reh5108's 4 Banging SHITBOX tUrBo 4x4 Build

Send that shit to the scrap bin. I have resistors to defeat it if you need em. Also going way back to your question of whether or not to use a water cooled center section... I'd say absolutely, it increases the reliability of a good setup a lot and a setup with no tune can benefit even more since you'll have temp spikes from improper fueling. I've got a little Garrett T3 with water cooled center sitting in my garage waiting for when I can set aside some time for my truck. And yes going even farther back, sorry I didn't get a notification I guess, the Apexi SAFC II is designed to alter the MAF reading to force the ECU to fuel more or less depending on various conditions you set and it reads bases off some sensors (two of which can be a wideband and MAP)

 

I've kept it because from my understanding it keeps cylinder temps slightly cooler. Without having any way to control fueling and the temps I was seeing I didn't want it going any higher.

 

@Speedytech7 will that allow decent AFR in closed loop? From my understanding the ECU wants to see 14.7 in closed loop all of the time. Now if I'm tweaking the MAF reading to see more air coming in so that the ECU adds more fuel. The afr will be reading rich. What keeps the ECU from tuning out the MAF tweak so its happy with the AFR reading?

I kept the original housing. I couldnt find a cheap ebay turbo with the water cooled housing so i kept mine and used the turbine and turbine housing from the ebay cheapo.

 

It only keeps cyl temps cooler when load is Uber low but not idling. It's useless, it's designed to cut down on emissions in specific cruising scenarios. But never under any load or idling.

Don't quote me 100% on this, but I'm pretty sure the SAFC is only for open loop tuning. The Tacoma ECU is designed for efficiency, and while it doesn't exactly shoot for 14.7, it does shoot lean for most ranges. It really only shoots for 14.7 at idle and light throttle cruising, 14.7 is lean for an unboosted engine under load or heavy throttle just like it is for a turbo setup in boost, just less dramatically. Anyhow, you might consider a real piggyback or a standalone soon. The Haltech 2000 makes a great piggyback with Toyota ECUs. But that's what it is going to take to have real part throttle ignition and fueling control relative to boost and load. Anything else is going to largely be throwing bent darts at a moving Target until something gives. Stock you have a way too finicky ignition advance setup and fueling that's too conservative. Fixing the fuel issue can improve the timing a bit because the knock sensor won't pick up lean detonation as much, so if you can't go all in then that's the one you should try to cheat. Toyota ECUs are a bitch because they count knock even in open loop so you can still lose all your power with all that extra fuel because it will have to count up .5° per second until another knock even occurs, because Toyota reliability haha.

Also, maybe consider this manifold since you bounce your truck around, that thin stainless is just going to keep fracturing especially with hard welded spots now.
https://www.treadstoneperformance.com/toyota-tacoma-turbo-manifold/p103622

 

I wasn't aware that there was another cast option other than LCE. Good to know.

Thanks for the info. I guess I need to pay attention to how much boost I can make and still be in closed loop. If it's only a few psi I think I'll be fine with the SAFC2. Ideally I'd love to go standalone but $1500 isn't in the cards for awhile.

 

It's not so much the boost, the ECU has zero concept of boost or manifold pressure. What you are doing with that turbo is basically breaking all of the rules of physics to it, because that computer relies on the knowledge of an air mass that exists at atmospheric pressure only. Engine speed and calculated load (usually throttle position in conjunction with MAF) tell it when to go open, it isn't going to be the same all the time.

 

How is load calculated? Can the tps signal and MAF be altered to see OL sooner? I clearly don't have a great grasp on this. I've read URDs pdf about the Toyota ecu and thought I understood what was going on.

 

You can do a MAF calibrator, basically what the SAFC is and that may or may not make it go into OL sooner. Altering the TPS is bad news bears, that needs to be working properly since the computer uses TPS and engine speed to calculate fuel and ignition on the fly with the pre-programmed map (and trims) before the sensors can chime in and fine tune it (because sensors are too slow to do that immediately). Pretty sure calculated (not exact) load on a Toyota is MAF/TPS/Engine speed, but it may just be MAF and Engine Speed. I spend way too much time reading about this kind of stuff, feel free to ask anything and if I know of good links about it I will post them as well.

 

Any links are welcome. Slowly learning to comprehend this stuff. Its a bit overwhelming having no background at all in this, like learning a new language. I appreciate you input.

 

EGR is officially gone. Was definitely loosing some power. Noticed I could accelerate up the hill in 4th that I couldn't the other day. @Speedytech7 what ohm resistor do I need?

 

10K ohms, and I think 5watts dissipation

 

Did you just plug all the vacuum ports for the EGR and plate off the crossover between the exhaust and intake?

 

Good question, always good to remove the shit and block it too, that's what I did. Though if the EGR valve is closed it can stay

 

That's how I've always known it to be done, but I'm sure there are other ways to accomplish the same thing.

 

A good cheater way is replacing the gasket with a piece of Tin can haha

 

Tin can?
I feel like that definitely wouldn't seal on the exhaust side.

The intake, sure.

 

Your exhaust gaskets basically are tin can parts already. You could use two gaskets and a tin can piece, the goal here is just to stop flow to the EGR but still have it look like its there if you have emissions testing

 

ah gotcha. Yea that could def do the trick.
Those spots are pretty high pressure areas that i've struggled with trying to get to seal before. I hate the noise of an exhaust leak.

 

I've had good luck with exhaust stuff, just gotta not cheap out on gaskets and on Toyotas make sure for the main manifold gasket you have both surfaces perfectly flat and clean since they use MLA gaskets.

 

Yea I've definitely learned that the hard way with using quality gaskets and not re-using them even if you can haha