Turbocharger Information Thread
The information contained in this thread is intended for off road use only.
Choosing your compressor
Before you start peeking through the Garrett catalog or play Add to Cart with a multi-thousand dollar turbokit, you should know what you're buying and how it's going to work. Moreover, you should know whether or not it'll mesh with what your plans are.
First things first: Kill the ricer within you now.
Everyone wants a strong motor, but a bigger turbocharger is NOT necessarily better unless you know how to select it.
We will use high-school algebra to figure this all out, so grab a beer and start reading.
First, let's look at a compressor map from something smaller, such as a Garrett T04E-40 trim.
In case you want to follow along with a different compressor, here are a bunch more maps to play with on this website:
I can already see some of you squirming behind your monitors. Relax. If you had the mental capacity to beat Super Mario World, you can nail this.
Before we start, take a good look at the graph. The island shape in the center is the region of values that this compressor is capable of creating. We'll learn how to find out where we are on this map, given a certain set of conditions that most of us usually see while driving. From this map, you'll be able to figure out the minimum RPM a compressor can support, the maximum RPM it can sustain a certain pressure, how much horsepower you're going to make and how hot the intake air is going to get, both before and after the intercooler. These bits of information are enough to know what parts you'll need and how fast you're going to go.
I'll break down the compressor map into four sections:
* Compressor Efficiencies: These are the concentric "islands" within each other on the map. The more to the center of the map you go, the higher the compressor efficiency. Efficiency means the compressor heats the incoming air less. Compressor maps will usually give a general value for each efficiency island, such as "65%" and so on.
* Compressor Wheel Speed lines. These lines run across the map and give you an idea of how fast the compressor is spinning when you are in a certain efficiency zone. Measurement is in RPM, so yes - 98,000 is really an RPM value. Most compressors spin at least 10 times as fast as your vehicle's crankshaft. Start thinking about using Synthetic Oil.
* Surge and Choke Zones. (No-Man's Land). Outside of the map, the left side represents the surge region. Surge means your engine is not producing enough airflow to operate the compressor at a certain pressure ratio. The right side is the Choke Zone, or overspeed area. This is where the compressor will spin well beyond its designed maximum speed, but never create the pressure you're looking for. In short, these are bad regions. You do not want to be there. If you find yourself outside the map, find another compressor. That's the core of this whole article.
* X and Y Axis. These axes represent Airflow (in CFM, lb/min or CMS - Cubic Meters per Second) on the X-Axis and Pressure Ratio on the Y-axis.
Pressure ratio is simply the ratio of what boost you're planning on running, with respect to the current atmospheric pressure. At sea level, that pressure is 14.7psi. At higher altitudes, it goes down. If someone is running 1 bar of boost at E-town in Jersey, they're running about 14.7psi. If they start drag racing in Denver, 1 bar of boost is 12.2psi. However, both of them are running a Pressure Ratio of 2.0. I'll explain this shortly.
Airflow is a measurement that's easy to understand. It can be measured by volume or by weight. You can have air at normal, sea level pressure, which can be measured by how much fits in a single cubic foot. Alternately, you can measure air by how many pounds pass through a certain region per minute. Compressor maps can use both of these values, depending on the map. It is important for us to know what altitude the compressor is working at, because air is thinner and lighter at higher altitudes and our values will change.
Engines create vacuum when they run, even if they have a turbocharger bolted on. When you boost, the 15psi you see on your boost gauge doesn't mean your turbocharger created 15psi worth of work. In reality, most stock engines will pull in the ballpark of 20 inches of vacuum at idle. That means your turbocharger has to compress the vacuum to zero, then keep working until the positive 15psi registers on your gauge. Mathematically speaking, the compressor has put nearly 30psi-worth of work into that airflow. This is known as "Absolute Pressure." Absolute Pressure is like driving 10 miles south of your house, then turning around and driving 20 miles north. You may only be 10 miles north of your house when you're done, but your car drove 30 miles to do it. Absolute Pressure is heavily affected by atmospheric pressure. We must determine how hard the turbocharger has to work, so let's take altitude into account by using the Pressure Ratio:
Determining the Pressure Ratio for 15psi of boost at sea level [0 ft] looks like this:
Pressure Ratio = (Target Psi + Atmospheric Psi) / (atmospheric psi)
Pressure Ratio = (15 + 14.7) / 14.7 = 29.7 / 14.7 = 2.02
Had you been in Denver, you would've replaced all the "14.7's" with "12.2's". If you still want to run 15psi in Denver, things change considerably. You can see the turbocharger runs a higher pressure ratio (2.23) to run the same boost you did in E-town where your pressure ratio is 2.02. That means it's spinning faster to compress thinner air to the same pressure. What happens when something spins faster in an engine? You create more heat. Anyway, back to New Jersey.
Draw a horizontal line across the map, starting at the "2" on the compressor map. You can see it cuts pretty nicely right through the middle of the map. That's good.
On the X-axis (bottom scale), we must convert the Lb/Min airflow value (or Cubic Meters per Second, depending on the map) to Cubic Feet per Minute to work with our equations.
To convert Pounds per Minute or Cubic Meters per Second into CFM, you need to take the air temperature into consideration, since the ideal gas law tells us that the hotter a gas gets, the more it expands and the less it weighs per cubic foot. It's the same thing as watching how much cash your wallet holds during the holiday shopping season.
The typical compressor map assumes an 85 degree outside air temperature. Most maps also show the temperature formula on the bottom of the map, if you decide to fiddle with making your numbers absolutely exact.
SCIENCE: One Cubic Foot of air at 85 degrees weighs 0.07282 lbs.
Therefore, convert lbs per minute to CFM by multiplying by the lb/min value by 13.73.
SCIENCE: One Cubic Meter per Second = 2118.64 Cubic Feet per Minute, assuming above temperature.
Therefore, convert CMS to CFM by multiplying any CMS values on the X-axis by 2118.64
Now look at that line you drew on the map. The entry and exit points on this map correspond to 15lbs per minute and 35 lbs per minute of flow. Just look down at the X-axis to see what I mean. Multiply those two by 13.73 and you get 205 CFM and 480 CFM. That means if you want to make 15psi with this compressor at sea level, you will need airflow between 205 and 480cfm to do it. As you rev a motor, you increase the CFM of exhaust it spits out. So, in essence what you're learning now is "where does the turbo spool up and where does it start falling off boost at higher RPM's?"
Let's figure out a few things. An engine is basically a fancy air pump.
First, how big is the pump? (Displacement)
Second, how fast is it spinning? (RPM) Pick an RPM to find out what's going on at that speed.
Now plug that RPM into this equation:
CFM for 4 stroke = ((Displacement in Cubic Inches) / 3456) x RPM x VE
So for my 3S-GTE engine, my stock displacement is 1998cc's, or 121.9 cubic inches. At 6000 rpm, it flows:
CFM = (121.9 / 3456) x 6000 x VE = 211.6 CFM x VE (Cubic inches= Litres*61.02)
VE is volumetric efficiency, which is a percentage measurement of how much air ACTUALLY makes it into the cylinders on each stroke, compared to how much can THEORETICALLY make it. It's almost always less than 100% unless you've got serious mods or lots of money in headwork. For now, assume your average near-stock engine at 6000rpm has a 90% VE.
CFM = 211.6 x 0.9 = 190.5 CFM
Now, we already know we need 205 CFM for that turbo to make the boost we want. The good thing is, you've just calculated how much air the motor would move if it were a naturally aspirated motor.
Now you need to figure out how much it'll do under boost. That requires something called Density Ratio.
To calculate Density Ratio, we use our Pressure Ratio and figure out how much the compressor's going to heat the air up.
The equation is:
Temp Out (in F) = (((Temp In (in F) + 460) x (Pressure Ratio ^ 0.283)) - 460)
So 15psi of boost at sea level, on an 85 degree day looks like this:
Temp Out = (85 + 460) x (2.02)^0.283 - 460 = 205 degrees F
This assumes a 100% efficient compressor... which is ideal but not realistic. Take a SWAG (Scientific Wild Ass Guess) as to compressor efficiency by averaging the values of the map. On this map, 70% looks like a decent neighborhood to start with, so let's use it.
That makes our compressor's outlet temperature:
Actual Temp Change= (Ideal Temp Change) / Efficiency
For our example, the Ideal Temp Change is 205F - 85F or 120F:
Actual Temp Change = 120F / 0.70 = 171F
So the compressor is going to heat the air 171 degrees above the outside air temperature. Add 171 to 85 degrees and we get 256 degrees coming out of that turbo, going toward your engine. This is where an intercooler comes into play. Speaking of which, what happens when that air hits the IC?
First the temperature drops a bunch and second, the pressure drops a little. Your average pressure drop for a smaller high quality side mount IC is around 0.5psi. For a larger front mount it could be over 1psi. For the IC, we will assume a 65% efficiency, which is reasonable for a decent sidemount. For a larger front mount, you could assume perhaps 70 to 85%. If you're using water spray or fancy nitrous foggers on the IC's surface, you could increase efficiency up to 100%, maybe even more. The main factor is airflow. If your front mount is mostly blocked by the bumper and isn't properly ducted, it isn't going to work. If you're driving a car that looks like it has a metal mouth and none of the IC is blocked, it's going to work a hell of a lot better.
To determine efficiency, you can measure the temperature at the compressor's outlet and at the throttlebody inlet. If the compressor heats up the air 150 degrees above ambient, but the intercooler takes all the added heat away and drops it back to the same 85F temperature as outside, then you have a 100% efficient intercooler. In the end, you can usually ballpark your figure by assuming 65% for the average sidemount and 80% for the average front mount.
The formula looks like this:
T IC drop = (T IC in - T ambient) x IC efficiency
T IC drop = (256 - 85) x 0.65 = 111F
That means the IC drops the turbo's outlet temp by 111 degrees. That transforms our 256 degree temp into 145 degrees and drops the pressure from 15psi to 14.5. Don't forget the pressure drop. Pressure ALWAYS goes down when temperature goes down, all other things being equal.
So what does this do for our "normally aspirated engine"? Well, density of the air is increased by a certain ratio:
Density Ratio = ((Temp In + 460) / (Temp Out + 460)) x (Pressure Out) / (Pressure In)
Where "Pressure Out" is your Pressure after the IC, plus the Atmospheric pressure
And "Pressure In" is simply the Atmospheric pressure.
For example, we get:
Density Ratio = ((85+460)/(145+460)) * ((14.5+14.7)/(14.7)) = 1.79
That means you're packing 1.79 times the DENSITY of normal atmospheric air into the engine with this compressor and IC combo as you would if the engine were operating without any forced induction. Add the appropriate amount of fuel and you're off to make more power.
Go back to the original 190.5 CFM value we got. Multiply that number by our density ratio of 1.79 and now we have 341 CFM (or 24.8 lbs per minute). Look at the compressor map and you'll see that 24.8 lbs @ 2.02 lands you right in the middle of the "island" to make the boost we want. Now you know you're making 24.8 lb/min of airflow at 6000rpm at sea level on an 85 degree day, with 15psi of boost (pressure ratio of 2.02). Excellent!
If instead your calculations landed you outside the compressor's islands, you simply wouldn't be getting 15psi out of the compressor at that rpm. At lower RPM's, surging the turbocharger would sound like pops and backfires coming out the intake. At higher RPM's scale, boost would fall away as you kept revving the motor and the compressor would overspeed.
This is exactly what happens when smaller turbos tend to lose boost at higher rpm's.
The 341 CFM value falls within the highest efficiency range (dead center island) on the map, so that means the actual temperature at the throttlebody will be a little lower than we'd calculated and our density ratio a tad higher. It's close enough to give us a good idea of what we're working with. If you REALLY wanted accuracy, you could go back and redo the calculations with the new efficiency you've deduced, to get a more accurate CFM value. You'll find the values can change upwards of 5%.
Now the fun stuff: Approximating Horsepower Output
The basic crank HP formula is:
Crank HP = Manifold Air Pressure (in absolute psi) x Compression ratio x (CFM / 228.6)
The compression ratio for a Gen II 3S-GTE such as mine is 8.8, so we plug in the real numbers into our HP formula and get:
Crank HP = 29.2 x 8.8 x (341/228.6) = 383 HP
Toss in a rough 20% drivetrain loss and you'll have 306whp at 6000RPM.
Remember one thing. The Basic Crank HP formula is exactly that: Basic. It doesn't take into account all the frictional losses from oil, spinning engine accessories, octane limitations or piston friction. It has no idea what Base Specific Fuel Consumption is or how awesome your race-prepped head flows. It's simply a one-size fits-all equation. Because of that, it's reasonable to take away another 5% and claim it as "frictional losses" from the reasons above.
Frictional Losses = 5%, Therefore:
306whp x 0.95 = 290whp.
Given my exposure to this compressor's real-life results, not too far from what I've seen on built motors with good tuning.
Volumetric Efficiency isn't a static number. It's constantly changing as you rev a motor and modify it. Because the turbine and wheel will affect the volumetric efficiency's behavior, it will also put a limit on overall HP output. For example, my stock CT-26 turbine and its housing are so restrictive that it easily drops the engine's VE well below 90% at the 6000RPM we looked at. The compressor is capable of plenty of power, but the rest of the plumbing is not. A stock MR2 turbine housing mated to this 40 trim wheel would create a maximum of 260-270whp. That's close to 30 horses shy of what we'd calculated. Big difference, eh?
Turbine sizing and A/R really DO make that much of a difference. On a T3/T4 turbo using the same compressor wheel but a larger turbine outlet, you could be closer to 290whp at 15psi. Realistically, 290whp (based on the additional 5% frictional loss) is a reasonable expectation. Anytime energy is transferred, you're going to lose energy in friction, so don't get disappointed if your compressor needs you to pull out the stops and run racegas to get you where you calculated it could.
One other thing we should check now that we have the numbers, is whether the compressor will be forced into the surge line. Surge is caused when the engine cannot ingest enough air to keep the compressor inside its map and the symptoms we listed above, will happen. Surge KILLS your turbocharger's bearings, so it's something we want to prevent. We saw that at a 2.02 pressure ratio, the surge line is around 15 lbs per minute, or 205 CFM.
Let's mathematically rearrange the CFM equation with respect to RPM, to find out exactly how low on the tach we can make 15psi before we start backfiring out the intake and ruining our turbocharger. Let's use a higher VE of 95% due to the lower RPM range we're operating in:
CFM for 4 stroke = ((Displacement in Cubic Inches) / 3456) x RPM x VE
Remember to first divide your CFM value by your density ratio of 1.79, then plug it into:
RPM = ((3456) x (CFM)) / ((Displacement) x (VE))
RPM = ((3456) x (114.52)) / ((121.9) x (0.95))
If you did your calculations right, you'll end up with 3417 RPM.
Now you know this compressor won't make 15psi below 3417 RPM. The VE might be better than we assume, but don't play around when you're that close. Basically, compressor supports 15psi @ 3500rpm and that's it. 3500rpm is your surge limit and you can easily plug in your CFM value for the other end of the map and find out at what RPM it begins to choke. (Hint: it's 8002 RPM).
Now let's translate what we have learned into English. This is a compressor that will give you 15psi from 3500 to 8000rpm, on a 2.0L engine with a decent ebay intercooler, on a hot summer day, at sea level. Peak charge efficiency (the "center island" in the map), will occur in the ballpark of 5000 to 6500 RPM. This is a hot street turbocharger. It can hit 15psi just after 3500rpm, carry power past 6500, and wheeze out over 8k. This is the type of turbocharger that loves on-ramps, twisty mountain roads and autocross, because it supports a mid to upper range RPM band, yet gives you enough breathing room if you need to stay in gear a little longer for that slalom. For a drag racing application, you would want a turbocharger that is in peak efficiency closer to redline, with the widest possible efficiency island to support your rev range and with headroom for more boost at higher RPM's.
You can control spool on most turbochargers through the turbine housing's size, or "A/R." A smaller A/R would focus the exhaust energy more onto the turbine blades, encouraging faster spool at the expense of becoming a restriction at higher RPM's and pressure ratios. The larger A/R delays spool and allows exhaust to flow with less restriction and thus improve VE at higher RPM's. Another option is a turbocharger with an Anti-Surge compressor housing like a GT30R. This housing actually extends the compressor surge line more to the left, allowing more stable pressure at lower airflow numbers and helping make the compressor's behavior more flexible on response-based applications.
Now it's time for questions. Are these numbers what i want? Do I want more power? Do I want to have more power at a different rpm? Do I like where the surge line is? Is this amount of boost pressure okay or can I run more? Will my car always be at sea level or am I moving to Denver in a month? Can I actually enjoy this turbo or will i have to rev the piss out of it just to get the car moving?"
Now you can tailor your turbo to fit your needs.
AR is the rated volumetric efficiency of a turbos 2 sections, so to speak. imagine if you have a garden hose spraying water out, at a pinwheel......................
with the hose open ended the pinwheel spins okay......
but put a nozzle on it an the pinwheel will spin like mad................
but there is issues, with the nozzle on the end, you lose volume but gain pressure. with the nozzle off you gain volume but lack pressure and cant turn the pinwheel as much..............
real simple, on small displacement motors, a smaller AR is nicer, on larger obviously larger due to exhaust volume.
a larger AR will spool later and provide a higher power band, if you motor is capable of reaching the RPMS it should be used in.
How to decipher Garrett/Precision model codes
I still see alot of people confused on the Garrett GT model #'s and especially the Precision models #'s that use the GT series parts. Im going to try and explain the part #âs so everyone can understand whats going on inside the turbos that we use here on H-T on a daily basis. I am going to start with the Garrett GT series and then explain the Precision SC/PT/GT line up.
The basic GT model code format is: GTaabbcccc
The first two positions are always GT.
Position "aa" tells you the turbine family and bearing system(does not mean ball-bearing) that the turbo uses. Position "aa" is considered the base model # and is often used as a shorthand name for the turbo.
Position "bb" tells you the compressor wheel family the turbo uses.
Position "cccc" is used to tell you special features of a specific turbocharger. Not all four positions are always used. Here are a few of the codes used(the only ones we really deal with):
L- Watercooled center housing
R- Ball bearing
S- Internally wastegated
After the model code you can list specific wheel trims of the wheel family's and designate the housings.
Here is an example of how these codes are used and often mixed up:
"GT35R"- this is a base part # in short hand. There are many variables of this turbo.
The "GT3540R" is most often the turbo that the "GT35Râ short hand part # refers too. To designate the exact specs on this turbo you would specify the family and trim and call it a "GT3540R 56 trim"
Another variable of this turbo would be a "GT3540." Notice there is no "R," this means it is not ball bearing.
It is a good idea to designate the specs for the wheel that you are refering too in the part #. An example is a "GT3540 56 trim" and "GT3540 54 trim" This lets you know exactly what wheel from the GT40 family the turbo is using. The 56 trim GT40 wheel uses a 82mm exducer while the 54 trim GT40 wheel uses an 88mm exducer. If there are two wheels in the same family with the same trim you should then clarify the exducer spec.
Another variable of this turbo is the "GT3040R" Notice the change in the "aa" part of the code. This tells you the turbo is using the GT30 family turbine wheel/bearing system. In short hand this turbo would be referred to as a GT30R. (Alot of people will like to call it a GT35R and then say it has the GT30 turbine side. That is not correct. What they are trying to do when they refer to it in that way is to tell you that it is using the GT40 compressor wheel that comes in the "GT35R.â
Are you guys starting to see why there are so many misconceptions and false information going around about these turbos?
It gets even more confusing when you start mix and matching these GT wheels with T/E/B series wheels, E/S compressor housings, and 5 bolt turbine housings.. This is what happens when Precision comes into the picture.
Precision manufactures Garrett performance turbos. This means they use Garrett wheels and CHRAâs and make their own custom housings, upgrade the bearing systems, and provide their own full custom line up of turbos with their own nomenclature. By now most of us have already memorized the Precision naming system(or lack of naming system, its very confusing) for the SC line up of turbos. Now we need to learn the GT line up of precision turbos and how they name them when they mix and match them with GT parts.
The format I use for Precision turbos is: XXYY
Below are the codes used in the "XX" spot.
SC- (stands for Sport Compact) These are T3/T4 hybrid turbos that use standard T series bearing systems.
PT- (stands for Precision Turbo. duh.) These are strait T4 turbos that use standard T series beaing systems.
GT- These turbos use Garrett GT turbine wheels/bearing systems and they can be T3/T4âs or strait T4âs.
(Sometimes the SC line up and PT line up cross paths, like when you put an SC61 in a T4 turbine housing it now becomes a PT61. Easy enough to understand.)
The "YY" spot is used to tell what compressor wheel the turbo is using.
When refering to the T family of compressor wheels the "YY" code tells you the size of the inducer on the compressor wheel.
Exampleâs: âPT67" and âPT70â- The PT67 has a compressor wheel with a 67mm inducer and the PT70 has a compressor wheel with a 70mm inducer.
To determine the turbine wheel being used you must specify this after stating the turbos name along with the compressor housing and turbine housing A/R you want as well. A âPT67 w/ T350 76 trim w/ .70ar compressor housing and .68A/R turbine housingâ is an example of doing this.
When refering to E family compressor wheels the âYYâ code tells you the trim of the wheel. The only wheel that directly represents itâs trim # is the 50 trim found in the SC50. The other wheel trimâs have desginated #âs that represent the trim #. For example, an SC34, uses a 57 trim E family compressor wheel and an SC32 uses a 54 trim E family compressor wheel. (Why they use those #âs to represent the trim I have no idea and as far as I can tell it is not a predictable system and you must memorize it.) All E family compressor wheels are mated with T31 turbine wheels.
When refering to B family compressor wheels,(well we actually only use one of them) the âYYâ code tells you the compressor wheel its using and also the turbine wheel. The only B family wheel we use is the 60-1 compressor wheel and it is found in the SC52,53,54, and 60. Each of these turbos uses a different turbine wheel and precision assigns each one of these #âs to represent a different turbine wheel while the compressor wheel stays the same for all of these turbos. For example an SC60 uses a 60-1 compressor wheel with a T31 turbine wheel and an SC52 uses the same 60-1 compressor wheel but with a T350 76 trim turbine wheel. With these #âs you do not have to state the turbine wheel being used but you do need to state the housings.
Now lets mix them up with GT series parts and get confused.
When Precision uses standard T series bearing systems with T series turbine wheels the SC/PT part # coding is used. When they put a GT series compressor wheel in a turbo and still use a standard T series turbine wheel/bearing system they go by the code for the T series parts. In the T series coding the âYYâ spot is designated for specifying the compressor wheel inducer. An example of this type of turbo is the âSC61.â The âSC61â has a T series turbine wheel/bearing system and uses the GT40 56 trim compressor wheel that has a 61mm inducer. (As far as I know the GT40 56 trim is the only official GT wheel that precision is mating with standard T series turbine sides and bearing systems. The 67mm 63 trim compressor wheel found in the PT67 is not officially a GT family wheel, although it was designed around the same time, it is designated a Garrett Performance wheel and was originally designed for use by HKS in the T04R.)
When they switch over to GT series turbine wheels and bearing systems is when they switch over to the GT series part # code.
The GT series code for Precision is:
The first two positions tell you its a GT series turbo.
The âaaâ positions tell you which turbine wheel family and bearing system it is using.
The âZâ position tells you which compressor housing it comes with. (I think they specify this because the Garrett GT stuff all comes with âSâ compressor housing standard while the Precision stuff comes standard with âEâ compressor housing standard. âSâ housings are available as an option.)
To specify Ball Bearing just add BB after the short hand part code.
Precision leaves their names in shorthand and does not specify which compressor wheel is being mated with the âGTaaâ turbine/bearing set up. It is assumed in most cases, like in the case of the GT35e. The GT35e turbo comes with the GT40 56 trim compressor wheel(this is also used in the SC61 and has a 61mm inducer.) I have seen Precision etch GT3561e into these turbos so I like to refer to it in that way so that there is no confusion.
Precision offers the 5 bolt (TA31) turbine housing standard with the âGTâ line up but the 4 bolt is an option. Ball Bearing is also an option that you can upgrade too. (you do get the GT ball bearing system if you order a GT series turbo. remember it comes w/ a GT bearing system. However if you order an SC61 ball bearing w/ out the GT turbine side you will get a standard T series ball bearing set up.)
Hope that clears up some confusion and doesn't add too much more. There are alot of #'s and symbols so its takes some time of seeing it over and over again before it soaks in. I left out alot but I tried to put everything in their that I felt was pertenant to the turbos we actually use in the honda
Choosing your Manifold
As you progress through the different manifolds, each of them have their benefits and their downfalls. Picking the correct manifold is based on your individual needs for your setup...just because its "cool" to have a topmount, does not mean you "need" one on your stock block build.
-The cheapest of all the manifolds. Log manifolds can easily be made to allow AC and power steering. A log manifold will spool up a turbo rather fast because of its short runner length, but due to it being less than ideal for high volume flow, top end power on a log can be greatly restricted. Logs such as the Inline Pro have a rather good design and ARE able to flow quite well at higher RPMs. A log will work perfectly fine for most street setups...especially stock block
-Built with a 4-1 collector, mini rams flow better than a log and are still fairly compact and inexpensive. These manifolds are a good mix of short runner design (quick spool) and better flow at higher RPM. This is what i run on the street...i would recommend it for most people who DD their cars, but want better overall flow than a regular log manifold.
- More equal length than the last two. Ramhorn manifolds have longer runners; therefore, taking longer to spool, but runners are closer to being equal length (better top end flow). Since these manifolds are bottom mounts, it is more difficult to fit a large diameter downpipe or easily manipulate the turbo.
-The blingest of all manifolds apparently. A topmount is generally very close to, if not completely equal lenght meaning all runners are the same. This is important because of the cylinder exhaust pulses. Rather than overlapping in a non-eq manifold, in an equal length topmount, all exhaust pulses enter the turbo uniterrupted. This allows the most efficient use of exhaust energy without having deadspots created where there is no exhaust energy in the turbo...even if it is for just a millisecond. Topmounts are generally able to accomodate 4" downpipes and larger turbos due to the placement in the engine bay. For those of us who "need" a Borg Warner S372 under the hood, this is the ONLY choice.
2. Mini Ram
Overall Power Potential
3. Mini Ram
Choosing the right spark plug
The BKR7E has the "V Power" electrode and is not pre-gapped.
The BKR7ES-11 has the standard electrode and is pre-gapped.
So which one should you get? That is up to you but according to the techo geek NGK dude, you should get the "V-Power" model for a turbo application. He said they have found this to be far superior to it standard counterpart when it comes to forced induction. (If I had more info, I would post but that is all he told me) The pregap is kind of useless for our applications because they are pre-gapped too big anyway (.035). The techo NGK dude recommend .030 gap (as do most H-T people) for our turbo applications.
Now, this brings me to my next point that he started to talk about. That is the step at which you go in spark plug "coldness". Here, I am speaking for the D Series guys because that is what I know. Our plugs are the ZFR5J-11 (For the D16Z6 from 92-95 at least). He told me go 1 step colder for every 75-100 horse extra you make. So, for most of us that is the ZFR6J-11 plug UNLESS, you are in a warmer climate (AZ, FL, CA, etc, etc) or you are making gobs of power from a built motor or whatever.
Now, I also asked him about the racing plugs that NGK has. The plugs are R5671A-8 (part #4554). These are the racing plugs he recommended for the people with big boost applications. These plugs are non-resistor type and he said they could possibly interfere with the electronics in the car (for sure the radio but also things like the ECU?) I want to know if anyone has experienced using these and did you notice any problems with the ECU acting up?
Choosing the right size injectors
So, how much power is this injector good for? That depends on the air/fuel ratio that is used, but a good rule of thumb is to divide this flow figure by 5 to get a hp capability. So, 322cc divided by 5 = 64hp maximum fuel flow with this injector. If you want to be pedantic, it's the mass of the fuel (not the volume) which is the critical factor. Assuming a "normal" fuel density, the mass of the fuel in pounds per hour can be worked out by Dividing the cc per minute figure by 10.5. For this injector, that gives a mass flow of 30.6 pounds/hour. To convert from pounds/hour to horsepower capability, multiply the figure by 2.04. So 30.6 pounds/hour multiplied by 2.04 gives a horsepower capability of 62.4hp - the same as we got from the cc/minute figure.
The power ratings discussed above are for each injector. This means that you need to multiply this rating by the number of injectors that are to be used. So, if you were using the Impulse RS 322cc injectors in a 4 cylinder engine (with one injector per cylinder) the max power that the injectors could deliver fuel for would be about 249.6hp. All of these figures are assuming that you are running an average fuel pressure of ~43psi and at 90% duty cycle.
* Conversions 500cc per minute is approximately equal to 49lbs per hour which is equal to approximately 100hp.
* lbs/hour = cc per minute / 10.5
* lbs per hour = HP / 2.04
* cc per minute = lbs per hour x 10.5
* cc per minute = HP x 5
* HP = cc per minute / 5
* HP = lbs per hour x 2.04
Wiring a resistor box
High horsepower boosted cars often need large injectors. Most large capacity injectors are available in peak and hold form - about 2 ohms impedance, whereas most stock injectors from about 92 on are saturated (8-10 ohms impedance). Honda engine computers require a total injector impedance of about 10 ohms so a resistor pack is needed whenever the stock saturated injectors are swapped with peak and hold.
Early model injected Hondas; 90-95 Prelude and Accord; 89-91 JDM B16A Hondas all ran external resistor packs with low impedance injectors.
This wiring diagram shows the wiring for saturated (upper), and peak and hold injectors (lower). The engine computer activates the injectors by grounding each injector in turn.
Converting to Peak and Hold injectors
Near the brake master cylinder on OBD I cars is a connector that distributes power to the injectors and a number of sensors. Verify with a multimeter which wires go to the injectors. Cut all 4 and connect the wires coming from the injectors to the resistor pack. Connect the power wire from the resistor pack to all 4 of the unused wires coming from the power connector. OBD II cars may have this connector somewhere under the intake manifold.
12V power distribution connector
Connector showing injector pins
Resistor pack in place
What and how to install Catch Cans
Recommended Setup: Basically the only effective way to route this catchcan is to have it go back into the intake stream and hook up 1 of the nipples to the charge pipe. You really can't run this open to atmosphere due to the fact it does not have enough nipples on it and ventilation. So I recommend running both the PCV line and the Valve cover to 1 nipple. So they must share 1 line, not only will the valve cover be able to release crank case pressure, but the line coming from the PCV Canister. Use the other nipple on the catchcan and connect that to the charge pipe/intake stream. The line going to the charge pipe will give the vapors/crankcase pressure a place to exit. I suggest also baffling the greddy catch and help it even further with oil seperation. Less change you get crud in your intake stream and help prevent detonation. This will no way get rid of 100 percent of the crud going into your intake stream, but this will help tremedously.
Here is a quick diagram-You can run this open loop if you do not connect the hose to the charge pipe and just leave it hangin. Have it go to the ground.
Endyn Catchcan setup. This is by far one of the best canisters out there. It is a modified Moroso catchcan. This not only lets you run a closed loop setup, but a very good open loop setup. The catchcan also provides the block even more crankcase ventilation and has a cool drainback system. Also this also completely gets rid of the stock PCV Canister as you can see.
Recommended Setup: Like in the picture above that ARTURBO provided this catchcan setup gives you nipples to thread into the back of the block. These are old casting holes and when those plugs are removed crankcase/oil vapors can exit the block more effectively. Not only do you have 2 exits for ventilation now, but you also have a much larger hose to let the crankcase/oil vapors out. The best way to route this catchcan is open loop. This setup provided you with a filter on top of the catchcan to let the vapors EXIT unlike the Greddy.
Now let me try to explain the install. The catchcan has 3 nipples. 2 on the side of the catchcan and 1 on the bottom of the catchcan. The 2 nipples on the side of the catchcan are connected to the 2 nipples on the back of the block. The nipple on the bottom of the catchcan is connected to the 1 of those hoses with a T and acts as a drain back system. The only problem is that most people can't mount the catchcan high enough for this feature to work. It is hard to find a location in most bays that will put the catchcan high enough for this to work, especially with the large filter on the top.
Another option: You can also T the valve cover to 1 of the hoses that connect to the side of the catchcan. OR you can get another catchcan just for the valve cover. That is a little extreme and not needed, but hey whatever you want. It's your money But I do suggest plumbin the valve cover to 1 of those hoses coming from the back of the block. Also If you can't mount the catchcan high enough for the drain back feaature to work, then go to your local AUTO PARTS store and replace the bottom nipple with a radiator drain cock. Then all you gotta do is drain the catchcan every few weeks. Some may have lots of build up, and some may not. It all depends on how much blowby and crankcase pressure you may have.
Now would you really want all that crap in your intake stream? I have a brand new motor and I put this setup on it. There is no crap in my intake manifold. It almost looks like new. There is not a lot of buildup like my old b16 manifold with the stock PCV system. This will help!
Also a lot of people may not know this, but a open loop catchcan setup can also help you out during a headgasket blow. WHY you ask? Well when the radiator fluid mixes with the oil, the radiator fluid seperates itself from the oil and shoots out of the valve cover nipple as well as the other crankcase ventialation holes. Your catchcan will catch this build up rather than it being sucked back into your intake stream. I rather have it gather in the catchcan and overflow the catchcan rather than going into my motor. Also it helps even after you change the oil because 1 oil change doesn't usually get rid of 100 percent of the gunk, and trust me, it will work its way out, even WITHOUT VACUUM!
You can run a closed loop setup with the Endyn. It provides you with a new PCV valve. I recommend that for all motor use though, and this for turbo use. It's up to you. I am really tired of typing, hope this helps someone.
The catchcan we sell hooks up just like the Endyn catchcan, but it utilizes the stock PCV canister. Ours is cheaper, but it all depends on what you want.
How to install your new larger fuel pump
1. Remove the back seat, remove the cover using a philips head screwdriver. Then remove the 6 (10MM) bolts supporting the pump inside the gas tank. Also disconnect the fuel lines and electrical connections to pull the Pump out at a 45 degree angle.
2. Remove the pump from the brace by unpluging the connection then removing the clamps, lifting up on the pump to get the bottom lose the pull outward.
Stock Pump vs Walbro Pump
3.Install the new pump using the new fuel hose cut a bit shorter due to the larger size of the walbro. Use stock as a comparison to get a general idea. Connect the electrical connection reusing the plastic connection lock.
(Note. I had to reuse the screen)
4. Reinstall by CAREFULLY sliding the new pump in at that same angle, tighten the 10MM bolts then reconnect the fuel hoses and electrical connections. I tested before I tightend just to make sure. Then just screw the cover back on and install the back seat.
Choosing your intercooler piping size
.4 Mach is the point at which air becomes turbulent and losses in efficiency start to occur exponentially. The key is to stay under that speed. You want to use the smallest piping possible that still flows enough to meet your needs. Larger than necessary piping increases lag time with no measurable gain
The velocities are in miles per hour and mach, and the flow rates are in cfm. Measurements for the piping are in inches.
1.57 x 2 = 3.14 sq in
300 cfm = 156 mph = 0.20 mach
400 cfm = 208 mph = 0.27 mach
500 cfm = 261 mph = 0.34 mach
585 cfm max = 304 mph = 0.40 mach
3.9740625 sq in = 1.98703125 x 2
300 cfm = 123 mph = 0.16 mach
400 cfm = 164 mph = 0.21 mach
500 cfm = 205 mph = 0.26 mach
600 cfm = 247 mph = 0.32 mach
700 cfm = 288 mph = 0.37 mach
740 cfm max = 304 mph = 0.40 mach
4.90625 sq in = 2.453125 x 2
300 cfm = 100 mph = 0.13 mach
400 cfm = 133 mph = 0.17 mach
500 cfm = 166 mph = 0.21 mach
600 cfm = 200 mph = 0.26 mach
700 cfm = 233 mph = 0.30 mach
800 cfm = 266 mph = 0.34 mach
900 cfm = 300 mph = 0.39 mach
913 cfm max = 304 mph = 0.40 mach
5.9365625 sq in = 2.96828125 x 2
300 cfm = 82 mph = 0.10 mach
400 cfm = 110 mph = 0.14 mach
500 cfm = 137 mph = 0.17 mach
600 cfm = 165 mph = 0.21 mach
700 cfm = 192 mph = 0.25 mach
800 cfm = 220 mph = 0.28 mach
900 cfm = 248 mph = 0.32 mach
1000 cfm = 275 mph = 0.36 mach
1100 cfm max = 303 mph = 0.40 mach
7.065 sq in = 3.5325 x 2
300 cfm = 69 mph = 0.09 mach
400 cfm = 92 mph = 0.12 mach
500 cfm = 115 mph = 0.15 mach
600 cfm = 138 mph = 0.18 mach
700 cfm = 162 mph = 0.21 mach
800 cfm = 185 mph = 0.24 mach
900 cfm = 208 mph = 0.27 mach
1000 cfm = 231 mph = 0.30 mach
1100 cfm = 254 cfm = 0.33 mach
1200 cfm = 277 mph = 0.36 mach
1300 cfm max= 301 mph = 0.39 mach
Honda Pilot crew and former Sol Owner
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