[abbike18]

One of my big goals was to hit high boost even at really high altitude (10,000ft plus) where the atmospheric pressure is over 4psi below what it is at sea level.

Here's a log from 9500ft from a bit ago:
https://www.bootmod3.net/log?id=63308530d10b432642ac7f90

Really pleased with how the VTT GC is hitting boost pressures no problem, with plenty of WGDC left.

89-90% WGDC for a pressure ratio of 2.45 at 42 lb/min flow rate (5200ft elevation)
93% WGDC for a pressure ratio of 2.93 at 42 lb/min flow rate (9500 ft elevation)

Keep in mind, everything is on OTS maps. Will likely be getting a custom tune this winter, hope to hit higher torque in the top end with that tune.

[glennbk]

You ever thought of a Dinan setup?

[abbike18]

Originally Posted by glennbk

You ever thought of a Dinan setup?

What do you mean?

[abbike18]

Quick update...working with subpar tuning now. On the 4th revision. So far experience with Doug has been really really good. Will post logs once we get further down the process. Just establishing a baseline now.

[abbike18]

On Rev7 currently, got a decent baseline 91 tune so far. Haven't tried to push it, just getting it running smooth.

https://datazap.me/u/abbike18/v17-2?log=0&data=4-23

Can't wait to start adding E

[335is-dct]

Great thread. I am clueless re: performance at altitudes like yours so just watching and learning.

[abbike18]

Originally Posted by 335is-dct

Great thread. I am clueless re: performance at altitudes like yours so just watching and learning.

The big thing we worked through in the tune was getting the wastegate control correct for the pressure ratios and ambient pressures at altitude. The OTS tunes deal with it by limiting the max boost and PID. Subpar had to properly tune the turbine power tables for altitude for me.

[abbike18]

Finally finished tuning this thing. Ended up using two different custom tuners. The first tuner was really focused on maximum power tuned for a very specific set of conditions (IATs & altitude/ambient pressure) and here in Colorado I need a tune that can adapt to a wide range of those conditions.

I ended up with Odin, and I couldn't be more happy. He knows how the logic in the DMEs actually works, he can was able to put together a tune that adapted across conditions. We spent a lot of time tuning and testing the compressor map/PID for a wide range of ambient pressures/altitudes. We started tuning in the winter and ending in spring, so we were able to test the tune against a super wide range of IATs (we're talking mid 20s to 130s f) to get the ignition correction tables just right. This is super important for our cars, which are really dependent on IATs for the correct ignition timing. Odin is super communicative and was great to work with.

We pushed the tunes to the limit, and then I actually had him back off a bit because I was looking for something very reliable rather than trying to get those last few hp.

The final tune is flex fuel, but here are two logs with different amounts of E, from Denver altitude:
91 - https://datazap.me/u/abbike18/final-...?log=0&data=25
E30 - https://datazap.me/u/abbike18/final-...?log=1&data=25

This car is now a real beast!

[COM40]

Any idea how much your mods shaved off 50-70 or 60-100 time? I.e. before and after data logging.

[abbike18]

Originally Posted by COM40

Any idea how much your mods shaved off 50-70 or 60-100 time? I.e. before and after data logging.

Unfortunately no. The best I have is some 0-60 data from before, but I haven't even done a single 0-60 with the new setup ha.

Old 0-60 is here:
https://x3.xbimmers.com/forums/showp...87&postcount=1

I was never in to chasing numbers, but agree with you that they would have been nice to have.

[COM40]

Originally Posted by abbike18

Unfortunately no. The best I have is some 0-60 data from before, but I haven't even done a single 0-60 with the new setup ha.

Old 0-60 is here:
https://x3.xbimmers.com/forums/showp...87&postcount=1

I was never in to chasing numbers, but agree with you that they would have been nice to have.

I don't care about 0-60 personally, since I'm not launching the car and don't want the accelerated mechanical wear. But something like a 2nd or 3rd gear pull is a great way to quantify the increased performance without the abuse of a launch.

I was just asking since some #s make it easier to appreciate the difference as a random guy on the internet (who will never ride in it). But if just the tunes knocked off well over half a second from the 0-60 , that thing must seriously scoot with the upgraded turbos!

I've been going back and forth on tuning mine and that post is swaying me. Knowing what you do now, would you still have gone with the BM3 tune?

[abbike18]

Originally Posted by COM40

I don't care about 0-60 personally, since I'm not launching the car and don't want the accelerated mechanical wear. But something like a 2nd or 3rd gear pull is a great way to quantify the increased performance without the abuse of a launch.

I was just asking since some #s make it easier to appreciate the difference as a random guy on the internet (who will never ride in it). But if just the tunes knocked off well over half a second from the 0-60 , that thing must seriously scoot with the upgraded turbos!

I've been going back and forth on tuning mine and that post is swaying me. Knowing what you do now, would you still have gone with the BM3 tune?

Totally agree with you on the 0-60. When BMW engineered the drivetrain, they thought about the absolute worst case it sees - launch control with the stock engine at 369 ft lbs. First gear is a ratio of 5, and the final drive is 3.385. So that's 1845 ft lbs through the transfer case and 6208 on the axles (distributed). I'm pretty sure I'm putting out about 500 ft lbs now - so that's 2500 at the transfer case and 8400 at the wheels. That's a huge huge difference in the max stress design case.

You raise a really good point though about getting some data. I went back and looked through my logs for 4th gear pulls in the same location and I was able to put together my 50-95 times. I know that's a weird number, but my reasoning is:
50 - this is about 3500rpm, which is below any post shift rpm but is above the rpm where boost is fully kicked in
95 - I consistently hit 95 in my 4th gear pulls, but 100 occurs pretty much right at redline so I often shift before this, so it wouldn't be consistent between pulls.

See below for the data. Keep in mind this is not a best 50-95 time, as it was fully in 4th gear. For a proper 50-95 I would start in 3rd. Hope that helps you decide what you want to pursue. Happy to answer any other questions you have.

Re: BM3. I used BM3 when I was running TU pump & AA DP for OTS tunes. When I wanted to go to flex fuel, the BM3 software had serious issues with the Dorch Canbus ECA in my G01. Every few seconds the software would read an ethanol content of 255% (no matter what it actually was) which would cause the DME to advance timing for a few cycles. This was really dangerous. So I switched to MHD at that time, and their software did not have any issues.

I found that for OTS tunes, BM3 has more torque down low and less up top. MHD OTS has less torque down low and more up top. The approach is slightly different - BM3 OTS goes for as much boost as possible, whereas MHD OTS has slightly lower boost but more timing. I Personally actually liked the MHD OTS more, as the car feel like it pulls harder to redline, whereas the BM3 tunes feel like the engine gives up at higher RPM. The engine doesn't 'egg you on' as much to redline with BM3 in my opinion.

I liked the boost limiting option in BM3 as opposed to the power reduction in MHD. However the coolant target options in MHD are better (with multiple options for engine temp and ability to separately control the intercooler circuit). If you are between the question of OTS tuning vs not...definitely try out a stage 1 tune. It really livens up the car.

Seeing that you are west of Denver (I'm north of Denver) keep in mind that the stock turbo struggles to hit the OTS tune boost targets at our altitude. I've done extensive testing between Denver altitude and in the mountains. MHD OTS might suit you better given their boost/timing approach, but it might also be a gateway drug to the VTT GC .

[COM40]

Originally Posted by abbike18

Seeing that you are west of Denver (I'm north of Denver) keep in mind that the stock turbo struggles to hit the OTS tune boost targets at our altitude. I've done extensive testing between Denver altitude and in the mountains. MHD OTS might suit you better given their boost/timing approach, but it might also be a gateway drug to the VTT GC .

Solid post, really shows the tuning potential of the B58. E30 wakes it up a ton but then I suppose you have to deal with the inconvenience of finding E85 and mixing it.

I'm not *that* far west of Denver, just on the edge of the foothills so my house is right round 6k ft.

Given the drawbacks of either tune at altitude, would you say it's worth going the custom tune route for a bone stock car? It's been a while since I've tuned a car, but I had a volvo with some bolt ons a while back that was "remote" tuned. Basically loaded with a conservative tune, I data logged a 3rd gear pull, sent it to the tuner, and he adjusted it, then repeat until we were in a good place. Not sure if MHD or BM3 offer something similar but that's the route I'd prefer.

[abbike18]

Originally Posted by COM40

Solid post, really shows the tuning potential of the B58. E30 wakes it up a ton but then I suppose you have to deal with the inconvenience of finding E85 and mixing it.

I'm not *that* far west of Denver, just on the edge of the foothills so my house is right round 6k ft.

Given the drawbacks of either tune at altitude, would you say it's worth going the custom tune route for a bone stock car? It's been a while since I've tuned a car, but I had a volvo with some bolt ons a while back that was "remote" tuned. Basically loaded with a conservative tune, I data logged a 3rd gear pull, sent it to the tuner, and he adjusted it, then repeat until we were in a good place. Not sure if MHD or BM3 offer something similar but that's the route I'd prefer.

You can get a custom tune on either BM3 or MHD. But I don't think it is worth the cost if you aren't adding a turbo. I really found that even stage 1 was a very noticeable improvement over stock. Look at my numbers - by simply buying a tune and flashing it you are getting 58% of the gains of my 91 and 34% of the gains of my E30. And I did custom tune, TU pump, FF ECA, AA DP and turbo.

After having had both MHD and BM3 and testing with the stock turbo, I would suggest you get MHD because they target higher timing and lower boost, which helps here in Denver. I would also suggest using the sliders when you flash to 90% or 95% of full power - that's just my experience with our 91 octane fuel and what delivers a reasonably clean log.

Or maybe I need to let you take my car for a test drive next time I'm going up I70 so you can experience the dark side

[COM40]

Originally Posted by abbike18

You can get a custom tune on either BM3 or MHD. But I don't think it is worth the cost if you aren't adding a turbo. I really found that even stage 1 was a very noticeable improvement over stock. Look at my numbers - by simply buying a tune and flashing it you are getting 58% of the gains of my 91 and 34% of the gains of my E30. And I did custom tune, TU pump, FF ECA, AA DP and turbo.

After having had both MHD and BM3 and testing with the stock turbo, I would suggest you get MHD because they target higher timing and lower boost, which helps here in Denver. I would also suggest using the sliders when you flash to 90% or 95% of full power - that's just my experience with our 91 octane fuel and what delivers a reasonably clean log.

Or maybe I need to let you take my car for a test drive next time I'm going up I70 so you can experience the dark side

I wouldn't turn down a trip to the dark side I'm only 10min from the dino lots off I70.

Seems like there's a ton of folks that do custom MHD tunes. But if you can make the OTS tune more conservative with the sliders (presumably through the app), that would be good enough for me.

Have you ever looked at the sport displays that show hp/tq? I'm not sure how exactly those are calculated, but I'm curious if those would change with the increased power from a tune.

[wlfpck]

Originally Posted by AusX3

The intercooler or associated system is always my first mod on an induction car before enhancing overall performance.

Reliability and repeatability are my main objectives and you just can't get repeatability on this car. Over a few days we did 30+ dyno runs getting my tune to where I and the tuner was happy and on a 3rd back to back pull the IAT/ low pressure cooling circuit start to climb dramatically, to the point where the ecu wizardry and protections start to kick in.

I am in Australian and summers are 35-40 degrees, so this testing on the back end of winter was helpful.

I also love a challenging mountain drive and have found with my current set up the ecu backing off to protect, so consistent with dyno information.

General driving and 1 traffic light drag here or there, the system can cope

Yeah... I know the F series sedans had CSF (I think) upgradeable auxillary radiators. Was a simple install. Just remove wheel, peel back the fender liner, and pull the old one and install the new one. The F series had 2 auxillary radiators. On the G01, we just have 1.

Wondering if we could add the 2nd auxillary cooler like on the F series and if anyone will make any replacements.

Would also be nice to have the main radiator upgrade option.

[abbike18]

Originally Posted by COM40

I wouldn't turn down a trip to the dark side I'm only 10min from the dino lots off I70.

Seems like there's a ton of folks that do custom MHD tunes. But if you can make the OTS tune more conservative with the sliders (presumably through the app), that would be good enough for me.

Have you ever looked at the sport displays that show hp/tq? I'm not sure how exactly those are calculated, but I'm curious if those would change with the increased power from a tune.

Yes, it's an option in the MHD tunes to increase their max value so they can display the DME's calculated values.

[Burr001]

Originally Posted by abbike18

Yes, it's an option in the MHD tunes to increase their max value so they can display the DME's calculated values.

So its been about 3 month since finalizing the tune, How you like VTT so far?

I'm asking since I'm really looking into power adders, Im considering the GC-Mid, what model did you go with again? Its on backorder for who knows how long, but the fact that I don't have to worry about the core is appealing..