chassis dyno

[Mike Taylor 3601]

Only have used Dynojet on it you get car in hi gear or 1-1 get rpm steady as can for start RPM hand held controller gives operator green light then driver goes WOT get to upper RPM point let off throttle dynojet has airbrakes on drum that stops drum after pull.
You can start whatever RPM you want but has to be around converter stall,if you try to start below that it's just going to go straight to flash point of converter anyway.
Dynojet has knurled rollers the one I used has 48'' rollers the bigger the rollers the better the traction you get I've heard small rollers are hard to get repeatable results on,I still like engine dyno over chassis anyday,It's alot easier to get them to repeat,one reason is you eliminate a bunch of varibles getting rid of driveline and you can control your oil/water/air temps on engine dyno.
As far as numbers go the Dynojet numbers were real close to what they should've been compared to what engine did on our Superflow 901,the HP was about 25% less at the wheels than engine had on Superflow 901,the dynojet is about 275 feet from the Superflow and cell.I'm just talking about one car I know well my own.
When you start getting big #'s it starts slipping tires,had Procharged SBC was in 990's HP range @ wheels,had 10.5 X 28.5 MT's it was spitting a little rubber mist out the back,had dodge w/cummins was flat lineing TQ from 55-85 mph on graph TQ shows up to 1200lbs graph went up steeply 55 mph would flat line till about 85mph don't know how high it peaked took about 1.7 seconds to go through pull,may had traction issues,but could'nt notice them.
The main thing is don't get caught up racing dyno's,don't worry about what someone makes on another dyno,learn how fast X amountHP&TQ on dyno you are using will make your car go.
Mike Taylor 3601