BBK-3B - my new favorite turbo
Apr 9, 2014, 01:29 AM
#77
Does the bbk-b bb turbo come with surge ports?
if not, have you been able to generate any surge with the bbk-b bb?
fwiw, i can generate some surge on my hta grn, if i experience such, i just dial down my pcduty in the area of concern for my ebc & problem is solved.
I would imagine such is the same if experienced with a basic bbk.
if the response is similar between the bbk-b bb vs the jb bbk, then maybe the bbk-b bb is the turbo for me...
if not, have you been able to generate any surge with the bbk-b bb?
fwiw, i can generate some surge on my hta grn, if i experience such, i just dial down my pcduty in the area of concern for my ebc & problem is solved.
I would imagine such is the same if experienced with a basic bbk.
if the response is similar between the bbk-b bb vs the jb bbk, then maybe the bbk-b bb is the turbo for me...
Apr 9, 2014, 01:58 PM
#79
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That's probably not surge. My guess is that its just MAF confusion as the DV/BOV bounces open and shut at part throttle partial lift. My 3B and Full both do this. The difference is when I go WOT at low rpm. If the boost builds too early, the Full would start to buck even though the DV/BOV is held shut while the 3B does not.
Apr 9, 2014, 03:00 PM
#82
1) The BBK-3B has more svelte blades, so the wheel looks lighter. And it has a 1.5 mm smaller diameter than the 65 mm HTA Green turbine wheel which also helps reduce its moment of inertia.
2) The BBK-3B blade design is much more open and looks less restrictive. This is especially apparent from the top view. It looks like its much easier for exhaust gases to exit the BBK-3B turbine and should result in lower exhaust manifold pressure. Without having used the turbo, I would have guessed that this would hurt turbo performance, and perhaps it does in some way, but when paired with the 57 mm compressor wheel on the 3B, there is no sign of any inefficiency.
NINJA EDIT: My HTA Green is the older variant with the 65 mm turbine wheel. New Greens currently use a 67 mm diameter turbine wheel.
Last edited by mrfred; Apr 9, 2014 at 03:27 PM.
Apr 10, 2014, 10:07 AM
#85
I had part throttle issues with my setup (3b on 2.2L) that I just finished working out last night. I had run a vac line from the manifold to the 3port ebc, then to the wg. There were two problems with this setup:
1) If you ignore the ebc for minute and just look at the vac source to the wastegate spring, it is always trying to make the manifold pressure match the wastegate spring pressure. If you are wot, the differential pressure across the throttle plate is very low and the manifold pressure is basically the intercooler piping pressure. If you are at part throttle, there is a large dp across the throttle plate... but the wastegate is still trying to make the manifold pressure the same as it was at wot. Now your piping pressure is higher and the turbo is running at a low flow high pressure part of the curve (surge line...).
2) Bring the ebc back in the picture. I had my min load for boost control table setup at relatively low load numbers. My target load at wot was in the 310-320 range, but min load for boost control was in the 200-220 range. At part throttle, as soon as I hit 200 load the wgdc would start being adjusted to try and hit the target load of 300. Basically the wgdc would go up rapidly, even though my throttle plate was partially closed. Add this effect to that of item 1), and you can get some pretty high piping pressures at low flow rates.
Not only did the above two issues cause the turbo to run close to the surge line, but holding the throttle at 50% would result in an increasing rate of acceleration over time. Not good when you want part throttle in a slalom or steady state corner! By tuning the min load for boost control table, 100% wdgc table, wgdc correction vs tps table, and relocating my vacuum line to the i/c piping upstream of the throttle plate, my car is way more controllable and has no more funky behavior at part throttle. WOT behavior remained the same.
Sorry for the thread jack, but this may be useful info for anyone running a 3b, bbk, etc with part throttle issues.
-Aaron
Apr 10, 2014, 12:06 PM
#86
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https://www.grimmspeed.com/content/i...ne_version.pdf
Apr 10, 2014, 12:17 PM
#87
... and relocating my vacuum line to the i/c piping upstream of the throttle plate, my car is way more controllable and has no more funky behavior at part throttle. WOT behavior remained the same.
Sorry for the thread jack, but this may be useful info for anyone running a 3b, bbk, etc with part throttle issues.
-Aaron
Sorry for the thread jack, but this may be useful info for anyone running a 3b, bbk, etc with part throttle issues.
-Aaron
Apr 10, 2014, 02:44 PM
#89
I have used the same location in some turbo applications other than Evo, and never had surge, until I had an Evo - yet never reasoned through or connected the dots like you did.
I have to think about what you said, and the difference, to understand it well, and will certainly try it.
Thanks for sharing.
I have to think about what you said, and the difference, to understand it well, and will certainly try it.
Thanks for sharing.