FW Motors and Snail Performance - DYNO DAY!!
05-12-2015, 10:22 AM
#62
I recall some discussion about this in the past where the numbers are super low because you're effectively adding drivetrain loss to a car that otherwise has less.
But I don't know the details of it.
Plus I want to compare results with VD to see how close or not close they are.
But I don't know the details of it.
Plus I want to compare results with VD to see how close or not close they are.
05-12-2015, 11:56 AM
#63
Perhaps. I feel it would be more realistic to have rolling resistance to the front wheels as you have to push those anyway.
I think it breaks down with the notion of wheel horsepower. I think road horsepower would be more specific. How much power the car can transfer to the road.
But IDK... I think GST leaves the dyno coupled regardless of F/A/RWD.
I think it breaks down with the notion of wheel horsepower. I think road horsepower would be more specific. How much power the car can transfer to the road.
But IDK... I think GST leaves the dyno coupled regardless of F/A/RWD.
05-12-2015, 05:11 PM
#64
So this is just from a basic understanding of physics and a dyno. That said, I'll throw my opinion out there. If its coupled then the 2 driven wheels will be responsible for the rotational mass of 4 rollers and the non-driven wheels, each step further from the driven wheels has an increased moment of inertia, so more kinetic energy from the driven wheels (source: torque from motor) will be required to increase the angular momentum of the rollers. This would require more torque to accomplish the same job resulting in a lowered reading. That doesn't take into account how the dyno is setup and how the software/dyno accounts for load etc. I'm sure the software could be written to properly accommodate the differences but with the same software I don't see it as possible, without uncoupling or mechanic adjustments. There's a reason you can set the dyno up differently and a reason people use the appropriate setups; and I don't believe it's just for the fun of it. Also, if there are flaws in my explanation please correct them....something I doubt I needed to ask for on a forum
05-12-2015, 06:18 PM
#65
Los Banditos de Moist
Join Date: Apr 2008
Location: Roseville
Posts: 216
Car Info: 98RS slutbox
So this is just from a basic understanding of physics and a dyno. That said, I'll throw my opinion out there. If its coupled then the 2 driven wheels will be responsible for the rotational mass of 4 rollers and the non-driven wheels, each step further from the driven wheels has an increased moment of inertia, so more kinetic energy from the driven wheels (source: torque from motor) will be required to increase the angular momentum of the rollers. This would require more torque to accomplish the same job resulting in a lowered reading. That doesn't take into account how the dyno is setup and how the software/dyno accounts for load etc. I'm sure the software could be written to properly accommodate the differences but with the same software I don't see it as possible, without uncoupling or mechanic adjustments. There's a reason you can set the dyno up differently and a reason people use the appropriate setups; and I don't believe it's just for the fun of it. Also, if there are flaws in my explanation please correct them....something I doubt I needed to ask for on a forum
Dang, you used some pretty big words in there. I'm impressed!
05-12-2015, 06:41 PM
#66
Because Mike, like most of us, know that it's just numbers. And they mean nothing. Most people get tied up in them and don't look at the curves or the area under them or really the tune itself. They like to brag about a peak number they make, which means nothing really. Hell, my car made over 1000hp one day, just to prove a point.
Dang, you used some pretty big words in there. I'm impressed!
Dang, you used some pretty big words in there. I'm impressed!
myself included
and thanks (waits for Rob to find error in theory)
05-12-2015, 08:32 PM
#67
Agreed with all of it. Was going to post something along those lines anyway.
In my case though, I already know what the curves look like, it's more an exercise in comparing Mustang to VD to trap speeds.
So far I observed that ~280 = 105, ~320 = 110, ~360 = 114, and ~450 = 120. It would be cool to compare to a real dyno.
So far we know that 365 on FW's dyno = 115
anyways, back on topic lol
PS: 201 in the miata resulted in a 103 trap hehe
In my case though, I already know what the curves look like, it's more an exercise in comparing Mustang to VD to trap speeds.
So far I observed that ~280 = 105, ~320 = 110, ~360 = 114, and ~450 = 120. It would be cool to compare to a real dyno.
So far we know that 365 on FW's dyno = 115
anyways, back on topic lol
PS: 201 in the miata resulted in a 103 trap hehe
Last edited by Vladi; 05-12-2015 at 09:02 PM.
05-12-2015, 11:22 PM
#68
That seems like a worth while comparison. I'd be interested to see the correlation as well, even though I doubt I'll run at the strip the data correlation intrigues me. If everything works out please post up findings
05-13-2015, 08:00 AM
#70
Sure thing, will do.
Good point. Your car is like 400-500lb lighter. All the other numbers I posted were for wrx's and sti's, so 3200-3350lb range.
Miata should be in the 2500 range cause I got a big fat heavy porker with every option hehe
Dude. LOL. It's Wed. Today.
Come on out
Miata should be in the 2500 range cause I got a big fat heavy porker with every option hehe
So did you run last night? Ryan go out as well?
Come on out
Last edited by Vladi; 05-13-2015 at 08:08 AM.
