Good dyno tests of modifications (video & screenshots)
 

There are a lot of people out there who will test something on a dyno and post a video or a screenshot of the readout showing HP and torque changes. Often, the tests are done to see how the car overall is doing after several modifications and tuning. But this thread is for collecting links to a smaller set of videos and posts that test individual mods. Some are good tests, and some are not good tests. But any video where they make a reasonable effort to control conditions as well as isolate the mod to reveal its effect on power output on the dyno is good enough for this thread. If this thread goes anywhere and a real list develops, I will come back to add an index to this post, with permalinks for results below.

First up, a pretty good test of a throttle body spacer by LHT Performance. LHT is a great veteran Honda modification outfit. I came across this test a few months ago. The heart of the testing begins at 11:40:
https://m.youtube.com/watch?v=hO58Dmt6uMY

A pretty good test of a K&N airfilter versus stock and no airbox. K&N made more power and torque above about 3000 rpm, but no improvement below. No airbox LOST power.
https://m.youtube.com/watch?v=PSTl3aAuX98

BUT have you also accounted for famous K&N lack of filtration? The tales of dusted Ford turbo inlet wheels..........

Yeah, good point. Beware how K&N might accomplish high flow through an otherwise stock throttlebody/manifold. The thing is not even designed for a specific vehicle, so ... not much "tuning" involved.

Until high quality aftermarket and OEM examples of electric superchargers and turbos started appearing, the little pointless novelty fans that called themselves electric turbos got nothing but the mockery they deserved. Cletus even got in the act, making a funny dyno test video of a cheap electric turbo. Then he got shipped this high quality item, decided to dyno it, and got millions of views with their dyno results. Enjoy.

https://m.youtube.com/watch?v=7a_J2X88fSE&t=135s

The popular YouTube channel "ChrisFix" runs a dyno test of a fuel additive and ... MORE POWER! Hahaha... YMMV
https://m.youtube.com/watch?v=VDUogAQzLAc

Two videos.

1) A dyno test of the "first" hybrid race car of its class (not F1). Results are somewhat disappointing because it was still in development:

https://m.youtube.com/watch?v=BCKgxGhM2eA&t=673s

2) This previous video itemizes the hybrid features before they were installed: thoroughly a serious race car:

https://m.youtube.com/watch?v=IzhvaGnEkJo

So this guy spends two whole days dyno testing multiple runner lengths, diameters, bellmouths, and bends (even some peaches cans). He comes to the conclusion that the OEM arangement with filter was best for producing power:

https://m.youtube.com/watch?v=nqYkmCLrlEo

:thumbup:

EDIT: Oops, wrong Tucker video. This one is about peak HP, not top speed. Sorry.

An unusual dyno test of a Tucker (#44) where top speed and not HP is measured... so not really a "dyno test" ... not a test of a modification either unless TIME is the mod. ... but c'mon, aint it cool to see this old steel hit top speed?

https://m.youtube.com/watch?v=eg9BnSiG-rI

Interesting tests (maybe not "good")
 

Here a dude tests an underdrive pulley. Although he is careful to use the same machine before/after, we don't learn anything about the ambient air temp or the condition of the car. And I am very skeptical that an underdrive pulley can make this much difference:
https://m.youtube.com/watch?v=66HabFCHTAc

This video is a nice dip into car culture on the subcontinent. Not realky adyno test of a mod, but more of a dyno test of loss of power due to age. These guys think they have shown there was almost no loss of power in 12 years. However, the change in HP could just be an artifact of the test itself:
https://m.youtube.com/watch?v=Pog0uNl8jO8