Stock boost?
- Thread starter xblzr03
- Start date
viperman5
Member
Re: Stock boost?
I believe max stock boost is 14.7. The 2 bar MAP sensor can not read anything higher than that. Next step up in turbo would be a 20g if you want to keep stock appearing or PTE make great kits. Race Proven Motors also makes a Garrett turbo which will work with the stock downpipe.
I believe max stock boost is 14.7. The 2 bar MAP sensor can not read anything higher than that. Next step up in turbo would be a 20g if you want to keep stock appearing or PTE make great kits. Race Proven Motors also makes a Garrett turbo which will work with the stock downpipe.
VermontTy
Support Our Troops
Re: Stock boost?
http://sportmachines.com/maintenance/recipe1.php
http://sportmachines.com/maintenance/recipe2.php
The cheap way to get a little more from the stock turbo is with a 20G upgrade. John Waller is one that does the 20G upgrade. It'll get you probably another 100cfm out of the turbo; you'll need a 3BAR MAP though.
http://sportmachines.com/maintenance/recipe1.php
http://sportmachines.com/maintenance/recipe2.php
The cheap way to get a little more from the stock turbo is with a 20G upgrade. John Waller is one that does the 20G upgrade. It'll get you probably another 100cfm out of the turbo; you'll need a 3BAR MAP though.
PPI Typhoon
DIY Madman
Re: Stock boost?
There is a boost controller that is controlled by the ECM regulating it to 14.7 psi.
With the proper programming/chip, you can go up another 14.7 psi in boost (theoretically).
I personally ran 26psi out of my stocker, but anything after 22'ish psi, it doesn't make much of a difference.
To achieve this, I basically disabled the boost control
xblzr03 said:
There is a boost controller that is controlled by the ECM regulating it to 14.7 psi.
With the proper programming/chip, you can go up another 14.7 psi in boost (theoretically).
I personally ran 26psi out of my stocker, but anything after 22'ish psi, it doesn't make much of a difference.
To achieve this, I basically disabled the boost control
Re: Stock boost?
See I am getting ready to drop a turbo setup on my 2003 Blazer Xtreme. To start out... I would like to limit the boost at 7-8 psi until I get my new intake manifold to upgrade the injectors (Mercruiser MPFI intake).
Everyone keeps telling me to get the next turbo up for a sy/ty. I have a turbo already... the stock 17c but it could use some freshining up.
See I am getting ready to drop a turbo setup on my 2003 Blazer Xtreme. To start out... I would like to limit the boost at 7-8 psi until I get my new intake manifold to upgrade the injectors (Mercruiser MPFI intake).
Everyone keeps telling me to get the next turbo up for a sy/ty. I have a turbo already... the stock 17c but it could use some freshining up.
Re: Stock boost?
New lower compression forged pistons are planned..... L35 heads flow better.. L35 rods are pretty damn beefy....as for a cam I am getting one from CompCams so I can get rid of the valve overlap.... since the turbos seem to like it better.
so the only other area that needs attention is the nodular caps?
New lower compression forged pistons are planned..... L35 heads flow better.. L35 rods are pretty damn beefy....as for a cam I am getting one from CompCams so I can get rid of the valve overlap.... since the turbos seem to like it better.
so the only other area that needs attention is the nodular caps?
VermontTy
Support Our Troops
Re: Stock boost?
I'm wondering how you plan to get the fueling right for the additional air. The difference between our speed density and your mass flow systmes will no doubt raise an issue (will your MAF sensor accurately read boost instead of just vacuum? you may know that already, I have NO clue). Your MAF sensor is going to "tell" your chip what duty cycle to run your injectors at to get proper fueling. If your MAF sensor cannot differentiate 10lb vacuum from 10lb boost, you've got a big hurdle to overcome.
That's an aread where we can get in trouble; if we run a 2bar MAP sensor (14.7vacuum - 14.7 boost) and are running more than 14.7psi, the computer will only read 14.7 from the MAP sensor, and fuel accordingly, where it may actually need fuel for 20 or 25psi. You need a 3bar MAP sensor for that (14.7vacuum - 29.4psi)
I'm wondering how you plan to get the fueling right for the additional air. The difference between our speed density and your mass flow systmes will no doubt raise an issue (will your MAF sensor accurately read boost instead of just vacuum? you may know that already, I have NO clue). Your MAF sensor is going to "tell" your chip what duty cycle to run your injectors at to get proper fueling. If your MAF sensor cannot differentiate 10lb vacuum from 10lb boost, you've got a big hurdle to overcome.
That's an aread where we can get in trouble; if we run a 2bar MAP sensor (14.7vacuum - 14.7 boost) and are running more than 14.7psi, the computer will only read 14.7 from the MAP sensor, and fuel accordingly, where it may actually need fuel for 20 or 25psi. You need a 3bar MAP sensor for that (14.7vacuum - 29.4psi)
Re: Stock boost?
The MAF shouldn't be too much of a problem. I mean guys are running 12lbs with a s/c on the stock MAF.
Getting fuel into it is going to be the hardest obsticle. Our stock manifolds only accomodate 19/hr injectors just like the 5.7 L98 Vortec motors. I have found a MPFI manifold off of a 4.3 Mercruiser motor that will allow bigger injectors and make them easier to replace because of the fuel rail setup....
Boat Manifold:
VermontTy said:
The MAF shouldn't be too much of a problem. I mean guys are running 12lbs with a s/c on the stock MAF.
Getting fuel into it is going to be the hardest obsticle. Our stock manifolds only accomodate 19/hr injectors just like the 5.7 L98 Vortec motors. I have found a MPFI manifold off of a 4.3 Mercruiser motor that will allow bigger injectors and make them easier to replace because of the fuel rail setup....
Boat Manifold:
dgoodhue
BuSTeD 4.3
Re: Stock boost?
Actual MAF is easier to tune for than MAP cars for fueling. It just reads air flow, it doesn't car about pressure. When you modify a MAP car for better airflow (better flowing heads & cam), the pressure reading could be the same (ie 15psi), but the combustion event could have a lot more air. So no more fuel would be added. MAF would compensate and more fuel.
MAF Ecm compensate much better, but MAP Ecm's have better resolution for fueling which lead to the potential to run better and smoother under more conditions.
Actual MAF is easier to tune for than MAP cars for fueling. It just reads air flow, it doesn't car about pressure. When you modify a MAP car for better airflow (better flowing heads & cam), the pressure reading could be the same (ie 15psi), but the combustion event could have a lot more air. So no more fuel would be added. MAF would compensate and more fuel.
MAF Ecm compensate much better, but MAP Ecm's have better resolution for fueling which lead to the potential to run better and smoother under more conditions.
Re: Stock boost?
The best part about the tuning is that the 01+ S-Series have a LS1 style ECM. LS1Edit works on my truck.... so when I get it all running I got a guy here locally that tunes for the GM Performance division.
I'd like to keep the boost at 8 psi for now, I still need to figure out how I am going to limit it.
Also, I need to figure out if a FMU will work until the manifold gets here?!?!?
dgoodhue said:
The best part about the tuning is that the 01+ S-Series have a LS1 style ECM. LS1Edit works on my truck.... so when I get it all running I got a guy here locally that tunes for the GM Performance division.
I'd like to keep the boost at 8 psi for now, I still need to figure out how I am going to limit it.
Also, I need to figure out if a FMU will work until the manifold gets here?!?!?
dgoodhue
BuSTeD 4.3
Re: Stock boost?
I think you might be a little confused. The stock actuator open at 8-9 psi when connected to a vacuum/boost source, (the stock turbo has this port). The ECM controls the boost above 8-9 though information from the MAP (ie what boost level its at) and a boost solenoid. The boost solenoid is between the actuator and vacuum/boost source and doe so by bleeding off to delay the opening of the wastegate.
So if you ran just the actuator, it will open at 8-9 psi and this can be adjusted a little bit by the length of the wastegate rod. The manifold has nothing to do with boost control unless it has a big hole in it (ie this would create little to no boost)
An aftermarket boost controller would go in place of the boost solenoid and ECM.
xblzr03 said:
I think you might be a little confused. The stock actuator open at 8-9 psi when connected to a vacuum/boost source, (the stock turbo has this port). The ECM controls the boost above 8-9 though information from the MAP (ie what boost level its at) and a boost solenoid. The boost solenoid is between the actuator and vacuum/boost source and doe so by bleeding off to delay the opening of the wastegate.
So if you ran just the actuator, it will open at 8-9 psi and this can be adjusted a little bit by the length of the wastegate rod. The manifold has nothing to do with boost control unless it has a big hole in it
(ie this would create little to no boost) An aftermarket boost controller would go in place of the boost solenoid and ECM.