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what gear to dyno in ???

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Old Dec 17, 2004 | 10:38 AM
  #21  
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From all the dyno's I've seen, there is almost nothing common between them. Kinda like cylinder head porters, be we won't go there....

I'm sure they could apply a conversion factor to a 2nd gear pull, but that factor would be based on an average variance of 2nd / 3rd pulls over a variety of vehicles. I've never had a dyno operator apply a 2nd correction or ask to apply one. I have been told by the operator that 2nd gear numbers are a little lower, which I already knew. I personally don't think there is an accurate conversion. Rotating weight, diameter, gearing, converter, transmission, etc.. all vary so much between vehicles.

I've tried both 2nd and 3rd. Most of mine have been 2nd gear runs. The times I've tried 3rd gear runs, I found myself standing waaayyyy back. Those freaking wheels were turning fast. "Is it safe to run 135+ on the dyno?" Not likely and I don't plan on doing it again.

Yep, its about time we all meet up, pull our motors, and run them on the same engine dyno.
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Old Dec 17, 2004 | 10:42 AM
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Ok, I'm at a loss now. I have nothng to argue about in your last post. Post up something dumb and illogical please so I have something to do. LOL
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Old Dec 17, 2004 | 10:55 AM
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Originally Posted by F8L Z71
Ok, I'm at a loss now. I have nothng to argue about in your last post. Post up something dumb and illogical please so I have something to do. LOL
STS turbo's can't make good power.
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Old Dec 17, 2004 | 10:56 AM
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Originally Posted by F8L Z71
Ok, I'm at a loss now. I have nothng to argue about in your last post. Post up something dumb and illogical please so I have something to do. LOL
Rear mount turbos are t3h suX0r.
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Old Dec 17, 2004 | 10:58 AM
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Jinx.
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Old Dec 17, 2004 | 11:03 AM
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Originally Posted by BigTex
Jinx.
LOL!!!!
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Old Dec 17, 2004 | 11:14 AM
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[QUOTE=BigTex]Thats just like running the 1/8th mile and applying a 1/4 mile conversion factor to it. It will be close, but its not the same as running a 1/4 and knowing the truth. If you want numbers that are pretty close but not exact, try a GTECH. Why even mess with a dyno at all?

I use the dyno to get an accurate a/f reading for the most part. I'm always trying to keep my most recent experiment from blowing up.
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Old Dec 17, 2004 | 11:38 AM
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Damn you two!!!

LOL
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Old Dec 18, 2004 | 01:40 AM
  #29  
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Originally Posted by BigTex
I've tried both 2nd and 3rd. Most of mine have been 2nd gear runs. The times I've tried 3rd gear runs, I found myself standing waaayyyy back. Those freaking wheels were turning fast. "Is it safe to run 135+ on the dyno?" Not likely and I don't plan on doing it again.
I'm with you. I had no idea the dyno operator was going to run my truck in 3rd, and ignorant as I was, I assumed it would be 2nd. There were people standing 12-15 ft from my truck when the driveshaft came apart at 141 mph, and half of the shaft flew out and came to rest about 2 feet from one of the bystanders. I felt thumps under the floorboards when it split in half, before it separated from the front U-joint. Pretty scary ****. We were all very fortunate that no one was hurt.

That incident changed how I look at speed and also how I look at professionals who are supposed to know what they're doing. Going forward, I will not trust anyone to do my thinking for me. From now on I will be doing all of my own research, like I should have been doing in the first place, like I already do in other areas like law (lawyers) and medicine (doctors).

As far as dynoing my vehicle, any future runs will be done in second gear. I pretty much have to with a 5" x 72" aluminum driveshaft and its associated critical speed. I don't care if it shows less power. I will also be standing very far away and/or behind something from for my vehicle's and all other's dyno runs. All it would take would be some manufacturing defect in the rear end or a nail in a tire to show itself at 125 or 130 mph, and someone loses a limb, an eye, or their life.

My $.02.
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Old Dec 18, 2004 | 10:47 AM
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Ahh the dyno argument....I have not seen this one in a while
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