XHP for those of us with the 6AT transmission

[NMX1]

Order is in for xHP flash license and map packs, MHD super license and MHD Wi-Fi installer! Should have everything with time to install by the 2nd week in July.

[wheela]

Originally Posted by NMX1

Order is in for xHP flash license and map packs, MHD super license and MHD Wi-Fi installer! Should have everything with time to install by the 2nd week in July.

Awesome, you're in for a treat!

[NMX1]

I installed xHP stage 2 today and drove 70 miles mostly on freeway. Only got to do a little bit of MILDLY aggressive driving when I got off the freeway and drove a few miles on semi-rural streets. I did get a first impression, though, that the shifts are smoother and crisper, and the car responds to pedal input much more quickly when it's already rolling/ in gear. Lane changes with acceleration on the freeway are much improved. And blipping the gas to time a little burst of speed on the down sides of speed bumps is way more satisfying. I'm disappointed, though, that if I mash the pedal to the floor from a stop it still takes the car half a second to GO (it is a consolation that when it does go, everything from that point forward is brilliant). I don't know if going back into the xHP controls will give me an option to improve off the line acceleration. I also have my MHD license so I'll install that soon, I just wanted to give pure xHP a chance first (plus I nearly toasted my battery, had to switch from a lithium jump starter that didn't seem to work to a battery minder).
Oh, and by the way, drive mode was completely tolerable, kept the car in low RPMs which I'm sure will improve gas mileage without feeling as sluggish as the factory tune.

[NMX1]

OK, got it out on the road again, and here are a few more impressions of xHP stage 2 in an otherwise unmodified X1 35i MSport: Still feels annoying slow to get going from a stop. It idles at around 700 RPM, and when I floor it it slowly creeps up to about 1800 (during which time I can think about which groceries I need to buy at the store), then something noticeably kicks in (I'm guessing turbo), and it starts pulling respectably with some sensation of being pushed gently back in the seat until it hits about 2500 RPM, at which point it takes off like a rocket ship. Once driving, all shifts are quick and acceleration instant because it maintains RPMs above the wallowing and semi-wallowing levels. I do feel like once the power kicks in the car is fun to drive, but the sudden transition seems ridiculous and it definitely ruins the effect of trying to enjoy a highly spirited drive when there's stop and go involved (and would embarrass the heck out of me if I had a passenger during such driving).
Honestly, I find drive mode much more enjoyable with a more linear feel when there's stop and go. Unless I can get this issue fixed I'm afraid that after all this I may just end up using that mode nearly all the time.
Another thing that's annoying about sport mode is when I'm driving at a constant speed/ constant grade requiring use of the accelerator it can end up staying in very high RPMs. I realize that the computer isn't always smarter than me and doesn't know I'm just driving my kids to camp up a hill. The fix for this is easy, though - just shift back to drive mode, which is very smooth and completely tolerable.
I'm guessing most of the initial acceleration issue is turbo lag, but wondering if having a higher RPM idle or some other electronic tweak would make it less egregious. Or if MHD does something to address it?

[NMX1]

Another update:
I flashed MHD to the car today (I can only go stage 1 without physical mods to the vehicle) and it didn't really add anything to xHD stage 2. Still super sluggish initial acceleration off the line. When I went into the user's guide for MHD it said there's a throttle sensitivity adjustment feature, but I couldn't find it on my program. Turns out when you read the fine print it's only offered on the N54 package, not on the N55 E or any other package.
I wrote to MHD to see if they have an explanation or a fix for me. If not I'll probably ask for a refund and get a pedal tuner.

[cwickberg]

I have Alpina B3 TCU flash, JB4 tune and the Burger Pedal Tuner...IMO works great... bit old school no BT app etc but all works together on the N55 with 6 speed... some times old school with hydraulic steering and smooth 6 is worth it

[gregthegr8]

While I haven't tried the Burger one, I would highly recommend the sprintbooster as the sluggishness and laziness off the line and in low rpms was really detracting from the driving experience. Maybe half of that was alleviated by the dinan tune, but the sprintbooster made it oh so nice, completely smooth, linear, and progressive and can dial it in where you want it to be.

I drove a 2015 Macan S for a weekend, and similar issues, it felt so lethargic and sluggish off the line, was annoying, lest you were in full on sport mode. Was so nice when I got back the X1, though shame we have to go to all these measures with these electronically controlled throttle bodies.

[NMX1]

Wow. I just got what seemed like totally patronizing and unhelpful responses from both xHP and MHD when I wrote to them. They both wrote my problem off as turbo lag pure and simple and I know there has to be a built in electronic lag beyond that. They both suggested I try “brake boosting” (keeping the left foot on the brake and pushing down on the accelerator to build up boost, then taking the foot off the brake to launch). Even if that’s not bad for the car, it’s gotta be an awkward way to drive.
So it looks like the next step is to order a Burger pedal booster. When it comes I’ll try driving the car with just xHP and the booster, then with both of those plus MHD. I suspect that for what I set out to improve in the car’s performance, plus the fact that adding MHD to xHP so far hasn’t impressed me, I will probably not want to keep MHD. I’ve enquired into the possibility of a refund since I don’t want to have an initial trial period run out but so far they haven’t responded to that question. They just tell me that 100,000 people have installed MHD and been happy, which I guess is supposed to make me happy, too?

Edit: Just ordered my BMS pedal tuner! Hopefully will be here by the end of the week, early next at the latest.

[wheela]

Sorry your're having that bad customer experience with xhp and mhd. That lag from a dead-stop is annoying for sure. I thought xhp seemed to help a bit from a dead-stop, but it's hard to tell. I don't believe what we're experiencing is turbo lag, you can feel that there is no transmission engagement as the rpms build. Plus, try hitting the gas when you're in park, the response is amazing. It kind if sucks, but i've noticed that from a dead stop, the transmission will hook up much sooner if you DON'T floor it. So I've kind of trained my right foot to not totally hit it right off the line- I give it a fraction of a second until I feel it hook up, and then put it all the way down. That seems to get rid of that horrible lag where it feels like the car is saying "omg, he floored it, what should I do? Are you really sure you want to do this?" WTF I can't understand why any transmission would be programmed to work like that. But other than from a dead stop, it's a totally different car for me in sport mode.

Also that point around 2500 rpm where it all the sudden throws you back - I don't think that's turbo lag either - I think that's related to the tune. Justin from twisted even mentioned in the mhd thread that the OTS tunes are set up to limit torque below 2500rpm (from what i've seen I think they do it with load request) so that people don't lug the engine in high gears at low rpm. Our turbos are TINY, the only thing they're good for is making torque down low. To the point where you need to be careful tuning it, as that tiny turbo spools quick enough to bend rods if you ask for too much load down low in the rpm's.

I haven't tried any of those pedal tuner solutions, but if you do, you may want to consider still keeping MHD. If you ever want to custom tune, you'll need a way to flash it to your car, and you'll need a way to log and monitor how your car is running. MHD is great for both of those things.

I guess being AT we have to learn how to game the transmission engagement with our right foot... Oh yeah, the brake boosting thing they mentioned works, that absolutely takes out the slack, and drops about 0.2 - 0.3 seconds off your 0-60 time. But there is no way I'd do that with normal driving around town, that's only for the rare occasion I want to test my 0-60 or something like that. And even then, it takes practice figuring out what rpm to let off the gas. When I do it, it still feels boggy sometimes if you don't let off right. Plus it's probably not great for your car.

[NMX1]

Yeah, all that sounds right to me. The turbo lag explanation just doesn't fly, and it's a sorry excuse for those lot to hide behind. And your electronic torque limitation explanation makes sense. I did notice, perplexingly, that the car seemed more lively off the line in "D" mode than "S" mode, but then when I decided to try flooring it in "D" mode it definitely was no better. I think the difference was that I wasn't asking for everything all at once under normal driving and you're right, it ramps up better when starting out with a lighter foot on the gas.

I did try a brake boost start once, and it certainly worked. Snapped my neck back and had me in the insane tuned power band right away. If I wanted to do a 0-60 time or race somebody out of a stoplight I suppose it could be useful. But I felt like it was putting a strain on the car - if nothing else, the brakes had a hard time holding me back as I got up to around 1500 RPM. Suffice it to say I won't be counting on that to fix my problems, and I'm still irritated at xHP and MHD that they suggested that as a "fix."

As I get more used to driving with xHP/ MHD, I see your point that the lag gets more tolerable. When I'm accelerating normally out of stops it does seem to have reasonable pickup, it's only when I want to launch faster I have the issue. Somebody in an old post mentioned the lag being not only annoying but also downright dangerous in the event of needing to hurryup across a road when somebody's coming fast across the other way (it would be hard to remember to gently ease onto the gas under those circumstances, or other similar situations requiring quick acceleration). He got a pedal tuner (I believe BMS) and said it solved his problem. I'm also just frustrated coming from years driving a 2002 Subaru WRX with manual transmission, tune, intake, exhaust, original small turbo and lightweight flywheel - that thing would GO when it was time to go. In fact, I kept that car for 20 years until some hoodlums stole it and blew up the engine joy riding it last year. So I really won't be satisfied unless I have something that will GO when it's time to go, I think you get where I'm coming from.

[NMX1]

I installed the Burger Motorsports Pedal Tuner today and I have to say I'm still left scratching my head. I get a bit more movement off the line but even stomping the pedal down to the floor it still lags annoyingly until around 1800 RPM, and then shoots off abruptly at 2500. It seems like the car actually hesitates a moment before launching as if to say, "get ready sucka, here it comes," and then takes off like a rocket ship with an impressive scream.
The car is an absolute beast from that point onward, but the only way I've come up with to get off the line quickly is the brake boost start, which I can't imagine is good for the car. I'm beginning to think what I'm experiencing may actually be turbo lag like the folks at xHP and MHD claim, although with a big engine, small turbo and reasonably lightweight car I find that hard to believe.
I suppose I just need to bite the bullet and buy an electric sports car.

[wheela]

It has to be related to the way the transmission engages when you punch it from a stop. Did you try punching the gas in park? The throttle response is instantaneous, and fast - way way way faster than my last car, which was manual transmission and naturally aspirated.

I still don't buy turbo lag. Let me look for a screenshot I took about a year ago from a different forum. It seemed to show the load ceiling table from an mhd ots map (not sure how they got it?). You can see they left the first load point stock before upping the load request ceiling at later rpm. I think this is what we're feeling around 2500rpm - we're hitting the higher load request at that point.

Edit: Found it. Forget about that first cell with 111 in it - he changed it for illustrating something he was working on. You see the second row (2000 rpm) the load ceiling (the max load target when you floor it) is 145%. This is basically the stock value for that cell. But then the next row (2800 rpm) has a load ceiling of 176%. So when WOT, from 2000 rpm to 2800 rpm your load target interpolates from 145% to 176%. I believe this is the "2500 rpm kick" we're feeling - load target shoots up dramatically between those two points.

[wheela]

If I ever get around to trying a self tune, that's one of the things I want to play with. I'd like to try upping the load ceiling earlier to confirm/deny if that 2500 rpm bump we feel is due to that load request profile vs. turbo lag. I suspect we can get rid of that bump and get out of the hole faster by raising load ceiling at lower rpms. I don't think that will have any impact on that horrible delay when fully flooring it from a dead-stop, but it would be nice to get into that power band as soon as the transmission hooks up.

[NMX1]

Agreed. I'm still with you on the impression it's not turbo, but being essentially illiterate when it comes to computer programming I'm at the mercy of tuning programmers when it comes to my car's performance. I see that there is a "flash a custom map" option in MHD. I wonder if there's a local tuner who is familiar with MHD and would be able to remap mine (quickly and cheaply, I'd guess) to increase the load ceiling at lower RPMs in stage 1. It is just ridiculous to have a car that can barely creep off the line but becomes an immensely capable racing machine once it hits around 2,000 RPM.

[wheela]

Originally Posted by NMX1

Agreed. I'm still with you on the impression it's not turbo, but being essentially illiterate when it comes to computer programming I'm at the mercy of tuning programmers when it comes to my car's performance. I see that there is a "flash a custom map" option in MHD. I wonder if there's a local tuner who is familiar with MHD and would be able to remap mine (quickly and cheaply, I'd guess) to increase the load ceiling at lower RPMs in stage 1. It is just ridiculous to have a car that can barely creep off the line but becomes an immensely capable racing machine once it hits around 2,000 RPM.

An email tune can be had for $400 - $500. Basically you send them a log and your stock bin file (you can down load it from the MHD app), tell them what mods you have (if any), they send you an updated bin file, you flash it and take some logs to send back. It's an iterative process, generally 5 - 9 revisions of that and you should be dialed in. Some reputable n55 tuners that come to mind would be Motiv, Twisted Tuning, David Shoupe, or Wedge Performance. A lot of compromises exist with the OTS tunes to account for many different cars and abuse from customers. You should be able to get a better tune from one of these guys. Tell them what's important to you, and they should be able to hook you up. They all use MHD, it's basically the standard flashing app for e-chassis n55.

If you want to poke around the bin yourself, you can download TunerPro (it's free). You just need to also download your defenition file (XDF), just google your bin ID (mine is 9e60b , you'll see this when you download your bin from the mhd app) and go to the github site. Marshall from mhd has the defenition files available there for download for free. The defenition file is the key that tunerpro uses to make sense out of the bin file.

[NMX1]

Well shit.
I was driving on the freeway today out here in the great wide open NM high desert at a speed we’ll just call somewhere slightly north of 120 when I suddenly felt a jerk and lost power. Engine code says “2774 - Air volume, plausibility: Air volume too high.” And now it is all messed up, alternately lugging in low RPMs and whining in high ones when I accelerate. The car tells me I can drive carefully back to the dealer (unfortunately 70 miles away), I’ll do that tomorrow.
My friend who works for BMW says he thinks the most likely explanation is it overboosted and popped the charge pipe.
WTF!?! Running xHP stage 2 and MHD stage 1 were not supposed to do that. Or so they say…
But I’ve only been driving it about a week since installing the flashes and I’ve had it much faster before the install (140+) with no problem.
I’ve uninstalled the flashes and will drive it in to the dealer tomorrow, hopefully they will cover it on the extended warranty but I won’t lie if they ask me if I had any mods on the car.

[NMX1]

MHD has been very responsive to my emails, Apparently the plastic cargepipes on these cars are prone to failure at higher boost pressures and replacing with a metal part is recommended when it happens. I have yet to figure out if that’s in fact what’s gone wrong in my car but it sounds most likely. 🤞

[cwickberg]

Originally Posted by NMX1

MHD has been very responsive to my emails, Apparently the plastic cargepipes on these cars are prone to failure at higher boost pressures and replacing with a metal part is recommended when it happens. I have yet to figure out if that’s in fact what’s gone wrong in my car but it sounds most likely. 🤞

If this happened you will know it. It will throw codes and go into limp mode

[NMX1]

Codes, limp mode and indeed the charge pipe was blasted off where it connects in back just past the sensor. I thought I could reattach it with a new clamp but it blew right back off because part of the end of the tube where it attaches had cracked off.
I’m coincidentally at the dealer now getting a tire replaced (I got my Pilot Sports through BMW on a great deal and they cover nail punctures), they don’t have the plastic part in stock and it’s $400 if they order it in so that clearly ain’t happening.
So now the search is on for the right aftermarket metal charge pipe and in the mean time my daily driver is a Ram 2500 Cummins turbo diesel with a slide-in camper.

[wheela]

The stock charge pipes are crap - they're known to blow off at the t-body even without a tune. Plus they're more expensive than a decent metal aftermarket one. Just commented about my experience with my vrsf chargepipe in your other thread👍

[bosstones]

Your tune may have been the factor that did your CP in but that would be because it was already on its way out. Like others said, it's a common fail point that pre-datea our X1s.

[NMX1]

Yeah, when I talked to the guy in the BMW parts dept today at the dealership he didn’t accuse me of monkeying with the engine and didn’t try to talk me out of getting an aftermarket metal charge pipe.