way for the consumers to learn about the product despite of their validity.


I second this opinion. It's a good way to have some reference point to see if the
product is doing anything. As long as you're having fun with your car, that what
it all matters despite the plots.

 

BuckDodgers wrote: As long as you do your baseline and test on the same dyno, it should be a reasonably acccurate picture of your gains. Temperature, humidity, etc. can all affect the results, and SAE correction can do different things for forced induction than it does for naturally aspirated engines. The whole point is to get a reasonable idea of the effect of the mods, and dynoing the same car on the same dyno is about as close as you can get to finding that out.