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low hp on dyno..whats wrong

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Old 05-29-2009, 10:21 AM
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low hp on dyno..whats wrong

I ran a dyno for the first time on my car yesterday.
its 05 6MT coupe
i got 227hp. *updated* 235 actually.
its bone stock except ARC intake box.
the guy at the shop said since its revup engine, it should have done at least 260hp at STOCK..
so wtf?
why does my car hp so low?
what can i do to achieve 260 at stock?

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Last edited by laksjd84; 06-01-2009 at 02:50 PM.
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Old 05-29-2009, 10:50 AM
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Hmm... that is kinda low. I believe the bhp on the 05 is like 280 or something isnt it? Did he give you any graphs or anything showing your power curve?

Edited: Sorry, just looked it up, looks like its 298. http://74.125.95.132/search?q=cache:...ient=firefox-a
 
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Old 05-29-2009, 10:58 AM
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I'm not going into too much detail here b/c I'm on my BB, but the factory "298hp" is measured at the crank, not the wheels. Losses and inefficiencies in the driveline will reduce that number somewhat, some use a 20% loss factor for driveline.

Another factor is your dyno. No 2 dynos will read the same. A dyno is simply a tool and is best used to determine power gains/losses when tuning or adding parts.

Your shop guy is incorrect when he says it should put down 260. 225 to 240 would be a "normal" range for an 05 revup.
 
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Old 05-29-2009, 11:04 AM
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Probably on a mustang dyno, also depends what settings it is. But that is about normal for a stock car. My G37 only put down 260 stock. Too many factors to compare dyno to dyno.

If you want highter, boost it and put it on a dynojet.
 
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Old 05-29-2009, 11:06 AM
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Ah, good call on that, bhp is at the crank and whp is at the wheels....duh, lol. My mistake.

Been a long time since Ive been on a dyno, isnt the baseline run normally done with that 20% calculation accounted for in the initial numbers? I wanna say our local dynojet has does that calculation. As well as the calculation for difference between the jet and the mustang.

Id still be interested to see your printout if you can provide it laks.
 
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Old 06-01-2009, 12:35 AM
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yeah, read my number wrong. its 235. i'll post the sheet tomorrow when i get to work and scan the biatch.
and whosyourbuddie, how did you know it was mustang dyno?>
does mustang dyno generally read low?
my friend with 03 stock 350Z with pop charger and nothing else got 237..
 
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Old 06-01-2009, 07:15 AM
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temperature, humidity, elevation... many factors.

a 1/4 mile slip will tell you much more about the vehicles power.
 
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Old 06-01-2009, 09:14 AM
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Originally Posted by laksjd84
does mustang dyno generally read low?
my friend with 03 stock 350Z with pop charger and nothing else got 237..
Yes, it does read lower. Not entirely sure why. Some say its because the mustang automatically adjusts for aero resistance and such, who knows. Most dynojets, when setup, will be adjusted to read like a mustang will read (which I believe is a 12% or 15% adjustment).

As for a 1/4 mile slip telling you more about the vehicles power.....??? Not quite true. It will tell you more about how the vehicle will respond on the track. But the dyno is a great way to see your power curve; i.e. power and torque numbers in relation to applied modifications.

What does the track actually tell you? Unless you're data logging, all you learn at the track are trap speeds, 60' times, 1/8th times, 1320 times... everything on the slip when you're done. There is no way at all to tell what kind of power numbers your vehicle is putting down at the track.
 
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Old 06-01-2009, 12:55 PM
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dynos are good for testing and comparing power adders, given the same test conditions and same dyno.

1/4 is for testing the vehicle and its driver. which both shows the vehicles power along with the drivers capabilities.
 
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Old 06-01-2009, 02:43 PM
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read original post for updated dyno printout
 
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