Subject	What are you asking?
Posted by	Technomancer on August 10, 2004 at 10:43 AM
	This message has been viewed 76 times.
In Reply To	dyno pull-3rd or 4th gear posted by eriksu9 on August 10, 2004 at 10:35 AM
Message	The engine output is multiplied by the transmission gears. The multiplication differs for each gear. The dyno machine needs the gear info to work...it will "correct away" the gearing (but not any inefficiency of the transmission). One reason to select 4th gear: some dynos have a limit of how much uncorrected horsepower they can measure. A high HP Z might need to use 4th gear just to stay below that limit. One reason to select 3rd gear: most dynos have a speed limit that protects users who might not have Z-rated tires. That will stop the data-taking before you finish 4th gear. This happened to me --- incomplete runs suck. I had Z-rated tires but the operator forgot to tell the dyno that fact and /or didn't realize how steeply-geared the Z is. From your post, it sounds like you are trying to cheat the dyno or something. It probably won't work. Choose a gear based on the above. - John
Follow Ups	dyno pull-3rd or 4th gear - eriksu9 10:35:38 08/10/04 Proper gear is 4th - ImTheDevil 10:37:43 08/10/04 What are you asking? - Technomancer 10:43:43 08/10/04 4th gear is 1:1 - eroc77 10:49:16 08/10/04 I don't see why - Technomancer 10:55:08 08/10/04 It's not that 4th is more efficient - Rob'Z 11:07:32 08/10/04 Im claiming that it will give the most accurate.... - eroc77 11:11:06 08/10/04 1:1 has the least amt of friction being transferred through - Chris(NJ) 11:11:45 08/10/04 Sorry, I'm not trying to be dense here but I still don't see - Technomancer 11:28:29 08/10/04 Relax and stop overthinking it. - SeedyROM 12:57:17 08/10/04 This is the theory - Chip(GMS Racing) 13:07:15 08/10/04 "directly connected" just isn't true - Technomancer 13:19:10 08/10/04 I was regurgitating what I read somewhere - Chip(GMS Racing) 13:23:24 08/10/04 I don't think the dyno needs to know the gearing info. - Marshall 13:22:31 08/10/04 yes, I'm claiming that the number is needed as an input to t - Technomancer 13:30:53 08/10/04 4th gear is 1:1 so it will give "correct" numbers - Rob'Z 10:48:45 08/10/04 Did you forget the existence of the rear differential? - Technomancer 10:54:24 08/10/04 ? (n/m) - Chris(NJ) 11:04:44 08/10/04 Huh? So you're saying I should divide the RWHP numbers - Rob'Z 11:11:22 08/10/04 Yes, I'm saying that is what the dyno does - Technomancer 11:25:40 08/10/04 i believe 5th is only closer in a 6spd. (n/m) - Chris(NJ) 11:32:07 08/10/04 correct-5th is usually 1:1 in a 6sd - Rob'Z 11:44:33 08/10/04 Ugh you guys! Multiply by the rear diff - Technomancer 11:51:27 08/10/04 Free your mind - Rob'Z 16:10:40 08/10/04 You get no torque multiplication from the tire. (n/m) - Technomancer 16:30:44 08/10/04 Yeah I was being a little sarcastic there - Rob'Z 11:41:21 08/10/04 a lot of shops do not know how to dyno autos. kinda sad - Chris(NJ) 11:04:08 08/10/04 didn't the dyno shop you took us to ask us if our cars - ZEngineer (TT) 13:02:02 08/10/04 Use the dyno as a tuning tool, not a contest - vorpalZ 12:07:14 08/10/04 I have gotten better numbers in 4th than 3rd on the - AzHeat 12:17:37 08/10/04 Oh geez you are so wrong! - Technomancer 12:26:17 08/10/04 He is correct about turbos spooling quicker in higher gears - Chip(GMS Racing) 12:32:25 08/10/04 Yes I have nothing to say about the spooling - Technomancer 12:51:54 08/10/04 A real world example - Chip(GMS Racing) 13:21:02 08/10/04 An interesting tidbit: - Marshall 13:31:56 08/10/04 I agree, I FIRMLY believe that my car would have been faster - Chip(GMS Racing) 13:55:02 08/10/04 That's where torque mulitplications comes in a - AzHeat 12:35:30 08/10/04 you are confusing engine RPM and drum RPM - Technomancer 12:47:25 08/10/04 Show me where in the HP equations and the - AzHeat 13:18:04 08/10/04 OK, let me soften my stance: - Technomancer 14:02:03 08/10/04 Please give the mathematics equation for this - AzHeat 14:33:21 08/10/04 for what part? (n/m) - Technomancer 14:41:52 08/10/04 The gear ratio is already accounted for in the - AzHeat 15:25:42 08/10/04 yep - Technomancer 16:24:14 08/10/04 Re: dyno pull-3rd or 4th gear - eriksu9 13:42:12 08/10/04 good luck. This has been very interesting! (n/m) - Technomancer 14:03:02 08/10/04 Dyno at 1:1(or gearing closest to 1:1) to compare >> - I am Z-ing Double 15:23:59 08/10/04 I'm surprised you tech-heads haven't mentioned dyno - vorpalZ 15:59:47 08/10/04
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