Ratios (:1)
Automatic Automatic Manual
1st gear 2.563.........3.933
2nd gear 1.552 ........2.478
3rd gear 1.021 ........1.700
4th gear 0.653 .........1.250
5th gear 0.470 .........0.976
6th gear - - 0.771
Reverse 1.846 1.846 4.008
Final Drive Ratio 4.428 4.428 3.286

 

5th gear is closer to a 1:1 ratio than 4th is. now i understand there is a speed cut. but my car doesnt have that. should i still dyno in 4th?

 

4th
the dyno shop will know and may run it in a few gears for comparision

phee: I was only poking fun in brake thread-

 

4th

 

i understand that the general concensus is to run in 4th. but why not 5th considering its closest to the 1:1 ratio.

 

^because 5th gear is an overdrive gear. The load you are putting on the engine will not be as accurate as in the lower gears compared to actual load you see on the street.

Plus its a really LONG gear....you'll just be spinning things faster causing your car to work harder to make the power.

 

how is it an overdrive gear? its closest to the 1:1 ratio which would mean it would actually be the most accurate

 

ok well maybe its not an "overdrive gear" but like I said before it is a long gear, and you'll just be making your car work harder to get the power.

Do the dyno in 5th gear if you want to, see if it makes a difference. Be a guinea pig.

 

To be honest, I didn't even look closely at the ratio chart you had up there...I was basing my overdrive gear statement on the T56 transmission I am familiar with that 5th and 6th gears are both overdrive gears and 4th gear is 1:1 ratio.

Like I said...be a guinea pig, see if you can yield better results in 5th than 4th.

 

I always thought that for accurate results, not better results, you should be using the gear closest to 1:1...but I could be off as I'm no professional.

Use quarter mile times to compare your car, dynos are so variable IMHO.

 

yes close to but not below 1 to 1....
.9 is less than 1 and that is considered overdrive or underdrive depending on where you are from

closest without going under the actual retail price !!