All Forums » Nitrous, Super Chargers, & Turbos » Turbo for 2004 model
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ORIGINAL: CumFortN469
I shoulda just bought a evo because it is built alot better to hold the hp turbo's put into a car i had originally wanted the evo but got the eclipse instead now i wish i didnt im seriously thinking of trading it :(
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its not all that detailed but it got a video of my dyno run at 5psi i made 168hp with 195tq im gonna do some checks on the engine and tranny to make sure its safe then up the boost to 8 daily 10 for track thw why i figure it i made 13.6 hp per psi so at 8psi i'll break the 200whp mark and at 10 i'll be lose to my 250whp goal for now the car pulls so much harder then stock its crazy the other day i chirped 2nd like it was a stick haha but anyways hers the video i have a couple others but i cant host them at the moment
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I'm picking this up from another thread, I felt more of you should get a better understanding of your cars and boosting them.
Again, we are not talking about just boost....It has nothing to do about compressor size or maps. It’s a combination of engine design and electronics.
Lets look at this logistically shall we, and please, save the sarcasm for your friends.
Part 1 the break down:
The 6G72 is not the flagship engine for Mitsubishi, it's really just and engine designed to get descent power for a descent platform. There are several weakness' needed to be addressed. I am going to explain the difference between a turbo and the conditions it will create versus our supercharger system (SDS) and why it simply works with this application (application being the key word). I know it’s long, but it’s packed with facts not opinion, there’s a big difference, what’s common knowledge in this industry is not always applicable everywhere.
Pistons weaknesses:
It’s not so much the design but more the metallurgy of the piston. They are very porous and brittle, which makes them extremely delicate to the exhaust heat and backpressure created under turbo boosted conditions.
Stock manifolds and back pressure:
The second problem in the V6 configuration is the factory exhaust manifolds. They are of an extremely poor design. In initial testing we bench flowed them to a maximum of 740CFM. If you do your math you'll see a turbo pushing 5psi will flow well over 1000-1300cfm with ease, in fact our Vortech V5 G-Trim will flow more like 1600cfm. Which means your stuffing 10lbs of **** in a 5lb bag? If you cannot move the air and heat away from the weak exhaust side of the piston something will have to give, namely the piston. They don't seize, they chip and lose compression.
The third problem is the turbo configuration itself. Conventionally, when your installing a turbo system you will pipe bolt banks together or "Y" them into one and up into your turbo of choice in front of the transmission. So you come out of your poorly designed manifolds on both sides of the block and then across the cross member (about 4 inches from the ground which sucks for ground clearance) and up past your transmission pan (over heating the Trans fluid, causing all those Trans problems) and into your turbo. Since the room is limited most commonly you'll see the same size pipe throughout the build let’s saw 2inch to 2.25. After which you’ll need to come out of the hot side of the turbo with an exhaust pipe, which should be the biggest of them all, but there is simply no room so you use the same size pipe again. It’s obvious at this point there will be a ton of back pressure, this condition will cause boost creep or compressor surge, I’ll get into the problem with that later.
Problem #1 is there is no way for the heat to expand from all 6 cylinders into one very restrictive pipe. Problem #2 this car NEEDS to see the O2 sensors, both before and after the cats and there respective variables. So, since you removed all 3 cats and all 4 O2’s the ECU (explained in detail below) will never ever adapt properly.
So in closing... unless you upgrade your pistons and magically fit up stepping pipes a single turbo system will not work, properly and will cause engine failure and run problems.
Electronics that are to smart:
The last and biggest problem with this car is the electronics, they are simply to smart for dumb electronics (AFC, AFR, FMU, MSD). As you may or may not know, these cars have "adaptive technology", which means they are able to adapt to certain condition and programmed to reject others. Now keep in mind we have spent the better part of the past 3 years working only with the 6G72 platform, so this is not hear say, its' fact.
The turbo set up and the electronics:
Normally when you’re setting up a turbo system you simply place it in line with the factory electronics and use a fuel controller of some sort and move forward with an MSD timing master to control injection retard under boosted conditions. So you would place the factory MAS in front of the turbo and such through it.
Problem #1:
I can only explain this as a running condition:
Once you’ve been through the trouble of installing a turbo system AND GETTING THE CAR TO “RUN” this is how it computes the info being feed FROM INITIAL START UP:
1: Turn the key and crank, it will take longer to crank because the MAS is now over 4 feet from the TB (explained in detail below). Once it fires to life the idle will be sporadic from the larger injectors it’s trying to trim. But it can’t get a proper reading because the EGR valve in not offering a proper reading, so it refers to the O2’s the 02 are not warm yet, so it goes into a limp mode and the idle is either caught high or low. So you try to tame it down with the idle screw but the ECU is controlling the idle with the IAC valve so no dice it does what it wants. Finally is warms up and if sort of calms down.
2. The first drive; once you decide its time for a drive and you step on the gas the MAS air send its info to the ECU: 70 degree’s air temp, 100MPH air velocity, “X” Barometric pressure…. And so on. But! Now all those readings are being “bent and twisted and heated and cooled through the system you built, so as the ECU is preparing for the readings you just feed it, what it getting is completely different. So as it’s advancing the timing to deal with the increased air velocity the turbo is sucking in, the MSD Boost retard you installed is trying to pull timing away. The ECU reads this and throws the 300 code (detonation) even though its not detonating, its reading the resistance at the crank sensor and it goes into limp home mode again.
Now from there the O2 pick up the enriched fuel mixture since there is no cats it reads hotter temps so it pulls the injector pulse down to nothing and you get your lean under boosted conditions. Causing a piston failure and extremely hot under hood conditions.
Keep in mind the ECU will find a “spot” were it will run even with all these variances, but not reliably and not with all the power it can make.
In this car you simply cannot run those piggy back electronics and get away with it. Now I know, some of you have an Apexi AFC or something similar, and I know you had it tuned and you think it's tuned, but let me explain. THE TUNE YOU DID has already been canceled out by there factory ECU, the same day you tuned it and within 9 miles of driving or 3 new key starts. Which means, if you’re running an air filter, headers and AFC... The ECU has already canceled out 75% of the performance gains you thought you bolted on. (Sorry).
Why when you upgrade this car it knows:
Because the ECU knows the difference between the factory configuration and modifications! I know it's bold, but it’s the truth, even if you have installed your mods and taken it to the DYNO, it still will over ride the modifications. It does this mostly through the MAS and the O2's.
Here's how it goes, this ECU is programmed to see the MAS about 12inchs away from the throttle body, when installing a Cold Air System (CAS) you generally move the MAS further down the line, which is why sometimes your car will stall or have an odd hesitation in traffic or pulling from a standing start. The ECU doesn’t know the difference between the distances and cannot compensate timing.
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