'11 5.0 with 395 RWHP on Inside Line
03-25-2010, 03:39 PM
#1
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'11 5.0 with 395 RWHP on Inside Line
I apologize if this is a repost but I didn't see it anywhere here yet.
http://www.autoguide.com/auto-news/2...and-video.html
395 RWHP from the 5.0 in a manual '11 GT. If this is the case I am VERY impressed! Could be around 440 flywheel horsepower. I hope this is the case. Ford is doing a good job of tempting this GM owner.
http://www.autoguide.com/auto-news/2...and-video.html
395 RWHP from the 5.0 in a manual '11 GT. If this is the case I am VERY impressed! Could be around 440 flywheel horsepower. I hope this is the case. Ford is doing a good job of tempting this GM owner.
03-25-2010, 07:19 PM
#3
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As someone on another forum mentioned, this dyno run was done in 4th gear. It should have been done in 5th gear, which is a 1:1 ratio.
03-25-2010, 08:13 PM
#4
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03-25-2010, 08:22 PM
#5
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"InsideLine says all pulls were done on a Dynojet 248 chassis dyno in 4th gear using 91 octane and with a 3 percent weather correction factor."
It doesn't say anything about a correction for the gear (if they have to correct for that, why wouldn't they just do the dyno run in 5th gear?), just for the weather. I would love to know if this beast is really underrated by that much. I'm not going to get overly excited just yet...
It doesn't say anything about a correction for the gear (if they have to correct for that, why wouldn't they just do the dyno run in 5th gear?), just for the weather. I would love to know if this beast is really underrated by that much. I'm not going to get overly excited just yet...
03-25-2010, 08:54 PM
#6
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"InsideLine says all pulls were done on a Dynojet 248 chassis dyno in 4th gear using 91 octane and with a 3 percent weather correction factor."
It doesn't say anything about a correction for the gear (if they have to correct for that, why wouldn't they just do the dyno run in 5th gear?), just for the weather. I would love to know if this beast is really underrated by that much. I'm not going to get overly excited just yet...
It doesn't say anything about a correction for the gear (if they have to correct for that, why wouldn't they just do the dyno run in 5th gear?), just for the weather. I would love to know if this beast is really underrated by that much. I'm not going to get overly excited just yet...
You don't dyno in your highest gear because few cars can redline their highest gear. Plus I don't think they want cars doing 180mph on a dyno.
03-25-2010, 09:26 PM
#7
Join Date: Dec 2009
Location: Wantagh, NY
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Thank you 83gtragtop. Sounds like you have quite a bit of knowledge here. I cannot wait to get my hands on one of these new GT's! This was just posted:
"Jason, the engineer who dyno'd the 5.0 in the article actually responded to the very same issue in the comments section of that article:
"Jason Kavanagh replied to comment from rrocket
10:14 PM, 03/24/10
The Dynojet itself doesn't care what gear the car's in. Remember, there's a final drive gear reduction after the transmission, which further alters the wheelspeed - engine speed relationship beyond what the transmission does, so there's nothing magical about 1:1.
In fact, dynoing in a gear that's 1:1 usually results in a hair less (yes, less) driveline loss as its a more (the most) efficient ratio in the gearbox. That's why a lot of dyno operators like the 1:1 ratio. Plus, when using an inertia dyno like a Dynojet, higher gear ratios have a lower rate of acceleration, so less power is soaked up in accelerating the rotating masses, which further props the numbers up.
Higher gears do tend to result in higher tire losses since the wheelspeed is higher... at this point all you're doing is trading off one loss mechanism for another. Generally, though, what I've seen come out in the wash is that on an inertia dyno, higher gears will result in higher numbers than lower gears.
Furthermore, higher gears also load the engine for a longer duration, requiring more cooldown, plus put more heat stress on driven tires. As the dyno operator, I don't like either of those things."
"Jason, the engineer who dyno'd the 5.0 in the article actually responded to the very same issue in the comments section of that article:
"Jason Kavanagh replied to comment from rrocket
10:14 PM, 03/24/10
The Dynojet itself doesn't care what gear the car's in. Remember, there's a final drive gear reduction after the transmission, which further alters the wheelspeed - engine speed relationship beyond what the transmission does, so there's nothing magical about 1:1.
In fact, dynoing in a gear that's 1:1 usually results in a hair less (yes, less) driveline loss as its a more (the most) efficient ratio in the gearbox. That's why a lot of dyno operators like the 1:1 ratio. Plus, when using an inertia dyno like a Dynojet, higher gear ratios have a lower rate of acceleration, so less power is soaked up in accelerating the rotating masses, which further props the numbers up.
Higher gears do tend to result in higher tire losses since the wheelspeed is higher... at this point all you're doing is trading off one loss mechanism for another. Generally, though, what I've seen come out in the wash is that on an inertia dyno, higher gears will result in higher numbers than lower gears.
Furthermore, higher gears also load the engine for a longer duration, requiring more cooldown, plus put more heat stress on driven tires. As the dyno operator, I don't like either of those things."
03-26-2010, 09:41 AM
#8
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03-26-2010, 12:07 PM
#9
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It would only make it dyno lower. Generally you want to dyno in the highest gear possible because the drum is spun by inertia, at higher speeds(rpm's) the drum takes less energy to spin.
You don't dyno in your highest gear because few cars can redline their highest gear. Plus I don't think they want cars doing 180mph on a dyno.
You don't dyno in your highest gear because few cars can redline their highest gear. Plus I don't think they want cars doing 180mph on a dyno.
The ONLY way to get an accurate HP and Torque measurement from a dyno is using a 1:1 ratio gear. Generally it's 4th for stick cars, and 3rd for an automatic.
You don't want it in the highest gear possible. You want to know what power the engine is actually making. Not how it can be magically multiplied by the gear.
