pulley kit and other basic mods comparison

[Spuds]

Originally Posted by nikitopo

Math do not lie, but you have to model the problem correctly. You asked twice about total weights and diameters. A total weight and diameter is enough ONLY for the solid pulley. On the OEM pulley you have two different pulleys the one inside the other joined together with a rubber. You need the diameters of both and the weights of both. No one can really provide these numbers, unless someone takes apart the pulleys and measures the two weights. Then you have to create a model that the inside pulley is rotated by the center hub and the outside pulley is rotated by the inside pulley. With such model you would find that the rotation inertia is MUCH BIGGER and it not only relevant to the weight difference. As said before it is a complex problem and there are unkonwns in the equation (i.e. the weights of the OEM pulleys). It is much easier to make some measurements and see how the car behaves with standard tools like the virtual dyno app.

Are you trying to imply that the inside and outside parts of the crank pulley rotate at different rates? The angular velocity and acceleration of all three pieces (inside metal, outside metal, and rubber gasket) are the same. They can be treated as a single item for this purpose.

I'll tell you what, I'll even pretend the pulleys are thin-walled cylinders of the outside diameter to give you the maximum possible inertia improvement. I still feel modelling the pulleys as solid disks is the best approximation for a comparison, seeing as aftermarket can't actually change much about the inside hub or outside surface without compromising function, but whatever.

[Tcoat]

Originally Posted by nikitopo

Of course I have done this many times and published results in scientific journals. It is very common when you are modeling a problem mathematically to verify somehow your conjectures or even have an expert from another area that will check the results and tell you if they make any sense or not. There exist even journals that will not accept any theoretical model without additional practical evidence or some kind of application.

The Flat Earth Weekly is NOT an accredited scientific journal.

[nikitopo]

Originally Posted by Tcoat

The Flat Earth Weekly is NOT an accredited scientific journal.

No, I am not posting on this one. I am posting on the Flat Earth Monthly

[churchx]

Tcoat: blashpemy. Flat Earth IS fundamental science. You are old man that hangs on to old misconceptions opposing modern creationist scientist findings! There are brave heroes on youtube, that build rockets to prove the flat earth truth that reptiloids tried to hide from humans. Luckily there is hope for humanity. Once creationism will be taught in US schools, there will be more and more people enlightened with divine truth!
Now .. do you want to talk about God? I have some bibles to sell ..

[nikitopo]

Originally Posted by churchx

Tcoat: blashpemy. Flat Earth IS fundamental science. You are old man that hangs on to old misconceptions opposing modern creationist scientist findings! There are brave heroes on youtube, that build rockets to prove the flat earth truth that reptiloids tried to hide from humans. Luckily there is hope for humanity. Once creationism will be taught in US schools, there will be more and more people enlightened with divine truth!

Truth is that Tcoat knows to be in a good mood!

[wparsons]

Originally Posted by Spuds

And I'll repeat my question. What is the actual weight (well, mass really) of your car at the time of the run, and how much fuel was in it? I'm pretty sure virtual dyno follows an equivalent energy strategy to calculate output. For that you need an absolutely accurate mass.

A heavier vehicle takes more energy to accelerate to a given speed as a lighter vehicle. If that acceleration is over the same period of time, the heavier vehicle will have had greater power applied. Virtual dyno probably starts with the acceleration numbers and back calculates the amount of energy that must have been put into the vehicle using the kinetic energy model. If your mass is off, your power output calculations are off.

Plus it assumes a 100% perfectly flat road with no wind. To rule out slope or wind you'd have to do pulls in both directions and average out the graphs.

[tomm.brz]

Originally Posted by nikitopo

I have also logs with 3rd gear and the results in virtual dyno are a bit better in the range of 198 whp. For me it doesn't matter if it is 194 or 198, but that they are much higher of what a stock car would give. You cannot really attribute these figures on the catted +17 OEM header or the tune. Something else must contribute to these numbers!

"fantasy" can contribute much to these numbers on your car
lol, now 198whp, every week something more
engine wear must do miracles for you

[nikitopo]

Originally Posted by tomm.brz

"fantasy" can contribute much to these numbers on your car
lol, now 198whp, every week something more
engine wear must do miracles for you

It is well known that higher gears will give more hp on the wheels even on a stock car, but as usual you like to make personal attacks.

[Ultramaroon]

Originally Posted by nikitopo

Of course I have done this many times and published results in scientific journals. It is very common when you are modeling a problem mathematically to verify somehow your conjectures or even have an expert from another area that will check the results and tell you if they make any sense or not. There exist even journals that will not accept any theoretical model without additional practical evidence or some kind of application.

I dunno, man. I smell what must be either troll, or the crazy.

[KR-S]

Originally Posted by nikitopo

We are not trying to prove here how much the gains are, but if there are in general any gains at all.

I don't get this then. Assuming there are MARGINAL gains at best, it would still be unwise to install a pulley kit because the drawbacks still far outweigh the benefits.

It honestly sounds like you're trying to justify out your ass your purchasing of the pulley kit.

[nikitopo]

Originally Posted by wparsons

Plus it assumes a 100% perfectly flat road with no wind. To rule out slope or wind you'd have to do pulls in both directions and average out the graphs.

I checked for elevation differences with a gps device. Your comment to make pulls in both directions doesn't make much sense. You cannot make the test at the same time and if there is wind, then it might not be steady. It can change direction or intensity. The best option is to avoid windy days.

[tomm.brz]

Originally Posted by nikitopo

It is well known that higher gears will give more hp on the wheels even on a stock car, but as usual you like to make personal attacks.

it is not a personal attack since i do not offend or literally attack you in any way
it s just that you say your car makes 198whp together with other things that have no sense, i say it s impossible and since it s an open forum I answer when i want. Report my replies to a mod/admin if you thing you should do it, i guess they will decise wheter I m attacking you or no?
Virtual dyno is not a proof, proove what you say with a dyno and everybody will stop debating with you, you can trust this
open a crowfunding if you don t have money to take a measured real world dyno, I could even contribute to it : )

[D_Thissen]

Originally Posted by nikitopo

I checked for elevation differences with a gps device. Your comment to make pulls in both directions doesn't make much sense. You cannot make the test at the same time and if there is wind, then it might not be steady. It can change direction or intensity. The best option is to avoid windy days.

The best option is put the car on a dyno, do multiple runs and then compare results.

[nikitopo]

Originally Posted by tomm.brz

Virtual dyno is not a proof, proove what you say with a dyno and everybody will stop debating with you, you can trust this
open a crowfunding if you don t have money to take a measured real world dyno, I could even contribute to it : )

Hahaha ... are you serious? No one will stop debating. At least not the known ones over here. They'll start questioning about the accuracy of the dyno, the number of the pulls, the way the car was strapped down, the weather or temperature conditions and whatever else you can imagine. It has been done numerous times and not only about pulleys.

I remember similar debates when the same people were questioning about different air intake systems. They were insisting that there were zero gains even after real dyno evidence. Of course, no one from these people would accept the more obvious thing that a different air intake could provide REAL gains just because it was manipulating the MAF readings and you could have a leaner AFR. It is what it is with stubborn people. They'll never change ...