Overview
So what exactly does it do?
To sum it up: VHPA simulates the performance and handling of a vehicle and analyses the results.
A sentence which really does not convey the quantity and usefulness of the information that VHPA presents.
There are possibly hundreds of questions you could ask about how a vehicle will handle or perform, or how handling and performance would be altered if component 'x' was changed from setting 'a' to setting 'b'. VHPA endeavours to answer as many of those questions as possible, with a useful degree of accuracy.
Some examples:
Fancy an engine upgrade? Find out how much faster your vehicle will be,
even race the before and after versions aginst each other and really see the performance gain.
Thinking of fitting stiffened lowering springs? Find out how roll balance will be effected, how the dampers will work with your new springs,
how suspension travel changes under hard cornering and more.
For a complete list of program features with screenshots, visit the features page.
How is that useful to me?
There are two obvious benefits to using this program.
Firstly, this program can help pinpoint the source of handling issues or performance weakness so you know where to start making changes.
Secondly, an infinite number of changes can be made to the vehicle and the differences abserved without parts needing to be modified, bought, installed, etc.
A real time and money saver.
How much does it cost?
Best of all, VHPA is free (for personal and educational use)!
That said, please consider for a moment that this program has been created by one man
who has spent a huge amount of his personal time creating this application, plus some of his own money to run this website.
If you would like to make even a small donation toward these efforts,
it would be greatly appreciated and would help to spur the development of updates:
For users seeking to use this program in a commercial environment, please contact the author to discuss licencing.
How accurate is it?
Within the listed constraints and limitations,
this program has shown to be very accurate given correct input data.
By far the most easily comparable figures are for acceleration.
Taking the acceleration timings of some real cars, for example the Mazda RX-8 and Ferrari F40,
and comparing the numbers against those generated by the simulation.
| Mazda RX-8 | Ferrari F40 | |||||
| Real | Simulation | Difference | Real | Simulation | Difference | |
| 0-60mph: | 6.1s | 6.5s | +0.4s / +6% | 3.8s | 3.8s | None |
| 0-100mph: | 16.0s | 16.1s | +0.1s / +1% | 7.8s | 7.5s | -0.3s / -4% |
| Standing quarter mile: | 15.3s 93mph | 15.2s 97.2mph | -0.1s / -1% +4mph / +4% | 11.9s 126 mph | 11.8s 129.6mph | -0.1s / -1% +4mph / +3% |
| Standing kilometer: | 27.3s 119mph | 27.1s 125mph | -0.2s / -1% +6mph / +5% | 20.9s unknown | 20.8s 164.4mph | -0.1s / -1% ? |
| Top speed: | 148mph* | 147mph* | Negligable | 201.4mph | 201.1mph | None |
*Electonically limited by rev limiter in 5th gear, while 6th gear is for cruising only. Another 10mph would be available with different gearing.
This data gives two good examples of the typical accuracy of acceleration simulation the program. Worst case scenarios should be out by no more than 10%, even at that point I would begin to question either the source data or the accuracy of the real measurements being compared against.
Other aspects of VHPA should be at least as accurate as the acceleration simulation, however they are much harder to prove, and in some cases even quantify, making comparisons increasingly difficult.
Copyright © 2004-2024 Ben Ponsford