Alright, we're gonna try this again... let's keep it going and get all the info we need this time...
Alright kids, we're gonna do a little turbo FAQ here for the new members, old members, stupid members. So let's bring up some topics that we would like to see in the FAQ, and then we will go from there as far as organizing it into one document.
I think some good things to put in it would be differences between the DET motors, what parts can be used off of RWD DET's, engine management options, Z32/Cobra MAF stuff, etc.
I'll start it off and add to it as more people comment (correct me if I'm wrong on anything; I'm pretty new to it myself).
Glossary
CHRA = center housing rotating assembly or a turbo without the compressor and exhaust housing but complete from compressor blade to exhaust blade.
Compressor Inducer = smaller diameter of compressor blade (inlet from the air filter)
Compressor Exducer = larger diameter of the compressor blade (outlet to intercooler}
Turbine Inducer = larger diameter of exhaust blade (inlet from the manifold)
Turbine Exducer = smaller diameter of exhaust blade (outlet to exhaust)
Inducer = inlet
Exducer = outlet
A/R= Aspect Ratio or Area / Radius =Different people say different things but basically it is the area of the housing divided by the radius of the housing. As the housing A/R factor increases numerically so does it's potential to induce or exduce a specific volume .
Wastegate (W/G)= Vacuum dependent device used to limit boost by drawing exhaust flow away from the turbine blade. This is done near or before the inducer of the exhaust blade.
Internal Wastegate = This type of wastegate is an integral part of the exhaust housing. It consist of a flapper door inside of the exhaust housing that is controlled by a vacuum/boost referenced actuator valve that is attached to the compressor housing. Most OE manufacturers use this type of setup because it is cheap and there are no fitment problems like those of external wastegates. Because of the flapper door size this type of wastegate is not efficient at high boost levels . Since it can not relieve enough exhaust flow to maintain the maximum boost setting boost creep will sometimes occur when driven hard. Most actuators are preset from the factory with max a boost level that can not be adjusted unless a boost control device is added .There are aftermarket racing actuators on the market have an adjustable rod that allows for boost level changes.
External Wastegate = This type of wastegate is also vacuum/boost referenced but it is separate entity from the turbine section. External wastegates are connected in many different ways but the most efficient method is to connect it with it's own section of piping near the collector flange of the manifold. This type of connection will allow exhaust flow to be drawn from all primary tubes equally. Of course this type can not be applied to all street cars because of the space limitation factor. The physical size of the wastegate valve, which is 35mm or larger for small external wastegates, and connection point makes the external W/G a better choice for mild to wild setups. If the the dump tube for the W/G is to be routed back into the exhaust piping for a closed loop setup it is best to make the tube as long as possible. Flow from the W/G tube that is re-entered back into the exhaust too early can cause a restriction in flow by creating back pressure.
Manual Boost Controller (MBC) = Commonly called VVC (variable valve controller), VBC (variable boost controller) and a couple other unique names. MBC are mechanical devices plumbed between the W/G and it's vacuum/boost source. Basically the MBC will manipulate the vacuum/boost signal to the actuator valve or wastegate. Everything from fish tank valves to reducer T's are used as MBC's. MBC's should be mounted as close as possible to the wastegate to prevent problems that can be caused by using long vacuum lines and it will prevent you from cranking up the boost every time someone spanks your butt.. The main drawback of MBC's is the W/G will begin to open as soon as boost registers even though an MBC has been an properly installed. This premature opening acts almost like an exhaust leak and can hamper the low and mid range performance of your engine.
Electronic Boost Controller (EBC) = Also referred to as EVC (Electronic Valve controller). EBC's use a solenoid box controlled by an ECU. The best EBC's use Fuzzy Logic programming to control the boost and give features that help traction handicapped turbo cars. Unlike the MBC the EBC holds the w/g completely closed until the preset boost level is reached and then it opens completely until the throttle is closed. This feature allows for more low-end and midrange power that may have been lost when using an MBC. Some EBC's can also be setup to use a scramble boost (SB) setting. SB holds the boost at a preset low boost level for a preset amount of time and then it automatically changes to the high boost setting of your choice. Other features of EBC's include gear based boost levels, rpm based boost levels and hi/lo settings.
Blow Off Valve (BOV) = vacuum/boost sourced device plumbed between the throttle plate and compressor outlet used to prevent a boosted charge from back pedaling it's way to the exducer of the compressor when the throttle is closed (also known as Back Charge or Negative Charge). BOV's allow the charged flow to be expelled to the open atmosphere (EPA doesn't like this) or be re-circulated back into the inducer side of the compressor. On OE turbo setups this called a re-circulator valve. The re-circulated flow will aid the spool up on street cars that have a problem with turbo lag and it is stealthier because the psst sound of the BOV will not be heard. Without a BOV or re-circulator valve the back pedaling negative charge will cause the thrust bearing of the turbo to fail or it can cause the shaft to break if high boost levels are being used.
Glossary curteousy Charlie2020
What are the differences in the different SR20DET engines?
GTI-R
8.3:1 Compression
Quad Throttle bodies
444cc injectors
T28 turbo
TMIC
U12 Bluebird
8.5:1
370cc injectors
T25 turbo
TMIC (I think)
U13 Bluebird
8.5:1
370cc injectors
T25 turbo
FMIC (I think)
Avenir W11
8.5:1
370cc injectors
T25 turbo (ball bearing)
FMIC
The Coveted SR20VET
9.0:1
???cc injectors
?? turbo
TMIC
Keep in mind, this 276hp engine is nearly impossible to get over here.
What is 3bar and 4bar? What is stock?
Fuel Pressure using approx. 1 bar = 14.7psi
3 bar = 44.1psi
4 bar = 58.8psi
Stock Fuel Pressure for SE-R, NX2000, SE, SE-L = 3 bar
Upgrades needed for 4 bar - Fuel pressure Regulator, Fuel gauge, Engine management upgrade (SAFC, ECU, etc)
What are the specs on xxxxx Turbo?
http://importnut.net/turbosizing.htm
Some opinions on turbo selection:
What guages should I get? Where do I hook up the oil pressure guage?
Boost and oil pressure are the first two on my list. Next, water temp. Maybe EGT. A/F is a total waste unless you buy a nice wideband (~$600+). As for where to hook up the oil pressure, do it at the stock oil pressure sender location and the Nissport adaptor comes in handy there.
