[stratos_335]

Which gear do you select when you dyno your car?

I use 5th gear as the gear ratio is 1:1 and represents the actual power transfered from the gearbox to the diff, ignoring the losses.

[themyst]

Originally Posted by stratos_335

Which gear do you select when you dyno your car?

I use 5th gear as the gear ratio is 1:1 and represents the actual power transfered from the gearbox to the diff, ignoring the losses.

If your car doesn't have a speed limiter, 5th is ideal for sure. We tend to use 4th to avoid pegging the limiter.

[stratos_335]

Originally Posted by themyst

If your car doesn't have a speed limiter, 5th is ideal for sure. We tend to use 4th to avoid pegging the limiter.

Procede offers speed delimiter for sure.

I think 4th gear tends to give more hosepower and better under the area power.

I just wanted to know which is the most appropriate gear for a dyno and which gear represents the most accurate hospepower and torque results

My mistake: my car is 6MT

[onebadmofo]

4th

[Jeff@TopGearSolutions]

5th is more accurate cause of the 1:1 but its so much speed I recommend 4th.

[stratos_335]

4th gear ratio is 1.192:1

This means that you get 19.2 % more power than with 5th gear, ignoring tranny losses.

Forgive me if I'm wrong. Tuner's opinions would be appreciated after their vas amount of dyno pulls

[enrita]

4th

[Mike@N54Tuning.com]

4th

[G.I.Joe]

I've tried 4th, 5th and 6 th gear on the same dyno on the same day, there's virtually no difference. I prefer 4th, simply because it stresses the car the least

[saxon]

i did 3rd gear as the dyno operators dont like 120+mph speeds on there dyno.... my car stock put down 254hp and 274tq so i dont see it mattering all that much as long as the dyno is synced properly

[son_of_siggy]

Originally Posted by stratos_335

4th gear ratio is 1.192:1

This means that you get 19.2 % more power than with 5th gear, ignoring tranny losses.

Forgive me if I'm wrong. Tuner's opinions would be appreciated after their vas amount of dyno pulls

Wouldn't you actually show less power on a dyno with a lower gear since you're actually needing less engine power to perform the same amount of work (turning the dyno drums) as in the 1:1 ratio? If the amount of work (Z) to turn the drums is constant (and maybe it's not and that's my problem) and you need (W) amount of engine power times the torque multiplication of the gears (Y), wouldn't W go down as Y increases assuming you're trying to hit Z, which is unchanging? I know this is probably over-simplified, but that's how I always though of it.

^^ Genuine question btw . . .

[Bleep]

Dyno takes into account gear ratios so it technically shouldn't matter what gear you do it in. A longer gear will give you more data points however. 4th is a good compromise.

[stratos_335]

So, a well calibrated dyno will show up the same results with any gear.

I remember from my 2 dynos I performed, they left the car rolling for a while and then they inserted the selected gear, rpm, wheel specs and current speed to determine the overall gear ratio.

After they revved up my car to 7000 rpm they left it rolling until the dyno determines the overall tranny and wheel losses.

Next time I'll dyno my car, I'll try it both with 4th and 5th gear (as long as the wheels will not slip on 4th gear).

thank you everyone for your opinions