Akraprovic Evo Exhaust, Dinan Intake, and BPM stage 2 Tune: Baseline and Mod Dyno

[ImmortalBimmer]

So I finally got around to buying and installing goodies for my car. My car is at 110K miles with rod bearings done at 100K along with spark plugs. I first got a baseline dyno from Driver Source in Houston back in May 2017 with a healthy baseline RWHP of 347 in 4th gear and 345rwhp in 5th gear on a dynojet SAE corrected. Today, I went back to Driver Source to get a dyno of my car with the following mods: Dinan Intake, Akrapovic Evo Full Exhaust, and BPM stage 2 tune(93 Octane) with 240E update. The car pulled a 344 RWHP at the dyno in 4th gear and 345 in 5th gear SAE corrected. The last run I’m assuming was heat soak and ran a 339 RWHP in 4th. Needless to say I’m very disappointed. I only saw an increase under the curve for torque but no peak HP increase at all. My car feels stronger after the mods although the Dynojet says otherwise. The dyno was done by the same technician three years ago… so that should help with consistency in setup somewhat. However, I know some people believe base line and mods should be done in the same day to see the real readings, but I can’t believe there’s not much change besides under the curve with all the mods.

Baseline Dyno

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Akrapovic Evo Exhaust, Dinan Intake, and BPM stage 2 tune.

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Baseline and mods overlayed

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[BPMSport]

Please send us the .DRF files for review. You can email them to support@bpmsport.com and we'd be happy to take a look.

If you were to dyno without the tune and exhaust again, there is no question that you would be producing in the 320's range. There are a lot of factors and variables involved with dyno testing, and these charts are definitely not representative of the gains.

A baseline from three years ago introduces far more variables. You should always perform the comparisons in the same gear and ususally three runs are required to receive stable results. The difference between the first and third runs is commonly 10+ wheel more. Given the M3's are extremely sensitive to hot intake air temperatures, and that the air flow on a dyno is significantly less than what the vehicle would see at 100+ MPH on the road, power gains aren't realized as well. For example, two years ago a customer discussed his dyno results with us and didn't see a large gain in a high humidity setting. After running a car that he had raced many times previously and had been even, the difference was seen immediately on the street as he pulled away.

For reference, please see this thread for other vehicles that have been tested on the same dyno before/after (within a short time period, or still strapped down): https://www.m3post.com/forums/showthread.php?t=1597045

It is also possible that adaptive factors over the years (such as knock control) have reduced the output, or aging of the engine or other components such as oxygen sensors have impacted the result. Has the airfilter been replaced or cleaned? Dynos are great tools for testing, but note that wheel size, gear, number of runs, humidity, fuel quality, and even strap down tension can cause 10-20 HP variations.

Please obtain and send over the .drf files so we can have a look. Thank you and stay safe!

[ImmortalBimmer]

Originally Posted by BPMSport

Please send us the .DRF files for review. You can email them to support@bpmsport.com and we'd be happy to take a look.

If you were to dyno without the tune and exhaust again, there is no question that you would be producing in the 320's range. There are a lot of factors and variables involved with dyno testing, and these charts are definitely not representative of the gains.

A baseline from three years ago introduces far more variables. You should always perform the comparisons in the same gear and ususally three runs are required to receive stable results. The difference between the first and third runs is commonly 10+ wheel more. Given the M3's are extremely sensitive to hot intake air temperatures, and that the air flow on a dyno is significantly less than what the vehicle would see at 100+ MPH on the road, power gains aren't realized as well. For example, two years ago a customer discussed his dyno results with us and didn't see a large gain in a high humidity setting. After running a car that he had raced many times previously and had been even, the difference was seen immediately on the street as he pulled away.

For reference, please see this thread for other vehicles that have been tested on the same dyno before/after (within a short time period, or still strapped down): https://www.m3post.com/forums/showthread.php?t=1597045

It is also possible that adaptive factors over the years (such as knock control) have reduced the output, or aging of the engine or other components such as oxygen sensors have impacted the result. Has the airfilter been replaced or cleaned? Dynos are great tools for testing, but note that wheel size, gear, number of runs, humidity, fuel quality, and even strap down tension can cause 10-20 HP variations.

Please obtain and send over the .drf files so we can have a look. Thank you and stay safe!

I just emailed the guy at Driver Source. Hopefully, I will get the files tomorrow. The wheels size and gearing have stayed the same. Air filter has about 20k miles on it. The temperature from this run is actually lower at 77F compared to 85F in the past, however today's humidity was at 55% compare to 42%. I thought the SAE correction would help factor into that? I have not replaced my o2's since I had the car. If I replaced them would that help correct some of the power lost that dramatically? Thanks for trying to help me understand some of the causes.

[Ervin87]

20K miles on an air filter is quite a bit, especially if you live in a heavily populated area.

Not saying that the filter is the main culprit, but you should at least inspect it to see how it looks.

[Vedubin01]

Where in Houston are you located?

[ImmortalBimmer]

Originally Posted by Vedubin01

Where in Houston are you located?

I live in Sugar Land.

[GORDON.M3]

Far too many variables involved saying that the BPM Sport tune is disappointing. The problem lies with the maintenance and upkeep of your car.

The baseline was done 3 years ago, a lot can happen over the years if you haven't kept up with the maintenance.

Depending on the mileage of your car, spark plugs, coils, and injectors can easily rob power away from your car without you truly "noticing" it.
Just because there are no "lights" on it doesn't mean it doesn't require servicing. If you are on original O2 sensors since you got the car then I would definitely look into that first. If you follow along with a few threads people have been changing spark plugs and o2 sensors every 15-20k miles just to keep up with the loss of power.

Your Dinan filter at 20k miles is due for a replacement, I clean my filter every time I do an oil change but that's just me. It's better for the engine in the long run and it is not a difficult task to do.

That also being said, a stationary dyno isn't the best way to prove if a tune is good or not... after 8 runs your car is probably heat-soaked. The S65 and ECU are very temperamental when it comes to temperatures. Tunes are only good when proven in real-world scenarios where an ample amount of airflow is reaching the car, dynos figures are never really a good way to prove if a tune is good or not. It's easy to make big numbers for a few seconds but difficult to make them last.

I would start by looking at the list of maintenance items before drawing conclusions that the tune isn't doing it for ya.

[ImmortalBimmer]

Originally Posted by GORDON.M3

Far too many variables involved saying that the BPM Sport tune is disappointing. The problem lies with the maintenance and upkeep of your car.

The baseline was done 3 years ago, a lot can happen over the years if you haven't kept up with the maintenance.

Depending on the mileage of your car, spark plugs, coils, and injectors can easily rob power away from your car without you truly "noticing" it.
Just because there are no "lights" on it doesn't mean it doesn't require servicing. If you are on original O2 sensors since you got the car then I would definitely look into that first. If you follow along with a few threads people have been changing spark plugs and o2 sensors every 15-20k miles just to keep up with the loss of power.

Your Dinan filter at 20k miles is due for a replacement, I clean my filter every time I do an oil change but that's just me. It's better for the engine in the long run and it is not a difficult task to do.

That also being said, a stationary dyno isn't the best way to prove if a tune is good or not... after 8 runs your car is probably heat-soaked. The S65 and ECU are very temperamental when it comes to temperatures. Tunes are only good when proven in real-world scenarios where an ample amount of airflow is reaching the car, dynos figures are never really a good way to prove if a tune is good or not. It's easy to make big numbers for a few seconds but difficult to make them last.

I would start by looking at the list of maintenance items before drawing conclusions that the tune isn't doing it for ya.

I've kept up with the major maintenance items such the rod bearings and throttle actuators along with the valve cover leaks, DCT transmission leak, and thermostat over the years. I never thought about the injectors, coils, and o2s as power robbing. I never blamed the tune because I felt the changed with the exhaust, and maybe it brought me back to the original level that I didn't realize I lost. I was just disappointed by the results of the dyno and tried to figure out whats going on with the car. I was discussing this with the dyno tech. I just wanted people to know my results and at the same time fix the unknown issues that maybe robbing me power. Injectors, o2s, coils and air filter are now on my to do list.

[pbonsalb]

you probably don’t want to pay for a bunch of dynos but it would be fun to learn which of the items on your to do list makes a difference rather than that all 4 of them together made a difference.

[Willem3]

I experienced a clean airfilter is very important when running stage 2 because the engine consumes more air.

On high rpm the engine can’t breathe enough and struggles on high rpm.
Intake noise increases and throttle response is better with a fresh filter.

I have also a Akrapovic evo and stage 2, my car runs much better with a fresh air filter!

[Scharbag]

Ya know, my post added zero value. I have deleted it. Sorry. Bit of a day.

So, I will try again. 344 baseline RWHP is pretty good. Typically, I have dynoed in 4th gear consistently with my M3. I know it is not 1:1 but that is a moot point as there is a diff in the way. A good dyno should not really care though as HP is simply a calculation based on torque. Torque is calculated by T=Ia where I = moment of inertia and a = angular acceleration. So, gearing, tire size, speed, etc. should have minimal effects. It is best to use a higher gear to avoid wheel spin and as mentioned, strap tension can affect the results by minimizing any slip.

I know it is not apples to apples, but I ran 383 RWHP with similar mods to yours (different brands, but same approach). I do know that O2 sensors can go bad on these cars without throwing a code. Also, plugs play a huge role in performance and are relatively cheap and easy to replace. Check both of those for sure.

Cheers,

[GORDON.M3]

Originally Posted by ImmortalBimmer

I've kept up with the major maintenance items such the rod bearings and throttle actuators along with the valve cover leaks, DCT transmission leak, and thermostat over the years. I never thought about the injectors, coils, and o2s as power robbing..

These in my books are more like repairs, you can do them early but those are known to fail over time.

Get in the habit of doing regular service intervals for filters, injectors, coils, and o2s. The S65 is a MAFless car so the o2's play a crucial role in making power for these cars.

Originally Posted by Scharbag

Ya know, my post added zero value. I have deleted it. Sorry. Bit of a day.

So, I will try again. 344 baseline RWHP is pretty good. Typically, I have dynoed in 4th gear consistently with my M3. I know it is not 1:1 but that is a moot point as there is a diff in the way. A good dyno should not really care though as HP is simply a calculation based on torque. Torque is calculated by T=Ia where I = moment of inertia and a = angular acceleration. So, gearing, tire size, speed, etc. should have minimal effects. It is best to use a higher gear to avoid wheel spin and as mentioned, strap tension can affect the results by minimizing any slip.

I know it is not apples to apples, but I ran 383 RWHP with similar mods to yours (different brands, but same approach). I do know that O2 sensors can go bad on these cars without throwing a code. Also, plugs play a huge role in performance and are relatively cheap and easy to replace. Check both of those for sure.

Cheers,

Strap down tension also plays a big role. I would also dyno the car in 6th.

[pbonsalb]

1:1 is the ideal gear. 5th. Will the car do redline in 6th? I guess theoretically if the top speed limiter is removed. No aero drag on the dyno so maybe it would do 195 or whatever redline is.

I doubt wheel spin on the dyno is a problem with only 250 lbs of torque and a very gradual/fiat torque curve. I get wheelspin on the dyno with my turbo E36M3 but it goes from 200 lbs to 500 lbs rwtq in 2000 rpm.

[SYT_Shadow]

Originally Posted by pbonsalb

1:1 is the ideal gear. 5th.
\.

For sure. Besides most dyno operators want to keep it under 160mph wheel speed

[GORDON.M3]

Originally Posted by pbonsalb

1:1 is the ideal gear. 5th. Will the car do redline in 6th? I guess theoretically if the top speed limiter is removed. No aero drag on the dyno so maybe it would do 195 or whatever redline is.

I doubt wheel spin on the dyno is a problem with only 250 lbs of torque and a very gradual/fiat turquoise curve. I get wheelspin on the dyno with my turbo E36M3 but it goes from 200 lbs to 500 lbs rwtq in 2000 rpm.

Good to know, I haven't dyno'd the M3 yet, I'm interested to see what my engine pulls after 10 years of being on the road.

[Scharbag]

Originally Posted by pbonsalb

1:1 is the ideal gear. 5th. Will the car do redline in 6th? I guess theoretically if the top speed limiter is removed. No aero drag on the dyno so maybe it would do 195 or whatever redline is.

I doubt wheel spin on the dyno is a problem with only 250 lbs of torque and a very gradual/fiat turquoise curve. I get wheelspin on the dyno with my turbo E36M3 but it goes from 200 lbs to 500 lbs rwtq in 2000 rpm.

I have heard this a lot but it would be nice to know why 1:1 is the ideal dyno gear. Not trying to be difficult, I would like to know the reason behind this.

Cheers,

[BPMSport]

Originally Posted by Scharbag

I have heard this a lot but it would be nice to know why 1:1 is the ideal dyno gear. Not trying to be difficult, I would like to know the reason behind this.

Cheers,

A ratio of 1:1 reduces frictional losses induced by gearing changes.

[Scharbag]

Originally Posted by BPMSport

A ratio of 1:1 reduces frictional losses induced by gearing changes.

This is a good little summary.

The difference in losses in a good manual should be moot between gears. I have been told that 1:1 was best but never really thought about why. After reading more about it, it seems that it really should not matter with our modern transmissions. I have dynoed in 4th in my 6MT and it seemed to work fine.

And 1:1 in a DCT car is 7th gear. With the 3.15 FD, you would need to run out to ~200MPH to hit 8600 RPM... Not sure many dynos would like that.

Any chance you could test a car in 4th and 5th back to back just to see if it makes any difference?

Cheers,

[amrazM]

Originally Posted by Scharbag

This is a good little summary.

The difference in losses in a good manual should be moot between gears. I have been told that 1:1 was best but never really thought about why. After reading more about it, it seems that it really should not matter with our modern transmissions. I have dynoed in 4th in my 6MT and it seemed to work fine.

And 1:1 in a DCT car is 7th gear. With the 3.15 FD, you would need to run out to ~200MPH to hit 8600 RPM... Not sure many dynos would like that.

Any chance you could test a car in 4th and 5th back to back just to see if it makes any difference?

Cheers,

Still no answers to the low dyno reading?

[BPMSport]

Originally Posted by Scharbag

This is a good little summary.

The difference in losses in a good manual should be moot between gears. I have been told that 1:1 was best but never really thought about why. After reading more about it, it seems that it really should not matter with our modern transmissions. I have dynoed in 4th in my 6MT and it seemed to work fine.

And 1:1 in a DCT car is 7th gear. With the 3.15 FD, you would need to run out to ~200MPH to hit 8600 RPM... Not sure many dynos would like that.

Any chance you could test a car in 4th and 5th back to back just to see if it makes any difference?

Cheers,

You can dyno in third gear and it would "work fine"
also. We have seen variances from gear to gear on the dyno, some cars more than others. There are multiple factors at play. You are correct about DCT gearing.

[Willem3]

I have the same result! see my graph...

Akrapovic evo with oem 241 (update) software vs Evolve Stage 2...
Nothing, with OEM software the cars runs even better and smoother!

I like the torque curve although... almost 295lbf /400nm between 3000 - 7000rpm!