FAQ - In Alphabetical Order
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Blow Off Valve
How do they work???
What are blow off valves and can I put them on my naturally aspirated car?
Questions from beginner car enthusiasts on where to get blow off valves for normally aspirated cars are not uncommon as they don’t know what blow off valves are for, and how they work. It is not possible for you to install a blow off valve onto a normally aspirated car, they are for forced inducted engines. No matter how much you like the sound. Hehe.
Normal engine operation.
Let’s ignore how turbochargers work and just assume it works since this post is not about turbochargers. The engine receives the turbocharged air through the intake. That’s assuming the throttle is open. Now what happens when you lift your foot off the pedal? The compressed turbocharged air has no where to go. It hits the closed throttle plate and goes back up the intake manifold the opposite direction. Back into the turbine. This high pressure air hitting the turbine blades from the wrong side of the turbo slows down the spinning turbine, thus reducing boost. When you press the accelerator pedal again, the turbo has to slowly spin up again to gain maximum boost. This is bad. Very bad. The reverse surge of turbocharged air could also damage the turbine. This is also bad. Very bad.
This is why blow off valves exist. It releases turbocharged air coming down the wrong direction of the intake manifold out to the atmosphere. You get longer turbocharger life, quicker spool, and better transient response. Of course, there is the issue of the stock standard ECU expecting air but not getting air, and pumping too much fuel in, but that’s a different issue. For cars with that problem (usually because of the usage of Mass Airflow Sensors) there is a different type of blow off valve that recirculates turbocharged air back into the intake instead of releasing it into the atmosphere. Sounds a lot less cooler though heheh. BOVs need a strong vacuum to open, which is caused by the butterfly being in the closed position.
Recirculating blow-off valves send air back into the intake You can’t put a blow off valve on a naturally aspirated car because induction (the sucking of air into the engine) is done using vacuum. The engine itself sucks air in, instead of the turbine pushing compressed air in. When the throttle is closed, no air is being sucked in, and there is no boost bouncing back into a non-existent turbocharger turbine. There is nothing to “blow off”. So that’s what blow off valves are for, and that is why you only put them on turbocharged cars. So if you want that cool sound that turbocharged cars have whenever they shift gears, you need a turbocharged car. BOV Info sourced from: http://paultan.org/archives/2006/03/16/what-are-blow-off-valves-and-can-...
Mount Engine
Available at present from REPCO
Model Year Engine Trans Mount Part No.
AB, AC 84-85 4G37 Auto Front MT8343
AB, AC 84-85 4G37 Auto Insert MT8697
AB, AC 84-85 4G37 Auto Rear MT8691
AA, AB, AC 84-89 4G62T Auto/ Man Front MT8343
AA, AB, AC 84-89 4G62T Auto/ Man Insert MT8697
AA, AB, AC 84-89 4G62T Manual Rear MT8719
AA, AB, AC 84-89 4G62T Auto Rear MT8691
MT8343......$51.00
MT8719......$145.00
MT8697......$60.00
Note: Part Number MT8343 is a 'complete' engine mount whereas part number MT8697 is only an 'insert' for that mount.
* All mounts are avaliable at most repco stores.
* All prices are GST incuded.
Prices are as at 17/10/06 and may change without notice!
Oil
What grade is suitable for 4g62?
I have been running 'Titan GT Plus 20W-50 ($21.95)' This oil is suitable for use in turbo engines, and seems to flow and perform well in my 4g62 motor. I bought a 5L bottle, and was left with a litre extra oil! So the 4g62 engine takes between 3.5 and 4 Litres of oil! 
STEVE
Overdrive (5th gear)
How does it work???
Parts
- Available at present from REPCO
Air Flow Meters
AA and AB gsr only
OEM no. E5T00274
After Market No. AM00274 $269.00
Ecu's
AA and AB gsr
OEM No. MD071027
After Market No. MD071027CO $465.00
AC gsr
OEM No. MD103657
After Market. MD103657CO $542.00
E101
AA, AB and AC gsr
OEM No. E101
After Market No. ME120 $378.00
Galant VR4
Crank Angle Sensor
OEM No. J928
After Market No. SC072 $169.00
ECU
OEM No. MD165810
After Market No. MD165810CO $930.00
All Prices Include GST.prices are a guide
Vaccuum Hoses (minimal hookup)
What hoses to use...
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My Blog -
the manual scans i have uploaded so far.
yes the parts are are available from repco now
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Cordia's are the root of all evil
Thankyou! I've Edited the thread!
I've just added a very good description of how a Blow off valve works in the first post of this thread, I found it interesting, even though I already knew how they worked!
also it might be worth noting that BOVs need a strong vacuum to open them which is caused by the butterfly being closed
Thankyou, I have added this to the description! And also an extra couple of diagrams...
New section! OIL Ok so i need to do my oil change and im wondering what to get and also how much goes into a 4g62.
I thought i read somewhere it was about 6L ran 15W40 which seemed alright but what are you guys using?
Section updated!
hmm i though it was way more than that. hmm i dont think i have lost that much oil
I've added these diagrams to the gallery section "Diagrams & Illustrations" and have included these in the FAQ Sheet.
Thankyou
5th Gear/ Overdrive.
The Cordia GSR gearbox(KM164) is not a five speed gear box, it is an 8 speed, 4 low range gears 4 high range gears. In the cordia, gears 1-4 are low range 1-4. The 5th gear is actually high range, 4th gear. The way box shifts range is via a rod, located driver side toward the front top of the casing, push it in, (toward passenger side)= low range, Pull it out=high range.
Attached to the end of the rod is the Vacuum Selector or actuator (VS). Applying a vacuum to one side of the diaphragm causes the rod to move in (low range) apply vac to the other side rod moves out (High range). When driving in gears 1-4 vacuum is applied to keep the rod pushed in. When you change to 5th the 5th gear switch in the front/ bottom of the gearbox is switched on. This causes the Vacuum solenoid (S) to switch the vacuum to the other side of the Vacuum selector diaphragm (VS) causing the rod to pull out, giving you High range 4th- or “fifth” gear. In the past people have by-passed the 5th gear switch to a switch in the cabin. So they can select gears high range 1-4 at will.
The longer gear ratios can give better end times on the ¼ mile. – much more stress on components though i.e. Shorter serviceable life. Also if gunk and crap builds up and causes the rod to become hard to push in and out the selector rod can stop in the middle between high and low range, and you go nowhere.
It ALWAYS worth checking the selector rod if you “Just lose the gears” before assuming something more major has happened.
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Contact me on: 1972rainman@gmail.com
tried to delete
How are the high and low gears set up? can the gearbox be made to be 8 gears? eg: 1low, 1high, 2low, 2high, 3low, 3high, 4low, 4high? where the high shifts are made by putting the clutch in and hitting a paddle shifter?
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Token Italian and all round bastard...
i'm not sure if you have been in one raff but some trucks have a split diff opperated by a switch on the gear lever, in theory you can set up something similar in place of that switch (on the gearbox)
the way the truck one works is in most cases air operated and all you do is flick the switch when your coming up to the gear change and when you want to change range its just a matter of doing the normal clutch throttle movments but there in no need to move the gear lever, the air pressure just does it when the load comes off the diff and it can make the change
i cant see why you would want to make it into an 8 speed though... i promise you driving it in traffic you gonna get sick of it very quickly (it may be something beneficail for drags though as previously stated
cheers Jamie
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Jimi yes but you will neeed a switch on the gearstick to switch on and off as you up through the gears, the sswitch becomes the padddle.
yeh it would be a bitch, i was just thinkin for driving in the hills it might be great as when you shift down your revs wouldnt drop as low as there is a gear in between eg 3 high might be an inbetween gear ratio in relation to 3 low and 4 low. really just depends on the ratios. has anyone got any info on the ratios of all the low and high gears?
that what i was meaning rainman.. just didnt say it very clearly... was meaning you could set up a switch on the gearlever in place of the one on the box.. you could even set it up on the steering wheel so if you were doing some hard driving and wanted to keep both hands on the wheel as much as possible
im guessing you'd need to pop the clutch in to shift from high to low correct?
yeah... you could just jump off and on the throttle but the change mite be a bit harsh
definatly need the clutch.
ICS – computer uses this to control the idle rate of the motor.
E101- Ignition module, passes the ignition pulse from the distributor to the computer if the knock sensor is activated the e101 retards the timing signal from the dizzy to the computer to prevent knocking. Knocking/ pinging/ pre-detonation kills your motor real fast.
BOOST SENSOR- As the name suggests, Boost cut function is in here as well if engine boost goes over a specific level (14psi AA&AB, 12psi AC) it signals( via the yellow wire) the computer to cut fuel to the motor.
BALLAST RESISTOR- Has something to do with the fuel injectors anybody?????
TPS- How the computer sensors the throttle position.
COOLENT TEMP SENSOR- this is the one for the computer not your dash display, it tells the computer when the engine is warm enough for 'normal operation'. When the engine is cold the computer uses different fuel amounts(richer) idles higher, and MAYBE AFECTS THE WAY IT ACCELERATES-anybody??? Short story: let the car warm up before you kick it in the guts, its cheaper and your motor lasts longer.
KNOCK SENSOR- Sits below the intake manifold on piston one. Sensors predetonation, &causes the E101 module to electronicaly retard the timing
ERROR CODE PLUG –If a electronic component of the engine management system is not working properly the computer tells you by flashing a number through this plug, use a multimeter or 12volt LED to read the code, a bulb will not work.
Error codes:
the coolant temp senor does both pooter and dash.. the one on the radiator is for the thermo fan
also some people call the ics an isc (idle speed controller)
Jamie,
The coolant gauge has its own sensor, the other is for the ECU to control injection.
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This thing will decimate all.......once I've put another fifteen grand into it!
uhuh... dont mind me.. i had a blonde moiment... was forgetting about the sensor on top of the manifold... i didnt look at the picture that closely
No probs.
An Answer to the most FAQ:
Vacuum hose hook up.
Thats a really useful diagram dude thanx for the input.
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Damn Red Truck
Location
Thankyou for starting the FAQ Sheet! I have removed your initial post as I require 'Admin Only Access' to edit this sheet.
Sorry for the post drop on your account!