[GreenF30N26]

Hi All,

I finally flashed BM3 last night and went straight to stage 2 91. I would say that I am less than impressed as going from stock w/ catted DP to Stage 2 I thought I would be getting a better experience. Looking at my logs it seems there is boost deviation once I get over 5000rpm and increases until shift. Does this mean I have a boost leak?

http://www.bootmod3.net/log?id=5d2f1aeeae729b490396f68a
http://www.bootmod3.net/log?id=5d2f1d65ae729b490396f69a
http://www.bootmod3.net/log?id=5d2e6ed1ae729b7276120a07

Any recommendations based on my logs would be great.
thanks

[SoCalCarGuy]

first 2 logs are pulling some timing. last log looks good. Perhaps it could be heat or lack of octane. Maybe splash some torco/boostane in there or look for some e85.

what was outside temp?

[GreenF30N26]

Thanks for the quick response. Was running shell 91 on almost empty tank for the last 2 logs then filled up petro 94 and ran the 1st log. Maybe I should run a few more logs now that I have some miles on 94?

Temp was around 75 but very humid pushing it likely to high 80s.

How do you interpret the timing being pulled? Variance between ignition timing 1 thru 4?

[Etto]

So I'm not an expert but since you said you went from stock to stage 2, yes I agree the logs seem a little underwhelming for that, but bear in mind you haven't upgraded your FMIC yet (?)

Now of course you can technically run stage 2 without a FMIC upgrade but bear in mind even under stock boost our intercooler is GARBAGE at keeping low temps.

I would suggest replacing your chargepipes soon ( on an N26 you're a lot less likely to blow a chargepipe, but it's still definitely possible ) along with the Intercooler and I figure you'll probably lose most your problems

[GreenF30N26]

Originally Posted by Etto

So I'm not an expert but since you said you went from stock to stage 2, yes I agree the logs seem a little underwhelming for that, but bear in mind you haven't upgraded your FMIC yet (?)

Now of course you can technically run stage 2 without a FMIC upgrade but bear in mind even under stock boost our intercooler is GARBAGE at keeping low temps.

I would suggest replacing your chargepipes soon ( on an N26 you're a lot less likely to blow a chargepipe, but it's still definitely possible ) along with the Intercooler and I figure you'll probably lose most your problems

Meant stock tune to stage 2. I’m running VRSF 5” HD FMIC, ER CP & catted DP. I didn’t replace the TIC CP as I haven’t read of anyone on N20/N26 breaking this one.

[BettyFkinCrocker]

Originally Posted by Green33

Meant stock tune to stage 2. I’m running VRSF 5” HD FMIC, ER CP & catted DP. I didn’t replace the TIC CP as I haven’t read of anyone on N20/N26 breaking this one.

It's an unpopular opinion, but the CP failure was prevalent in the N54/55. N20 has (from what I have found) very few failures comparatively. I know anecdotal evidence is mostly irrelevant, but I've had stock CPs for 50k miles while pushing 21-24 psi (different tunes) with no issue.

In regards to your logs, you may want to give some time for all adaptations. I'd say do at least 100 miles of varied driving with some WOT. If you've already done that, I'd do as others said, and get some octane booster or even put a small amount of E85 in the tank (less than 10% of total tank).

You did have knock in the first two logs, which also point to octane issues. An Oil Catch Can may also be beneficial in case your ringlands aren't in the best condition. Blow by is common in most turbo vehicles, so catch can is a good preventive/supporting mod even if you aren't experiencing knock/timing pulled.

[GreenF30N26]

Originally Posted by BettyFkinCrocker

It's an unpopular opinion, but the CP failure was prevalent in the N54/55. N20 has (from what I have found) very few failures comparatively. I know anecdotal evidence is mostly irrelevant, but I've had stock CPs for 50k miles while pushing 21-24 psi (different tunes) with no issue.

In regards to your logs, you may want to give some time for all adaptations. I'd say do at least 100 miles of varied driving with some WOT. If you've already done that, I'd do as others said, and get some octane booster or even put a small amount of E85 in the tank (less than 10% of total tank).

You did have knock in the first two logs, which also point to octane issues. An Oil Catch Can may also be beneficial in case your ringlands aren't in the best condition. Blow by is common in most turbo vehicles, so catch can is a good preventive/supporting mod even if you aren't experiencing knock/timing pulled.

I definitely agree CP failures on the N20 engine are minimal so I am not sweating the TIC CP.

Sounds good, I'll run the car for a few more miles and see if it decides to figure itself out on the 94 octane gas that I put in. I'm in Canada so access to E85 is not readily available. I've never actually seen it at the pumps before, likely have to find a specialty place to get it. If the 94 doesn't do well I'll drop some octane booster in and see if that fixes it. Doesn't bode well for me if the 2 supposedly best gasses I can get don't allow for good tunes. I say this post in the canada region so might be just crap overall up here.
https://f30.bimmerpost.com/forums/sh....php?t=1626699


The first bolt on I did to the car was a catch catch about 1000 miles ago. I'll check to see if it's collected anything but from what I've read and seen it seems to be important for our cars longevity.

thanks for the info. I'll post another log or two in a couple of days. Hopefully this tune peps up as I'm feeling let down so far.

[GreenF30N26]

After running the tune for a few hundred KM’s it got better. Thanks for the recommendation BettyFkinCrocker.

I decided to flash stg2 93 and I’m now very happy with the butt dyno results. I spoke with PTF about boost deviation over 5500rpm and they said it’s meant to taper off closer to red line. Not sure I agree it should be off by 4-5psi but have no info to contradict them.

Finally got a cool morning to run another log. PTF says this is clean. I see one knock but I don’t think they consider that an issue.
http://www.bootmod3.net/log?id=5d38443fae729b2135acd1c6

I’m also running stock NGK sparks with OEM gaps with no issues at all.

[andino]

Boost at map sensor seems kind of low compared to your target. Rest of that last log looks great though. I'd check to make sure everything is tight because it seems like how much boost you're producing is way lower than the target. I'm usually within a psi of target and how much is read at MAP

[rjd_F30]

Originally Posted by Green33

After running the tune for a few hundred KM’s it got better. Thanks for the recommendation BettyFkinCrocker.

I decided to flash stg2 93 and I’m now very happy with the butt dyno results. I spoke with PTF about boost deviation over 5500rpm and they said it’s meant to taper off closer to red line. Not sure I agree it should be off by 4-5psi but have no info to contradict them.

Finally got a cool morning to run another log. PTF says this is clean. I see one knock but I don’t think they consider that an issue.
http://www.bootmod3.net/log?id=5d38443fae729b2135acd1c6

I’m also running stock NGK sparks with OEM gaps with no issues at all.

That last log looks pretty darn clean to me. Boost does taper in the higher rpms as the little turbo in our cars runs out of steam. It's not uncommon to see 17psi or thereabouts above 5500rpm on a perfectly healthy, well-running stage 2 N20. I'll say that the boost in your car seems very slightly too low, as it should be around 21 below 4000rpm. But, your target is accordingly low, so I don't think it's an issue. Looks good to me.

[GreenF30N26]

Originally Posted by andino

Boost at map sensor seems kind of low compared to your target. Rest of that last log looks great though. I'd check to make sure everything is tight because it seems like how much boost you're producing is way lower than the target. I'm usually within a psi of target and how much is read at MAP

Was thinking I should check my pipes and that I put my rings on in the right direction when I changed my CP. But I assumed if I put the rings on wrong I would have seen boost issues over the last few months before flashing. Will give everything a double check though.

[GreenF30N26]

Originally Posted by rjdnyy224

That last log looks pretty darn clean to me. Boost does taper in the higher rpms as the little turbo in our cars runs out of steam. It's not uncommon to see 17psi or thereabouts above 5500rpm on a perfectly healthy, well-running stage 2 N20. I'll say that the boost in your car seems very slightly too low, as it should be around 21 below 4000rpm. But, your target is accordingly low, so I don't think it's an issue. Looks good to me.

Thanks for confirming the details on taper in the higher RPM range. I took another log late last night and see I my target is still only 20 below 4k and I only hit 20 PSI from 4000-4500rpm. Wonder if it's something with my year N20/N26 that the OTS doesn't target >20 PSI until 5500rpm.

Either way I am happy with the performance. Next stop transmission tune as I can definitely feel the hard shifts now that I am tuned.

[Linc0909]

Originally Posted by Green33

Thanks for confirming the details on taper in the higher RPM range. I took another log late last night and see I my target is still only 20 below 4k and I only hit 20 PSI from 4000-4500rpm. Wonder if it's something with my year N20/N26 that the OTS doesn't target >20 PSI until 5500rpm.

Either way I am happy with the performance. Next stop transmission tune as I can definitely feel the hard shifts now that I am tuned.

Have you upgraded the BOV/diverter valve? A bleed there would cost you psi.

Just a thought ...

[mike@x-ph.com]

OP, Did you send these logs to PTF?

[GreenF30N26]

Originally Posted by Linc0909

Have you upgraded the BOV/diverter valve? A bleed there would cost you psi.

Just a thought ...

I had the same thought as well but at 20k miles and only stage 2 boost(~+4 PSI) I don’t think it would stress out the diverter valve too much. I know lots of people have replaced it but I’ve been hearing our small turbos aren’t enough to cause issues for most. Personally I thought the target PSI would be higher than 20. I’m going to check around to see other logs for my engine to compare.

[GreenF30N26]

Originally Posted by mike@x-ph.com

OP, Did you send these logs to PTF?

I did and they were very pleased with the results. likely an issue managing my expectations.

[Linc0909]

Not so much the size of our turbo but the amount of boost. I watched the Kies Motorsports vid on replacing the BOV and the factory spring looks pretty puny. BUT, you're right, at 20k it shouldn't be an issue even w the added boost.

Hope you figure it out

[GreenF30N26]

Originally Posted by Linc0909

Not so much the size of our turbo but the amount of boost. I watched the Kies Motorsports vid on replacing the BOV and the factory spring looks pretty puny. BUT, you're right, at 20k it shouldn't be an issue even w the added boost.

Hope you figure it out

If the install wasn't such a PITA I might just do the BOV for the low cost, but I think my problem is only perceived. I went back and looked at a log I took after I installed my DP but no tune and I hit 19.5 PSI boost. I am wondering if my car was just naturally over boosting as I always felt that it was running great with the DP only before the tune. Best case now I'm only getting 1 PSI more of boost at peak on stage 2 compared to stock tune. Obviously the sustained boost is way better on stage 2 but I was already getting the close to peak PSI so likely why I didn't feel like it was a crazy jump.

Stock tune 93 with DP: http://www.bootmod3.net/log?id=5cedc64dae729b2e438fde09

Stage 2 93 with DP: http://www.bootmod3.net/log?id=5d4a1ed4ae729b5812b01932

Anyway tune is good and car is definitely fun.

[Linc0909]

PITA??? Eh... no pain no gain!! 🤣🤣