Torch Red GT

Lower gears also make dynos read lower

siggyfreud

I would say its 'aggressive'.

Blacksmoke

What do you mean by lower gears?

you mean 4.10's would read a lower HP torque number than 3.55's?

Why is that?

siggyfreud

I'm guessing he meant numerically lower?

RAMAIR

Yes 4.10's would read lower HP numbers than 3.55's because dynos don't measure hp they measure tq and calculate hp changing to lower gears effects that calculation so the numbers drop a bit.

I don't know all the math involved and honestly don't want to lol.

I am sure someone else can explain it better but I tried.

siggyfreud

Oh I get what you're saying now. Lower gears multiply the torque factor of the engine more, thus the engine doesn't have to work as hard to net the same result. The outcome of that is it shows slightly less hp, not because it HAS less HP, but because it has to use less of it to move the engine/car the same speed. Just another example of why car dynos are really only a good measuring tool when all factors outside of the engine remain the same.

breathegood

I'm not sure where he did the tuning, but I think it was at dyno dynamics. I had it tuned by Scott Patten. He came very highly recommended from other ColoradoStangs members. There are lots of dyno tuners in the metro area that will tune whatever you bring them, but Scott pretty much specializes in Mustangs and Lightnings.

www.pperformance6.com

dkersten

Gear ratio doesn't matter.. a dyno measures torque. All a lower gear does is lower the amount of time it takes to put the torque to the ground.. If gear ratio mattered, then every transmission on every car would skew the results.

Horsepower is derived from torque, so if torque goes up, HP goes up.. it has NOTHING to do with gears.

Furthermore, a dyno test is a benchmark for a certain set of circumstances. You use the tool to get a baseline reading, then change something, and test again under the same circumstances to see if there is a change. If you had tested before any mods with that dyno, then added the mods and uploaded the tune, then tested again and only saw a 30 hp gain from stock, I would say your tune needs work. However, given a tune, CAI, cams, and headers, I would expect more like a 50 hp gain. Since you didn't baseline it, it is irrelevant.

If you are that worried about it, you can do one of two things: have an experienced tuner get it back on that dyno and see if he can tweak the AF ratio and spark advance to gain some more power, or go to a different shop with a different dyno and test again. Chances are if you go to a different shop you will get far different results. Maybe you will eventually find the numbers you are looking for, but it isn't going to change how your car drives, it's just a number.

MustangRacing4.6ltr

i know its just number but it makes me 'feel better' to know that it can at least show a respectable 300 + on the dyno ....and yep im defantely getting a second opinion on this at another dynoshop for sure ....as far gear ratio and all that im not sure whats true lol

by the way dkersten - nice vert

siggyfreud

Sorry, but I'm going to have to disagree here.

There is a reason that you dyno a car in whatever gear is the 1:1 ratio. It's because every transmission WILL skew the results. Look at the dyno video in the 5.0 section where they dyno it in both 4th gear (not 1:1) and 5th gear (1:1). The results are different.