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View Full Version : can someone explain all the systems related/necessary for FI?



chubbychu
03-27-2003, 11:48 PM
Can someone please tell me that if i were to get turbo what would be needed to make the car run ideally for the turbo?
also if you could post what each individual thing does that would be awsome!
for example (the turbine-copresses the air that goes into the chamber-ect....)i generally understand how the turbo works ect...but there are little subsystems i have never heard of that are needed for a turbo to work properly for our SI's. like...whats a turbo manifold, fuel controller ect...

thanks!

CSMsi311
03-28-2003, 12:55 AM
Everyone correct me if i'm wrong

Turbo manifold: is the exhaust manifold that connects the engine and the turbo.
Down pipe: (Not sure about this one) It goes from the turbo to the b-pipe

In addition to the extra volume of air going through the engine you will also need to an more fuel. basically AIR + FUEL = Power.

To get more fuel:
1.) Raise fuel pressure as a function of boost.
2.) Use larger injectors along with a "fuel controller"(V-AFC, hondata, AEM EMS, SMC+, emanage, ...) to control the injector pulse so you get the right amount of fuel. Much better option than number 1

TUNE everything on a dyno with a wideband O2 to make sure you are getting the right amount of fuel.

Now you have lots of power so you'll need a new clutch b/c it won't be long until your stock clutch starts slipping.
Larger diameter exhaust will increase the performance

Hope this helps
Jason

CSMsi311
03-28-2003, 12:59 AM
"Maximum boost" by Corky Bell is an excellent book about turbos. My friend read it and he is now putting together his own system. Teachs you how to calculate with turbo will work the best for you. Depending on your displacement, HP goal,...

I have "Supercharged" by Corky Bell since i have a jrsc. Incredibly helpful. Even though there is not as much flexibilty with superchargers.

chubbychu
03-28-2003, 01:00 AM
i thought there were more...like titanium valve thingamajiggers...iuno...i hear all this car jargon but i would really like to know what the WHOLE setup of turbo involves.

it helped a little...but itsnt it way more complicated than that?

because right now it sounds like....turbine, intercooler, catback exhaust, manifold, and A/F tuner...and thats it. is that it for a turbo to run low psi's and not have to worry about ANYTHING blowing up?

CSMsi311
03-28-2003, 01:21 AM
That is pretty much the basics to run a small amount of boost. I guess you could also include gauges. I would recommend boost and exhaust gas temperature (EGT). and A/F gauge is almost useless even though i have one. :(

Most important thing to remember to do is get some sort of fuel management. IMO this is where things get complicated.

It also gets more complicated when you get to install the turbo. For example, you have to tap the oil pan for the oil line to the turbo. I forgot to include things like wastegates and blow off valves. I admit i'm not entirely sure what the difference is between the two.

Titanium valves, low compression pistons, block guards.... is over kill if you are running small boost levels.

chubbychu
03-29-2003, 02:28 AM
thank you thank you! im glad that our stock engines can handle that! so...how much does all that stuff cost?

Tekdemon
03-29-2003, 03:48 AM
I too second the recommendation that you buy Maximum Boost...even though I haven't finished reading it, it's a great read to get your hands dirty with Turbos...

It should let you have enough info to design your own kit...if you want to.

SI02civic
04-06-2003, 08:15 PM
Just to let you know CSMsi311.
Our civic si's and basically all the K-series engines does not come with a return fuel line. So basically the usual trick of adding a boost sensitive fuel pressure riser to keep the cars from running lean is eliminated. so if and when you do get turbo make sure you either install a custom fuel return line or add a stand alone fuel management system to adjust the fuel curves and ignition. this is the biggest problem with our k-series cars.

CSMsi311
04-06-2003, 08:28 PM
i thought i read somewhere that AEM was developing a fuel pressure regulator for K-series engines. it will be non-traditional of course.

rewsnaeht
05-01-2003, 10:17 PM
you dont really need a FPR, just get a bigger pump and it will make more PSI just because it has no reuturn line. Pump, injectors and a way to control fuel will be adequate.

CaptainMurphy
05-09-2003, 10:22 PM
As far as the difference between blow off valves and waste gates, I believe blow off valves release some of the boost pressure when your revs drop or whenever you don't need all the pressure. If you have any gran turismo game you'll hear the little "pppssst" noise if you let up the throttle or up shift.

Waste gates I read somewhere release exhuast gases to keep the turbo from spinning too fast and damaging itself. I would assume they would be on smaller turbos that aren't designed for high RPMs. Keeping in mine that I think turbos spin at very high rates.

If I'm wrong please feel free to call me dumb. But that was my understanding of it.

EDIT: http://auto.howstuffworks.com/turbo.htm

that guy is my hero...

SF-SI-02
05-11-2003, 06:41 PM
I thought the wastegate sderved the following: when you have low exhaust pressure, no turbo, but when it gets high enough, the wastgate opens, and starts spinning a turbine, which is roped to another turbine which pushes the air into your engine, i.e. wastegate=thermostat in a sense, determines the critical point at which the turbo kicks in.. let me knw if I am wrong

CSMsi311
05-11-2003, 07:06 PM
Originally posted by SF-SI-02
I thought the wastegate sderved the following: when you have low exhaust pressure, no turbo, but when it gets high enough, the wastgate opens, and starts spinning a turbine, which is roped to another turbine which pushes the air into your engine, i.e. wastegate=thermostat in a sense, determines the critical point at which the turbo kicks in.. let me knw if I am wrong
I've done some reading and believe you've got that backwards. The wastegate is closed until the desired boost level is achieved. Then the wastegate opens to bypass a portion of the exhaust gases around the turbine which limits the turbine speed. If there was no wastegate, the turbo would spin too much at high rpms causing it to run outside it's maximum efficiency range thus heating the intake charge more than necessary.

SI02civic
05-11-2003, 07:21 PM
OK.. wastegates purpose is to release all the excess boost that you are not running... for example you set your turbo for 8 psi but when you start climbing rev's the boost starts to build up and to cancel out all that extra boost the wastegate opens and releases it all into the air. hence the name WASTEgate... basically throwing away all the boost you don't need to run the 8 psi. now for the bypass valve true purpose is to not create compressor surge basicallywhen you put in the clutch the throttle body plate shuts and where you think all that forced air goes, bounces right back to your turbine and can seriously screw your turbo . so all that "pssst" sounds you hear is the bypass valve releasing the air back into the air instead back at your turbine when you shift or put in the clutch. hope this helps

sniperSI
05-11-2003, 09:19 PM
great, now someone talk about the basic concept of a boost cont.

CSMsi311
05-11-2003, 09:53 PM
I'm not entirely sure that is how a wastegate works.

1.) Why would you want to compress the all the air beyond the boost level you want to run. Thereby, heating up the air more than is necessary; just to vent the excess boost to the atmosphere?

Wouldn't it make more sense if you limited the turbine/compressor speed to limit the amount of boost that you run. Then you only compress the air you are going to use and you avoid adding unnecessary heat.

SI02civic
05-12-2003, 08:03 PM
sorry that's what i was trying to say.... a wastegate is a valve used to bleed off excess exhaust pressure on the turbine to maintain optimal boost pressure without over-spinning the turbine wheel.

andy
05-12-2003, 09:13 PM
Originally posted by CSMsi311
I'm not entirely sure that is how a wastegate works.

1.) Why would you want to compress the all the air beyond the boost level you want to run. Thereby, heating up the air more than is necessary; just to vent the excess boost to the atmosphere?

Wouldn't it make more sense if you limited the turbine/compressor speed to limit the amount of boost that you run. Then you only compress the air you are going to use and you avoid adding unnecessary heat.

The wastegate helps bleed off the extra pressure because there
is no (easy) way to control turbine speed. The turbine speed
is a function of the speed of your exhaust gases - higher engine
RPM = higher RPM on the turbine. So the wastegate gets you
around that.

Someone else asked about a boost controller...these range from
very simple ("manual") ball and spring type devices to AI fueled
electronic devices. They essentially keep the wastegate closed
by controlling how much pressure it will open at. With the
boost controller on my WRX, it connects directly to the wastegate,
and will only allow it to open when the spring in the ball/spring
valve can't hold it in. Hence the term manual - because you set
the spring rate by tightening a bolt/screw.

I'm not entirely certain how Electronic BC's work, or how they
work in non-wastegate situations...

This month's Sport Compact Car had some pretty interesting
articles on turbos (in particular, compressor efficiency maps), but
it's not the overall coverage that the Maximum Boost book offers.