Finally stage 2!

[BoozeRS05]

Congrats. I did this recently too..

 

Def adds a bit of smoothness in the powerband, which was nice. I'm using the 91oct map for just a little more safety, and I'll be installing my GS EBCS when I get proper tuned. Loving it so far.

[Sideways the Seven]

Thanks, guys! It took forever (uppipe and downpipe installed) and I just got the maps uploaded. I'll be giving her a run tonight but, unfortunately, I'm going to have to run an open downpipe until I can get to the exhaust shop on Monday.

 

ELH? It's funny that you say that because the guy who was helping me actually asked the same question. I'm good for now. LOL!

[chimera]

EBCS not necessary for a stage 2 setup. Very, very minimal gains. But it's cheap, and if your tuner recommends it, go right ahead. It'll give him some more room to work with

Excuse my noobness, but how does an ECBS provide power gains? I understand the basics of what it is and what it does, but can't see how it provides any gain in power? I would have thought it would just provide a finer/more responsive boost rather than more power? Is it simply because the tuner has finer levels to work with? So just throwing an ECBS in wouldn't provide any power increase by itself, and needs to be tuned in further?

[iNVAR]

Excuse my noobness, but how does an ECBS provide power gains? I understand the basics of what it is and what it does, but can't see how it provides any gain in power? I would have thought it would just provide a finer/more responsive boost rather than more power? Is it simply because the tuner has finer levels to work with? So just throwing an ECBS in wouldn't provide any power increase by itself, and needs to be tuned in further?

With a VF40 at stage 2 levels and boost, you're pretty much hitting about 90% WGDC to maintain boost towards red line. A lot of tuners taper this off for most customers because it's really not worth it to try to wring that much from the tiny VF40. Also, because boost targets are much more easily achievable in higher gears, so dialing in something like 90% WGDC in the upper revs in 3rd gear would cause a big spike in 4th gear if you floored it at those same revs.

 

This happens because:

1. the VF40 runs out of steam up top, it's really small
   
2. the stock BCS is scaled differently
   
3. the stock BCS is a bleed type controller, which means the WG actuator will inevitably see some pressure which causes it to open, even if you're at 90-95% WGDC
   

 

The 3 port won't do anything for (1) since that's a function of the turbo's size and the volume of exhaust gas it needs.

 

But it will address (2) and (3) since the 3 port is an interrupt style BCS. It can effectively prevent your WG actuator from seeing any pressure which might otherwise force it to be opening a bit.

 

This allows you to run lower WGDC numbers and maintain the same/very slightly higher boost levels up top with it. That doesn't mean that with a WGDC though that you should try to force VF40 to generate 18# at redlin by still running 90% WGDC. There is such a thing as an efficiency zone for every turbo and for the VF40, that's way out of its zone.

 

Also, with the finer control with a 3 port, you can actually do a much better job of reining in the spikes that I mentioned above. So I have much higher WGDC levels dialed in my tune, which allows me to achieve a boost curve that hits all of my targets in 3rd (I need high WGDC in 3rd at upper revs to hit the targets) but allows 4th and 5th to also follow the curve, without much of a spike at all.

 

So basically, the 3 port allows you to eek out just a teeny, tiny bit more, if you really, really want to squeeze that much out.

[iNVAR]

Here's some more so you can actually see what I'm talking about.

 

On the left side of the screenshot for the maps, you can see the old tune that I had. This was a paid for custom tune Stage 2 tune by a reputable tuner. This was on the stock BCS.

 

On the right side is my own new map, same parts, except a 3 port GM BCS purchased from Amazon. The rows have been rescaled and some targets have been adjusted so you can't just look across and compare the values, which is why I've graphed it into Excel. At first glance, the tables look like I'm running the same or even more WGDC than the original map, which is true in some parts.... The high RPM section is definitely higher, where I have an 80% value plugged into redline to hit my 12#.

 

But here's what my images don't show you: I hit those targets in 2-5, with minimal overshoot in 4 and 5. The old setup, I struggled to hit the targets in 2 and 3, especially if it was hot out. And only in 4th and 5th, I'd be able to hit them easily (well, at least in 4th. I've never redlined in 5th ).

 

And also look at the WGDC at about 2500. I run lower WGDC across the boadr all the way to 5K where I'm able to ramp it up to squeeze out a tiny bit more at redline in lower gears.

 

Just a footnote: the original tuner that did my car did nothing wrong. He made things run safely and I had made it clear to him when I was tuned by him that what was my priority, this being my DD. His way is definitely safer, since it won't overshoot in the higher gears when flooring it at upper revs.

 

I suspect that a fair number of people who are tuned balls to the walls that then go on the track and experience high gear + high revs end up with detonation resulting from the large spike they may see with a map that doesn't rein in the spike properly with well adjusted Turbo Dynamics values.

[idiot4hire]

^^thats why I love forums.

[Sideways the Seven]

+1. I'm over here scribbling tons of notes.

 

Sent from my SGH-T699 using Tapatalk 2

[iNVAR]

After looking at my graph, I may actually reduce my high end WGDC some to reduce my 4th/5th gear spike some more. You really get very diminished returns once you start pushing the turbo past its efficiency range.

[chimera]

Legend! Thanks invar