Bnr k04-gt28
We have boost! So it was a blessing in disguise that this happened because then I was able to find and fix the boost leaks with the MAF and tMAP sensors, but this is what happened...
The wastegate solenoid
looks like a 'T'. One line goes to the top of the wastegate can, the far side line goes up somewhere near the intake manifold/above the engine (I forget), and the third line used to connect somewhere on the stock turbo. With the GT2871 that third line (the one right next to the one going to the top side of the wastegate can) isn't connected to anything so I capped it instead of having it open to atmosphere. Well, for some reason that made me lose boost. After messing around with a bunch of stuff I uncapped it and now have boost again. Maybe someone can explain to me why, but all I know is that for some reason it works. To me it looks like the wastegate can is open to atmosphere, which doesn't make sense, but oh well.
Thanks for all the suggestions about things to look for. Like I say, it was probably a good thing since I did find that I needed to tighten the MAF and close those holes near the tMAP.
The wastegate solenoid
looks like a 'T'. One line goes to the top of the wastegate can, the far side line goes up somewhere near the intake manifold/above the engine (I forget), and the third line used to connect somewhere on the stock turbo. With the GT2871 that third line (the one right next to the one going to the top side of the wastegate can) isn't connected to anything so I capped it instead of having it open to atmosphere. Well, for some reason that made me lose boost. After messing around with a bunch of stuff I uncapped it and now have boost again. Maybe someone can explain to me why, but all I know is that for some reason it works. To me it looks like the wastegate can is open to atmosphere, which doesn't make sense, but oh well.
Thanks for all the suggestions about things to look for. Like I say, it was probably a good thing since I did find that I needed to tighten the MAF and close those holes near the tMAP.
Former Vendor
Joined: 06-03-08
Posts: 4,169
Likes: 8
From: Grand Rapids, MI
We have boost! So it was a blessing in disguise that this happened because then I was able to find and fix the boost leaks with the MAF and tMAP sensors, but this is what happened...
The wastegate solenoid
looks like a 'T'. One line goes to the top of the wastegate can, the far side line goes up somewhere near the intake manifold/above the engine (I forget), and the third line used to connect somewhere on the stock turbo. With the GT2871 that third line (the one right next to the one going to the top side of the wastegate can) isn't connected to anything so I capped it instead of having it open to atmosphere. Well, for some reason that made me lose boost. After messing around with a bunch of stuff I uncapped it and now have boost again. Maybe someone can explain to me why, but all I know is that for some reason it works. To me it looks like the wastegate can is open to atmosphere, which doesn't make sense, but oh well.
Thanks for all the suggestions about things to look for. Like I say, it was probably a good thing since I did find that I needed to tighten the MAF and close those holes near the tMAP.
The wastegate solenoid
looks like a 'T'. One line goes to the top of the wastegate can, the far side line goes up somewhere near the intake manifold/above the engine (I forget), and the third line used to connect somewhere on the stock turbo. With the GT2871 that third line (the one right next to the one going to the top side of the wastegate can) isn't connected to anything so I capped it instead of having it open to atmosphere. Well, for some reason that made me lose boost. After messing around with a bunch of stuff I uncapped it and now have boost again. Maybe someone can explain to me why, but all I know is that for some reason it works. To me it looks like the wastegate can is open to atmosphere, which doesn't make sense, but oh well.
Thanks for all the suggestions about things to look for. Like I say, it was probably a good thing since I did find that I needed to tighten the MAF and close those holes near the tMAP.
Senior Member
Joined: 02-16-10
Posts: 8,383
Likes: 1
From: Queen Creek,AZ
We have boost! So it was a blessing in disguise that this happened because then I was able to find and fix the boost leaks with the MAF and tMAP sensors, but this is what happened...
The wastegate solenoid
looks like a 'T'. One line goes to the top of the wastegate can, the far side line goes up somewhere near the intake manifold/above the engine (I forget), and the third line used to connect somewhere on the stock turbo. With the GT2871 that third line (the one right next to the one going to the top side of the wastegate can) isn't connected to anything so I capped it instead of having it open to atmosphere. Well, for some reason that made me lose boost. After messing around with a bunch of stuff I uncapped it and now have boost again. Maybe someone can explain to me why, but all I know is that for some reason it works. To me it looks like the wastegate can is open to atmosphere, which doesn't make sense, but oh well.
Thanks for all the suggestions about things to look for. Like I say, it was probably a good thing since I did find that I needed to tighten the MAF and close those holes near the tMAP.
The wastegate solenoid
looks like a 'T'. One line goes to the top of the wastegate can, the far side line goes up somewhere near the intake manifold/above the engine (I forget), and the third line used to connect somewhere on the stock turbo. With the GT2871 that third line (the one right next to the one going to the top side of the wastegate can) isn't connected to anything so I capped it instead of having it open to atmosphere. Well, for some reason that made me lose boost. After messing around with a bunch of stuff I uncapped it and now have boost again. Maybe someone can explain to me why, but all I know is that for some reason it works. To me it looks like the wastegate can is open to atmosphere, which doesn't make sense, but oh well.
Thanks for all the suggestions about things to look for. Like I say, it was probably a good thing since I did find that I needed to tighten the MAF and close those holes near the tMAP.
Senior Member
Joined: 10-08-06
Posts: 3,043
Likes: 0
From: Scottsdale, AZ
Senior Member
Joined: 02-12-09
Posts: 2,129
Likes: 0
From: Phoenix
BNR website reveals all...
BNR Supercars - Bryan Nickell's Rotary Supercars - Solstice, Sky, Cobalt SS, HHR SS
BNR Supercars - Bryan Nickell's Rotary Supercars - Solstice, Sky, Cobalt SS, HHR SS
Anybody...
Anybody at all...
Okay but seriously...I remember about the line coming from the valve cover and that has to stay open, getting a breather filter, etc, but not this other line.
Senior Member
Joined: 10-03-09
Posts: 2,649
Likes: 0
From: Warrenton, MO
so the line going from the valve cover to the stock turbo is left open now? And the line that connects from the valve cover to the intake still is in tact right? there are 2 lines and just trying to get it straight.
Senior Member
Joined: 08-12-08
Posts: 829
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From: Huachuca city, AZ
Senior Member
Joined: 07-25-08
Posts: 12,450
Likes: 6
From: Florida
Vince might have lowered the WG desired DC percentage in the lower RPMs to keep the boost from spiking if it is boosting a little later now that it got retuned. Your WG rod nuts (LOL) could have come loose as well.
Senior Member
Joined: 09-04-09
Posts: 2,218
Likes: 0
From: Alabama
After doing some research on the 2860 and then comparing it to our stock turbo I'm a bit confused.
People have seen 35 lb/min on the stock K04, the GT2860 is rated at 35 lb/min. But here is whats confusing, the compressor is bigger on the GT2860 and the turbine is slightly bigger.
So in theory in the GT2860 should make more power all the way through the rpm band on our cars then the K04 since the turbine and compressor are bigger?
So how can our k04 make 35 lb/min witha smaller turbine and compressor and then the 2860 make 35 lb/min witha bigger turbine and compressor? Are people pushing the k04 out of its effeciencly range to get 35 lbs/min?
So in theory you should be able to push the GT2860 above 35 lbs/min on our cars with good tuning?
People have seen 35 lb/min on the stock K04, the GT2860 is rated at 35 lb/min. But here is whats confusing, the compressor is bigger on the GT2860 and the turbine is slightly bigger.
So in theory in the GT2860 should make more power all the way through the rpm band on our cars then the K04 since the turbine and compressor are bigger?
So how can our k04 make 35 lb/min witha smaller turbine and compressor and then the 2860 make 35 lb/min witha bigger turbine and compressor? Are people pushing the k04 out of its effeciencly range to get 35 lbs/min?
So in theory you should be able to push the GT2860 above 35 lbs/min on our cars with good tuning?
If it senses an underboost condition it will still increase to the 95% anyway. Just had this talk with Vince yesterday about why I asked for 75% MAX WGDC and still saw 95% at times..On the Subaru's and some other cars you can literally set the MAX point and it will never go over it, I thought this would work the same but Vince tells me otherwise.
After doing some research on the 2860 and then comparing it to our stock turbo I'm a bit confused.
People have seen 35 lb/min on the stock K04, the GT2860 is rated at 35 lb/min. But here is whats confusing, the compressor is bigger on the GT2860 and the turbine is slightly bigger.
So in theory in the GT2860 should make more power all the way through the rpm band on our cars then the K04 since the turbine and compressor are bigger?
So how can our k04 make 35 lb/min witha smaller turbine and compressor and then the 2860 make 35 lb/min witha bigger turbine and compressor? Are people pushing the k04 out of its effeciencly range to get 35 lbs/min?
So in theory you should be able to push the GT2860 above 35 lbs/min on our cars with good tuning?
People have seen 35 lb/min on the stock K04, the GT2860 is rated at 35 lb/min. But here is whats confusing, the compressor is bigger on the GT2860 and the turbine is slightly bigger.
So in theory in the GT2860 should make more power all the way through the rpm band on our cars then the K04 since the turbine and compressor are bigger?
So how can our k04 make 35 lb/min witha smaller turbine and compressor and then the 2860 make 35 lb/min witha bigger turbine and compressor? Are people pushing the k04 out of its effeciencly range to get 35 lbs/min?
So in theory you should be able to push the GT2860 above 35 lbs/min on our cars with good tuning?
Skewing the MAF airflow or correction for ethanol blends will increase the MAF lb/min in error.
At my altitude the bast I have logged with the stock K04 is 30.5Lb/min VE.. I imagine I might be able to squeeze out 31lb/min when I get up to phoenix to to some runs next weekend.