turbo info!!!

[90lx]

:bigthumb I am wanting to go turbo, but know nothing about them other than if not careful things can go very badly... I know of a few here on Stangbangerz that built their own kit.. So I wanted to know who still or might be willing to build a kit minus the turbo and blow off?? Plus what turbo to use and what blow off to use.. I've heard a lot about the master power 70s. Are these good turbo to start with and a lil room to grow with? I don't have the welding skills to do this on my own or to even try to build one. So I am tuning to Fabers that might be interested in making a few dollars or anyone who can point me in the right direction.. Thanks guys and gals..

p.s I would like to make around 400-500 HP so that's why I need to know about the master power 70..

~James:bigthumb

[PaulFiveOh]

Kelly, 89Notch has built quite a few of these him self. He is probably the man to talk to.

He is just about done with my aluminum headed MP 70 build.

[bobtsgt]

sign up over here and start reading. many good things on that site. building a kit from scratch is easy. Even if you can't weld you can tack the pipes and have someone else weld it up. The cold side is all couplers and clamps. MP T70s work very well.
http://www.theturboforums.com/smf/index.php

[Goober]

I'm subscribing to this thread.

[Goober]

Some info from Smokinhawk from SRDayton.com

Some good reading for the basics about turbochargers and understanding compressor maps
thanks to Jose (JZ 97 SS 1500) for this
http://www.forcedinductions.com/help.htm

What other things do i need when i boost my beast

You need the proper balance of fuel, air and ignition

the more air you put into your engine the more fuel you will need
so bigger injectors and bigger pump are a must., after ALOT of power increase you will have to upgrade your fuel lines and fuel rails.

Tuning, you need to have it tunned properly
the only HP limit the lsx engine see is tunning, no one tha i know of have split their block because they made to much power, but i have seen alot of times where they put a hole through their block because of poor tunning.

Drivetrain: you need to have stronger componets to handle all that extra power your now running. You need a stronger clutch, built tranny, stonger driveshaft and rear end.

Suspension: you have to put the power to the ground if you want to make use of it, so get your suspension worked out. Get a strong torque arm too, so it doesnt end up braking.

How much boost can i run
0-infinate Psi
basically you are limited to octane and timing, the more boost you use the more easily the mixture can pre-ignite (which causes knock), so you have to use a fuel that ignites on a higher temperature (aka higher octane fuel) or pull enough timing.
to give a ruff estimate most people use about 7psi on a stock compression ratio engine (10.1-10.5:1)
if you lower the compression ratio in your engine by larger combustion chamber heads, thicker gaskets or dished pistions, this will also allow you to run more boost on the given octane.

What size turbo should i use
http://www.forcedinductions.com/help.htm has alot of good information on selecting a turbo that will suite your needs.
Basically you need to start by knowing your power goals. Select a turbo that will support that power level.
next where in the RPM range it makes its power is also important. This can tuned by selecting the A/R of the exhaust housing. the smaller the AR the faster the turbo will spool and make more power, lower in the RPM range, but will choke off power in the upper RPM range. A larger AR will spool later in the RPM range, but will make more power in the Upper RPM range.

why isnt anyone running 30psi or more on an LSx engine like the imports do
psi or boost is resistance to flow
psi is irrelevlant, how much air goes through your engine is important. ALot of people give an example of two straws one really thin, one large. If you blow into the small staw it is harder as the velocity of the air increases, but not a whole lot of air is moving. Switch to the larger staw, it is easier velocity is low but your pushing alot of air through it.
these 346 cubed or larger engines flow very well. so 15psi can make around 700rwhp.
UPDATE: casper from W2W has ran a 6.866@205 with around 30-40lbs of boost. First production LS-style block in the 6's! so hows that for comparing it to import boost level.

how much power will i make if im running Xpsi or increase it xpsi?
there are alot of varibles and some other thing in contribution, but if you start out with what your engine makes NA
(0psi) you double the power at 1 atmosphere (14.7psi or 1 bar) so we can come up with a rough formula of
new power = [ ( NA power / 14.7 ) * amount of boost ] + NA power

Can i run a turbo on my high CR engine and low lsa cam
Not really, well yes but it wont do as well. WIth a higher CR then stock your going to have problems not running high enough octane, you will be fighting knock so you wont be able to use enough boost to make it worth your while.

The low lsa cam also isnt best for your turbo, it will bleed off boost and not give enough gas flow velocity till the upper part of the RPM range.

what cam should i use with my turbo set up?
There is alot of debate here but first off the stock cam does pretty well. a higher lsa seems to be more desirable 114-117. this will bring the exhasut gas velocity up faster and spool the turbo more in the rpm range and not tend to bleed off boost. It needs to be matched to your setup also when you want the power to come on, and how high you plan on spinning your motor.
for the duration it needs to be matched to your engine size, intake and exhaust manafolds. The larger the engine the higher overall the duration should be. It was explained once to me that you want the intake duration larger then the exhaust that way you have a higher exhaust velocity which helps spin the turbo better.
Other theories have said that it depends on your headers, if you have a good flowing header that the exhaust duration should be greater then the
intake, if you have an inefficiant header that the exhaust duration should be lower then the intake duration. If you have a good intake and header set up they should be equal.
Id like to see specific testing so there could be definate answers.

should i go witha twin or single
either or i dont beleive in performance that it matters. As long as the exhaust to and from the turbo chager(s) are of equal effiency both will spool the same (depending on the selection of the turbos) and make similair power if the right turbos are choosen.
if buyng a kit, choose the one that will fits your needs.
if building your own, the things that should be the desiding factor should be packaging, ease of being albe to work on it, cost, availabilty, weight.
Note alot of race classes twins are outlawed. And most of the realy heavy hitters are using a BIG single.
Most turbo companies say a twin is better for the street for good spool up, but the singles are more efficient on the top end with regards to racing.
some more reading, also talks about compond charging http://www.hotrod.com/techarticles/e...bo/index2.html

What intercooler should i go with
you have two choices in IC's Air to water or air to air

which one is right for you.
generally people use aire to air for the street and air to water for the track.
with the A2W IC you can put ice in the water box you can get the IAT down below ambiant temperature. Member testing shows that A2W ic's with just water works well on the street.
A2A is a very simple design. With a properly sized core it will work well and generally be less expensive then a A2W. It will also do a good job on the street or track if properly sized

(pics are dead now)
What parts make up a basic turbo kit?
Most turbo kits come with the following parts, these are talked about in further detail later in this FAQ

Hot side exhaust
Turbocharger
Wastegate (If turbo does not have a internal wastegate)
Blowoff valve
Silicone Connector pipes, tbolt clamps
Intake piping, downpipe.
Boost referenced fuel pressure regulator

Optional parts are
Intercooler & Intercooler piping

Most kits do not come with fuel components, tuning software or wideband o2 sensors, all of which are a good idea!

[Goober]

Whats up with methonal/alcohol/water injection?
Methonal injection is methonal (high octane fuel) and injected into the intake pipes, this helps prevent detonation when you are running on lower octane fuel and or non-intercooled applications. Methonal injection systems can be had for a few hundred dollars.
It can be mixed with water or run straight.

Alcohol is also a "high octane fuel" which helps surpress detonation like methonal, it to can be run straight or mixed with water.

Water injection cools the intake charge which alows you to run more boost with surpressed detionation.

What is "hot side exhaust"
Hot side exhaust is the exhaust piece(s) that bolt onto the heads and work their way to the turbo(s). These pieces can be purchased from several different kits if you are making your own custom setup or if you really want, several sponsors on here can make custom hot side exhaust to fit any application.

Parts of a turbo

Here is a basic cutaway image that shows different parts of a turbo, this image does not show the exhaust inlet which can be seen under the Exhaust Turbine section of this FAQ

What is the downpipe?
The downpipe is a pipe that connects to the turbo on the other side of the exhaust turbine, this pipe generally connects to the factory exhaust system.

How is boost controlled?
The amount of boost generated by a turbo is controlled by a large valve called a Wastegate. The Wastegate is mounted on a flange that is generally welded onto the hot exhaust piece close to the turbo flange.

When boost reaches the desired level, a boost controller diverts pressure into the wastegate allowing the valve to open and vent exhaust gas out the other side of the valve, this prevents the turbo from spooling faster than it is already going and potentially slows it down some depending on how far the gate opens. There is a wide range of boost controllers manual and electronic available for fairly reasonable prices.

Note : Some turbos have internal wastegates, which means the hot exhaust piece will not have a wastegate flange on it.

What is a blowoff valve?
Blowoff valves are to relieve pressure when your throttle blade closes, if your turbo is spooled up and pushing major air, and you let off the throttle without one, it can cause your turbo to backspin and cause excessive wear on the bearings. This valve is more important to cars with manual transmissions.

What is A/R?
The A/R of the exhaust is a ratio of the exhaust housinginlet area to radius. the smaller A/R will spool faster, but choke off sooner.
the higher A/R will spool later but make more power and higher in the RPM band.

What is the Exhaust Housing?
The exhaust side of the turbo is usually darker in color, this is where exhaust gas flows through the turbo to spin the compressor side. Inside the exhaust housing is a turbine, pictured in the cutaway view above.

What is the Compressor Housing?
The lighter, or polished in some caes side of the turbo, spun by the exhaust turbine this part of the turbo actually creates the pressure by spinning the compressor wheel.

When you hear people talk about the compressor turbine (or "compressor wheel") you might hear the words Inducer and Exducer size, here is a visual representation of what thoes are.

To find the trim of your turbo use the following formula
Trim = (Inducer / Exducer) ^2 * 100

Where can I tap and return oil on the LS1?
There is a number of places you can tap and return oil on the LS1, here are a few of them.

Tap Locations:
Above the oil filter, there is a blockoff plate that you can get filtered pressurized oil from.

Return Locations:
Oil returns need to be someplace oil can drain back into your oil pan freely, it must be above the oil level in your oil pan, and below your turbo, remember that if you make this line hard to flow oil through, your turbo may have problems with seals in the future.

The gravity oil drain line from a turbo should not be at any more than a 30 degree angle when leaving the turbo.

Who makes the "best" turbo kit?
Who makes the best cam? What is the best grind? Which turbo is best? None of these questions can be answered because each car has its own goals, so if your posting asking for help with kit selection do some homework instead of just asking which kit is best, and know what your goals are. Here are some things to consider while selecting a kit.

What is your horsepower goal?
Do you want to keep your A/C?
Do you have tuning software?
Are you willing to put the money into your fuel system?

How do I select fuel injectors for a forced induction application?
First you need to figure out what BSFC (Brake Specific Fuel Consumption) value you will use, BSFC is the pounds of fuel the engine burns per HP per hour.

Here are some BSFC guidelines.
.45 for N/A motors
.55 for supercharged
.65 for turbo

Injector Size in LB/HR = ((Desired Flywheel HP) * BSFC) / (# of cyls * Duty Cycle % / 100)

These simplified versions can be used for V8 motors with 80% duty cycle
Turbos : LB/HR = (Desired HP * .65) / 6.4
Superchargers : LB/HR = (Desired HP * .55) / 6.4

Example
600 * .65 / 8 * .80

Gives me
390 / 6.4

Result : 60LB/HR

For more information on this topic, see http://www.holley.com/HiOctn/TechSe...cl/Artcl07.html

[90lx]

wow, I just learned a lot on a turbo and all the parts it takes to build or buy on!! Yes I am still going for it... THAK YOU FOR THE INFO...

[PaulFiveOh]

dude that was seriously some good posts right there.

rock on fang