The diameter doesn't affect the output, but the extra weight of the tires does. Also, higher gears tend to be slightly less efficient than lower gear ratio's in the rear end. So those two together lower the numbers.

The dyno doesn't gather TQ, it's actually reading the HP output. If you ran it without an RPM input, you would still have a HP reading, but not a TQ reading. It then figures the TQ from an engine RPM input.

 

had mine dyno and I have HP171.73
TQ 191.47

 

Everything I have read indicates the opposite: That horsepower is derived from torque via a mathematical equation.

 

I think you guys are talking about two different types of dynamometer.

An inertia dyno measures the acceleration of a mass, often a weighted drum or drums, and infers a horsepower curve from the acceleration curve. A torque curve can be derived from RPM and the inferred HP curve.

A brake dyno measures actual brake torque vs RPM to create a torque curve. The horsepower curve is calculated from the torque curve.

 

Yes and no.

The dyno knows what RPM it's spinning at, but not the engine. So it figures out the TQ applied to it at whatever speed the to figure out the HP. However, these TQ reading don't match up with engine TQ readings until it applies the math from the RPM input.

 

Tractorman, I don't know what kind of dyno you have been using but the ones I use are also connected to the engine and knows what its rpm is. HP is a derived figure, you can't measure it directly. The brake torque is measured and HP is calculated from that.

 

I'm talking about a chassis dyno that's connected to the drive tires.

If you don't have an RPM signal, it will give you a HP reading, but no TQ reading.

 

Came in the mail today :)

 

tell me how that super chip does for you..

 

should of got a custom tune instead of superchips

 

I'm curious about this Programmer....

Does the Superchips Programmer come with tunes for a Ranger or does it simply allow you to adjust timing, tire size and transmission shift pressure?

 

I think super chips come with 1 genaric tune dont know for sure,but a custom tune is just for your truck.

 

I am also talking about a chassis dyno. It is very easy to pick up a signal from the engine to know the engine rpm. That is not the point though. You cannot measure horsepower directly. It is calculated measuring torque over a period of time. 1 hp = 550 ft·lbf/sec.

 

Do not buy this tuner is a generic tune for Ford gas vehicles. The shift points are horrible and way to high I legitimately could hear the valvebody or something crackling. Also is got rid of the speedlimiter in all honesty why turn that off anything over 80 is dangerous and stupid in this truck also the rev limiter was raised and it didn't go away. I called superchips and told them I wasn't happy, and I'm getting my money back horrible tuner don't waste your time.... buying and xcal3