blownrunner

NTRO:

I thought that seeing how many vehicle owners also add suspension and engine upgrades along with wheels, tint, alarms, body kits, etc in addition to audio upgrades to customize their ride, I thought I might share my forced induction experience to anyone considering diving into this area of auto customization.

Second only to tuning an audio system, Forced Induction is what I am asked about the most at shows and events as the process is multi-faceted and intricate. Ask Senor Honda how it took me 20 minutes to explain how to tune a Naturally Aspirated-modified-Forced Induction system!

Feel free to add comments as technology advances quite quickly. I cannot claim to know everything about everything for every application.

I will shed a little light on my supercharger install and hit the main points with some general concepts and theories. Let's get started...

blownrunner

OVERVIEW:

The main concept to comprehend, far above the rest, that will make more power in an engine, in my opinion is this: The more increased fuel and oxygen an engine can burn together at the right ratio will effect power increases of said engine more than any other modification.

Although different, turbo and supercharging add more air into the cylinders in the same physical way. Turbocharging uses an exhaust gas powered air compressor, a supercharger is an parasitic engine accessory much like an alternator, and although minor, decreases crankshaft engine torque output.

In addition to forcing more air into the engine, a few other areas must also be addressed to get maximum effect from the supercharger and to allow safe operation of the engine:
-Increased fuel delivery
-Engine parameter modification
-Engine parameter monitoring
-Driveline strengthening
-Increased heat

Ideally, the method of upgrading and installing a complete forced induction system, if done in steps, is as follows:
-Engine parameter monitoring device installation
-Stock engine parameter monitoring
-Driveline strengthening, fuel delivery, and heat control modification installation
-Engine parameter electronics installation
-Supercharger/turbo installation
-Tune at idle
-Street tune
-Tune on Dynamometer for maximum horsepower

Totally opposite of what you might expect, huh?

WHY ALL THE DAMN HASSLE? Cars are fun to work on and look at. Lots of bling and plenty of show for everyone. I like to get in my ride and listen to a true Sound Quality sound system because of the way it makes me feel. The same feeling that stimulates the brain by way of the auditory canal in the temporal lobes of your skull can also be transmitted by way of the Gluteus Muscles. Getting sucked into your seat is a hell of a thrill and makes you feel phenomenal. Supercharging/turboing your car is the best dollar to horsepower value out there sure to put a ear to ear smirk on your face. No intake or muffler even comes close. While there are many different areas that need attention, when the vehicle is properly tuned and set up and all parts are optimally working together it is like falling mutually in love with someone... there is chemistry.

I will address these individual areas individually in further installments. Remember, this is just the basic of the basics, but you will have an overall idea of the size of the mountain that is before you before you decide start to climb it.

Please post responses and opinions as to the accuracy of my logic! Thanks for looking!

blownrunner

I will cover the engine monitoring device installation and monitoring of the stock engine now. Monitor the engine and learn how it operates at open/closed loop, partial and wide open throttle, and warm-up. This will be duplicated during the tuning process!

What information do I need to know that is indicative of wether my engine is safely making more power or if I am putting an aluminum internal coating to my headers? There are must haves:

-Boost/Vacuum gauge. Ensure that it reads from -20 to the max boost you want to achieve! You need a manifold air pressure (MAP) sensor hooked to a gauge. Gauges usually run on 5 volts, achieved either by a 5 volt output on the accompanying gauge or by a 12-5 volt power supply.
-Wideband air/fuel ratio. This is the most important gauge in your arsenal. This will instantly tell you if you are harming your engine. Forget narrow band sensors that only tell to if you are 13-15:1 air to fuel (A/F) ratio. You need a wideband system to monitor from 10:1 to above 15:1 AFR. A bung needs to be welded into the exhaust system (generally) and a wideband O2 sensor installed, attached to a wideband control computer, and then attached to the display/gauge. I recommend permanent installation rather than temporary installation like at the dyno. This should always be monitored and will tell you more that any other gauge the condition of your forced induction system!
-Fuel trims: This is the amount of correction above/below the stock fuel map that the stock fuel injectors, controlled by the engine CPU, is injecting into the cylinders. You need to know how these 'function' so they can be duplicated when the supercharger is installed and then the system is tuned. These can be only temporarily installed, because after the final tune is completed, the wideband AFR meter that you permanently installed will generally indicate that the fuel trims are off after you know what to look for. Just get a OBD2 scanner that has real-time PIDs (able to monitor engine CPU inputs in real time)
-Open/Close loop: This is very important because in closed loop, the engine CPU is monitoring and then altering the engine parameters accordingly. In open loop, like at wide open throttle (WOT, or 'when you floor it)' or during engine warm up, the engine CPU is not using engine sensors to alter the AFR. It only controls the injectors according to the fuel map programmed into it and is blind to the fact that you are now forcing 10 psi into the cylinders, the AFR will spike, cylinder temperatures rise, and holes get eroded into the pistons, essentially melting your engine. Use the temporary installed OBD2 gauge for this as after the engine is tuned, the wideband AFR gauge can monitor for unsafe conditions.
-Engine speed (RPM): This, along with your boost gauge, will enable you to adjust the fuel trims in the right areas of the new fuel map. If your car doesn't have a tach, use the OBD2 gauge or permanently install one (you need to know engine speed anyway from damaging the engine from excess speed).

Things that are nice to monitor, but are secondary indicators to the primary gauges are:
-Exhaust Gas Temperature (EGT) If you are running at 11:1 AFR at max boost, I cannot see how a extremely high EGT can be achieved as the extra fuel does not get burned below 14.7:1, but instead cools the cylinder. (no kidding, huh?)
-Transmission temp: You will be putting more stress on the driveline, especially the automatic transmission in the form of heat in the torque converter. Installation of a large stacked-plate transmission cooler (motorhome size) will generally cure this heat condition along with valve body modification (more on this later). Install a gauge if you like to tow a lot or drive at low speed/high torque conditions like soft sand.
-Timing: this is only needed when the timing needs to be adjusted during your street tune. Use above mentioned OBD2 scanner for this temporally installed.
-Intake air temperature (IAT): The incoming air to the throttle body needs to be as cold as possible because it will be compressed and heated by the supercharger/turbo. If you are not running an intercooler, the amount of boost you can run is usually limited to about 10psi due to heat saturation (the heated air, even those more dense, will decrease the amount of contained oxygen compared to a cooler, less dense intake of air). Find out where your air filter should be placed or if that new intake of yours should be dubbed 'hot-air intake system'. Use OBD2 scanner for this temporally installed.

Whew! More later!

blownrunner

DRIVELINE STRENGTHENING:

For this segment, we will cover only the automatic transmission in light detail. If you are making insane amounts of power over stock, CV joints and axles might need to be addressed along with traction bars for the leaf spring people to prevent wheel hop.

Generally, the problem with modern automatic transmissions is not lack of strength, but clamping pressure from hydraulic line pressure and slow shifting between gears due to the transmission being designed for 'luxury shifting'. When the general public is shopping for a car, they do not want the transmission to shift firmly and transmitting that 'jerking' feeling into the passenger compartment. To combat this, the valve body of the transmission is 'programmed' for soft shifting by gradually applying pressure to the clutch packs over a longer period of time. This shifting time is increased when the engine output is increased such as during WOT.

FYI, the valve body of the transmission is like a mechanical computer for the transmission. The transmission in my 4Runner is shared with other vehicles such as the Jeep Cherokee and the Toyota Supra, but obviously the valve bodies vary from vehicle to vehicle according to the needs of the vehicle manufacturer.

In the case of my 4Runner, there were only two companies in the U.S. that specialized in that transmission, whom did the R+D on it of removing the valve body, modifying it, reinstalling it, and testing the results. This is done many times to get it right and the good news is that the transmission shop can set up your valve body for general health of the transmission, towing, or all-out 1/4 mile drag racing! Ever go to the track and hear a car chirp the tires between 1st and 2nd, and 2nd and 3rd? Chances are it couldn't do that in stock form and was modified for faster 1/4 MPH times by decreasing shift length! And you thought you could just add more HP to your motor to win a drag race...

My valve body was retuned to me after it was separated, orifices were modified, it was reinstalled with new seals and solenoids, the line pressure was adjusted, and I was given new springs to install inside the accumulators. All that R+D pays off as it shifts stock when grandma drives it, but when driven more sporty, the shifts shorten up resulting in a more firm, quicker response shortening the time between the shifts.

Finish it off with some quality ATF such as AmsOil and a huge transmission cooler, and you are good to go. At least transmission wise...

blownrunner

FUEL DELIVERY:

If you are installing forced induction systems on your ride, you are increasing the air into the engine, but the fuel system needs to be addressed as well. This is typically where most of the future tuning comes in as the amount of additional fuel can be adjusted, more on that later. In the meantime, we need to get our fuel system installed first, and then set for zero changes over the stock fuel map. You can safely drive the car like this until the following weekend when the supercharger gets installed.

-Fuel pump: I don't care home much positive trim is dialed into the vehicle or how big your injectors are, you need to get fuel to the motor first. Don't be surprised if you increase your power output by 1/3 more but require a new fuel pump that increases fuel delivery by 1/2 more! During my dyno tune, despite a larger fuel pump of 190LPH over the stock 150 or so LPH pump resulted in leaning out at WOT despite increasing the fuel trims above 5,000 PRM and 8PSI. I dropped my fuel tank and installed a larger 240LPH pump, which solved the problem. Forget installing a pump halfway between the engine and tank... the optimal location is in the tank, and should touch the fuel to the engine first before it enters the fuel line. What you want to increase is fuel volume, not pressure. Any unneeded fuel volume is routed back to the tank and pressure is maintained by the fuel delivery system regulator. What you need to ensure is that the new monster fuel pump does not draw addition amperage beyond the limits of the stock vehicle wiring. This is a whole another subject and will not go into it here!

-Next you need to either install larger fuel injectors, re-jet your carburetor, or do what I did and go the simple route and install a supplemental fuel system. You save $ going the latter route as the vehicle normally controls the engine during no-boost conditions, during warmup, and general driving. The supplemental system adds additional fuel when in high boost conditions and the stock CPU doesn't even know it is there, it only monitors the effects of the extra injected fuel, such as at the stock O2 sensors. With a supplemental system, you only add raw positive adjustments. When you change all the fuel injectors, you need to buy more injectors and you need to start your tuning at idle the moment you fire it up for the first time with the turbo/supercharger installed. Supplemental systems are really simpler to dial in and cheaper to buy. I simply plumbed a small fuel line from the RH fuel rail to my 7th fuel injector right after the throttle body butterfly and called it a day!

-The last thing you need is some way to control your new injector or injectors. The easiest way of doing this installing an injector computer electrically into the stock vehicle wiring before the stock CPU. The basic supplemental controller does not alter the signals going into the stock engine CPU, it only shares the stock sensor information such as ignition timing and of course is powered in the same way. As a matter of fact, there were only five wires from my first additional injector controller on my first system: positive, ground, tach input, and positive and ground to the new injector! Additionally, it is also a plus to be able to retard engine timing during low RPM and high boost conditions such as during driving up freeway inclines doing 65MPH. The stock CPU cannot monitor boost conditions and will not compensate for this because obviously it was designed to run the engine naturally aspirated!

-Another thing which is nice to control but requires extra hardware is decreasing the AFR closer to 11:1 in closed loop under partial hard throttle, say when you are only producing 3PSI of boost. Remember you need this extra fuel to cool the cylinder down in boost, so running at optimal fuel efficiency (14.7:1) is not desired. Doing this is a little more in depth in that you are modifying a signal going to the stock CPU, fooling it to do what you want my misleading it with altered, false information. Essentially, for example, the wire that tells the CPU what the pre-cat O2 AFR is is cut, one end is sent to your piggyback computer, is altered, and then the altered signal is sent to the other end of the stock wire you just cut. It really is not rocket science when you get down to it...

-Keep in mind these are things to consider if you buy a forced induction system that does not include fuel modifications, if you buy a system for an older vehicle, or are building some custom creation yourself from scratch. The newer systems for the new cars, while more expensive due to the completeness of the kit, usually are now including all the fuel modifications and piggyback computers already pre-programned. My supercharger system, which only addressed the increase in air pressure, was $2500, whereas complete systems are easily twice that. But the new systems are truly plug-n-play and don't require a supercharging for dummies book to set it up.

****Word of warning! Do not believe when people tell you that your stock fuel system can handle the extra fuel requirement of a forced induction system over stock! Optimally, your fuel system is designed for a maximum of 80% of capacity use. This is your safety/buffer zone and ensures the maximum health for your injectors and engine. By increasing the air into the system, or driving at very cold temperatures, fuel delivery needs are increased, and is why this buffer was designed into your vehicle from the factory. What you are doing in a boosted car with the stock fuel system is using that extra 20% and then the vehicle 'leans-out', fuel pressure decreases, AFR climbs, and your EGT spikes, and you burn holes in the pistons. This is a no-bullshit scenario. Side effects of this are also decrease in engine power and lower vehicle maximum speeds. Some people are disappointed by this and think that installing a smaller pulley on the supercharger to stuff even more air into the engine will fix things! On my vehicle, people claim to receive 30-40 extra HP by adding the additional fuel to the supercharged engine. Not bad seeing you only get 50 or so extra ponies over the supercharger by itself using the extra 20% of fuel trim available from the factory!

blownrunner

SUPERCHARGER INSTALL!

-I will not go too in-depth here except to recommend a pre-made kit from a reputable manufacturer. They did all the research for you on things you don't think about such as bracket material thickness to combat the stress the belt tensioner is applying to the supercharger.

-A turbo system uses wasted power going out the back of your car from the exhaust and seems to be the more desired route over the supercharged route due to that it puts parasitic drag on the motor, requiring engine torque to spin it instead of the tires. Keep in mind though that I heard complaints from the Nissan Z crowd how tight all that extra plumbing makes your engine bay and how bringing that extra exhaust gasses back into the engine compartment can melt under-hood wiring! A good location for a turbo is actually out by the rear end near the mufflers eliminating the turbo heat problem. You will lose a few pounds of boost over engine compartment mounting, so just get a turbo capable of putting out a few extra pounds of pressure over what you want. There are systems for Corvettes for example that go this route.

-If you can, install the largest intercooler you can in front of your radiator to reduce heat soak and cool the boosted incoming air. An intercooler is what can help you run insane boost pressures, compared to what I am limited to at about 10PSI at sea level. Doubt the legitimacy of this? I have heard of systems for the Ford Lightening that place an air conditioning evaporator between the supercharger and the intake manifold greatly decreasing the incoming air temperature and doubling the HP produced by the supercharger alone!

blownrunner

TUNING!

-This is the fun part, strapping your car to a chassis dynamometer, making a run while your buddies watch, looking over data, and then making adjustments and verifying your results. But hold on... street tune that thing first!

-Street tuning is done on the street, either by observing real time data by your buddy in the passenger seat from a laptop or your injector controller, and making adjustments as you drive. Or you can go all Formula One and install a data logging system to record your test drive which is viewed later.

-Start by observing your fuel trims at idle and driving around town at low speeds and mimic the long and short term fuel trims you observed without the forced induction system installed. You will tune from low RPM and low PSI (or even vacuum) to high PSI and high RPM. Continue to use the fuel trims to adjust the additional amount of fuel you need to add so that they mimic stock, or if you skipped this step, the combined long and short term trims should not be higher that about +10 when combined. What you are trying to achieve here is to put large un-precise adjustments with you injector controller and let the stock CPU add the fine adjustments to it. Essentially, when the fuel trims go positive, add a little more fuel to your map, when the go too negative, remove some. Once again, my supplemental system is a breeze to tune as I only change the amount of fuel I am adding. I do no decrease fuel delivery of the stock CPU fuel map.

-When you are in open loop mode of the stock CPU, or when you alter the AFR in closed loop, you will discard the fuel trim data and observe the AFR data. When tuning in open loop, remember that the stock CPU DOES NOT MONITOR THE AFR! It only injects a predetermined amount of fuel based on what was programed into it by the manufacturer. You will want to aim for about 11:1 AFR at WOT/max boost/open loop. Then make that trip to the dyno and decrease your tuning time and dyno use expense.

-The dyno is useful in two regards: You do not need to worry about driving at 150 MPH to tune open loop, and a dyno can tell you at what AFR you make maximum power at. You also can hook all sorts of sensors to it with wires from the dyno computer seeing you will be going no where (but very quickly). Now you and I can have exactly the same vehicle with the same drivetrain, same forced induction system, and have different tunes due to the tolerance differences of our vehicles. When you buy a million dollar aircraft or a $200k Ferrari, you a buying parts engineered and machined to very exacting tolerances. Aconoboxes, although far better engineered that cars even five years ago, still have a lot of variances in manufactured parts from spec. As long as it is a range close to optimum, it is acceptable. This is why the custom tune has the potential to make more performance/power over a generally tuned car.

-Whew, I'm done. Please post up some comments!

blownrunner

Before everyone jacks my thread with DAYCARE LEVEL HUMOR, I would like to post up some really good references if anyone is interested in furthering their knowledge depth in the theory, installation, and tuning areas of forced induction:

-BASIC TUNING & INSTALL:
http://www.GadgetOnline.com/U-Tune.pdf

SUPPLEMENTAL FUEL SYSTEM:
http://www.gadgetonline.com/urd%207t...%20install.pdf

TACOMA-BASED TUNING:
5VZ - URD 7th injector tuning - cell value questions - CustomTacos.com Forum
(The basic principles from tuning a 6 cylinder Toyota is the same as a carbed Camaro to a Formula-One open wheel race car)

While very old, this is where a Toyota 4Runner owner experimented for years on delivering the correct fuel, timing, and electrical requirements to a forced induction system that did not include the other 2/3 of the installation: the fuel and electric areas:
Gadget's 4Runner

This is one-stop shopping for performance goodies for Toyota vehicles, but many of the electronics are generic parts that are used on other vehicles as well:
- Underdog Racing Development

My supercharger reads "TRD" on it, but it is really manufactured by this company out of California. If are lucky to get a used supercharger, for instance, they have resources to get it back to 100%:
Manufacturer of Supercharger kits, remanufactured superchargers and supplier of supercharger oil.

Company that rebuilt my auto transmission. Sick of getting beat by the people with manual transmissions?:
IPT Performance Transmissions | Performance Parts | Torque Converters

Here is the tuning software I used. Most kits are pre-tuned with included tuning modules built into the kit. If they aren't or you want the ultimate in controllability:
R4 Engine Programming Software

Put this in your Christmas stocking:
Supercharged, V8-powered, NASCAR-inspired Toyota Tacoma destined for SEMA

Good Supplemental fuel system write-up. This is the same system I installed with the AFR calibrator and timing control:
http://www.speedysgarage.net/sportru...thinjector.htm

SLICKS

WoW well said.

mitzu

lots to read...my Tacoma was supercharged but with all the mods it only put down 250hp/260tq...but for a bolt on supercharger its pretty good. my truck is now turbo'd what does your 4runner put down