03aristo

This is from NA-t forum, posted by Bean, pretty good thread hope it ill help answers your questions.

Bigger Power!



Keep in MIND!!! That all of this is how to get power reliably out of the MOTOR. The transmission and the rear end are completely different subjects. Your stock clutch WILL NOT withstand more than 300whp and last for very long. Your stock transmission WILL NOT WITHSTAND more than 400-450whp for very long and driven hard (your mileage may vary).
Autos are very different from the stock 5-speeds. Do your research on driveline modifications!

In the bigger power arena, you need to bypass several obstacles. One most notably being the stock ECU with regards to fuel metering. There are only so many bandaids you can run before you run out of airflow (even with the V8 AFM). This means by going to speed density!

Speed density is a completely different way of measuring the air intake in the engine vs the mass-air system used in the stock GE.

The stock GE system uses Karman Vortex as its way of measuring air. If you've ever taken apart your intake and see the sensor itself, you'll see a waffle-style (or honeycomb) front on it. What this does it cause small vortexes to form after the air enters the system. The more air that enters, the more vortexes (and the larger they get). The quantity and amplitude of these vortexes is measured by a small speaker inside the housing. You can see it if you look carefully. Do not damage the honeycomb up front, you will cause the sensor to read bad.

Speed density uses two seperate sensors to measure how much air has entered the system.
-The first sensor is a pressure sensor that senses how much pressure or vacuum is in the intake system. This is called the "MAP sensor" MAP is short for "manifold absolute pressure". By absolute, this means TOTAL pressure including atmospheric pressure (which is 1 BAR at sea level) by the way. If someone has a 3 bar map sensor, it means it can read 29.4psi of pressure ABOVE atmospheric (14.7psi = 1 BAR). Obviously, this is a little sensor, and causes no intake restrictions of ANY sort.
-The second sensor is an air temperature sensor. When air cools, it becomes more dense, with more oxygen molecules. This sensor allows the ECU to compensate with more fuel to keep a safe mixture when the temperature rises or drops. It is called an IAT sensor - or "intake air temperature" sensor. This sensor also causes no restriction.

Almost all aftermarket ECU solutions are Speed Density (also called MAP-based) and this includes the AEM ECU. It can run via AFM, but its a waste not to utilize the extra flow and control with MAP. The "MAP ECU" is a piggyback solution for the stock ECU. Like the older VPC, it translates a MAP-based signal into an AFM signal that the ECU can use (and isnt any the wiser). Both the MAP ECU and AEM allow you to run MUCH larger injectors.

Ok I'm running a speed density system, I am cool!
Not so fast! You need BIG fuel injectors for that too. Luckily, the stock fuel rail is a top-feed unit, has an FPR plug on it that is right around 1/4" NPT in size, and has a good enough internal diameter to flow enough fuel for over 700whp. Boost Logic, SP, Titan, etc now offer NA-T fuel systems that either use the stock rail or replace the whole thing completely. These systems are generally customizable to the size injectors you want and most use TWIN Walbro Fuel pumps. Nice eh?

After that, you will already need to be running a GOOD turbo header... the cast jobs work well in the low-power arena, but with the big boys its all about FLOW.... and cast units DONT On the header setups, you will already be using a larger wastegate (40mm+) and at least a 3" downpipe. A lot of companies will have a 4" downpipe and midpipe combo to upgrade to if you're going to be making big power (dont really need that unless you're hitting over 700-750hp).

A FRONT MOUNT INTERCOOLER!!! I'd laugh if someone tried this with a stock sidemount

A turbo that can flow the amount of air you want. Do some research, because there is a HUGE turbo selection out there and new ones are coming out all the time that offer better and faster spool, more flow and power, and more extras ( like jet sounds from the ported shroud housings hehehe )

At this point you MUST be running a thicker headgasket. Why? Because you cannot make over 400-450whp reliably with the stock 10:1 compression. Stock SupraTTs come with 8.5:1 compression and can run lots of boost from the factory. YOU can get to this point by running a thicker headgasket. Your stock gasket is very thin... like .2mm vs the GTE gasket which is 1.6. Do not worry about squish-volume problems too much, since the primary source of compression drop on the 2jz-gte is achieved by running a much thicker headgasket. 2.5mm will get you to 8.5:1 compression.

The only problem left is ignition, which can be solved by running lower gap on your plugs and an HKS DLI. It boosts the ignition signal and will allow you to still make spark at higher boost when it would normally be "blown out" from the excessive pressure.

After this point, you can start tuning, running racegas and making BIG power. The stock GE intake manifold (EGR delete please!) can flow over 800-850hp and there's no point in upgrading to a high-flow unit (such as the DaveH unit) until you eclipse this point.

There are lots of little things this guide didnt have for big power, which is detailed tuning instructions (get it tuned by a professional if you dont know what you're doing!), and small tidbits you should already know. (ie Beaded intercooler pipes, new gaskets for all hardware, etc)

Please understand that this is just a basic blow by blow of how to obtain power from this motor. If you can understand this so far, then congradulations, you can probably handle the whole deal just fine.
Remember that you can always just purchase a kit from a reputable manufacturer and it will come with everything you need.

Give one of the good shops a call and tell them exactly what kind of power you want with what kind of powerband (nothing too unrealistic here k?) and they will give you an invoice or statement telling you exactly what you need. They've answered these questions many times.

Krillah

What if your just running a 2JZGE with a turbo and slight mods... will the stock (auto) tranny and rear end require mods as well? just curious.. i recently just bought an 02 IS300 and im thinking about the 2JZGE with a turbo.. just wanted some insight on what else may need a little bumping up.

Htowncory

Good information.

When I read this.. My eyes glaze over and I this little voice in my head keeps repeating 2JZGTE 2JZGTE..

It seems like there are some diehards who will always want to stick with the NA 2JZGE but man, by the time you have to work on the trans, get new injectors, get piggybacks, etc, Jeesh, why not get 2JZGTE and boom your done!

Most of the swap engines Ive seen for sale come with the OEM aristo trans, all injectors, etc. 2JZGTE continues to look like the way to go.

JeffTsai

iTrader: (1)

The main reason I decided to stay NA-T in my daily is for emissions and such. My car has zero check engine lights and I just passed the state inspection plug-in OBD-II testing with flying colors. No way you will be able to do that with a GTE swap running on the GTE ecu or a standalone. The JDM ecu uses a completely different coding for the bus. It's different than OBD-II, so shops here won't even be able to hook the car up to their machine to run the test. There is one way to do it, but it involves a bit more work. I can just drive into any regular oil change place and get the car inspected now instead of having to pay somebody $80-120 to "pass" the car

As for my other car, well all bets are off for that one in the emissions department lol.