I dont have a dyno test place anywhere nearby and am considering an in-car dyno device. Any recommendations, advice, or opinions on quality, accuracy etc.
Thanks
Thanks
In car Dyno Questions ???
- Thread starter Snakin
- Start date
If you can find a level road, know the accurate weight of your vehicle, and you have a device that can accurately datalog instantaneous vehicle speed (VSS sensor) as well as measure acceleration to a reasonable degree of acuracy and this acceleration sensor is aligned properly front to back...........
Yes, it would be a more accurate measurement than you could get on any dyno for actual power output and you would get real world effects such as aero drag and better cooling. If you took into account aero drag as well as temp/humidity you could correct to a SAE corrected RWHP measurement. The cost of doing this right would be a hell of alot more than going to a dyno, however you still couldn't compare your numbers to a dynojet measurement, as a dynojet doesn't load your car accurately.
Yes, it would be a more accurate measurement than you could get on any dyno for actual power output and you would get real world effects such as aero drag and better cooling. If you took into account aero drag as well as temp/humidity you could correct to a SAE corrected RWHP measurement. The cost of doing this right would be a hell of alot more than going to a dyno, however you still couldn't compare your numbers to a dynojet measurement, as a dynojet doesn't load your car accurately.
And you do know your RWHP will vary inversely with the instataneous acceleration of the vehicle at that point? Your peak hp will come when the vehicle is not accelerating at all.
This may not make sense, but think of this. If you jack the tires up in the air, and you get in your car and you floor it, you made essentially 0 RWHP (your tires did no work other than heating up the air) yet all your HP was asorbed (albeit in a short amount of time). Essentially all your hp went to accelerating rotating parts with some consumed by static friction. Hence, you make less rwhp in first than you do in 6th in the real world, because in 1st your accelerating faster.
Gotta love physics.
If this is anything like the Corral, someone without any degree whos likely not even driving yet will tell me I'm an idiot and wrong.
Flame on.
This may not make sense, but think of this. If you jack the tires up in the air, and you get in your car and you floor it, you made essentially 0 RWHP (your tires did no work other than heating up the air) yet all your HP was asorbed (albeit in a short amount of time). Essentially all your hp went to accelerating rotating parts with some consumed by static friction. Hence, you make less rwhp in first than you do in 6th in the real world, because in 1st your accelerating faster.
Gotta love physics.
If this is anything like the Corral, someone without any degree whos likely not even driving yet will tell me I'm an idiot and wrong.
Flame on.
Even cooler, if you had loads of time, we could measure your cars static friction, and the rotating mass of everything, and from that back calculate your static FWHP.
Yea I'm a geek. I made a spreadsheet that can input everything about your car and tell you the optimum shift points for every gear (its not the same for all gears ;-) ) Will even calculate a 1/4 mile time if you guess your slip and input how long it takes you to shift.
Yea I'm a geek. I made a spreadsheet that can input everything about your car and tell you the optimum shift points for every gear (its not the same for all gears ;-) ) Will even calculate a 1/4 mile time if you guess your slip and input how long it takes you to shift.
thanks for the info, I will sooner or later get to a dynojet for a real test but was wondering about the general accuracy of these devices on a day to day basis. Im not too concerned about accuracy against a dynojet test but just to make relative comparisons of my own car after making a mod ie: CAI, etc.
Are they accurate enough for that purpose?
Are they worth the money?
Also, any recommendations on manufacturer?
Are they accurate enough for that purpose?
Are they worth the money?
Also, any recommendations on manufacturer?
I think a gtec is accurate enough to measure a 5 hp difference as long as you A) stay in the same weather conditions B) Launch the same, a hard launch confuses it, launch from idle C) don't change the weight of the car (gasoline too) D)make sure its level and facing forward E) Use the same stretch of road.
Anyone else have an opinion or advise???
Its hard to believe that they do not have a Dyno in Southern California. We have at least 25 that I know of in South Florida.
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