About Blow Off Valves
Yeah, though most stock MAF's don't do well after the turbo due to the temp increase of the air. You'd probably have to be running an aftermarket sensor---in which case most people would use MAP for the simplicity.
QUOTE
Red:
Ooops, should have answered that...
The Haltech will NEVER be affected by your choice of blowoff valve. The Haltech bases it's entire fuel map on MANIFOLD pressure, so when you close the throttleplate and the manifold pressure drops into the basement, the Haltech sees every last millibar of pressure and the fuel delivery moves accordingly.
The Haltech can adjust fuel delivery faster than your ENGINE can deal with it. Haltech takes readings at 20ms intervals, faster than YOU could see it spike.
I LIKE! tongue.gif Cost for total system, inclucive of dyno time, install timefame, and will it work with RB26DETT(individual TB)/2JZ-GTE(single VATN turbo conversion)? It seems to be able to handle the applications very well, but with the independant TBs and the airstream fluctuation they cause within the stock manifold(any required conversion will not be a problem), and the possible VATN on the 2JZ-GTE, with pressure being modified consistantly with electronic wastegate and turbine blade aspect, is Haltech capable of being integrated with these components, or will another management system be required? Ooops, should have answered that...
The Haltech will NEVER be affected by your choice of blowoff valve. The Haltech bases it's entire fuel map on MANIFOLD pressure, so when you close the throttleplate and the manifold pressure drops into the basement, the Haltech sees every last millibar of pressure and the fuel delivery moves accordingly.
The Haltech can adjust fuel delivery faster than your ENGINE can deal with it. Haltech takes readings at 20ms intervals, faster than YOU could see it spike.
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QUOTE
Cheuk in Seoul:
So. If the intake stream is...
Turbo -> BOV -> MAF ... you can vent to atmos
MAF -> Turbo -> BOV ... vent back to intake after MAF and before the turbo
Cheuk shouldn't that be So. If the intake stream is...
Turbo -> BOV -> MAF ... you can vent to atmos
MAF -> Turbo -> BOV ... vent back to intake after MAF and before the turbo
Turbo -> BOV -> MAF ... you can vent to atmos
Turbo -> MAF -> BOV ... vent back to intake
How would you get yur MAF sensor to fit before the turbo? I'm sure it can be done but why would you want to.
Before the turbo you have an intake pipe that looks remarkably similar to any short ram or CAI...fitting the MAFS on there is pretty easy.
Also, remember though how a MAF sensor works--measures the cooling rate of a hot wire or film. If your air is too hot it may not draw enough heat out to get an accurate reading, or you may hit problems with the IAT sensor calibration. I can't speak for how the hyundai MAF sensors stand up to this but it is a potential issue.
And: You'd run WAY rich going Turbo > MAF > BOV. The measured air is not reaching the combustion chamber--it would be dumping too much fuel. In this setup you'd be measuring a lot of the air repeatedly. In both of cheuk's scenarios the measured flow at the sensor is the net flow to the IM. Recirculated air between the sensor and consumption point or before the sensor makes a zero net flow increase, it only causes heat buildup.
Also, remember though how a MAF sensor works--measures the cooling rate of a hot wire or film. If your air is too hot it may not draw enough heat out to get an accurate reading, or you may hit problems with the IAT sensor calibration. I can't speak for how the hyundai MAF sensors stand up to this but it is a potential issue.
And: You'd run WAY rich going Turbo > MAF > BOV. The measured air is not reaching the combustion chamber--it would be dumping too much fuel. In this setup you'd be measuring a lot of the air repeatedly. In both of cheuk's scenarios the measured flow at the sensor is the net flow to the IM. Recirculated air between the sensor and consumption point or before the sensor makes a zero net flow increase, it only causes heat buildup.
QUOTE
NeCRoASiAN:
I LIKE! :p Cost for total system, inclucive of dyno time, install timefame, and will it work with RB26DETT(individual TB)/2JZ-GTE(single VATN turbo conversion)? It seems to be able to handle the applications very well, but with the independant TBs and the airstream fluctuation they cause within the stock manifold(any required conversion will not be a problem), and the possible VATN on the 2JZ-GTE, with pressure being modified consistantly with electronic wastegate and turbine blade aspect, is Haltech capable of being integrated with these components, or will another management system be required? :confused [/QB]
The Haltech will plug into any piston-driven car that has between 2 and 12 cylinders, or any rotary car with 1 or 2 rotors (not the kickass 3 rotor ones tho, doh sad.gif ) The digital/PWM outputs can control basically anything you want to plug into them -- to include your electronic wastegate. You can actually create two seperate boost maps and use a rotary potentiometer to dial inbetween the two while you're driving.I LIKE! :p Cost for total system, inclucive of dyno time, install timefame, and will it work with RB26DETT(individual TB)/2JZ-GTE(single VATN turbo conversion)? It seems to be able to handle the applications very well, but with the independant TBs and the airstream fluctuation they cause within the stock manifold(any required conversion will not be a problem), and the possible VATN on the 2JZ-GTE, with pressure being modified consistantly with electronic wastegate and turbine blade aspect, is Haltech capable of being integrated with these components, or will another management system be required? :confused [/QB]
I don't know enough about how the variable vane turbo actuators work, but I don't think that is ELECTRONICALLY controlled but instead controlled by the turbo itself via a vacuum nipple. If that vacuum line is modified by an electronic solenoid of some sort, the Haltech can cover that too.
The Haltech is a full engine management system; it basically does exactly what you tell it to.
Most MAF turbos run the MAF -> turbo -> BOV back into the intake stream... as pointed out above. Mostly for MAF durability issues.
There is three advantages to having the MAF last in turbo conversions.
One... No BOV piping back into the intake..PITA
Two... MAF can remain in the relatively stock location, without lengthening the wires.
Three... theoritically it has a slight advantage with quicker / more accurate response. Because it will measure exactly the air going into the intake manifold without having being confused by minute boost leaks / hose expansion... etc.
But not all MAF can tolerate the abuse of heated boosted air.
There is three advantages to having the MAF last in turbo conversions.
One... No BOV piping back into the intake..PITA
Two... MAF can remain in the relatively stock location, without lengthening the wires.
Three... theoritically it has a slight advantage with quicker / more accurate response. Because it will measure exactly the air going into the intake manifold without having being confused by minute boost leaks / hose expansion... etc.
But not all MAF can tolerate the abuse of heated boosted air.
Oops, I also didn't realize you asked for a price on the Haltech.
Depends on the unit and the distributor... Mine was $1150 + shipping from Australia. Includes the E6K brain, software, unterminated wiring harness, all the connectors, 3-bar MAP sensor, TPS sensor, coolant sensor, air temp sensor and the 140+ page instruction manual. If you don't want to rip your car apart down to the bare metal and fully rewire it all yourself, expect to pay anywhere from $500 to $1000 for install.
Tuning will of course be extra.
Individual throttlebodies are covered because the *manifold* pressure can be drawn from a single runner -- which in a proper ITB setup will have equal vacuum/pressure across all runners in the assembly.
[EDIT] My website is currently working, see this link for a good idea of what's involved.
Depends on the unit and the distributor... Mine was $1150 + shipping from Australia. Includes the E6K brain, software, unterminated wiring harness, all the connectors, 3-bar MAP sensor, TPS sensor, coolant sensor, air temp sensor and the 140+ page instruction manual. If you don't want to rip your car apart down to the bare metal and fully rewire it all yourself, expect to pay anywhere from $500 to $1000 for install.
Tuning will of course be extra.
Individual throttlebodies are covered because the *manifold* pressure can be drawn from a single runner -- which in a proper ITB setup will have equal vacuum/pressure across all runners in the assembly.
[EDIT] My website is currently working, see this link for a good idea of what's involved.
In my experience with turbos, the bypass system(one that vents back into the intake) works well but isn't without fault(if thats what you were talking about)...Its a bit hard on the spring area and sometimes increases lag. It just tends to vent only at high vacuum which means it has to completely close the throttle plate. That lag is a bit large at times. BOV(literally ones that vent into the atmosphere) doesn't do that because it vents more earlier until atmospheric tempure which means less lag. I'm not sure I'm 100% right on this but ya thats my mini experiences with bovs so far. I am gonna get settled with a dual exit system bov soon though. They're just basically a system that routes 50% of the air back into recirculation and 50% into the atmosphere.
The VATN turbos by Aerodyne are mechanically controlled actuators running off the turbo outlet boost pressure. And you can run a mechanical or electronically controlled *wastegate* control in the vacuum line... just like other turbos.




