Dynomometer low cost ?

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Actually you don't need to automate it just flatten it put as you begin the pull. When we dynoed engines at the machine shop, you had a hand throttle, or commanded via computer increase to max no load rpm, then start the pull. Normally we'd go a bit light to warm it up, then game on. Throttle position never got moved off full, untill after the pull. Now I'm also talking about big diesel that typically didnt spin past 2100 rpm, but the same should more or less apply for what your doing, I would think.
 
Seandonato73 said:
Actually you don't need to automate it just flatten it put as you begin the pull. When we dynoed engines at the machine shop, you had a hand throttle, or commanded via computer increase to max no load rpm, then start the pull. Normally we'd go a bit light to warm it up, then game on. Throttle position never got moved off full, untill after the pull. Now I'm also talking about big diesel that typically didnt spin past 2100 rpm, but the same should more or less apply for what your doing, I would think.
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Ok I guess I need to read up on how to run a load test on a dyno !
 
I need someone to check my math please .
1. Ok I re-calibrated the load scale I used a speaker that I weighed at 4lb 10 oz or 74 OZ right ?>?
I use a load arm that is 1 ft / 12 inches long to get Ft/Lbs of torque so when I put the speaker on the end of the arm I get 74 Oz reading in my system. In my spread sheet I divide that # by 16 to get Ft/Lbs

2. I run a test and these are the results , I cant believe I am getting 16 HP !! ?? wth am I doing wrong ?? ( I also have CHT temps )
 

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Seandonato73 said:
I got 16.369hp @14634rpm w/5.875lbft. As peak hp.
Seams rather improbable, but the math is right.
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Ya something is wrong here ??? no way its 16hp from 32cc , I used to get 17 hp with a 100cc Kart motor on engine dyno , must be something to do with the drive train ? Maybe I have my ratio wrong ? , actually this run has the RPM direct from the flywheel so the drive train only deals with Torque not rpm values now.

Should I divide the LOAD by the drive ratio ?? Nope that makes it 2.8 hp ( 5.5 ft-lb / 5.7 ratio = .965 ft/lb @15690 rpm = 2.8 H.P.
 
Im gonna call Doug over at ESP and talk to him about it , and Ill make a adapter to go direct from the clutch to the load bar ! if they match then ???
21bangbang said:
Yall are taking this hobby way to seriously for me.?? my engine has this much ? power. Good enuff for me.?
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I made this Dyno for a DIY project for anybody so I want it to be right :cool:
 
Seandonato73 said:
Go direct off the clutch and get rid of the drivetrain.
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YEP ! I might need to buy a spare clutch LOL !! I think Im killing this one
Seandonato73 said:
Go direct off the clutch and get rid of the drivetrain.
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SOB well the drive train @ 5.7:1 is a Torque multiplier !!!!! so I need to double check my ratio again and re calc. !
 
Troopermaniac said:
There is no way thays putting out 12HP. I would recheck it with this https://www.amazon.com/gp/aw/d/B07DZB57H5?psc=1&ref=ppx_pop_mob_b_asin_image
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I have 2 tach's they agree on the RPM's , I agree 12 HP is not right , Im trying to figure out why .

I just re-calibrated the load cell and it is correct H.P. is an easy # to calculate rpm * load / 5252 or use a online calc. ,

open the Xcell chart and calc. it ! If you see anything I might be missing let me know !

https://spicerparts.com/calculators/horsepower-torque-calculator
 
buzzkill said:
I have 2 tach's they agree on the RPM's , I agree 12 HP is not right , Im trying to figure out why .

I just re-calibrated the load cell and it is correct H.P. is an easy # to calculate rpm * load / 5252 or use a online calc. ,

open the Xcell chart and calc. it ! If you see anything I might be missing let me know !
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That would be one valuable motor is its truly 12 hp. I would bet racers would pay a premium. However I really feel 12 isn't right. It would grenade before hitting those numbers.
 
They are all at the crank. Wheel hp has too many variables with these things, gearing, diff oil, ect. And I was saying for that particular motor, there's no way it makes that much when esp themselves rate way lower.
 
If we dive into the gearing its used to multiply torque. Im gunna go on a stretch here and say your probably around 6ish hp. Only reason I say this is a diesel tractor trailer engine rated at 500hp and say 500 ftlb has an output torque in 1st gear of roughly 1000 ft lbs of torque. Since these cars have 1 gear set its at its highest torque and as gearing increases torque decreases and hp takes over. I think your gearing and your software is clashing... since torque is twist your getting more force on your load cell fooling it into thinking it has more power
 
Rep732 said:
If we dive into the gearing its used to multiply torque. Im gunna go on a stretch here and say your probably around 6ish hp. Only reason I say this is a diesel tractor trailer engine rated at 500hp and say 500 ftlb has an output torque in 1st gear of roughly 1000 ft lbs of torque. Since these cars have 1 gear set its at its highest torque and as gearing increases torque decreases and hp takes over. I think your gearing and your software is clashing... since torque is twist your getting more force on your load cell fooling it into thinking it has more power
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I agree ! thats why my first runs used the gear ratio to divide the torque right ?? but im getting about the same numbers , Im making adapter to put the load bar right on the clutch output and then check the numbers. I tried div. the LOAD by the gear ratio of 5.7 and got 2.1 HP ! so 12 / 5.7 = 2.1 hp
 
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