A few dyno questions

[CT335xi]

Hi guys been around these forums for awhile with owning prior BMW’s, I have searched but haven’t found much so thought I would ask . I just picked up a 2014 x5 50i cpo with 40,000 miles (wife’s car lol) , I want to dyno it and get a baseline. I have had a lot of my prior cars on the dyno which where manual cars , so what is the correct way to dyno the 50i ? I know for sure turn of dsc/ put in sport+ , but what gear ? 4th? I’m sure the guy who will dyno the car should probably know but just in case he is not familiar with dynoing BMW, he tunes my fbo evo 8 . Once I have a baseline , I would like to do light mods, will start with fresh plugs , add piggyback, and do the M air filters.


Thanks John

[r33_RGSport]

John,

I believe it is between 3rd and 4th gear.
So, either one is good. The delta is the important number.
If you are trying to get base number to compare it to the BMW claimed power, good luck.

[CT335xi]

Originally Posted by r33_RGSport

John,

I believe it is between 3rd and 4th gear.
So, either one is good. The delta is the important number.
If you are trying to get base number to compare it to the BMW claimed power, good luck.

Thanks Ben! Your quick to reply. I will definitely post results when I get them.

[CeeTeeX5]

You might want to consider reaching out to Dinan or checking their site for base dyno numbers. They usually post the base numbers as well as the post-tune numbers.

They can prob also give you an idea of their process to dyno.

[joyride]

Just be sure to let the dyno tech know about the step down in the throttle. I'm not sure if manual mode overrides that or not. Ive seen a few mash it and cause for a start over.

Also, it might be 6th gear for 1:1 in the 8 spd trans, but might want to do 5th for quicker pulls.

[CT335xi]

Originally Posted by joyride

Just be sure to let the dyno tech know about the step down in the throttle. I'm not sure if manual mode overrides that or not. Ive seen a few mash it and cause for a start over.

Also, it might be 6th gear for 1:1 in the 8 spd trans, but might want to do 5th for quicker pulls.

I’m also curious if in manual mode if it will kick down, I thought I read something about the ZF 8 speed don’t but I could be wrong.

[DuSh]

When I did it - we did it in 5th gear and then 4th. It doesn't matter eventually - it will give same power values, but with 6th gear you may hit speed limiter, if you are stock, so probably staying with 4th and 5th is better.

Please post stock dyno numbers, I'm very interested. What kind of dyno?

[CT335xi]

Originally Posted by DuSh

When I did it - we did it in 5th gear and then 4th. It doesn't matter eventually - it will give same power values, but with 6th gear you may hit speed limiter, if you are stock, so probably staying with 4th and 5th is better.

Please post stock dyno numbers, I'm very interested. What kind of dyno?

Mustang dyno- I have had my fbo evo 8 on it and know what a stock evo 8 does on it so I’m curious to see what a stock 50i does on it vs it’s flywheel rated horsepower which I’m sure the 445 hp is underrated by BMW anyways.

[Rotzy]

I've dynoed my 50i M sport on a mustang dyno a couple of times. Here's what you need to know:

6th gear is the 1:1 gear, but you will hit the speed limiter before redline, so 5th gear is the one to use. On my vehicle, pulls in 5th and 4th produced the same numbers.

Use the following modes/settings:
-Make sure all doors and hood are closed
-Sport+
-Sport shift (transmission lever to the left) so that it doesn't downshift when you floor it. Sport+, Sport Shift and manual gear selection are all required to prevent downshifting.
-DSC & DTC completely off (hold the traction button for a few seconds)
-PDC off
-Accelerate and manually shift into 5th
-Introduce the back of the pedal to the carpet

[Rotzy]

Originally Posted by CT335xi

Mustang dyno- I have had my fbo evo 8 on it and know what a stock evo 8 does on it so I’m curious to see what a stock 50i does on it vs it’s flywheel rated horsepower which I’m sure the 445 hp is underrated by BMW anyways.

Dyno numbers here. They seem low, but believe me this thing is a beast.

[joyride]

Those numbers are pretty good, I know mustang dynos are different, I actually prefer those numbers, my buddies averages out ~18% lower then dynojets. The most important thing is the delta anyways.

[CT335xi]

Originally Posted by Rotzy

Dyno numbers here. They seem low, but believe me this thing is a beast.

Rotzy believe me I know these 50i’s are beasts, you can just feel that torque and thanks for the info about running on the dyno. I’m very familiar with how low mustang dyno’s read, some say awd plus auto trans can be as much as 25% drivetrain loss by the time it gets to the wheels , so in your case if you took a estimated 475 hp and multiple it to 75% it come out to 356 hp which is close to your 352 you did stock. I have had a few of my vehicles on mustang dyno’s with all results being low , for example bone stock evo 8 put down 205 awhp and factory rated at 276 flywheel hp ( 276 x 75% = 207) so damn close. My evo 8 is currently fbo / built stroker motor and currently puts down 460/400 on mustang dyno. Looking forward to seeing what my bone stock 50i does, probably similar to yours even though some dyno’s are calibrated differently.

[CT335xi]

Originally Posted by joyride

Those numbers are pretty good, I know mustang dynos are different, I actually prefer those numbers, my buddies averages out ~18% lower then dynojets. The most important thing is the delta anyways.

Joyride you are absolutely right as all that really matters is the delta to see if your mods actually made any power improvements.

[Rotzy]

Originally Posted by CT335xi

all that really matters is the delta to see if your mods actually made any power improvements.

Exactly.

[classic_erik]

Originally Posted by Rotzy

I've dynoed my 50i M sport on a mustang dyno a couple of times. Here's what you need to know:

6th gear is the 1:1 gear, but you will hit the speed limiter before redline, so 5th gear is the one to use. On my vehicle, pulls in 5th and 4th produced the same numbers.

Use the following modes/settings:
-Make sure all doors and hood are closed
-Sport+
-Sport shift (transmission lever to the left) so that it doesn't downshift when you floor it. Sport+, Sport Shift and manual gear selection are all required to prevent downshifting.
-DSC & DTC completely off (hold the traction button for a few seconds)
-PDC off
-Accelerate and manually shift into 5th
-Introduce the back of the pedal to the carpet

Hey just curious why the hood would need to be closed?

Too bad we don't have a Dyno mode setting!

[Rotzy]

Originally Posted by classic_erik

Hey just curious why the hood would need to be closed?

Too bad we don't have a Dyno mode setting!

Some vehicles will not go into gear with the hood open. You either need to close the hood or trick the sensors.

[classic_erik]

Originally Posted by Rotzy

Some vehicles will not go into gear with the hood open. You either need to close the hood or trick the sensors.

Got it, makes sense.

Have my first dyno scheduled for the end of the month and will make sure I have your checklist in hand. Thanks!

[M302_imola]

Originally Posted by classic_erik

Got it, makes sense.

Have my first dyno scheduled for the end of the month and will make sure I have your checklist in hand. Thanks!

I expect a full report.