I'm still lost and confused on one point guys:

Red says:
What is the difference from that and an adjustable FMU??? isn't it basically the same thing, I have the injectors and have the fuel pump, and running rich now, with an FMU it would've been crazy when boosting... so I ended up getting a regular FPR

I'm sorry if this should go on another thread, but I think it would help him decide too...

 

Some basic theory:

The stock MAF sensor can only understand a certain amount of airflow. Also, the stock computer can only understand a certain amount of signal coming from the MAF sensor.

This gives you three possible options:

1. The airflow is within the MAF's ability to sense it all, and is within the computer's ability to understand it. No changes needed.

2. The airflow is within the MAF's ability to sense it all, but is outside the normal operating range of the computer. Typically, you upsize the injectors by no more than 100% of stock (245cc is stock, so no more than 490cc), use an S-AFC to modify the MAF signal to approximately half, and thus fool the ECU into sending approximately half signal to double-sized injectors.

3. The airflow is outside of the MAF's ability to sense it all, and as such is also the normal operating range of the stock ECU.

This gets very tricky.

When the MAF is topped out, you cannot rely on the S-AFC to make adjustments by itself any longer. You still need to follow the #2 guidelines to allow for when the airflow is within the MAF's ability to read... But you also need to combat the problem when the airflow exceeds the MAF.

If you were the owner of a Honda vehicle, you would already have most of the solution in mind smile.gif

First off, we oversize the injectors shy of the 100% increase we talked about in %2. A good place for 300whp (from experience with the Honda/Acura crowd) is 370's or 440's. So let's stick with 440's because they're cheap and easy...

We then rip out the stock fuel pressure regulator and install an adjustable static regulator. This will give us our "base" fuel pressure when the car is not boosting. In the Honda world, this is typically set around 30psi. (Remember that injector flow rate is always measured at 44psi, so 30psi is going to make them flow less than their rating)

Next, we install an S-AFC to further adjust for the bigger injectors and to make sure the MAF doesn't send signal to the ECU above it's normal operating range...

Then, we install the boost dependant rising-rate fuel pressure regulator. The rate will need to be set per how much boost you're goig to run -- on a 18psi setup, maybe around 3:1 so you get an extra 54psi (at full boost) on top of your base 30psi.

Now do you see where we're starting to go?

The S-AFC can help control fuel at idle and during closed loop operation. Yes, I said closed loop, because if you don't use the S-AFC, the 440cc injectors (even at 30psi) are going to be too rich and still cause an OBD2 code (long term fuel trim error) because the computer will not be able to back out enough fuel on it's own internal programming.

During open loop operation, the S-AFC is basically there to make sure that no more than 4.6VDC is sent from the MAF sensor to the ECU, so that you don't get an error code. The MAF return signal will just top out once it's upper flow limit has been reached, so the S-AFC adjustment curves can stay pretty static after 4 or 5k RPM's on the hi throttle map.

Even still, what the ECU considers "full fuel" on 440cc injectors (80% duty cycle) is still not enough to feed 300whp -- this is where the rising rate fuel pressure regulator comes in. 440cc injectors at 60psi = 572cc, and at 83psi you'll be knocking on 680cc. Guess what? 680cc is enough to feed 300whp, easily.

Make more sense now?

Using a whole slew of bandaid fixes, it's theoretically possible to allow the stock ECU to get to this power level and even beyond. Of course, the interesting part is the fine tuning, as you really can only aim rich on the mechanical pressure components and pare it down with the S-AFC.

Hope all of that made sense...

 

Ok here is Random's list of parts. I tried to name good parts based on Random's parts list and I'm a bit short. Please help me complete the list, Please? smile.gif



[ October 23, 2002, 04:13 AM: Message edited by: lantraluvr ]

 

CNK pistons will not live to 300whp, no matter what Mister CK says. Hypereutectic pistons are fine and dandy for increased power under most circumstances, but are not heavy duty by any means.

The cylinder pressures involved in making 150 horsepower per liter gets a bit too much for the Hyper-U pistons to live through. Forged is your route when wanting 300+ wheel horsepower.

Rods: Crower.

 

Red do you actually think the stock rods will last with those heavy ass ross pistons?

Especially if your going with an over bore (2.1L)

i know the rods are nice and and strong... but we would be applying them to something heavier....

 

The weight of the pistons is like an extra 75 grams. That is absolutely nothing compared to doubling your cylinder pressures to get your requested 300whp.

Compressing half a liter of air at 1500psi over 3000 times a minute is more stress on the rod than an extra 75 grams of piston mass...

[ October 23, 2002, 08:55 AM: Message edited by: Red ]

 

red... you should write a book

 

Yeah, how to be a skinny red-headed white computer/car/math geek in 5 easy steps....

One. Dye hair red. The redder, the better.

Two. Bleach skin white. When a rainy day gives you third degree sunburn, you have reached the appropriate whiteness

Three. Stop shaving face, start shaving head.

Um... Four and five is the secret, gotta buy the book wink

 

blow off valve
Any flavor should work. MAF based cars should strongly consider a recirculating BOV.

hoses for oil/water
Stainless steel braided lines for oil/water. They are universal, you cut them to fit and put on fittings.

rings
Should come with the pistions, CNK, Ross, Wiseco,etc..

rods
Crower, pauter, etc..

fuel pump
Eclipse TURBO Fuel pump, RX7 TT fuel pump, Walbro 255LPH pump

Adjustable fuel pressure regulator
Universal style required, along with custom block plate for stock fuel rail/return line

a set of good fans
Fal 210's do the trick, or there are others just measure your radiator and you know what will fit. Got for at least 1000 CFM per fan, the higher the CFM, the more air it will flow. You will need "puller" style fans to mount them in the engine bay, "pusher" style fans to mount on the other side.

 

I need to do more research on pusher-style fans for my radiator. I know they're less efficient for sure, but I'm concerned about a new thicker radiator + having the fans on the "correct" side giving me lots less clearance for my turbo compressor housing.

I guess I should identify which radiator to use first smile.gif