# VRP Dyno 2.0 anyone have one?



## vaBcHRog (Feb 19, 2003)

How well does VRP Dyno 2.0 work with skinny wheeled TJETS?


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## Ogre (Jan 31, 2007)

I posted this on the other site but it will most likely be taken down.

http://www.purefidos.com/redline.htm

and I'm not saying it's better.


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## Boosted-Z71 (Nov 26, 2007)

Here is a dyno that I build, its a little different than most as you can adjust the load on the car to simulate what the car see's pulling itself along the track. 

https://www.youtube.com/watch?v=f5TGa0AYsp4

Boosted


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## alpink (Aug 22, 2010)

cool dyno set up


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## Boosted-Z71 (Nov 26, 2007)

I also have the VRP 2.0 dyno, its a very well built unit and works reliably every-time, I had an issue with the no load situation on the rollers, nothing to simulate the car pulling itself during the test, I found it gave readings on cars that while performed well (larger numbers on the dyno) but were not good performers on the track, as it lacked the torque needed for the track.

Its a good tool to tune with to see if you can tweak to get a higher number, or look for bent axles, or out of round wheels, it also has a 5v break-in feature on it which is nice. 

I just did not get the information from it that I wanted to evaluate the performance of a slot car, and certain that information obtained related to track performance. 

So I built my own dyno. 

2 cars that pull the same/similar numbers on my dyno will have almost identical performance on the track, torque is hard to measure as these cars produce so little that you have a small window to measure, The graph on the Simple Dyno software makes this nice as you can easily change the scale accordingly to see what is going on. The run is a full range of acceleration, holding the power constant at full power, as well as peak measurements during the cycle. Many times these little inconsistencies wont show up on a .01 (tenth) or even .001 (hundreth) meter, but the graphing software catches it all. 

With enough pulls of different cars I can easily tell / predict what the track performance will be as well, just by the graph and numbers. 

One thing a dyno will not lend much info towards is handling or how the shoes contact the rails while driving, About the only way that gets tuned in, is track time 

Boosted


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## alpink (Aug 22, 2010)

aha!!!
there is good reason you won that Yellow Jacket/SCRIG drag challenge!!!!
..... LOL .....
good info
thank you


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## vaBcHRog (Feb 19, 2003)

Boosted-Z71 said:


> Here is a dyno that I build, its a little different than most as you can adjust the load on the car to simulate what the car see's pulling itself along the track.
> 
> https://www.youtube.com/watch?v=f5TGa0AYsp4
> 
> Boosted




I had one that Paul Gianti built but its up and disappeared.


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## Joe65SkylarkGS (Feb 15, 2010)

I have the VRP dyno. Works fine on any HO slot car .Fat tires or skinny .It will tell you how high you can get them to rev too .

Very helpful tool when building cars ???


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## slotking (May 27, 2008)

You can email VRP and see how much the load control is.
he can add 1.

I just use how fast it spins up.

and I use amp draw, I know that good motors draw less amps when compared to other motors with the same top numbers.


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## Boosted-Z71 (Nov 26, 2007)

alpink said:


> aha!!!
> there is good reason you won that Yellow Jacket/SCRIG drag challenge!!!!
> ..... LOL .....
> good info
> thank you


Yes Al that car spent some time on the dyno, partly because I did not have a long enough straightaway to hold it, after I bounced it off the garage door twice, thinking I could shut it down soon enough I figured the dyno was a much safer bet for testing. And remember the issue with it not going fast for 2 passes was traction, Jim said it was spitting silicone off the tires most of the way down the track on the first 2 passes, your not going to see that on the dyno. 

Mike that amp draw is purely dependent on the load applied, Free spin equals less load, that will equal less amp draw, the car see's a load force from propelling itself on the track, You can easily increase the amp draw you see by pressing the wheels against the rollers. I wont say providing the resistive load electronically is impossible, but then your changing the current to the motor to start with or getting into feedback trying to restrain the arm electrically. Also adding friction by a mechanical means (think rubbing the roller with something) is really tough as well, as it only takes a very small amount, and a tad more is too much, so coming up with a mechanical means to apply / regulate the force was almost impossible.

I came up with a very creative simple solution that I am keeping to myself, but is very easy to duplicate the resistance the car see's as its propelling itself down the track, whether its a t-jet or inline. 

Wildman has a dyno like mine that I built for him for some hot in-lines, we had to step the drag up a fair bit on his model for the hot winds, with the Simple Dyno software its really easy to correct the load based from data of several of the measured factors. 

All in all these are quantitative tools, regardless of the brand / type you use (many guys tune by ear, am radio, etc) if you learn to read the results and tune for more track speed it's a win/win situation regardless of the tool. 

Boosted


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## slotking (May 27, 2008)

the load system he uses is electrical
I saw a demo of 1 he made. ice feature.

I understand what your saying on amp draw
because i figured it the same way.

But I am finding my better arms pull less amps.

my theory, which may be wrong, cause I am guessing, is the the arm with more torque spins the roller easier than a arm with less torque.???


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## super8man (Jan 29, 2013)

I have the VRP 2.0 along with the new ammeter attachment. Those two things are what a few of us use for fray racing. It works perfectly everytime and is very consistent. I highly recommend it.

Here's a picture of it on the bench at a race:


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## alpink (Aug 22, 2010)

nice pit bench ....
and do eyespy a Winning Edge puller/press?
a rare and exotic tool for sure!
the man sure had an inovative spirit and his tools show that


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## super8man (Jan 29, 2013)

alpink said:


> nice pit bench ....
> and do eyespy a Winning Edge puller/press?
> a rare and exotic tool for sure!
> the man sure had an inovative spirit and his tools show that


Correct, I picked up a rather large array of Winning Edge tools that have served me well.


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