[ihernandez7910]

so after reverting back to stock and letting map 7 adapt again..

same sh** is going on.. .tappering down to 16 psi is happeing at around 3500rpm...

I have attached logs. one in map 7 showing boost drop again. and a second one with map 2 where turbos hit target all the way through.


I am reaching out to Terry - to see if he has any insight - or can point me in the right direction.

[RSL]

Are you thinking the stock turbos are going to hold a 19-20psi target up top? Both logs above end at 16psi. Asking for much more than that over 6000 rpm on stock turbos is almost an exercise in futility. It can be done, but the efficiency and shaft speeds would be horrendous.

If you want to hold big boost over 6000 rpm, you need turbo(s) that can actually out-flow the motor at high RPM. Boost is a measure of restriction. The engine is an air pump and when it flows more air (high RPM) than can be fed to it (stock turbo CFM), the pressure inside (boost) falls.

Barring anything I missed in the thread, boost falling off over 5000 rpm is entirely the norm for stock (really small) turbos. If you're keeping 16psi at 6000rpm, you're doing just fine for stockers.

[Sgop335]

Originally Posted by RSL

Are you thinking the stock turbos are going to hold a 19-20psi target up top? Both logs above end at 16psi. Asking for much more than that over 6000 rpm on stock turbos is almost an exercise in futility. It can be done, but the efficiency and shaft speeds would be horrendous.

If you want to hold big boost over 6000 rpm, you need turbo(s) that can actually out-flow the motor at high RPM. Boost is a measure of restriction. The engine is an air pump and when it flows more air (high RPM) than can be fed to it (stock turbo CFM), the pressure inside (boost) falls.

Barring anything I missed in the thread, boost falling off over 5000 rpm is entirely the norm for stock (really small) turbos. If you're keeping 16psi at 6000rpm, you're doing just fine for stockers.

True to what he is saying, your maf peaks at 295g/s at 5000rpm and flattens to 285 after. Just for reference im stock, pulling 250grams/s.

[RnmEvo9]

Get some inlets

[ihernandez7910]

Originally Posted by RSL

Are you thinking the stock turbos are going to hold a 19-20psi target up top? Both logs above end at 16psi. Asking for much more than that over 6000 rpm on stock turbos is almost an exercise in futility. It can be done, but the efficiency and shaft speeds would be horrendous.

If you want to hold big boost over 6000 rpm, you need turbo(s) that can actually out-flow the motor at high RPM. Boost is a measure of restriction. The engine is an air pump and when it flows more air (high RPM) than can be fed to it (stock turbo CFM), the pressure inside (boost) falls.

Barring anything I missed in the thread, boost falling off over 5000 rpm is entirely the norm for stock (really small) turbos. If you're keeping 16psi at 6000rpm, you're doing just fine for stockers.

Thanks for your feed back! I am 6 months into this platform and I am learning as fast as I can. I appreciate you guys taking it easy on me. In conclusion, I guess I am asking the little snails more than they can handle.
RSL, your statement above makes perfect sense! Thanks for the info: I guess the best thing for me to do is run a custom map:6 with a set boost curve that is more appropriate for what the td03's can handle.

[RSL]

Originally Posted by Sgop335

True to what he is saying, your maf peaks at 295g/s at 5000rpm and flattens to 285 after. Just for reference im stock, pulling 250grams/s.

That did seem odd to me. Depending on elevation, temps, etc. 6000RPM MAF should be close to or over 400g/s. Since it under-reports load, JB4 may very well clamp MAF too.

Originally Posted by ihernandez7910

Thanks for your feed back! I am 6 months into this platform and I am learning as fast as I can. I appreciate you guys taking it easy on me. In conclusion, I guess I am asking the little snails more than they can handle.
RSL, your statement above makes perfect sense! Thanks for the info: I guess the best thing for me to do is run a custom map:6 with a set boost curve that is more appropriate for what the td03's can handle.

The 20psi peak tapering to 16psi is about as good as it will get without a lot of work. If you have MHD too, you can run flash only or use the MHD JB4 backend flashes in conjunction with the JB4 to do some fine tuning to the timing, AFR, VANOS, etc. to make the most of the boost you do have on your fuel/mods.

[ihernandez7910]

Originally Posted by RSL

That did seem odd to me. Depending on elevation, temps, etc. 6000RPM MAF should be close to or over 400g/s. Since it under-reports load, JB4 may very well clamp MAF too.

The 20psi peak tapering to 16psi is about as good as it will get without a lot of work. If you have MHD too, you can run flash only or use the MHD JB4 backend flashes in conjunction with the JB4 to do some fine tuning to the timing, AFR, VANOS, etc. to make the most of the boost you do have on your fuel/mods.

Thanks for the INPUT GUYS! Much appreciate it! Thanks to people like you my learning experience has been great!

[stanlalee]

Okay so what I've found so far in every log that has remained consistent is MAF g/s is being CAPPED at 286 g/s. On every log (I've logged twice a day for a week now) boost tapers exactly so that 286 g/s is maintained but not exceeded. WHY! Increasing load doesn't help as MAF request already exceeds 286 g/s. Increasing ceiling and adder does nothing useful because PID freedom doesn't seem to be the problem. the problem is whatever is causing MAF g/s to be capped. I don't know what that is. I would have killed to make 286 g/s on my old K04 GTI but this is WEAK on this platform. I also notice that the intercooler worked TWICE as well this time last year. Where temps rise 15 deg now they only rose 7 deg last year. I had stock airbox last year vs AFE now which may play a role but I don't even care about that right now. Did I mention the car runs and feels great right up to 5000rpm. I don't expect any miracles with the stock turbos but I'm definitely missing a couple lbs of boost in the 5300-6000 rpm range.

Here's a log showing what i'm talking about with the MAF g/s capping despite request for more. Everything has been massaged since OP log. Better overall but not there.
http://datazap.me/u/stanlalee/log-14...&data=19-20-23
I've tried broad range increases/decreases with base WGDC but that just messes with 2500-5000rpm boost control. I'm perfectly happy with everything up to 5300rpm.

All ears lol. BTW this is not a MHD tune. they are all based from OFT OTS tunes (with LOTS of changes) which all followed target boost to a T before this started happening. I'm going to throw a fuel pump at it since mine is weak but you can see in the above log it never dipped below 50 (but trims are horrible! Could that cause the cap?).

[RSL]

MAF req WGDC g/s is what most look at, sorry if I missed a different one was logged before. Yours is almost 370 at the top of the gear.

[fredcase]

went back to jb4 with backend pump flash. problem gone. The off the shelf mhd tunes are garbage.