[RollingCoal]

A handful of users have posted PerfExpert results in various threads. So, in order to not thread jack, this thread will be a good place to post results using the app. I've copied several posts from the JR Auto Performance Tune Thread......

Originally Posted by RollingCoal

I finally got a chance to do a few test runs with the PerfExpert app. This was a pretty clean 3rd gear pull (JR 2.5 Tune & Stock Open Exhaust, No Methanol).....



I really didn't like the scaling of the torque, but couldn't figure out how to change it. These are "to the wheels #'s" I'll try to get a few more clean runs (had to get out of this run a smidgen early) and hopefully post some verification runs. I'm really liking the app, just hard to get an open road to really test this out.

Originally Posted by TDIwyse

Nice.

You can export the data into a txt file, which you can change to a csv file, and import into a spreadsheet and make your own graph. It also contains the speed and rpm data. This is useful for verifying your "pitch" factor is correct for your setup (pitch affects calculated speed/rpm which impacts power/tq measurement accuracy).

I recently got a large screw in my right rear tire that damaged it beyond repair, and have switched tire configuration around. Now running a slightly smaller diameter tire in the front vs the back. This change required tweaking the "pitch" factor lower to get the rpm/speed calculation to lineup with measured rpm/speed data.

Attaching a couple screen images I just took to help you out for the exporting of the raw file data.

As an aside, I find 3rd gear doesn't load the engine enough to get full output. But, 4th gear pulls get you into license loosing speeds. So please be careful.

Originally Posted by RollingCoal

Awesome, thanks.

I got a really good run in this morning with no traffic around. I did a better job getting my phone in a fixed position (actually wedged in so it could not move independent of the car). I think I was getting a slight bit of movement in the graph above.

It's unreal just how close the run this morning is to the JR dyno. I'll post the specs and results along with a the raw data graph later tonight.

Originally Posted by f00dstamps

What other hardware do you need to run this software application?

Originally Posted by TDIwyse

Just a smart phone. But this seems like we're getting off the thread topic.

PerfExpert has it's own site/forum for support: http://www.perfexpert-app.com/

Originally Posted by RollingCoal

I don't want to continue down a path different than the JR Tune. Just thought this might be a good reference for the 2.5 tune I have.
Here is the run from this morning




Jarek's Results from Pg1 for the 2.5 Tune are:

HP 344.7 @ 3836 RPM vs My Results HP 345.7 @ 3836 RPM
Torque 543.3 @ 3021 RPM vs My Results Torque 550.9 @ 3022 RPM

Originally Posted by TDIwyse

Can't help myself ... I love data.

It looks like you either let off early, or might not have the correct wheel size, gearing, or pitch factor, or your test road isn't flat. From your curve it looks like the shift, or where you let off the fuel, happened at ~ 4500 rpm (you can move the marker to that edge to know for sure).



From my logs (I log parameters with Torque or TestO simultaneously with the PerfExpert pull so I can align rpm's and see what's happening across the pull and the accuracy of the PerfExpert results) the rpm the shift happens is ~4650 rpm with Jarek's remap and the stock transmission mapping.

[RollingCoal]

Originally Posted by TDIwyse

Can't help myself ... I love data.

It looks like you either let off early, or might not have the correct wheel size, gearing, or pitch factor, or your test road isn't flat. From your curve it looks like the shift, or where you let off the fuel, happened at ~ 4500 rpm (you can move the marker to that edge to know for sure).

From my logs (I log parameters with Torque or TestO simultaneously with the PerfExpert pull so I can align rpm's and see what's happening across the pull and the accuracy of the PerfExpert results) the rpm the shift happens is ~4650 rpm with Jarek's remap and the stock transmission mapping.

I did let off just a bit early because this was the furthest in the RPM range I've pushed my car. The wheel/tire settings are setup correct. As far as a shift, I never let the car shift to 4th. Here is the process I used:

Set the app for 3rd gear pull, w/ starting RPMs set at 1900
Pulled out slowly in M2 and shifted to M3 as soon as I felt possible and continued to hold the skinny pedal
Was on full throttle at approximately 1600 RPM all the way through 4712 according to my logs. Here is the same pull showing the line you marked.



I do need to bring my tablet along as well so I can log other parameters. I really think I was possibly beginning to hit the air flow threshold for my setup. Factory air box, filter with 23,000 miles on it, etc.

[TDIwyse]

Originally Posted by RollingCoal

I did let off just a bit early because this was the furthest in the RPM range I've pushed my car. The wheel/tire settings are setup correct. As far as a shift, I never let the car shift to 4th. Here is the process I used:

Set the app for 3rd gear pull, w/ starting RPMs set at 1900
Pulled out slowly in M2 and shifted to M3 as soon as I felt possible and continued to hold the skinny pedal
Was on full throttle at approximately 1600 RPM all the way through 4712 according to my logs.

I do need to bring my tablet along as well so I can log other parameters. I really think I was possibly beginning to hit the air flow threshold for my setup. Factory air box, filter with 23,000 miles on it, etc.

Oh, this is good stuff. I've found PerfExpert to be a fantastic tool. Like the developer describes, it works best if you can do tests on the same stretch of flat road, and follow a precise methodology, and it's best to have no wind (wind will distort things a lot if speeds are high).

It's good you have a procedure you plan to follow. The way you mount the phone should also be repeated. I wouldn't focus so much on the absolute numbers, but more on how different mods affect those numbers. Especially if you can duplicate the same results on back to back pulls. If you can't closely duplicate results over multiple pulls, then the information isn't going to be helpful.

The app also does a great job of pulling the local environmental data from your cell phone location and applying standard correction factors. My old Gtech couldn't do that, so there was inherent variations that were not accounted for in that tool. I'm maxing out the stock turbo's capability, and ambient conditions have a significant impact on the vehicles output. The DIN correction factor seems to work the best on my vehicle for reproducible numbers across varying ambient conditions for the same car/system/modification settings.

I have a flat testing location that's on the way to work, on isolated back county road that's surrounded by corn/bean fields, and I can see for miles, and I go very early in the morning so generally there's minimal wind, and not another car in sight, which allows for good, repeatable testing. I don't do a pull if I see other cars, so in case something goes wrong I only hurt/kill myself and my property. It also minimizes chances for speeding tickets...

Hope you find this tool as useful as I have :-)

[32valves]

seems interesting, is this app for iphone or any smart phone?

[RollingCoal]

Originally Posted by 32valves

seems interesting, is this app for iphone or any smart phone?

It is available for both. Very minimal cost and can do Dyno Runs or Timed Runs.

[gavronm]

What are people using for vehicle parameters and settings? I just downloaded the app yesterday and here is what I gathered from the interwebs:

Vehicle Parameters:
Car weight - 3950
Additional weight - None of your damn business
Displacement - 3 L
Wheel Dimensions - 255/35R18 (stock rear size)
Cd.A - 0.65
Transmission - Rear Wheel Drive
Final Drive Ratio - 2.81
Minimum rev - 1600
Pitch - 3 degrees/G
2nd - 2.34
3rd - 1.52
4th - 1.14

Settings (the settable ones anyway):
Timed Run trigger - 0.10 G (default)
Auto retrieving - Active
Correction norm - DIN 70020 (default)
Smoothing - medium

[RollingCoal]

Originally Posted by gavronm

What are people using for vehicle parameters and settings? I just downloaded the app yesterday and here is what I gathered from the interwebs:

Vehicle Parameters:
Car weight - 3950
Additional weight - None of your damn business
Displacement - 3 L
Wheel Dimensions - 255/35R18 (stock rear size)
Cd.A - 0.65
Transmission - Rear Wheel Drive
Final Drive Ratio - 2.81
Minimum rev - 1600
Pitch - 3 degrees/G
2nd - 2.34
3rd - 1.52
4th - 1.14

Settings (the settable ones anyway):
Timed Run trigger - 0.10 G (default)
Auto retrieving - Active
Correction norm - DIN 70020 (default)
Smoothing - medium

I have the same settings except my weight is showing the car @ 3649 lbs which does not include the weight of the fuel, driver, passengers or gear. You can choose each of those during the prep for a run.

[TDIwyse]

Here's a good reference for some of the North American 335d specs: http://media.caranddriver.com/files/2009-bmw-335d-1.pdf

I think your Cd*A is right, but your weight may be a bit heavy.

As long as you're consistent with those values and how you do the measurements, the relative impacts of tuning modifications should come through. I'd suggest using it as a tuning tool as opposed to looking for absolute numbers.

[cruising6]

Hi.

I wrote the program my 335d, the DPF is in the car(full stock car).







What do you think this is all right or some settings wrong?

My car in car peaper 1655 kg = 3648lb.


Thank you

[TDIwyse]

Originally Posted by cruising6

Hi.

I wrote the program my 335d, the DPF is in the car(full stock car).
...
What do you think this is all right or some settings wrong?

My car in car peaper 1655 kg = 3648lb.


Thank you

That looks pretty good. If PerfExpert shows a lower rpm where you shifted or let off the fuel (where the torque falls off), and you are on a flat road, then try lowering the Pitch Factor. 3 deg seems to work pretty well for 3rd gear and oem sport suspension, but for 4th and after changing dampers I had to lower it further (gearing in 3rd will apply more force to the wheels and cause the car to squat more than 4th, and 4th more than 5th, etc... you'll need a different pitch factor depending on the gear you use to do the dyno pull).

I wouldn't get hung up on the absolute numbers, but rather use this as a tuning tool to verify effects of modifications (assuming you are getting reproducible results with the methodology you are using).

[cruising6]

Originally Posted by TDIwyse

That looks pretty good. If PerfExpert shows a lower rpm where you shifted or let off the fuel (where the torque falls off), and you are on a flat road, then try lowering the Pitch Factor. 3 deg seems to work pretty well for 3rd gear and oem sport suspension, but for 4th and after changing dampers I had to lower it further (gearing in 3rd will apply more force to the wheels and cause the car to squat more than 4th, and 4th more than 5th, etc... you'll need a different pitch factor depending on the gear you use to do the dyno pull).

I wouldn't get hung up on the absolute numbers, but rather use this as a tuning tool to verify effects of modifications (assuming you are getting reproducible results with the methodology you are using).

In 3rd the car the wheel slips and the 4rd is also traction limited I need lsd from quaife.
It's stock Mtech suspension. I try 2 deg pitch after remove the dpf.

Thank you.