Full boost @ 4450rpm ?

[oVeRdOsE]

Hi,

so the car is now running great, and I wanted to check if it's possible to have more low-end power with my actual setup.

4450rpm full boost seems very late ; log 24psi

I KNOW , I must go with a tuner, this is in my plan after the car is 100%, but for now, what are my options?


- 6262G ballbearing divided 0.85ar speedtech top mount
- 450lph lpfp
- meth kit single nozzle 600cc
- jb4 alpha firmware + stock BEF

 

[carabuser]

That looks quite poor for a 6262. Should be spooling 600rpm earlier than that.

Maybe a boost leak somewhere or a plumbing issue stopping the wastegate closing. The JB4 has the wastegate fully closed so not something you'll fix with tuning.

 

[oVeRdOsE]

That looks quite poor for a 6262. Should be spooling 600rpm earlier than that.

Maybe a boost leak somewhere or a plumbing issue stopping the wastegate closing. The JB4 has the wastegate fully closed so not something you'll fix with tuning.

thank you !

makes sense, I always suspected my charge pipe since it's loose a bit. Ill do a smoke test.


Since you're there, with your tuning services, I understand I need to get rid of jb4, but is there a way to keep the meth kit since this is a BMS kit with the BMS controler ?

 

[carabuser]

thank you !

makes sense, I always suspected my charge pipe since it's loose a bit. Ill do a smoke test.


Since you're there, with your tuning services, I understand I need to get rid of jb4, but is there a way to keep the meth kit since this is a BMS kit with the BMS controler ?

I just stay away from piggybacks completely. I will tune with Reflex as an exception but just for port injection control but relying on meth for octane is risky. In my opinion the MHD FlexFuel combined with a Hydra HPFP overdrive will get you everything you need without needing any supplementary fuelling or extra modules.

 

[wheela]

That looks quite poor for a 6262. Should be spooling 600rpm earlier than that.

Maybe a boost leak somewhere or a plumbing issue stopping the wastegate closing. The JB4 has the wastegate fully closed so not something you'll fix with tuning.

If he's still running vanos settings for stock turbos, do you think there is any potential for spool optimization by adjusting those, given his big turbo?

I'm not disputing a hardware issue in his case, but I an curious about further optimization in the tune when running bigger/lower back pressure turbos with external wastegates - both for him and for myself for when I finally get my bigger turbo on. I haven't really read into vanos tuning yet, and this thread reminded me I need to

 

[oVeRdOsE]

If he's still running vanos settings for stock turbos, do you think there is any potential for spool optimization by adjusting those, given his big turbo?

I'm not disputing a hardware issue in his case, but I an curious about further optimization in the tune when running bigger/lower back pressure turbos with external wastegates - both for him and for myself for when I finally get my bigger turbo on. I haven't really read into vanos tuning yet, and this thread reminded me I need to

ive started this thread because there a discussion on FB group ''n54 single turbo', and people reported full boost in the high 3000rpm for a 6262 and indeed some reported some tweaking on the vanos setting.

apparently this can be done on a BEF too.


I know relying on meth is risky, but with the Jb4 integration is not really risky. The moment it fails, the jb4 kick you down ( I tried).
And no more carbon built.
I doubt I ''need'' meth right now. running 24psi , 7.5°t and 94oct ; should be enough without meth anyway.

All the issue I had, so far jb4 saved my ass few times and also help to the diagnostic. This is why for now Id like to find a way, and yes Ill change eventually.
Right now Im building a new house in a big city, not cheap ! trying to get most of my actual setup.

 

[carabuser]

You can extend spool mode further out past 2600 where most ROMs end, that will help. You can add overlap using the spool tables higher up where the ST is still spooling.

 

[wheela]

You can extend spool mode further out past 2600 where most ROMs end, that will help. You can add overlap using the spool tables higher up where the ST is still spooling.

Thanks for the tips!

 

[oVeRdOsE]

yeah tanks !

I already had a ''tuner'' flash file, and just look at my spool time, boom ! full boost is at 38xx rpm.

Same setup.

we never finished the tune because he wasn't paying attention on my setup (ignoring the meth ans ST setup) and told me I can't really go higher than 16psi and 8° on fuel pump. He never read what setup I had, despite the fact I reminded him many time that I had a ST and meth.

he never asked me a dime. I mean, the car was underperforming, slower than stock TT stock tune


I dont know what he did on is last revision, Im tempting to flash it back. However Terry told me to use his stock, it's should be better overall. doubt!

 

[wheela]

So you had started (but not finished) custom tuning before with a tuner, but then went with a BMS back-end flash, which had the poor spool in the log in your first post? But now switching back to in-process flash from the tuner, your spool is much quicker than the BMS back-end flash? What boost are you now hitting at 38xx rpm? Do you have a log of this quicker spooling flash?

 

[oVeRdOsE]

So you had started (but not finished) custom tuning before with a tuner, but then went with a BMS back-end flash, which had the poor spool in the log in your first post? But now switching back to in-process flash from the tuner, your spool is much quicker than the BMS back-end flash? What boost are you now hitting at 38xx rpm? Do you have a log of this quicker spooling flash?

no,

when I finished the E91 swap in 2024, I tough I needed a tuner. So reach few, and I was told to use one of them.
We did 3 JB4 revision and 2 flash file revision.

Then starting to have issues, and Terry helped me, since the tuner was 0 help. we flashed Terry's stock BEF file.
in fact pretty sure the ''tuner'' never read an email and only check the logs and send recommendation.

Then, figure out my issues was the bad TMAP sensor ( I update my thread on that).


Since then, still running BMS stock BEF, and the posted log is this, 4450rpm full boost.



But , I might want to flash the old BEF file from the tuner to see if I can get spool sooner. Because from my 2024 log I can see it was spooling wayyy faster.

 

[wheela]

Okay, thanks for explaining, I think I understand now