I know im gonna get flamed for this as I usually do, got a KAe-t with a to4e (although it says type t3/t4 on it?), I'm scared s*** of running boost on it since its completely stock everything, BUT, i have acquired the z32 maf, rx7 550cc injectors, and walbro fuel pump. I'm looking into buying my next piece but I can't decide what to buy next, either the wideband 02, ECU system, MSD BTM for timing retard, or an SAFC2. I just want someone to point me in the right direction because I fear of leaning out my engine and causing detonation even though I dont boost past 3 psi ever. This is my only car right now and if i blow this im screwed can someone help me out here?

If your running low boost you should
be safe using an FMU and always always
use a wideband A/F gauge.

so by FMU you mean like an SAFC2? So getting that and a wideband should at least keep me safe til I get my ECU tuned? Would I be able to install the fuel pump, z32 maf, and injectors I already bought? sorry for all the questions, I just want some guidance on what would be a good idea to spend my money on. Wish I was fortunate enough to drop thousands on my car, then the sucker would be built from the ground up

FMU stands for Fuel Management Unit. It's a rising rate fuel pressure regulator. You connect it to your return fuel line behind your factory fuel pressure regulator. It's reads manifold pressure from a vacuum line. When it "see's" boost, it increases fuel pressure. The most common one used on 240's is the 8:1 type. This means for every 1 psi of boost, it increases fuel pressure 8 psi. This takes care of all the fueling you'll need for a low boost setup. I would not run more than 8 psi without a true ecu tune, like something from Enthalpy or JWT.

Forget about the SAFC. Forget the MSD BTM.

The KA24E already runs pretty low compression, 8.5:1. So it's fairly boost friendly, I suggest retarding the timing at the distributor a few degree's.

The FMU is about goes from $100 to $180 depending on brand. I only have experience with the Vortech. But people have used Blox and OBX on these forums. Here's an ebay link.

I also suggest you buy a 255lph fuel pump. Like this one from Summit.

You're going to need a new fuel pump regardless of how you choose to tune your 240. The factory pump will not be able to keep up with the fuel demands.

Use the FMU until you save up for a proper tune. If you are happy running 8 psi the FMU will suit your needs for a long time and it doesn't require any sort of tuning.

Ask any questions you have, we'll do our best to answer them. Don't worry if they sound stupid, we've all been noobs before.

wow thanks so much!! now you gave me a better idea of what to do. I want to achieve a goal between 300 and 350rwhp which I have read everywhere is possible on stock internals but even then I dont plan on racing the car at the track. I just like to have the power if I want to use it. I've read that write up on ka-t.org about what you need to reach that power goal and I pretty much have everything on that list except for the MSD BTM, the SAFC2 and the ECU. I'm getting ready to buy the wideband o2 as I know I absolutely need that. So I can install the walbro 255 I have with no problems right? what about the z32 MAF? I read on another forum that ya its possible but then a few other guys said no its not and there wasnt a real clear answer on it. Maybe you guys know more about it than they did?

And also, if I were to buy that FMU does that mean I can drop in my 550cc injectors, or would I still need the tuned ECU for that?

mythic540 wrote:wow thanks so much!! now you gave me a better idea of what to do. I want to achieve a goal between 300 and 350rwhp which I have read everywhere is possible on stock internals but even then I dont plan on racing the car at the track. I just like to have the power if I want to use it. I've read that write up on ka-t.org about what you need to reach that power goal and I pretty much have everything on that list except for the MSD BTM, the SAFC2 and the ECU. I'm getting ready to buy the wideband o2 as I know I absolutely need that. So I can install the walbro 255 I have with no problems right? what about the z32 MAF? I read on another forum that ya its possible but then a few other guys said no its not and there wasnt a real clear answer on it. Maybe you guys know more about it than they did?

And also, if I were to buy that FMU does that mean I can drop in my 550cc injectors, or would I still need the tuned ECU for that?

There are a few things you need to understand. I explained what the FMU is, it's just a fuel pressure regulator. How would a fuel pressure regulator be able to control fuel injectors? It wouldn't. I'm not trying to be a jerk, I just want to you to understand what's going on here. I'm going to explain a couple of things for you and hopefully that will clear up the process.

There are really only 3 things to think about when you're adding boost, air, fuel and ignition. The turbo provides the extra air. The difficult part comes with fuel and ignition.

You want to add fuel in equal parts with the extra air. This can be done in two ways. Installing larger fuel injectors or using the FMU. I explained the FMU already, it's just a fuel pressure regulator that cranks up fuel pressure as boost rises. Therefore adding the extra fuel you'll need. This is the easiest route to take and requires no tuning. It's plug and play. The limitation to the FMU is the high fuel pressure that it causes. Which is why it's not recommended to use for more than 8 or so psi. Higher than that and the fuel pressure becomes a problem.

That brings us to larger injectors. You can't just add larger injectors unless you have a means to control how much fuel they're spraying. Injectors have a fixed orifice. In order to change how much fuel they spray, you have to control how often they pulse and how long they stay open. This is done by the ECU.

The SAFC is a piggyback computer that tells the ECU it's seeing less air than it really is by manipulating the signal coming from the mass air sensor. So your larger injectors aren't dumping in tons of fuel when you're not under boosted conditions, like idle and cruise. The SAFC is NOT a good idea for a beginner. My suggestion to you is to forget about it entirely. The SAFC also does not control ignition. More on that to come...

This leaves us with the proper ECU tune. When buying an ECU tune, you buy one that matches the components that you have. So your tune will have to be for 550cc injectors and the N62 MAF. If the tune doesn't match your parts, it won't work. The ECU tune will also control your ignition by retarding timing while under boost. Using a proper ecu tune is the best way to go about adding boost.

The MSD BTM is only for controlling timing retard while under boost. It isn't needed if you're using an ECU tune. If you're going to spend the money to buy a FMU/SAFC and MSD BTM, buy the ECU tune instead. It will provide a better tune and make more power for the same money.

In short, if you don't have an ECU tune the easiest way to run a low amount of boost is by using the FMU. You shouldn't drive the car at all without a method of adding fuel. If you do decide to use the FMU, retard the timing a little at the distributor. The FMU method is only good for 8 psi, no more.

In either case, ECU tune or FMU, you need to replace your fuel pump. The factory fuel pump is garbage and can't keep up with the demand for more fuel.

Hope that helps.

Thanks so much for clarifying that up. Don't worry about sounding like a jerk. If anything youre teaching me how not to blow up my engine. So what youre saying that if I'm maxing out at 8 psi I can get away with the FMU and wideband O2 along with retarding the timing a few degrees. If I want to go higher than 8 psi then thats when I just need to get the ECU tuned to be able to install my injectors and MAF right? I installed my walbro 255 last night so thats done. What I am taking from this is that if I am just using the parts I intend to use and only want to achieve a certain amount of horsepower then the tuned ECU should be all I need to get me there? Please correct me if I am wrong. Thanks again so much for your help!

Sounds like you've got a handle on it. When you're ready to install the parts you have, just get the ECU to match and you'll be golden.

Until then, use the FMU.

Quick question, once I get the ecu am I still gonna need the fmu?

Nope.

Thank you so much wd, you don't know how frustrating it's been to be on other forums ad people either telling me I'm asking the same questions, to search or just tell me the same stuff I have already read, you really opened my eyes up on what to do, I really appreciate it!!

Sometimes people forget what it's like to be just starting out. I was just as ignorant as anyone else when I first got into forced induction. I learned by breaking stuff

The only stupid question is the one you don't ask

Oh ya I forgot to ask, so my car hesitates usually before 3k rpm and when I come off a rev it bounces up and down instead of idling steady. Is this due to it not being tuned or is something else happening? I fixed a lot of the vacuum lines and thought it would cure it but it hasn't, any suggestions?

Busy day today, I'll get back at ya tomorrow.

Ok thanks!

There are lots of things that can cause your motor to run poorly. But it's probably easiest to wait until you have a tune in place before troubleshooting anything.

Things to do in general are: Replace pretty much all the rubber hoses under the hood. Use a little hairspray on the intercooler pipe couplers, this keeps them from popping off. Pull the plugs, hit them with a brass wire brush and gap them to .035. The trick to determining plug is to run the largest gap possible until the engine starts to run roughly on boost. The bigger the gap, the bigger the spark across the gap. This helps with the ignition process as a whole. I always start at .035 and reduce from there. The more boost you run, the less GAP you'll be able to maintain because of the pressure inside the combustion chamber will want to "blow it out" sort a speak. You may end up needing an ignition amplifier like the MSD 6 or similar.

Have you ever seafoamed your intake? If not, do so and then change your oil after. Follow the steps in this video and make sure you buy the can with the nozzle in the video. The old can was an ultra pita to use. Stuff works great at cleaning all the crap out of your intake.

[youtube]http://www.youtube.com/watch?v=Vqs8QWvssmg#t=72[/youtube]

As far as oil is concerned, change it early and often. You can use Supertech from Walmart, it's just as good as the name brand oil, unless you're using Amsoil or Redline. I see no need to pay that much for oil. I've been using Supertech in my cars for a long time, 10W-30 in the winter and 10w-40 in the summer. I change it twice a year minimum. If I have a track day, I change it after regardless of mileage. Change your trans oil and diff oil as well while you're at it. The last two should be done every 15,000 miles.

Tale some pics of your setup so I can see how you have everything plumbed.

Don't know if you can make sense of any of that but if you need better shots let me know what you wanna see

I can tell from the pictures your TPS settings are off. This is a bad thing.

Where does that line go that's connected to your VC?

By VC you mean vacuum control?

Oh wait never mind, stupid question haha, you mean valve cover, that's going to right before the maf

That's a bad idea. What comes out of that line will coat your MAF with oil and sludge. Route it to a catch can of some sort. Even a gatorade bottle is better than nothing.

TPS = throttle position sensor in case you were wondering.

Having the BOV open to the atmosphere will cause stalling issues as well.

Ok, how do you suggest I run the bov lines?

The BOV needs to be vented to return. Meaning it has to be plumbed back into the intake tract somewhere between the MAF and the turbo.

But if leave that opening in the maf the engine stalls, unless there's a way to make it work

I don't follow? I think you're misunderstanding what I'm trying to say. The output from the BOV need to be routed to the pipe between the MAF and the turbo. I also changed the title of your thread so the search engine will pick it up easier for others who have questions.

So ask anything you can think of and I'll try to answer as best as I can. I'll explain the BOV thing in depth tomorrow...to many beers today

Can't blame ya haha, it is Labor Day so by output you mean the opening where the pressure gets relieved? Not the vaccum lines it has? And what I meant was when I have pulled that line going from the VC to the maf before, the car would stall out, how would I keep the engine going if I removed it? What would I put in its place? I figured the bov was probably routed wrong, I'm guessing I could probably just look up a diagram on google right? Thanks for all the answers wd! You're awesome

Your car stalls when you remove the hose that goes from the VC to the intake pipe before the MAF? Are you sure it's before the MAF and not between the MAF and the turbo?

As far as the BOV goes, yes, I mean where the BOV vents, not the vacuum lines. When you recirculate the BOV to the intake it insures all of the air that has been calculated by the MAF stays in the system. If that air is vented it creates an overly rich condition because the MAF has already told the ECU how much air it is ingesting. So the ECU tells the injectors to spray the proportionate amount of fuel. Hence the overly rich condition that occurs if you remove some of that metered air.

Make sense?

Ah ok ya that does, I had a feeling I was running rich, as for the VC line let me take a closer pic so you can see how it looks

Here's some more pics of my setup, I tried to get better shots of it






So where would you suggest I place my bov? Or can I just hook a line from the output back into the intake from where it sits?

For the VC, what happens when you take the hose off of the VC side and block the hose? Will it run fine? If so, do this. You can get a breather filter from Advance to go on your VC until you rig up a catch can.

For the BOV, yes, you can just route a hose from the output of the BOV to the intake pipe. Just need to drill a hole and screw in the appropriate size fitting, which can be bought at any hardware store. Put some JB Weld around the base to eliminate leakage.