scheides

iTrader: (10)

Tehpra, I've been messing with the gear-based boost control (with mrfred's direct boost mod) and I just wanted to give you some feedback; it is awesome!

I dialed in boost with my BBK Full on the dyno but left error correction off so I could dial it in on the street in every gear. Initially I just turned it on with all the settings the same in every gear. This worked pretty good but there would be situations where I would overboost when hammering it @4500 in 4th gear, boost would get dialed back a bit, then come back up...basically inconsistent power delivery. Other times similar boost variations would occur simply doing a pull from 3000rpm. Not much, but enough that it got annoying during daily driving.

So, 4000-5500 I pulled out 1-2% WGDC in 3rd gear, and 2-4% in 4th and 5th gear and I am just super super happy with how smooth it is!

Here's the boost profile I'm going after(BBK on pump w/ oem wga works so good!):


I'll be playing with 1st & 2nd gear settings to maybe get boost to come on a bit earlier.

Also, I think I'll post up the changes I made to get mrfred's direct-boost mod to work with v7. It was quite easy, but I want to make sure its easy and accessable for everyone because tephra and mrfred have really created the ultimate boost control setup.

Side note for tephra: did you get your BBK Lite on before (insert bad memory here)? Wondering if you'd be willing to share feedback on it compared to the stock IX turbo, I have some friends shopping and I'd like more first-hand experience

nonschlont

iTrader: (3)

Congrats! "Direct Boost Control" + "Gear Dependent Boost Control" = awesomeness!
When you said you were gonna post up the "changes you made to work w/ v.7, You sorta lost me... Are you talking about the rom mods, in the "Direct Boost Control thread" or the rpm speed ratio stuff? I have this running on the v.6 beta rom for the 88590015, so Im just checking to see if I missed something new...

fostytou

iTrader: (15)

Nice not so curvy boost curve! Not bad on the power either


Someone beat you to already doing the implementation: https://www.evolutionm.net/forums/ec...ml#post7219773

Also, if I remember correctly I think bad things happened before the BBK was even out, but thats just my bad memory.

scheides

iTrader: (10)

What do you mean bad things?

I actually hit 388whp best on just pump gas

fostytou

iTrader: (15)

I mean I think there was a ball of metal in AU before the BBK was released to the public.

Nice work though, are you running a full?

0xDEAD

iTrader: (3)

The "inconsistency" sounds like it is hunting for achieving proper boost. Try playing with your correction map and reducing the timer intervel to a larger number. I have no issues and have been on the same boost maps for a year.

0xDEAD

iTrader: (3)

Search the term derivative in PID control systems, that is basically what the boost correction map does. The intervel timer is like the Integral of PID.

THUB

iTrader: (5)

I'm pretty sure he's talking about TBEC disabled completely when he had the variation. Look at his boot curve. He's definitely not having a problem.

0xDEAD

iTrader: (3)

My bad,

In that case look as to what is causing the overshoot. You have to watch how much load you put in the "100% wastegate under this value" . It is best to have the ecu controlling wastegate well before the turbo starts spinning at 100,000 rpm plus. It takes a while to wind down when at that speed and will cause the small overshoots. Also, at some point, just realize that the system will over shoot. It is an air system, and they are notoriously hard to control. However, mine has about half the overshoot of a typical MBC controlled system and gets rid of a TON of taper up top.

Also, the BBK's, from what I've seen, are slightly harder to control via ECU based boost. The boost just ramps up so hard and so fast that you have to be on your game to give the ecu a chance by tuning the maps planning for that overshoot. Else the ECU is in react mode, and it will always overshoot when that is the case.

tephra

iTrader: (6)

Best thing about full gear boost is 1st gear... 3rd/4th gear DC's are pretty useless for 1st...

tephra

iTrader: (6)

yeah 3 weeks before the roll..

didn't get a proper tune.

spool is about 0-100rpm slower than stock IX (as in 0 psi start, inter gear spool was faster)

boost held to 24+psi (instead of 20psi for stock ix)

good turbo owned a ferrari on a dodgey assd tune hehehe

fostytou

iTrader: (15)

Spool can happen over a 1500+ RPM range depending on gear. In 5th gear I can spool 20 psi by 2750 RPM, in 2nd it is more like 4k RPM. That is why gear based control rocks

scheides

iTrader: (10)

Yup, BBK Full.

I've played with the maps endlessly, and when it comes down to it if you're not paying attention or your driving style doesn't lead you to notice it, it doesn't matter. But, If you do a WOT pull from 2000-8000, 3000-5000, 4000-6000, or 5000-8000 (or any combo/sub-iteration) you'll get different results in every gear. I've messed with all of the tables quite a bit on several cars. Gear-based boost control makes it A LOT more consistent.

Any advice? Crank them up or what?

Exactly the problem.

Asmodeus6

iTrader: (7)

I turned the error correction off and left it off.

In my personal experience, the 30R gets up a head of steam and the error correction has too much liberty with the direct boost control. I found it correcting WGDC too far even when getting really close to the target boost pressure. It wasn't going hands off - and sticking to the preset WGDC at all. Which caused 32psi over shoots on a car set to run 26psi. This was especially apparent when you would tromp on it at a higher rpm. The WGDC correction would pull too much DC in and it would overshoot like crazy. Then freak out and correct the boost on the lower side of the "target range" like say 25.xx psi.

I still have some work to do tuning around these small problems. I left the maps basically the same as I had them for 26psi, raised them to about 26.5psi and left the correction off.

I still get a small spike if I nail it at higher rpm in gear, but it seems to be a lot more consistent w/o error correction on. It's only like a 28psi spike.

I just came back from vacation so I'll be trying to squeeze in some tuning time before the Shoot Out. If not, I'll play with it some more afterwards.

scheides

iTrader: (10)

Bryan@GST turned me onto killing the 'max upwards correction from TPS' or whatever, that really helped get rid of most of my spike issues initially, and truth be told yea, you could just turn off error correction and not worry about it, but the simple fact is that you will get inconsistent boost levels depending on conditions and gear.