I have to say my experience with chassis dyno tuning has also left a bit of a bitter taste.
3 times, different places, initially happy but not happy for very long afterwards, because the car doesn't drive on the street much better... even though i have a print out with a bigger set of numbers on it
i went fully computerised, i went to a guy with a portable set of rollers, and i went to guy in his 80s who's prehistoric dyno just lifted a large weight on a chain in the corner, he was the best but none of them spotted the issues.and the last guy charged my £80 on top for a set of NGK7 which i could have had for £30...
unless you are willing to pay for drivability tuning, and engage with the business for a full morning or day like you were doing full ecu mapping, and the dyno operator is engaged enough to allow you to swap springs in the dizzy etc
you end up with a 2 hour session that focuses on all out power and a result that gets you a little more BHP at a point in the rpm range you might just hit if you gun it off the lights. You get a nice print out with your bill/invoice, they might even put it in a folder, and you leave £200-400 poorer.... and with not a lot of difference on the street on the way home.
Its not like on TV or YouTube, their ain't no gang of cool car dudes with cotton reels in their ear lobes all doing amazing stuff to your motor to wring that last oz of torque out of it.
just a bloke in ear protectors who looks like he can't wait until you leave and he can get back to tuning something with his laptop rather than jets...
Seat of the pants is free
lambda sensor and gauge is 200-300 and you get to use it for ever.... not 2 hours
in summary if you go to a chassis dyno do not choose to do what they advertise, they all have their price list and its not for customers like us.
Make sure you tell them exactly what you want out of the session and get a quote.
Choose one that knows what a carburettor is or is willing to let you take part doing the stuff the laptop guys won't do...
maybe this is just a problem here in england...but many are supremely good at removing cash from your pocket for very little gain.
turn up with a nissan skyline or toyota supra and it may be a different experience....
Dave