MindBomber

Great information on boosting an motor, whether it be any H, F series or any other.

HOW TO: Boost an Accord
Accord Turbo FAQ and HOW-TO guide: By Accord R33

Iv seen many times on this board and other accord boards the question “What do I need to turbo my accord?” or “Turbo vs. Engine swap”. I’m going to give you a fairly quick and dirty crash course on the basics of turbo charging and what you need to go about getting the job done.

======Table of Contents======

Section 1 - The basics of Turbo charging
- How turbocharging works
- How much power can I gain?
Section 2 - What do i need? and what does it do?
- Turbocharger
- Exhaust manifold
- Charge pipes
- Down pipe
- Oil/Coolant lines
- Wastegate
- Engine management
- Intercooler
- Blow off valve
.

Section 3 - Accord specific information
- Accord Information
- Installation guide
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The Basics
Lets take a look at what happens in a turbocharged engine.

Every internal combustion engine burns fuel mixed with outside air to create power. In theory, the more air you can put into the cylinder, the more fuel you can add, which in turn yields more power. A turbo charger compresses air and shoves as much as it can into the cylinders. This is referred to as “Boost”.

With any internal combustion engine, exhaust gasses flow out of the exhaust ports after each combustion cycle. As the engine approaches higher and higher RPMs, these gasses begin to flow very rapidly. The flowing exhaust gas is “Free Energy” if you will. In a naturally aspired (N/A) engine, this energy is virtually wasted and sent out the exhaust system.

A turbocharger has 2 sections. The exhaust turbine and the compressor turbine. The two turbines (or wheels) are connected via a straight rod. So when one spins, the other spins with it. (much like a standard wheel and axle assembly).

In a turbocharged engine, the exhaust gas’ energy is put to good use. The flowing exhaust gasses spin the turbo’s exhaust turbine; much like water does with a water wheel. The exhaust turbine spins the compressor turbine, the air compression begins, and the compressed air is pumped into the intake manifold.

One big disadvantage of using turbo is what is called “Turbo Lag”. Because a turbo uses the gasses from the exhaust to produce power, it has to wait until the exhaust pressure is high enough to spin the turbine at a decent speed. While the turbo is “waiting” for enough pressure from the exhaust, you have a good old stock engine. As soon as the turbo spools, or begins to spin, you get thrown back in your seat and you can enjoy the ride J

As the compressor turbine spins, it begins to suck in air from the atmosphere. This air begins to spin around with the turbine and because of the shape of the compressor housing, the air begins to compress. This compressed air is sent through the compressor outlet, through the charge pipes and intercooler (if applicable) and into the intake manifold. Now instead of having to suck air in, air is being “pushed” into the intake manifold. The new, more dense air is put into the cylinders as well as more fuel to compensate and you have just “Boosted”.

So how much power can you gain from turbo? The more PSI (Pounds per square inch) of air you can put into the cylinder, the more power you can get. Of course there are many things that factor into this. With air being pumped into the cylinders under pressure by the turbocharger, and then being further compressed by the piston, there is more danger of knock. Knocking happens because as you compress air, the temperature of the air increases. The temperature may increase enough to ignite the fuel before the spark plug fires. Cars with turbochargers often need to run on higher octane fuel to avoid knock. If the boost pressure is really high, the compression ratio of the engine may have to be reduced to avoid knocking.

So back to the question, How much power can you get? Lets do the math. A N/A car technically has 14.7 PSI of air being sucked in already! That is the normal atmospheric pressure at sea level. Of course the pressure is equalized in the engine so it is not really “Boost”. The average turbocharger produces about 8-9 lbs of boost. As engine management continues to become more advanced, more and more boost is being put into stock engines with no problem. We will use 8psi for our math. So now instead of 14.7 PSI of air you have 22.7.

14.7 + 8 = 22.7

In a perfect, frictionless world, this would be about a 54% increase of power!! (Ill use my F22a6 as an example) lets say I have 140 stock HP and I run 8lbs of boost.

54% of 140hp = 75.6 extra HP.
140 + 75.6 = apx. 215hp!!! Wow!

Ok, now that I got your hopes up, prepare to be shot down. Unfortunately we don’t live in a perfect frictionless world, so a turbo is not going to produce a 54% increase in power. Friction takes over and turbo efficiency declines. Because of turbo inefficiency you might only get 35 – 40 % power instead of 54%. We’ll take the best-case scenario (40%) and see what our horsepower is.

40% of 140 = 56 extra HP
140 + 56 = 196HP. Still not to shabby!

This number increases of course with higher horsepower engines like the H22 for example. lets see how much we can pull out of that bad boy with 8lbs

40% of 200hp = 80
200 + 80 = 280hp!! Watch out STi’s!!
And that is only 8lbs!

Now well take a look at each part and see what roll it plays in a turbo set up!
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The Turbo Charger

As we know, the turbo is the heart of the system…hence why they call it a “turbo” system. And we already know how it works so I wont go into that again. A common question however, is “what turbo is best for me to buy?” There is no one perfect answer, and there are a few ways to go about calculating exactly what size turbo would best suit your application but I don’t have enough knowledge in that area to advise you, so ill tell you about some of the common turbos used on Hondas and such. (There are a TON of other turbos you can use, but these are the ones most used. If you have any info on other size turbos please feel free to email me. And I will put the information In along with crediting you for the info.)

When buying a turbo don’t skimp out. You get what you pay for with turbos most of the time. You can get one at a Junkyard or buy one brand new. Obviously brand new would be your best bet, but only if you have $400+ dollars to spend. Many junkyard turbos (from Saab, Volvo, DSMs) ect. will work with low boost applications just fine. Just be sure to check the shaft play, both laterally and vertically before you buy. You want the shaft to move as LITTLE as possible in both directions.

T25/14b - Perhaps the most common turbo used on Honda applications is the T25/14b turbo. This turbo comes from the DSM eclipse/talon/laser. So what is the difference between the T25 and the 14b? Well not much really. The T25 was made by Garret and is used more on the 2nd generation eclipse. The 14b was produced by Mitsubishi and is used more on the 1st generation eclipse. Mechanically they are extremely similar. The only visible difference is the compressor outlet. The T25 has a normal round outlet you can attach a hose or pipe too. The 14b has (o O o) type flange on the compressor outlet you need to either get an adapter or just use the stock eclipse elbow. These turbos are good for around 12-15psi or so iv heard. The stock wastegate actuator is set to about 8PSI. the eclipse gets around 12 out of it due to the factory electronics. It is a pretty fast spooling turbo (begins to produce boost quickly) at around 2700-3000 RPMs. This turbo is water and oil cooled.



T3 – This turbo is also very common on Honda applications. It’s a tad bit bigger than a T25. This turbo comes off most Saabs, but there are a LOT of different trims** available with the T3. Here is a list of the available trims.

-T3 "40"
- T3 "45"
- T3 "50"
- T3 "60"
- T3 Super 60

The number in quotes Is the trim. The trim is the size of the intake and exhaust inlets and the compressor size. The bigger the trim the bigger the turbo, the more boost it can produce. Because of the many different sizes of the T3 I am not going to go into detail about how much boost each can produce, but they will all be sufficient for 90% of Honda turbo projects and are a great turbo to use.

IHI RHB – This is a cool little turbo. It comes off the Mazda MX-6 (and turbo probes as well??) It is one of the smallest turbos used in Honda applications (about 4” in diameter) which has both its advantages and disadvantages. Because of the small size of this turbo is is perfect for lower boost applications. (below 10psi). It has almost no turbo lag (spooling at 2000RPMs on some engines). However due to its smaller size, it begins to die out at higher RPMs. If you are looking for a fast spooling and easy to mount turbo. This is it! (The IHI RHB has many different trim sizes like the T3, however I could not find a list at this time).

T3/T4 – Hybrid turbos are an excellent way to increase boost levels (and often efficiency) on an engine, while decreasing turbo lag. The Garrett T3/T4 turbo hybrid is a very popular hybrid turbocharger for smaller displacement import engines. The Garrett T3/T4 turbo has a T3 turbine and a T4 turbo compressor. Many T3/T4 hybrids are made by several aftermarket turbo companies, and most can be custom designed. To select the proper hybrid, the proper T4 compressor must be chosen
- (information provided by www.turbocalculator.com)

Keep in mind this is only a handful of the dozens and dozens of different turbos available. Turbos can be found on cars, diesel trucks, 18 wheelers and more. Its up to you to decide which turbo you want to use.
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The Exhaust Manifold
This is where the setup starts to get tricky and a little pricey. Turbo manifolds for accords are extremely hard to come by (except H22 accords). You have a few options however.

1. -- You can buy a manifold from a complete turbo kit, such as a drag kit. That will run you close to $400. You wont have to worry about it not fitting though.
2. -- On the F22a, and H23a blocks. A stock DSM (eclipse, talon, laser) turbo manifold will match up to the ports! You will need to do a little enlarging and re-drilling of the mounting holes to get it to fit though. The easiest way to do this if you don’t have a drill press is bring it to a local machine shop with your stock F22a manifold gasket and let them do it. Probably wont cost to much.
3. -- DIY. That’s right, buy a few pipe elbows, a welder, and start designing your own manifold! The possibilities are endless. This is probably the cheapest method (if you already have a welder) and most efficient (if you know what you’re doing).
4. -- If you have a H22, there are a few companies who make them, and even a bunch on ebay. You should not have a problem finding one. Again, buying them pre-made will be a bit pricey.
The turbo manifold is important to the efficiency of the turbo set up. The better flowing the manifold is, the more efficient the turbo will be. If you can find and afford a stainless steel manifold that would probably be your best bet. Cast iron will work just fine as well but is more prone to corrosion.
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The Charge Pipes
A charge pipe is just a fancy way of saying “the tubes that connect everything”. Charge pipes connect the compressor outlet to the intercooler, and the intercooler to the throttle body. They can be made of almost any kind of tubing you can get your hands on. They should be able to with stand at least 25-30PSI of pressure without leaking. They should also be able to hold up to the extreme heat that is generated inside the engine bay as well. People use everything from radiator hoses to custom mandrel bent piping.

You should try and find tubing with at least a 2” diameter. You could probably get away with a little smaller if you had too. (many cars with stock turbos only have around 1.75” charge piping)

What you use to connect the charge pipes is very important. If you have the means to have them welded together this would probably your best bet (just keep in mind that they are stuck there forever when they are welded.) Another very good option is using silicone connectors and hose clamps. Usually these can withstand tremendous pressure. They are a bit pricey as well however. Whatever you decide to use, make sure its not going to break or leak as this can lead to the loss of boost.

The distance your charge pipes have to travel is very important to your set up. The shorter your charge pipes are the faster your turbo will spool creating less turbo lag. If you 100 bends and twists in your charge pipes it will take much longer for you to feel the boost. Carefully map out where your charge piping is going to go BEFORE you install your turbo

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The Downpipe
The downpipe is your turbo and engines main breathing artery. It connects to the exhaust housing of the turbo, down to the exhaust system. The bigger diameter and less bends the better. This part almost always has to be custom made. Find an exhaust shop near you and have them custom bend a downpipe for you. You will also need to have a custom adapter plate made so that you can bolt it up to the turbo. You could cut off the flange that’s on your stock downpipe and weld it to the new downpipe so it connects to your existing exhaust.

Some people use the stock downpipe that is made for the turbo. For example, the O2 housing of a stock DSM turbo can make a great start for a downpipe if your car has the room. I don’t know how this works on an accord, I don’t know of anyone who has actually used this successfully on an accord. It has been done on civics and whatnot however.

The rest of your exhaust is also very important to letting your engine breath. When using a turbo setup it is always a good idea to make your exhaust pipes bigger. 2.5” is a pretty good size for lower boost applications. Also if you are able to remove your catalytic converter, or get a high flow one that helps as well. This will help you create more boost and create it much faster.

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The oil and coolant lines
A turbo spins and creates friction just like your engine does. And just like your engine your turbo needs to be cooled down! Some turbos spin at up to 120,000 RPMS!! That’s more than 30 times faster than your engine spins. At those speeds some heavy duty friction is created and some heavy duty cooling system is needed. Some turbos are oil cooled, some are water cooled, and some are both oil and water-cooled.


***The following oil line information is provide by http://www.homemadeturbo.com a write up from a member by the name of shortyz. ***

Selecting a lubrication oil.

Her is what u need to do : first, get a feel for what the lubricant is supposed to do for your engine and what special requirements your situation imposes on the lube. These data will tell you what type of oil will best fit your needs. Second, consider the climate and operating conditions the lube must endure. This info tells you what viscosity and level of severity luve will best do the job. In general it is best to avoid wide range multiviscosity oils, as the materials added that create the multiviscosity capability are the same materials that cause coking. Thus 20w-50 is clearly better turbo oil thean 10w-50. a straight viscosity is best of all, with a ten point higher viscosity in summer. If it is possible to determine the detergent tating and antioxidizing rating, good turbo oil will be high in these two categories.

Now you know the type and grade of luve that is best your best choice. The one remaining factor is the brand to buy. This boils down to availability, price, and what your R&D efforts tell you is the true the lubricant for your engine. One can be relatively certain that an oil formulated for turbo use, and so advertised, will be an adequate lubricants.

Types of lubricants.
There are two choices here: synthetic based or mineral based lube.

Synthetic lubes are manufactured fluids in which the basic structure of the lube is much more rigidly controlled than in standard hydrocarbon oils. The resultant product is a very consistent stable fluid with uniform molecular structure whose properties are highly predictable. Synthetics have clearly demonstrated their capability with the respect to frictional losses, high temperature stability and basic toughness of the molecular structure. Mineral based lubes are less expensive and more likely to coke.

Water cooled bearing housings

The turbo bearing housing with a water jacket around the bearing chamber has virtually eliminated the problem of oil coking. The cooling capability of the water is such in that the oil seldom reaches the temperature at which it begins to break down. Of course all oil subject to high temp use breaks down slowly over time so the need for periodic oil changes still exists. The oil change interval thus becomes slightly less than with an atmospheric engine.

What is coking?

Coking is nothing more then than charred oil residue accumulating in the turbo bearing section to such an extent that the proper flow of oil to the bearings is eventually blocked. The seriously compromised oil flow will kill the turbo in no time. Four things gang up on the turbo to cause a coking problem.

-Oil with inadequate high temperature capability
-Oil with a wide multiviscosity range
-Extended oil changes
-Excessive heat in the bearings

Oil flow and pressure requirements


The turbo survives with surprisingly low oil pressure and flow. Is is virtually certain that all engines in production have enough excess oil pumping capacity to adequately take on the additional load of a turbo.

To much oil pressure can create problems with turbos. It is possible to force oil past the seals that are in perfect condition if oil pressure exceeds 65-70psi at the turbo. If your engine has these high of oil pressures a bypass or a restrictor (needle valve) can be used.

Problems of oil pressure over powering the seals are evident in a frequent smoking problem.. Anytime oil exceeds the 65-70psi and smoking arises put a needle valve or bypass in.


Oil coolers.

Don’t be hasty and just go buy these cause every other kid has one. Oil prefers to operate in a given temperature range that supplies the viscosity needs for protecting the engine, doesn’t overheat the oil in the high end and when cool doesn’t add more drag to the system then necessary. These requirements are all easily met by the right oil type and viscosity operating in the correct temperature ranges.

Mineral bases oils are not as tolerant of high temps as the synthetics oils. For street engines, both synthetic and mineral based oils have the same lower temperature requirement (150F min), but synthetic can operate about 40F higher (270F) therefore, you may need an oil cooler if you use mineral based oil and perhaps not if you use synthetic.

It need to be understood that oil temperature below the these minimum will degrade durability just as surely as exceeding the maximum. The installation of an oil temperature gauge will tell the whole story. Do that before installing an expensive oil cooler system. There are occasions when both oil and water temperatures are on the high side but neither is out of bounds. The best oil cooling system would be a system controlled by a thermostat that directs oil to the cooler when at a certain temperature.

Oil filters

The turbo creates no special filtering requirements.

Oil to and from the turbo

The plumbing that feeds oil to the turbo and drains is back to the engine is perhaps the weak link in the entire scheme of turboing. This is defiantly the place for a fifteen cent part to fail and have oil spewing all over the ground and wreck your entire motor. Don’t cheap on the feed and return lines, if you do you could pay in the long run.

The oil lines feeding the turbo must meet pressure and temperature requirements it will endure. Also make sure it is hydrocarbon proof because this can cause the line to deteriorate fast if not. The best lines to use is a stainless steel braided line with a Teflon center, this line is very tough and durable. Another thing to take into consideration is where u have ran your stainless feed line. DO NOT have it rubbing on anything because the line will eat right through whatever it is.

The drain line is often overlooked and cheeped out on, this line is very important as it is just as vital as the feed. If this line is not straight down towards the pan it will foam up and cause smoking in the turbo. Make sure the drain line is matched with the hole in the turbo. If the exit hole is ½ your hose should be ID of ½ . When drilling in the pan for the drain hose nipple, make sure this hole is above the oil line of your engine because it will cause backup bad if its not.

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The Wastegate

The wastegate is your best friend in a turbo set up. Its sole purpose in life is to prevent overboost and the destruction of your engine. When the wastegate senses a certain PSI of boost in the manifold, it promptly opens its flap to let the excess boost travel out the exhaust rather than spin the exhaust turbine. This slows down the turbine which makes it create less boost.
There are two types of wastegates you can use.

Internal wategate: These wastegates are built directly into the turbos exhaust housing. The internal wastegates have a “wastegate actuator” which is hooked up to the cars vacume system. When the waste gate senses the boost level it is set to, (e.g..DSM actuators are set to around 8PSI stock) it opens the gas release door and lets out the flowing exhaust gas before it can spin the turbine.

External wastegate: External wastegates do the exact same thing as internal wastegates except they are not part of the turbo it self. In most cases an external wastegate I purchases because the user wants more boost than what there stock actuator is set at. Most external wastegates are fully adjustable to any boost setting your engine can handle. They also read the vacume line for boost and open its chamber accordingly.

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Engine Management

This is, in my opinion, the most important part of your turbo setup. This is what determines if you engine goes kaboom or varoooom! There are so many options for so many different applications it can get extremely confusing trying to pick the engine management that is right for you. The following I s brief rundown of some of the more common options you have:

1. FMU (fuel management unit)
2. AFC “hack”
3. Standalone management

[disclaimer]

***THE FOLLWING INFORMATION WAS TAKEN FROM HTTP://WWW.HOMEMADETURBO.COM

ALL CEDIT GOES TO JASON, AKA "TURBOEF9" THE CREATOR OF TURBOEDIT***

[/disclaimer]

FMU (Fuel Management Unit)

These devices are also known as rising rate fuel pressure regulators. Thier function is increase fuel pressure as manifold pressure increases. This allows for more fuel to be pushed through the injector opening during the same pulse duration. How does this work as a management solution? As manifold pressure increases, so does the amount of air pushed into the combustion chambers, this air needs to be compensated with fuel, otherwise, a lean condition is created, and engine damage will occur. The ratio of fuel increase to air increase is normally dictated by an interchangeable "disc" or "plate" in the FMU. Others maintain a static ratio. These devices are normally used in conjunction with check valves. These are small, on way, air valves (available at Pet Shops that sell aquarium accessories) that are connected in-line with the vacuum line of your vehicles MAP sensor. Honda ECUs are not designed to "deal" with positive manifold pressure, so when the ECU sees this, it will throw a check engine light. The check valves are used to "bleed off" the positive pressure (several check valves may be needed depending on your maximum boost setting), and the FMU is used to compensate fuel. Stock injectors are normally used on these low boost, high fuel pressure setups. This setup is normally good for ~6psi.

AFC Hack

The AFC hack refers to a MAP sensor input scaling device (AFC) "hacking" the signal to your ECU and fooling it into thinking that it is not seeing positive manifold pressure. These are normally small electronic devices connected in-line with your ECU. Some more elaborate devices, such as A'pexi's V/S-AFC, SMC, and so forth, accomplish the same thing, but have the feature of being able to tune a specific percentage of "cut" at designated RPM increments. How does this work as a management solution? As positive manifold pressure builds, the MAP sensor sends a voltage signal to the ECU. This signal, if above ~3.1volts on a stock Honda MAP sensor, will cause the ECU to "shutdown" and go into limp mode, rendering your vehicle inoperable until it is turned off and restarted. The AFC intercepts this signal and scales it by a user-defined amount. This scaling allows positive manifold pressure to build while keeping the ECU happy. Fuel compensation for this setup is done by installing larger injectors. These higher flowing injectors allow more fuel to flow through during the same pulse duration to compensate for MAP signal scaling (which decreases fuel flow). No fuel pressure regulator is needed. No upgraded fuel pump should be required. This setup is normally god for ~10psi.

ECU Mod (Standalone)

ECU modification is quickly becoming one of the more widely used management solutions. This is due to the abundance of great, FREE, software applications out there. ECU modification beings with removing the chip (EEPROM) that contains the software program that runs your vehicle. In this chip, the key to your entire vehicle lies. Everything from Fuel and Ignition tables, Rev Limits, Launch Control, Boost Management and more can be edited or added to this program code! How does this work and a management solution? There are several different approaches to dealing with the positive manifold pressure situation. One has been to write code into the ECU program that acts as an AFC, scaling the MAP sensor voltage by a static percent. Another has been to rewrite the fuel and ignition routines of the ECU program to redirect to expanded maps in the ROM. All of these methods are functional and work well, telling the ECU how to deal with boost, rather than making it think it doesn't see it. Commercial or DIY, ECU modification in conjunction with larger injectors is a benefitial way to manage boost. These setups are good for the maximum manifold pressure read by your MAP sensor (stock Honda between ~9.5psi - ~10.5psi).

Below are some common questions associated with engine management on Hondas:

What size injectors can be used with the "AFC Hack"?
Injector sizing is key to the AFC hack working properly. This is not because of fuel compensation demands, really, it is more of "how far" you must scale based on your maximum boost setting. To elaborate: As positive manifold pressure builds the MAP sensor signal voltage sent to the ECU builds.

Once ~3.1volts is reached, the ECU shuts down, and goes into "limp mode", rendering the vehicle practially in driveable until it is turned off and restarted. The use of the AFC here is key because depending on how much scale the signal back by direct effects how much pressure is takes to bring the modified MAP sensor voltage up to what the ECU thinks is 3.1v.

How does this effect injector sizing?
If your injectors are not large enough, and your maximum boost setting is too high, you'll create a leaning condition or a check engine light.I have not seen a definative scale as to the corolation of injector size vs maximum boost. If anyone has and solid, proven information on this I would low to post it. Typically, 450cc injectors are used with the hack at 8-10psi reliably. Others have boasted 12psi on the hack without a check engine light.

I have heard using an AFC Advances your ignition timing, is this true?

Yes. This is very true. How when the AFC is not connected to your distributor? It all lies in the fundamental basis of how the AFC works. Visualize this, You have a grid of say 15 x 17. This is your OBD0 (10x20 for OBD1) ignition table. As we know, the AFC scales down the MAP sensor input to the ECU, thus, shrinking the resolution of the ignition map to fit more points in the same space. Now, if we look at what happends when we are in vacuum, this part of the table is squeezed into the left most half of the ignition map. If you have ever looked at an ignition table before, you'll notice that this is the most radically advanced section of the table!! This is how your AFC decreases fuel (same thing happends on the fuel table, and to increase, it scales everything to the right part of the table)!! To compensate for this advance in timing, some of used a BTM (Boost Timing Master), retarded their static ignition timing at the distributor, or even chipped thier ECU and modified the ignition table itself.

What settings should I use for X size injectors with X amount of boost?

This is one of the most misunderstood concepts about using the AFC hack. Lets examine each part to determine your correct settings. To begin, please read question 2-2 before continuing. Now that you understand a little bit about injector sizing with an AFC, we can talk about settings. If you decide to use something other than 450cc injectors, you may want to start with lower boost settings (at the wastegate) and build up from there, keeping the same fuel compensation settings in the AFC.

This will give you the upper limit for the current injector size.
As for obtaining those settings there are a couple of things to explain. Fuel flow rate difference.

This is the difference in flow based on the stock injector flow rate. For a Honda, 240cc injectors are stock. If you increase to 450cc injectors, your flow rate difference is a 46% increase. How do we figure that? Simple math: percent_of_difference = ((240 / new_injector_size) - 1) * 100
Second, an AFC does not control fuel injector pulse duration. This means we cannot compensate for injector latency in the fuel table for our larger injectors. Injector latency describes the scientific characteristic of how long it takes the injector to physically open. The larger the injector, the higher the latency. Since AFCs do not control the pulse duration directly, we compensate with a fixed percentage subtraction, otherwise, we would run lean in lower RPMs, even though our fuel flow rate has been adjusted based on the exact percent difference. The scale for common injector sizes used is 5% for 440-450cc, 4%, 390cc, 3% for 310cc.. then subtract 1 percent per 500 RPM increase. This will give us are starting point. For a boosted application, running stoichiometric is dangerous because of the high volume of air. To "play it safe", you want to run a bit on the stoich/rich side, so we increase fuel flow by 1% per 1000 rpms, trying not to top out a 5% overall increase. Why 5%? ..because your fuel maps are still increasing in pulse duration. So you're increasing pulse duration, and percentage
of flow rate at the same time. You'll get rich, very quickly. If you have VTEC, enrich by 1% more over VTEC VTEC crossover.
So, lets apply everything we've learned, and come up with base settings for 450cc injectors.

1) 240/450 = 0.53
2) 0.53 - 1 = -0.46
3) -0.46 * 100 = -46

So we have a 46% difference, we add our 5% for injector latency compensation, which leaves us with these settings:

1000 - 40%
1500 - 40%
2000 - 39%
3000 - 38%
4000 - 37%
--- VTEC set to 4400 RPMs ---
5000 - 35%
6000 - 34%
7000 - 34%
8000 - 34%

Application of these ideals will find your AFC Hack producing the smooth, safe, reliable power.

What is the maximum amount of boost I can run using the "AFC Hack"?

Due to the scaling of MAP sensor signal, and maximum read boost amount by the MAP sensor, ~10psi is obtainable. Some of boast numbers reaching ~12psi. Other limitations apply, please refer to 2-2 for more information.

Will the "AFC Hack" in conjunction with my X size injectors effect my idle?

Yes. However, if the proper settings are applied, and a reliable AFC is used, your idle should be smooth as stock. Refer to 2-4 for information on how to calculate settings.

How much boost can I run on these DIY stand alone systems?

Maximum boost is limited not by the tuning software, but by the MAP sensor currently in play. All applications that allow tuning of the fuel and timing maps, theoretically, can support larger 2 and a 3bar MAP sensors, but the degree of difficulty in tuning becomes the deciding factor. Some of the DIY management applications have 2 and 3bar MAP scaling features built in, some do not. Consult the individual application's site for futher information (refer to 3-1 for a list of applications).

What is datalogging, and what do I need in order to accomplish this?

Datalogging is the real-time capture of a vehicle's sensor information for later analysis. The use of datalogging to performance tune a vehicle, be it naturually aspirated or force inducted, has been a vital tool for many years. Several different commercial applications natively allow for the collection of this data. Hondata, Motec and Zdyne (I believe) to name a few, have this feature. Support for datalogging is currently available is a few of the DIY Engine Management solutions available for download.
ECUControl, TurboEDIT, Uberdata (Coming soon), and ZControl all support datalogging at different stages for thier respective ECU Generations. All, however, use virtuall the same setup to accomplish this.
A TTL to RS232 converter board is nessisary to convert the ECUs stock communications protocol into a standard protocol that our PCs (and laptops) can utilize. A link to the MAX233A (the morepopular unit, available for $23) is in the Misc Links section of this documents. Simple soldering skills are required to assemble the unit (clear, color instructions are included) and pinout instructions for Honda ECUs are available on the ECUControl website under "How to mod my ECU" ( http://www.ECUControl.com ).

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The Intercooler
Intercoolers
When air is compressed, it heats up; and when air heats up, it expands. So some of the pressure increase from a turbocharger is the result of heating the air before it goes into the engine. In order to increase the power of the engine, the goal is to get more air molecules into the cylinder, not necessarily more air pressure.

An intercooler or charge air cooler is an additional component that looks something like a radiator, except air passes through the inside as well as the outside of the intercooler. The intake air passes through sealed passageways inside the cooler, while cooler air from outside is blown across fins by the engine cooling fan.

The intercooler further increases the power of the engine by cooling the pressurized air coming out of the compressor before it goes into the engine. This means that if the turbocharger is operating at a boost of 7 psi, the intercooled system will put in 7 psi of cooler air, which is denser and contains more air molecules than warmer air.

There are many different types of intercooler styles available, here are a few “Air to Air” intercoolers:

1. Side mount intercooler (SMIC)
2. Front mount Intercooler (FMIC)
3. Top mount Intercooler (TMIC)

In my opinion the front mount intercooler is the most efficient way to cool air. This is because more, cooler, outside air is able to travel across the fins and cool the charge air down.

The side mount intercooler acts more like a heat sink than anything, they work well for what they are made for, but just don’t have the same efficiency

Intercoolers can be found on most any stock turbo charged vehicle. They vary in shapes, sizes, efficiency and price. There are many intercoolers you can find at a junk yard for much less than the overpriced Sparcoo or Greddy intercooler kits which go for upwards of $1000+. Some of the more common “Junkyard” intercoolers that are used on Honda applications are the starion/conquest Front Mount intercoolers (FMIC) (perhaps the most popular) and DSM side mount intercoolers (SMIC).

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The Blow off valve
The Blow off valve (BOV) is the coolest part of a turbo setup. This is the part that lets that oh so addicting “Pssssssssshhhh” sound when you drive by you non turbo looser friends. BOVs are not just to gain style points however. They do have there purposes.

Lets again think about what happens when your driving a turbo car. You have your foot on the gas, the exhaust gas is flowing, its spinning your exhaust turbine which in turn spins you compressor turbine, compressing the air sending it through the intercooler to cool down and shoves it into your intake manifold! That’s a lot of pressure going into the intake manifold, which is no problem when your foot is on the gas. But what happens when you take your foot off the gas? You intake manifold closes up and doesn’t let any air in! At the same time your turbo is spinning at an incredible 120,000 RPMs, lets just say it doesn’t stop dead in its tracks just because you let your foot off the gas. The turbo continues to spin and continues to produce boost. Now the boost has no where to go because the intake manifold door is closed. Eventually the boost backs down the cold charge pipe (turbo to intake) back to the turbo. This air tries to spin the turbine the other way! That’s no good for your turbo, it will break in no time. This is where the BOV comes in. Just like the wastegate it is connected to the cars vacuum system. When the BOV senses vacume instead of boost, it knows the intake manifold door is closed and it opens up its valve letting out the excess pressure.

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Accord Specific information

Boosting an accord is not much different than any other engine. A few of the things that make it slightly more difficult is the turbo manifold. The DSM manifold will not let you keep your AC on the F22. The AC system will have to be removed.

With the DSM manifold you will also have to take out your front motor mount (F22) in order to have enough room for the compressor. This can be done, however it is suggested that you strengthen the remaining mounts with polyurethane.

The ECU on the F and H series engine is a mystery. No one really understands how it reads the fuel and ignition maps yet. This makes running standalone on a stock accord ECU close to impossible at the time being. HOWEVER you can use any OBD1 (On board diagnostics) Civic or Integra ECUs. The P06 ECU is the ideal choice for non-VTEC engines, and the p28 is ideal for engines with VTEC.

For more information on ECU chipping please visit www.pgmfi.org

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I am not the author of this information, the original posts can be found here: http://board.accordtuner.com/showthr...boost%20accord

K20Z3

This should be stickied cause these questions get asked like at least 5 times a day.

BlueEM2

iTrader: (1)

Just another awesome informative thread that noobs will never read Great writeup

MelJ

Lol. So true. This is very informative , and we just went over this stuff in fuels class, so reading it on here just refreshed my memory . I hope others actually read this because it needs to be. Vote for a sticky.

sdaidoji

iTrader: (1)

lastly, the most famous of all - sticky this to the top!

wade623

just saying but this didnt mention anything about air/water intercoolers

ShinyCoupe

Note: Noob reading thread

Great info. thanks

sdaidoji

iTrader: (1)

good point.
Want to add the info? We would be happy if you do

RamboAK47

Note: Nooblet #2 has arrived