Me taking cheap shots? Why don't you stop talkin' **** and acting like a baby? You even said yourself that the K&N doesn't do anything, and 93 gas, whoopie, I run that all the time. How is that cheating? There's 4 other people that said the same thing I did and you say I'm taking cheap shots? Please...

 

I have never seen a car run on the dyno in 5th?? Why would you get the numbers off 5th gear?

 

I believe it's because 5th for the Z is equivalent to 1:1.

 

What does the gear being 1:1 have to do with it? Does it make it easier to calculate?

Most dyno runs I have seen (on 6-speed cars in general) were done in 3rd, or 4th gear.

BTW: 15% drivetrain loss is generally the standard accepted loss for manual transmissions.

 

You're supposed to dyno in your 1:1 gear. Thats why auto f-bodies dyno in 3rd and manuals in 4th. I forget which way(higher or lower) it affects output but it does affect the readings if you dyno in a different gear.

 

Then its settled!! Me, Nizl, Zgirl and Phoenix are gonna

and have a big group hug.

Oh yeah, and that 420 guy too...where is he?

 

Anyone say 420?

 

heheh, SWEET! Let's go...

 

My guess is that the 1:1 ratio gear is an overdrive that bypasses much of the gearbox and connects a shaft directly through, thus having the least mechanical loss in the transmission? (I don't know in detail how the Z tranny works but from what I have learned of manual transmissions in general, this is how an overdrive often works.) I am just guessing here as to the relevance of this to dyno testing, so for any experts on the matter, please jump in and set the record straight.

 

Dude wake up. K&N filter doesn't do ****... A bag of ice does though

 

I dynoed in 4th by the way because I thought it was 1:1 and got 230HP at the wheels...

Damn I wish I knew so I could compare.

 

Overdrive by definition is a less than 1:1 ratio, hence the term, over-drive. The overdrive gear in the Z is 6th, which I think is .79.

The reason I assume you want a 1:1 ratio is that you want less gearing affects on the dyno. 1:1 gives you what is closer to coming out of the engine (with the obvious rear end differential effects still affecting it).

 

1:1 one means exactly what it states.

1 = input revoutions from the engine
1 = output revolutions from the trasmission

An example of "Overdrive" would be

.75:1

.75= for every 3/4 turn of the engine (input shaft on transmission)

1= you get one revolution of the output shaft of the transmission

Hence "overdriving" the input from the engine i.e. making the output shaft of the trasmission spin faster than the input shaft from the engine.

My cheezy drivetrain diagram... (im leaving rear end gearing out)

[ENGINE] -> [TRANNY] - > driveshaft ->REAREND

so... lets say your at 1000rpms

This would be the standard drive gear
1000rpms from engine to 1:1 = 1000rpms to the driveshaft to the rearend gear

This would be a overdrive gear.
1000rpms from engine to .75:1 = 1250rpms to driveshaft

1-4th gears work the opposite (examples)

1:.87
1:.72

(real low gear ratios look a lot different, but it's the same principal)


SO back tothe dyno stuff:

You want to be in a 1:1 because then the input shaft of the trasmission is spinning at the same speed at the output. Giving you accurate results. Using 1-4th would give bad results because of the transmission gearing.

 

I check the TQ #s again and "Corrected" are 231 1st run and 233 in 2nd run, the "cursor" was in some kind of peak.

 

Maybe you have a point, but there are some Z owners (not base) that pass the 240 hp in the Dyno. look in the search botton maybe you get it.

 

K&N filters have been known to lose hp on occasion. so maybe we're making more....

 

That's exactly what I was saying: it's 1:1 from input to output shaft in the transmission. This usually is done without any transfer of powers through gears, but by a direct link to the shaft that is normally spun by engaging one of the gears. This should result in less mechanical loss. As for getting more accurate HP reading because the tranny is 1:1, I don't see how that figures in: power at the wheels can be measured regardless of the internal gear ratios.