Articles tagged with: Comparison

Intake comparison on 4AGE 20V BlackTop

on Tuesday, 07 February 2012. Posted in Using PerfExpert

Performances difference between the original plenum and open velocity stacks

Here's a little comparison that has been done on Stephane's Toyota AE82 Twin Cam GT : seeing with PerfExpert the difference in torque and power between the original plenum (without the air filter) and open velocity stacks.

To perform reliably this test it was necessary to proceed as following :
- Always launch the car from the same mark on the road
- Always WOT at the same mark on the road
- Take measurements at the same direction of travel
- Be sure to follow the PerfExpert basic measurement procedures (phone calibration performed, impeccable phone fixation, little wind, free road, lift windows...)
- If the car remained parked in a while then drive a few minutes at medium speed to cool the engine bay in order to always make the measurements under similar engine bay temperature conditions 
- For each setup (plenum or open stacks), perform at least two measurements having less than 2% deviation to confirm their reliability. Indeed non-repeatable measurements (differences of more than 2%) reflect a poor phone fixation or poor conditions (road, wind...).


Toyota Corolla AE82 Twin Cam GT


At first, measurements with T3 open stacks

Toyota 4AGE 20V blacktop open stacks

PerfExpert 4AGE 20 blacktop cornets 1

PerfExpert 4AGE 20 blacktop cornets 2


Here are the results with this setup :
- 159.6hp at 7300rpm et 131.8Ft.Lb at 5500rpm
- 159.1hp at 7300rpm et 133.2Ft.Lb at 5300rpm



Lets see now the results with the OEM plenum and OEM stacks. Unfortunately we didn't have a cold air feed to the plenum for the tests. And note that the curved OEM stacks had been cut by the previous car owner...


4AGE 20V blacktop plenum 14AGE 20V blacktop plenum

PerfExpert 4AGE 20V blacktop plenum 1

PerfExpert 4AGE 20V blacktop plenum 2


Here are the results with this setup :
- 150.4hp at 7200rpm et 128.2Ft.Lb at 5200rpm
- 151.3hp at 7200rpm et 130.4Ft.Lb at 5200rpm

This shows a clear advantage of open stacks in power (more than 5%), and a slight advantage in Torque. But the most interesting is to see the curves comparison. Here is a Google Doc with an overlay made ​​from a fusion of data exports made ​​from the application :

Toyota 4AGE 20v blacktop : open stacks VS plenum

Not enough room for the legend so I'll give more details here :
- P1 & P2 are the 2 power curves in open stacks setup
- T1 & T2 are the 2 torque curves in open stacks setup
- P3 & P4 are the 2 power curves in plenum setup
- T3 & T4 are the 2 torque curves in plenum setup

Note that with the plenum there is a little more torque before 4000rpm and less torque after. So really, even if the open stacks give more torque maximum value, the plenum give a more torquey engine at low rpm.
A pity that we didn't have a 100% stock plenum (whose stacks are not cut) and the original airbox + filter. The comparison would have been even more interesting.

Highlight your PerfExpert vs Chassis Dyno comparison

on Monday, 22 June 2015. Posted in Announcements

Send us your comparisons to better convince the most skeptical ones about PerfExpert accuracy

Highlight your PerfExpert vs Chassis Dyno comparison

Most people find it hard to believe that a smartphone application can measure power and torque with an accuracy very close to chassis dynos, without any connection to the car or without any external measuring equipment. They generally think of a hoax, because they cannot imagine the real potential of the modern phones sensors, especially when they are combined with powerful algorithms and calculations. Thus, providing them the proof with "PerfExpert vs Chassis Dyno" comparisons seems to be the solution.

What could be better than seeing this proof brought by other car enthusiasts who tested PerfExpert by themselves?

If you carried out this kind of tests you can contact us to transmit us your results, by sending us the following elements :

  • A copy of the full report of the chassis dyno result, in other words, the result sheets, perfectly readable, scanned or photographed
  • An Image export of PerfExpert measurement curves, and, if possible, with two PerfExpert tests carried out under the same conditions (same road, same direction, same starting point, same day)
  • The links towards your tests on the Web PerfExpert Network
  • And for the fun, if you agree, a beautiful picture of your car, outside and/or on the chassis dyno! :) We will hide the license plates if they appear.

We will gather them in our Google + collection of PerfExpert vs Chassis Dyno comparisons.

Speaking about PerfExpert around you and showing that it is a reliable application when it is correctly used allows us to keep on improving it and creating new features! As a user, you now know how to answer those who ask you about the application's accuracy and reliability compared to chassis dyno's. In fact, this is often the first question people ask when they discover that the PerfExpert application allows them to measure your car engine’s power and torque using only your smartphone!

Here is an comparison example from our collection :

PerfExpert Car Dyno=> Power : 301cv / Torque : 370Nm

Cartec Chassis Dyno => Power : 300.5cv / Torque : 371Nm

Nissan 350Z

Nissan 350Z chassi dyno result

Nissan 350Z PFX result 


Introducing Dyno Tests Comparison

on Friday, 09 January 2015. Posted in Using PerfExpert

Make comparisons of your test results using the PerfExpert Analysis Tool

Introducing Dyno Tests Comparison

You requested it and it's finally there : you can now see several dyno test results overlaid on the same graph. This is very useful when you want to find which of your car's setups produce best performance, as we seen on the Corolla AE82 20V intakes comparison and the Mercedes 190E Turbo sizes comparison. This is possible thanks to our new Analysis Tool by using your mobile or desktop internet browser. This tool is available only for results that are online on the PerfExpert Network.

To compare your results :

1 - Log in to the PerfExpert Network and go to 'My PerfExpert'

If you don't have a PerfExpert Network account, you have to register by using our mobile Dyno & Timed Run app : go to 'Account' in the Test screen menu and follow instructions.

2 - Open the desired car to see its test results

Here, you will only see results that have been uploaded from the mobile app, either by clicking on 'Open web link' on the Result screen of the the mobile app or by sharing via the 'Web' method.


3 - Select the results you want to compare and click the 'Compare' button that appears at the bottom-right of the screen

You can select up to 3 results for comparison. For now, only dyno test results with the same units are comparable.

Results - selection 

4 - See results comparison at each point of the curves


If you have questions or feedbacks, feel free to contact us.


Turbo sizes comparison on Mercedes 190E 3.0 24v Turbo

on Wednesday, 26 February 2014. Posted in Using PerfExpert

Turbo spooling up differences

Turbo sizes comparison on Mercedes 190E 3.0 24v Turbo

One of the main goals of PerfExpert is to help you see the impact of your mods on performance when doing engine tuning, as you can see in the 4AGE 20V intake comparison performed on a Corolla GT AE82.

Here it's about another PerfExpert user's car : Georgi's impressive Mercedes 190E. It has a 3.0L 24V engine swap converted to turbo at 0.9bar boost, managed by a MegaSquirt standalone ECU with 660cc/min injectors.

We will see how he used PerfExpert to compare different turbo sizes on his car, when he was looking for the one that will provide the best spooling while maximizing power and torque.

Note that in order to perform accurate comparison, Georgi has carefully followed PerfExpert mounting requirements and measurement conditions. Check out the DIY phone mounting article for more information.

In the app, he created three Setups : one for each turbo. This allows better organization by grouping together results that belong to a specific turbo. Also, he took care of using exactly the same boost pressure, and not changing other parts in the engine or in the car : only the turbo. This ensures that the changes in power and torque are only due to the turbo swapping.

Dyno result with the T66

The first setup was with a T66 (A/R 1.15) turbo :

Mercedes 190E 3.0 24v turbo T66 DynoTest 

Max power : 451hp @ 6300rpm
Max torque : 520Nm @ 5900rpm

Not satisfyed because of the turbo lag, Georgi decided to replace this big T66 turbo with a smaller one. The purpose was to get full boost at lower rev. In other terms, he wanted to improve turbo spooling.

Dyno result with the smaller turbo

The 2nd setup was with a smaller turbo, that is a hybrid turbo built using Holset turbine and compressor wheels inside Garret housings (A/R .82) :

Mercedes 190E 3.0 24v turbo Hybrid Dyno test

Max power : 452hp @ 6300rpm
Max torque : 537Nm @ 4600rpm

As you can see, with the hybrid turbo, max power value and max power rev are still exactly the same, but max torque is acheived 1300rpm earlier and is a bit higher than with the T66.

Dyno result with the T6682

Unfortunaletly the hybrid turbo didn't last long and failed after a few weeks, so it was time to fit back the T66, but this time with a A/R .82 turbine :

Mercedes 190E 3.0 24v turbo T6682 Dyno test

Max power : 479hp @ 6200rpm
Max torque : 581Nm @ 4700rpm

Results are very good here : same spooling as with the small turbo (hybrid one) but with more power and torque! With still 0.9bar boost!

T66 vs Hybrid vs T6682 comparison

Now let's have a more detailed look at these different dyno results :

Mercedes 190E 3.0 24v turbo T66 vs Hybrid vs T6682 Dyno comparison

The T6682 setup is definitely the best one through the entire engine rev range.

This comparison has been made using OpenOffice spreadsheet desktop application from data files exported by PerfExpert mobile app (Tabulation Separated Values files).

The PerfExpert comparison feature is still in development and will be available in a few weeks on the PerfExpert Network. It will allow a user to overlay several dyno or timed run results on the same graph inside a web page.

For more details about Georgi's car, check out its topic on the PerfExpert Forum.

Mercedes 190E 3.0 24v turbo