info on dyno's

[MT]

hey guys,

was wondering what is the difference between the common floor dyno's and the newish hub dyno's. i know there is a important safety difference but apart from that, is there any major differences between the 2? in terms of power/torque output and things like that? cos we were messing around with a car on a hub dyno last night and the figures werent as much as i had thought they should be, but this car is much much much faster than a stock sportivo. any comments? (waits for rollamods cos he knows everything! :P)

[CHA54]

This exact question has been done to death on many forums. So I'll just make one statement.

Dyno's are a tuning tool.

[MT]

haha ok... sorry for re-posting

but i understand what u mean cos thats what we were doing, we were tuning the car on the dyno and changing the ignition timing for each run looking for gains over the entire rev range, i just know nothing about dyno's really and was only wondering if they are comparable with other results or only for comparing the percentage gains for the car in question... if that makes any sense?

and also if the results we got on a hub dyno would be similar to what the car would get on the floor dyno... or i guess it depends on each individual dyno?

Edited April 20, 2006 by micky_tee

[CHA54]

You can't really compare hub dyno's to rolling roads. The advantage of the hub dyno is you dont suffer from wheelspin (not a problem on sportivo's anyway), the advantage of the rolling road is less setup time.

With the rolling road dyno's the power figures can also vary with the amount of downward force applied with the tie down straps, and when you are trying to combat wheelspin on a vehicle with a lot of power/torque, this is also an issue.

[MT]

cool :D thanks mate. i understand now... no more stupid questions promise :P