Speedtech Tuning -- Boost Control - N54Tech.com

Timyoy0 · 2019-05-03 15_48_25_Gear-3_Map-6.csv (7.4 KB, 100 views)

Hey all.

I've been working with @jturboawd over the past few months on tuning this speedtech EFR 7670 on my PWG N55 E90. It's been pretty difficult to track down these boost issues and constant dips/overboosts. I've been working through the Duty Bias and PID tuning to get it to target something like 18 PSI, but no luck. I attached the most recent log of 100 to see how this looks, you can see it hits around target at 3200 during spool, then it dips down before overboosting and continuing.

That is a 3rd gear pull, if I start the pull off at 4k+ RPM then it almost always overboosts to 22-23 PSI, so I can't do a 40-50 roll for an example.

The same issue with a 2nd gear pull from a dead stop, It will begin to overboost and run lean.

I am hoping to gain more insight from this fourm, although it seems not many people are able to correct this issue and ditch the JB4, I've been using it for 3 years so I would hate to get rid of it, but as summer is approaching and I want to order a PI kit, I need to figure this out.

Current mods:
E35~, Walbro 450, VRSF Intercooler, BMS intake, CP, ******* **, muffler delete, MHD BEF. Not sure if I'm missing anything else, but it is a "FBO"

Timyoy0 · 05-08-2019, 11:15 AM

Can I get this moved to the support and log section please?

M-terkait · 05-08-2019, 01:19 PM

are you sure about the wastegate setting? try lowering it.
or maybe your wastegate arm is too tight.

Timyoy0 · 05-08-2019, 01:41 PM

Quote:

Originally Posted by M-terkait

are you sure about the wastegate setting? try lowering it.
or maybe your wastegate arm is too tight.

Do you mean the WGDC/FF? I have it currently disabled because the overboosts is causing it to drop, so it's been overboosting then being way below target to redline

M-terkait · 05-08-2019, 02:01 PM

Quote:

Originally Posted by Timyoy0

Do you mean the WGDC/FF? I have it currently disabled because the overboosts is causing it to drop, so it's been overboosting then being way below target to redline

try to lower the default WG position in jb4. it should lower the tip of reaching the boost. and post some logs.

Timyoy0 · 05-09-2019, 01:39 PM

Quote:

Originally Posted by M-terkait

try to lower the default WG position in jb4. it should lower the tip of reaching the boost. and post some logs.

Dropped it from 60-30 I believe. I played by dropping it to 40 and tweaked it but overall I didn't notice much difference. I dropped PID 18 from 20 and I tweaked duty bias a little bit but still no luck with the boost control.

Weehe · 05-10-2019, 08:08 AM

Sorry to say I can't see any way you will fix this with JB4/BEF. I fine tuned my BEF/duty bias setting for PS2 and have to go WOT 2500-3200rpms otherwise I get massive overboost every time. You can mess with wastegate settings to tame overboost but it will probably slow spool. Idk if tune only would be any better.

Timyoy0 · 05-10-2019, 08:17 AM

Quote:

Originally Posted by Weehe

Sorry to say I can't see any way you will fix this with JB4/BEF. I fine tuned my BEF/duty bias setting for PS2 and have to go WOT 2500-3200rpms otherwise I get massive overboost every time. You can mess with wastegate settings to tame overboost but it will probably slow spool. Idk if tune only would be any better.

I noticed that. The overboosts isn't massive if it's A WOT 3K.. BUT ONCE IT'S 4K+ Im seeing 23-24 psi with a 18 Target.

I only know of one person using speedtech with boost control. He had VANOS edits which I tried but no luck

M-terkait · 05-11-2019, 01:23 AM

Quote:

Originally Posted by Timyoy0

I noticed that. The overboosts isn't massive if it's A WOT 3K.. BUT ONCE IT'S 4K+ Im seeing 23-24 psi with a 18 Target.

I only know of one person using speedtech with boost control. He had VANOS edits which I tried but no luck

I Had the same problem when I used to run pure stage 2 with jb4, with flash only it was great no issues. but then no meth

Timyoy0 · 05-14-2019, 01:01 PM

Running out of ideas... I just received my PI I ordered, so little torn if I should go custom tune and drop the JB4 all together. Its a shame.

Terry @ BMS · 05-20-2019, 03:22 PM

WGDC isn't moving so wasting your time trying to resolve with PID related settings. It's VANOS table related.

Weehe · 05-21-2019, 09:08 AM

Would love to know the theory on vanos causing overboost. I understand it can improve spool up, but not sure how it can cause overboost.

Timyoy0 · 05-21-2019, 10:41 AM

Quote:

Originally Posted by Terry @ BMS

WGDC isn't moving so wasting your time trying to resolve with PID related settings. It's VANOS table related.

I saw a write up on this forum... is there any other documentation to solving this issue? I can try to edit the VANOS tables but not 100% certain what to look for.