F15 X5 Tune Thread

[Meehow]

All you N55 35i guys, I highly recommend MHD Tuning - had a JB4 and the it never felt factory smooth. Running the E30 map, and it's spectacular. About ~ 400hp.

[OFFWHITEX5]

Originally Posted by duercos

Did u have a racechip tuner installed?

yes. Update, on no errors or hiccups on the 12 hours back.

[CommoN81]

BMS Intake installed in Nov; Installed BMS Stage 1 on Monday. Install was easy... only issue I ran into was Battery Discharge message after I reconnected it. Drove it to work the next day in ECO mode to re-charge it and no issues since then. I think the BMS Stage 1 is great, definitely feel the power increase. You can really hear the change in the exhaust note and blow off is much more pronounced.

Should I change anything else since I did the tune? Not for more power but just to keep it all running smoothly.

[ABZ101]

Flash my N55 today with MHD. Really feel the difference right away, the power delivery is more refined, not turbo lag, and is pretty normal is Comfort mode. set the exhaust burble on sport only medium 1 second. Definitely worth it.

[M302_imola]

Originally Posted by ABZ101

Flash my N55 today with MHD. Really feel the difference right away, the power delivery is more refined, not turbo lag, and is pretty normal is Comfort mode. set the exhaust burble on sport only medium 1 second. Definitely worth it.

Sorry, I'm new to the MHD tune but you can control exhaust volume?

[ABZ101]

Originally Posted by M302_imola

Sorry, I'm new to the MHD tune but you can control exhaust volume?

You can control the duration and aggressiveness of the burble and whether you want in comfort or sport mode or both. I set it to medium and 1 second. I have an after market muffler so it's enough noise for me when I want it.

[Silververtu]

Maybe a little bit off topic, does anyone know which tuner also able to make engine temp into our instrument cluster?

Saw the attached photo on facebook

[ABZ101]

Vibrant muffler and MHD burble setting on medium / 1 sec. only in sport

[InsipidMonkey]

Originally Posted by Silververtu

Maybe a little bit off topic, does anyone know which tuner also able to make engine temp into our instrument cluster?

Saw the attached photo on facebook

No coding needed:

[Silververtu]

Originally Posted by InsipidMonkey

Thanks a lot!!

[nitemare]

I'm copying and pasting from my Walbro thread I started as it's not getting much traction. Being that this is the "tune thread" maybe we can spark up a convo.

This conversation is mainly for the x50i guys that live close to E85 stations. To start off I have been doing several hours of research on realoem.com, Walbro, Dodge Hellcat forums, and even searching on here in the X5M section.

The F10 535 guys have a direct swap option for the Walbro 39/50 style pumps i.e. 267/274/525 pumps. So I compared the F10 pump setup to the F15. They are different (obviously) as the F10 does not really have a bucket style system per say vs the F70/F15.

The F70/F15 in fact has a bucket style system, Item# 1 below:

http://www.realoem.com/bmw/enUS/show...diagId=16_0659

The F10 550 is a little different:

http://www.realoem.com/bmw/enUS/show...diagId=16_0779

The F10 535 looks exactly like the 550 except for the ending BMW part number is: 1301 unlike the 550: 1303

http://www.realoem.com/bmw/enUS/show...diagId=16_0779

I'm assuming the F10 550 has a higher flowing fuel pump vs the 535, for obvious reasons.

Now this is where it gets interesting apparently NO ONE has done any LPFP upgrade to the F10 550i/550xi to try and run full E85, I asked BPC and Sergey. Sergey told me the HPFP and injectors can't keep rail pressure. Obviously if the LPFP can't keep up with the required 30% more fuel demand required for E85 then yes you can't run high boost and full E85 on a Stage 2 or Stage 3 tune.

I come from the N54 world and the N54 on factory turbos with a single 450 Walbro can make 450-470whp on E85 before having to either overdrive the HPFP or adding in secondary fueling i.e. meth or port injection. This horsepower level is obtained from custom fuel scalars via TunerPro.

Going off of this doing simple math with 6 injectors vs 8 injectors.

N54 on E85 making 450whp / 6 = 75whp per cylinder/injector

on N63TU with E85 making 600whp / 8 = 75whp per cylinder/injector

Now comparing the Walbro 450 vs 525 "Hellcat" pump it flows 10-12% more across the board from 60-90psi. I do not know the flow figures of the factory BMW X70/F15 pump but what I did find out is interesting.

The F10 550 does not share the same pump as the M5.

The E70/F15 x50i in fact does share the exact same BMW pump part number as the X5M/X6M. Does this mean the x50i has a higher flowing factory pump than the F10 550i I can alsmost guarantee it does! As the X5M/X6M come with the more powerful S63.

The 550 does though share the same HPFP and same injectors as the X5M/X6M. So the limiting factor to me is not the injectors or HPFPs it's the intank LPFP.

So now we get into how much power can the factory X50i handle? I found two X5Ms that ran these:

11.42@122 JB4 and pump gas
11.34@123 custom tune and pump gas

Doing the online calculator for trap speed to horsepower at a race weight of 5460# and 123 trap = 685whp

https://robrobinette.com/et.htm

So going off this we can assess the factory x50i LPFP can supply enough fuel for roughly 700whp MAX on E10 pump gas. Which would equate to about 490awhp before running lean on E85 with a custom tune. Remember E85 demands 30% more fuel to maintain stoich/lambda.

I was on the Dodge Charger forums as the Walbro 525 is sometimes dubbed the "Hellcat" pump as this comes factory on the Hellcats. There are guys making in the high 600s low 700s on E85 with the single factory pump.

Math time for E85 Brake Specific Fuel Consumption at max effort assuming 850 brake horsepower (flywheel):

850bhp x 0.70 = 595lbs/hr

595lbs/hr / 6.2 lbs/gal = 96GPH or 364LPH of fuel required

Looking at the specs of the Walbro F90000285 @ 70psi pressure and @ 13.5volts the pump flow = 101GPH

So this tells me the Walbro will be able to handle 850 flywheel horespower on full E85 if low pressure stays at 70psi.....obviously if low pressure drops then flow will increase a little. Now this won't be a bad thing until it gets to the point where it gets too low and crashes the high pressure side. If you base this off of a 20% drivetrain loss it will roughly equal 680awhp.

I think if you can maintain above 55-60psi on the low pressure side your high pressure should be happy.

Cliff notes: I'm going to try and retro fit a Walbro F90000285 once I find the F15 M-Sport I'm looking for. This will need a custom tune to adjust the fuel scalar tables to account for the 30% more fuel demand with E85. Other mods I plan on doing:

- Secondary air box lid cut/modified to fit the Dinan filters
- Custom homemade behind kidney grille scoops to direct more air to box
- ARM catless DPs. Hi-Temp ceramic coated and wrapped
- Custom David Shoup tune with BM3 targeting 21.5psi. I'm trying my best to avoid the temptation of getting the 3.5bar TMAPs and kill the turbos at 25-26psi.

I think with the above mods with some good fine tuning hitting 21psi to like an 18 taper it should make 575-600whp on E85. Which is all I need for a fun daily/tow rig.....the 535 is the fast car.

Nick

[Vdesai0326]

Hi guys I'm new to the forum
I bought a 2015 f15 msport n55 in October
I want to start modding/tuning
What is the biggest difference between the bootmod3 and mhd?
There's a 50% price difference but besides that is there any difference in options?
I found an old Samsung phone I could use for the mhd.
I currently have no mods but was looking into the downpipes, I would prefer doing the catless however I live in NJ so with the tune not sure how I would go through inspection and if it would pass with the tune and catless down pipe.
Any help would be appreciated

[Jmo550]

same boat as you ^^

whos tune did you use for MHD tuning?

[Vdesai0326]

I haven't gotten the tune since I am trying to figure out the real difference in bootmod3 and mhd thanks for replying I wasn't sure if anyone would respond
If I go with mhd it would definitely be the stage one tunes since I don't have any other mods with step one colder spark plugs

[Jmo550]

You guys use the OTS stage 1 tune ? and for burbles are you on stock exhaust?

[Vdesai0326]

If I were to do the tune I would be all stock for the time being until I figure out the down pipe situation
So I would be stage one and no idea if there would be burble or not

[Vdesai0326]

Would anyone with mhd be able to help out?
Also how long did the initial tune install take, I don't have a battery charger to connect to the car and did you have to backup your stock dme to mhd to save?

[Vdesai0326]

Bump

[Rotzy]

Originally Posted by Vdesai0326

Would anyone with mhd be able to help out?
Also how long did the initial tune install take, I don't have a battery charger to connect to the car and did you have to backup your stock dme to mhd to save?

I don't think too many people around here have MHD flash tunes. Most are running BM3. That should tell you all you need to know about the preferred flash tune. However, if you want to find some answers as to the difference between the two, you may want to head over to the 3 series forum. There are a lot more modded F30/F31 series N55s than F15/F16.

[skoold2003]

Originally Posted by Rotzy

I don't think too many people around here have MHD flash tunes. Most are running BM3. That should tell you all you need to know about the preferred flash tune. However, if you want to find some answers as to the difference between the two, you may want to head over to the 3 series forum. There are a lot more modded F30/F31 series N55s than F15/F16.

I hadn't ever heard of them before reading this thread. It is good to hear about other options though because for some of us BM3 isn't an option at the moment.

[Vdesai0326]

Originally Posted by Rotzy

I don't think too many people around here have MHD flash tunes. Most are running BM3. That should tell you all you need to know about the preferred flash tune. However, if you want to find some answers as to the difference between the two, you may want to head over to the 3 series forum. There are a lot more modded F30/F31 series N55s than F15/F16.

Thanks for the reply, cost is the only real reason I was aiming towards mhd. Not sure I can cough up $700 for a tune and I'm getting restless being home so wanted to do something to the f15. Guess I'll either bite the bullet and get the mhd or just wait a little while longer to see if there's any other users chiming in using mhd
Thanks again

[Rotzy]

Originally Posted by Vdesai0326

Thanks for the reply, cost is the only real reason I was aiming towards mhd. Not sure I can cough up $700 for a tune and I'm getting restless being home so wanted to do something to the f15. Guess I'll either bite the bullet and get the mhd or just wait a little while longer to see if there's any other users chiming in using mhd
Thanks again

You can always buy a used BM3 tune to save some money. They usually resell for about 1/2 price. It can't be resold again, but it could be moved to another of your own BMWs if you get a different car in the future.