best gear to dyno on ??

[moparracing]

i'm likely going to the Mopar Dyno Day here in Vancouver on Saturday........ My question is what gear should i be in when i dyno ?
any other advice on the subject is appreciated, thanks.

 

[Dave T(BADVENM)]

You'll want to dyno in 4th gear, start the dyno recording around 2500 rpm up through redline or very close to it.

Make sure when you dont have obstructions behind the gas pedal like floor mats and stuff. Also, as I found out once when I did my stock reg cab I didnt have my foot all the way to the ground on the gas pedal, lowering my numbers. If its a Mustang dyno dont be alarmed if the numbers are a bit low...its typical. If its a Dynojet they'll be typically higher.

If you plan on further modding of your truck try to go to the same dyno...it will be like comparing apples to apples to compare the before and after your possible later mods.

 

[Silverback]

Dave is correct, kind of. With your truck it's done in 4th gear. But the thing is that dyno pulls should always be done with the transmission in a 1 to 1 ratio. That varies between vehicles.

 

[ViperTruck2933]

One other point that may or may not be well known....Your rear gearing will slightly affect your dyno reading.

On the same truck,
4.10 rear gears will read a little higher hp than 4.56s
4.56s will read a little higher than 4.88s, etc...

All the 4.88 gear dyno's that I have seen on our trucks have been comparatively low.

 

[moparracing]

thank you dave, john & tim for your input - much appreciated !!!!:rock:

anyone else ?

thanks.

 

[kcsr]

One other point that may or may not be well known....Your rear gearing will slightly affect your dyno reading.

On the same truck,
4.10 rear gears will read a little higher hp than 4.56s
4.56s will read a little higher than 4.88s, etc...

All the 4.88 gear dyno's that I have seen on our trucks have been comparatively low.

offhand, do you know what the exact differences would be?

 

[AWDisuzu]

people prefer 4th gear typically. I personally start my dyno readings at the lowest rpm I can. if you're spraying NOS or supercharged it's better to use a lower gear to put less strain on the motor. dynos are notorious for blowing engines because the engine is under a much higher load then it sees on the road. the gear you're doing the test in will not affect the final numbers unless you're spinning the tires on the drum.

 

[AWDisuzu]

I believe his statement is opinion, as there is no difference that I have ever seen due to gearing. that is, unless the dyno has incorrect numbers input from the beginning.

offhand, do you know what the exact differences would be?