7AT w/ I-H-C-E Dyno'd

wstar · 04-11-2009, 04:26 PM

Quote:

Originally Posted by azn370z

Why wasn't it dynod in 5th gear?

I don't know, why would it be? 4th tops out somewhere around 120-ish mph IIRC.

azn370z · 04-11-2009, 05:16 PM

5th gear on the auto is 1.0. Most cars are dynod in the gearing that is 1.0.

wstar · 04-11-2009, 05:19 PM

Quote:

Originally Posted by azn370z

5th gear on the auto is 1.0. Most cars are dynod in the gearing that is 1.0.

Interesting, does it make a significant difference? Seems weird to me that there would be a universal standard on what ratio to use on the transmission, considering the differential's ratio differs between cars as well, but then again I know nothing about the subject at hand.

semtex · 04-11-2009, 07:53 PM

Quote:

Originally Posted by wstar

Interesting, does it make a significant difference? Seems weird to me that there would be a universal standard on what ratio to use on the transmission, considering the differential's ratio differs between cars as well, but then again I know nothing about the subject at hand.

I respectfully disagree with Crash on the gearing not making much of a difference, at least for the 370Z. I say this because when I took mine to a DynoJet, the guy did pulls in both 4th and 5th. (2 pulls in each gear.) The 4th gear pulls came in around 10-15hp less than those in 5th for my car, if I recall correctly. In fact, it may have been even more, because I seem to remember that on his first pull (which was in 4th), the hp came in lower than my DynoDynamics number, and when I saw the number on the screen my immediate thought was 'WTF are you doing wrong, dude? There's no way I'm making less hp on a DynoJet than I'm making on a DynoDynamics'. (The 4th gear numbers were so bad that I had those pulls tossed from the graph, so I can't go back and look at them to verify the delta, unfortunately.) I suggest you tell them they need to re-do it in 5th gear. I mean, think about it -- you're getting less on a DynoJet than I got on a Dyno Dynamics (306.4). And I don't even have the headers on yet! I know I've got a 6MT while you've got a 7AT, but there's no way the delta between the transmissions is THAT big. There's just no way. Regarding Crash's statement that 4th and 5th reveal results within 5hp on cars making over 500HP, perhaps gearing makes less of a difference in dyno results the higher the hp a car has? I don't know. I have no reason to disbelieve Crash's statement. But I'm just telling you what I personally saw with my Z when it got dyno'd in both gears.

Edit: Check out this thread: Semtex, RCZ... What gear on the dyno DannyGT got a baseline done today on a DynoJet. 282whp. 5th gear. So the delta between his baseline and your number is 23hp. I know these are different cars, but still, with the full intake & exhaust setup you've got, you have to be making more than 23whp over stock. The cat-back and HFCs alone yield way more than that.

04-11-2009, 05:16 PM	#2 (permalink)
azn370z A True Z Fanatic Join Date: Nov 2008 Location: Seattle Posts: 1,722 Drives: z34 - R1 Rep Power: 489	5th gear on the auto is 1.0. Most cars are dynod in the gearing that is 1.0. __________________ 2010 k23 H&R sport springs / Spc rear camber arms / SSR SP1 / Berk cbe / Varis cf lip / Nismo S-Tune side skirts