StAndrew's Build

Ok. I was planning on getting the Bluetooth android obd2 interface for my old phone to use it as a gauge. The part I'm confused about is I thought you had to manipulate the info going to/from the stock ECU to change timing, not just adjust the timing of the extra injectors. I read that our trucks only have 20 degrees of available timing change to either retard or advance, and it's important to keep it within an area that can be corrected by the ECU in the event of knock. If we advance timing 20 deg in boost on a hot day, the engine will get damaged. Any help would be much appreeched

 

of this whole build. Can't wait to see the finished product!

 

The FIC can't advance from what I remember (spark timing, I don't know about injector timing ). It can adjust injector pulse width though.

I don't plan on doing much timing adjustments at all. Being able to retard timing is important for the TRD supercharger but as long as you keep boost low (8-12psi) and have a decent IC, you dont have to worry with your turbo. I wouldn't even try advancing timing past 0 unless you know what you are doing. You can get more power, but risk pinging.

Yeah, ditto

 

Come to think of it, wouldn't the timing of the extra injectors need to be advanced anyway because of the longer distance to the combustion chamber than the OEMs? Maybe I'm thinking about it too much lol

 

Yeah, you are, but I was thinking the same until someone explained it to me. The timing for the extra injectors can't be adjusted by either the AEM or MAP ECU and it really doesnt matter.

I thought you were talking about spark timing .

 

I was just kinda referring to everything timing related... but nevermind lol.
Have you done any research on MAF location and whether it's ok to put it pre-turbo? I know the complete kit you got comes with a MAF flange tigged to the charge pipes, but I was wondering if things would go smoother pre-turbo. I've heard of people doing that with no problems/better results and then I've also heard of people saying you will eff your truck up if you do that
I'd be willing to bet it would last longer pre-turbo because of the lack of pressure and extra heat.

 

Turbulence is the main issue. If you don't have some sort of flow straightener or the ability to clock the tubing that the MAF sensor is in, there is a possibility that a lot of erroneous readings will be had from the MAF sensor.

Having it to far away has from the intake manifold/ throttle body has also been reported to create problems. I have never specifically dealt with that issue.

Having th MAF pre turbo still can get you a turbulence issue, if smooth airflow through the air filter does not exist. Such as from filters which don't have a velocity stack, internally, and instead have a step lip where is fixes to the tubing. Thus creating a step transition for the air to flow over. Which would in turn create a highly probable scenario of turbulence across the MAF sensor.

Keep in mind, that relative location between filter/MAF/turbo inlet (as well as any bends right before the MAF sensor) will all be contributors to turbulence.

 

Chris, did you connect the exhaust line from your oil catch can back to the intake or do you just have it venting through the filter? Ordered my catch can yesterday.

Sorry about not being able to help with the fence but I was having my roof repaired. Three quotes $7000 for a new roof.

 

Gotcha. Dont worry about anything timing. You might need to retard spark timing if you are pinging, but at 8-10PSI and with proper AFR/IC, you should be ok.

Pretty much this. Generally the closer to the Throttle body, the better. Don't put it before the turbo. You also want to make sure your pipe is the same diameter as the stock intake (or properly fitted to the MAF you are using). The MAF needs to be positioned in the center of the pipes so its measuring air flow in the middle. If the sensor too close to one of the walls of the pipe, it will only measure the laminar flow, thus report too little air (the CxRacing kit is perfectly setup btw ).

If you plan to run a BOV you can potentially have stalling issues with the MAF. Two issues can cause your ECU to think more air is being used than reality but the MAP ECU and FIC have ways of minimizing this when running secondary injectors (more to follow).

1: If you place your MAF before the BOV then when the BOV opens and releases the air in your intake, your MAF won't know. The ECU still thinks you’re accelerating because its measure the air flowing threw the MAF without knowing the BOV isventing it off. This generally causes engine stalling after a high boost acceleration followed by removing your foot from the gas quickly (can be an issue when shifting causing your engine to hick-up or stall out).

2: If you position the MAF between your TB and BOV, you can have similar issues after a highboost accel followed by releasing the gas quickly. This is due to measuring the airflow twice. Once as it’s forced in via the turbo and again as the BOV vents it out (down stream from the MAF). This is still present without the BOV as the air has to flow some where when the TB closes, but with the BOV, it’s a more violent shift of air flow.

Bottom line is the MAF causes issues with turbos and BOV's amplify this.

I don’t plan on running a BOV. It’s not needed, wont damage the turbo, and can decrease performance (you lose boost way to fast every time you take your foot off the gas). Performance lose is more noticeable in manuals as you lose boost every shift.

Now for tuning, the MAP ECU3 and FIC 6 have an option to cap the MAF input signal. This keeps the ECU from seeing too much air and maxing out the primary injectors. It keeps the MAF fromi nfluencing the tune too much and allows you to tune with the piggyback's built in MAP sensor (which isn't affected by air flow/BOV's).

No worries, Brent, Clint, and Jay where a huge help. If it wasn't for them, my fence would look like a set of english teen after chewing rocks.

I vented the catch can instead of routing it back to the manifold.

What catch can did you get?

I got a cheap can which was empty with just the intake and output fittings sitting next to each other. I didnt want the contaminated air to get routed right back into the output fitting so I used some very thin metal sheet and roll it into a tube and jam it into one of the fitting holes, trying to isolate them. I then stuffed the can with some stainless steel wool to help the oil, etc... precipitate out.

 

I got the same one the OP purchased, the ADD W1. Think I'm going to try the same route he tried and if I'm not happy with the results I'll just vent it out like you did.

 

You bring up some very good points about the BOV, which I failed to mention.

I will say this though, I had struggled over a long period to get my system to work properly with the MAF sensor in the charge tubing. With the flow straightener and having the vent to atmosphere BOV placed far enough away from the MAF, I have not had one issue any more. For an auto transmission, there are some companies which say that a BOV isn't necessary or sell kits without them, unless you want to 'upgrade' to a BOV. STS come very quickly to mind...

The point is, that not having a proper BOV will cause compressor surge. Enough of that will damage the turbo, and your investment. Just because it isn't needed to vent off the pressure between shift on an auto, since the throttle body stays open, doesn't mean that one isn't needed when throttle is let off after a pull. That pressure has to go somewhere. An additional aid to prevent compressor surge, is a ported shroud on the compressor housing.

Furthermore, according to one of Borg Warner's EFR engineers, the closer the BOV is to the outlet of the compressor, the better. I.E. more efficient.

Aside from that, OEM's use BOV's on their vehicles due primarily to the statement about compressor surge. To make their turbos last. Some even integrate them on the turbo's compressor housing. Which is also what Borg Warner did on their EFR series turbos.

Additionally, URD, with their newer kits, has their MAF sensor between the BOV and TB. With their tuning device, they were able to locate the proper location of the MAF sensor, by clocking that specific charge tube, until their MAF readings were smooth. Their kits come with bypass and or BOV's. Regardless of auto or manual.

 

Oh ok, you got the nice one. Yeah, you shouldn't have much issue. Run it with the intake manifold not connected (plug the vav fitting) and see if it runs any diff. If its running smoother than normal, that's due to a vac leak in your PCV. Venting the catch can will fix this or you can get a new PCV.

There is a growing number of user's that argue against the idea of "compressor surge" on Customtacos.com and don't run BOV's. Im not quite convinced either way but its been proven that removing the BOV will increase performance

I don't plan on running the BOV currently but I might as its easier to just run the kit...

 

I have a video of it happening on my truck when it was STS' d. There are plenty of videos on YouTube, by reputable sources, that show compressor surge with specific BOV setups, versus others which eliminate it. Synapse Engineering comes to mind right now.

Besides that, the history of knowledge by the OEM's, turbo manufacturers, and major aftermarkets. Garrett turbo, Borg Warner, and Precision, didn't add ported shrouds to their compressors, then discuss the fact of what they do, if they didn't have proof of the damaging effects of compressor surge. MotoIQ.com discusses it; race teams know about it.

No need to take my word on it, but I can guarantee that their knowledgebase is far superior to a "growing number of users on Custom Tacos." Hell, half of those guys don't even believe that it is necessary to use an intercooler, or use a proper set of injectors tuned by a proper aftermarket EMS.... just plop in some larger injectors and dial back the boost when you hear it ping.....

 

I can offer my professional opinion on the matter, but this sums it up nicely.
http://www.motoiq.com/MagazineArticles/id/3118/ask-sarah-bovs-and-accusumps.aspx

 

Well, here is what I do know: The turbine wheel never spins backwards (myth) and doesn't slow down nearly as much as ppl think. Its said the BOV increases performance by letting the turbo spin but in actuality it decreases performance by venting the boost, causing your turbo to have to rebuild the boost.

I take any claim from a company that sells BOV's, regardless of how reputable, with a grain of salt. I understand the idea behind surge, but don't see how a little back flow of air damages a turbo.

Long story short, Ive been looking into both sides. Not convinced either way yet but what this user had to say on the MR2 forums makes a lot of sense, especially considering these were my initial impressions as well. Just makes sense from someone with a physics background.

I wouldn't say never, but its not the same pressure we see in the manifold. Its very diluted as it exits the diffuser. If air acts on an object at any velocity, there is always some pressure at play. It tends to be a very small change in pressure and dissipates almost immediately.

This is about as un-true as you can get. He doesn't quite understand Bernoulli, pressure or velocity... But I get what he is trying to say (see more below)...

Basically, as the air expands out of the diffuser, its losing pressure. Its a common misconception associated with compressor surge, that the pressure in your manifold is acting on the turbo. By the time it reaches the blades, its more or less wind. It might put some strain in the blades and the "axel" that connects the hot side and compressor side but not anywhere close to anything considered dangerous. I don't see how the force acting on the blades will affect the bearings at all.


He also has a graph of measured pressure at the turbo during compressor surge. I can't find the original thread that discusses the procedures for measuring, but the below graph is supposed to show the pressure at the turbo during acceleration and sudden release of the pedal (compressor surge). Assuming accuracy, compressor surge is there but rather small. What's funny about this graph is he contradicts his "VELOCITY and PRESURE" statement he makes



End of the day, its up to you. Im leaning towards no BOV

 

Not very professional nor summed up nicely

Stopped seriously reading here:

The rest of the article is over exaggerated and as stated, not proven.

this is proven wrong in the MR2 forums. Many journal bearings running without BOV's



I can go on about how that article is less than credible (especially when the author claims no credibility in the second sentence), but Im not trying to argue the point. There is a disturbing lack of evidence for BOV's and common sense tells me its not at bad as most ppl (and companies) make it out to be.

Like I said, still looking into it... To each their own.

 

Never thought about the BOV messing things up (duh me).

 

Ok good. Thanks

 

Is this thing turbo'd yet or what?

 

Shiiitt..... I can probably knock it out in two days or so but Im looking for a better IC mounting solution... Something that lets me mount an all-pro bumper... I need to look at some 1st gen mounts (in person) but its hard with so few 1st gens locally (most of the groups are 2nd gens).