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Discussion Starter · #1 · (Edited)
Some quotes from the "Boost Monkey" thread have forced me to bite the bullet and write another long thread on a BS topic.

gifty74 said:
i was wondering if anyone has noticed any side effects to PT/FB. i've read some many places that it can be very bad for the pre-turbo cat, and that it could break up. has anyone ever had any problems with this? don't you think people would be complaining about stuff melting or breaking apart if PT/FB=high EGT was a problem? who defines what is a safe egt anyway? not being smart, just wondered who determines what is too hot.
I am sick and freaking tired of the partial throttle/full boost/high EGT bullsh*t and I am going to end this discussion ONCE AND FOR ALL. For those of you that didn't read my original thread on this toolhead-generated-scare-tactic, click here.

The Boost Monkey device was developed solely to give paranoid WRX booster a little peace of mind and take a piece of their hard earned cash. I kept quiet for a little while and hoped somebody else would come to bat about this, but alas, I have to do it AGAIN!

pace said:
Jim

Although the jury is still out on this one, I would tend to agree with you. I do not see this phenomenon with my Unichip, and did not perceive any issues when I was running just an MBC. Interestingly, while I have been running without the Unichip this week I am actually seeing higher EGTs (running stock boost). Nutty, eh!? I'm seeing 800 celcius at part-throttle part-boost cruise situations, whereas I would see 750 with the Unichip. I don't know why this is happening, but disconnecting the Unichip without resetting the ECU may have had some implications. YMMV.

I think the part-throttle full-boost situation has more of a bearing on drivability than anything else.

-Pace
I agree with pace that getting full boost in 1/2 to 2/3 throttle can cause some unruly side effects, but I think the single-point-ground mod will fix the "jerkiness" felt by some (including myself) under these conditions.

Here is the DEFINITIVE EVIDENCE of what I have been saying all along (backed by God, nonetheless!!!)
There are several ways Subaru has reduced emissions on this engine. Some of them help economy as well. The most unique is their "Tumble Generator Valve". These valves look like extra throttle plates for each cylinder, but they are located directly above the fuel injector. At temperaturesbelow 60 degrees C, the computer closes the valves, forcing all the intake air to flow through a small idle air passage directly past the end of the injector. This high velocity, swirling air mixes with the fuel to provide excellent fuel delivery to the cylinders. The system works so well, that the engine can run at a stoichiometric 14.7:1 air fuel ratio as soon as the engine has started. Normally engines must run on the rich side during a cold start, but not this Subaru. After the engine has warmed up, the valve opens allowing full airflow to the engine.

http://ca.autos.yahoo.com/011121/11/ekk4.html
14.7:1 is IDEAL combustion. Until now this was impossible to achieve in gasoline engines. 15:1 is extremely lean by most standards and YES, the EGTs will be HIGH. This shouldn't be a news flash people, THE WRX IS DESIGNED FOR IT!!!!

The exhuast, including the stock uppipe and cat WILL handle higher EGTs and enjoy doing it for about 10 years under normal conditions.

Here's another FACT that I happen to know for certain:
Cataltyic converters work BETTER the hotter they get!

Are there any more questions?
 

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Uhm, maybe it's because I'm reading this at 7am on Wednesday morning but...


Are you saying the boost monkey is good or bad? :confused:

In your opinion is the boost monkey better or worse than an MBC?
 

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Discussion Starter · #3 ·
The boost monkey is a MBC that monitors the throttle position sensor (TPS) voltage and switches between two different boost settings.

Sure, it's neat and I'm sure it improves drivability, but do I think it is necessary to prevent high EGTs? NO. Do I think it will outperform my Joe P at the track? NO.

For a company that makes tons of claims about EGT control, I don't see any data logs from an EGT sensor. Did I miss it?

If you want to spend $120 for a boost monkey, be my guest. I'm sure it's a great boost controller and it probably improves driveability. Will it lower light throttle EGTs? Probably. Are my EGTs too high with my $48 Joe P? Maybe they are higher than stock at times. Are they high enough to cause concern? No.

Another question: Why does the best (IMO) WRX tuner in country, Shiv Vishnu, use an MBC set at 15psi for his Stage 0? I'll answer my last retorical question, "because he can."

-Jim
 

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um, I think you are saying what everyone (that knew wtf they were talking about) knew all along. The mbc is fairly safe, but you CAN F*ck things up if you're dumb.

At part throttle/full boost you DO run lean. Log the 02 voltage and you'll see it go full lean, at which point it starts to jerk. You pretty much have to try to get it to do that. Anyway, this happens with ebc's as well.

basically, "Common Sense Not Included" should be affixed to the ebc/mbc box. :)
 

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Discussion Starter · #5 ·
"Common Sense Not Included" very clever, Type C.

Of course, if you overboost your engine on a MBC, things are going to get hot. Let's face it, you can't have no idea what you are doing and modify a car. It you take the advice of the people who know and/or can prove what they are talking about, you'll be fine.

Just an FYI, I have had my Joe P, set at 16-16.5psi every day, since I had ~3000 miles on my car. The jerkiness is present, but the car does that stock. It is exaggerated a great deal with an MBC, however. I have taken my long trips and my car runs fantastic with almost 20k on the odo now.

-Jim

TypeC said:
um, I think you are saying what everyone (that knew wtf they were talking about) knew all along. The mbc is fairly safe, but you CAN F*ck things up if you're dumb.

At part throttle/full boost you DO run lean. Log the 02 voltage and you'll see it go full lean, at which point it starts to jerk. You pretty much have to try to get it to do that. Anyway, this happens with ebc's as well.

basically, "Common Sense Not Included" should be affixed to the ebc/mbc box. :)
 

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so in quoting my statement about pt/fb being a non-issue, you were agreeing with me, correct? to re-state, has anyone here ever heard of the pre-cat breaking up, or anything "melting" as a result of running an mbc w/out a boost monkey or other device? i am in agreement with your statements, and would like to see some proof that this is bad, specifically on the wrx, not a v-8 muscle car.

sg
 

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Jerkiness is completely and absolutely eliminated with the stage-4 spec. The only thing the car doesn't like is lifting off the gas when you are flooring it, if you don't depress the clutch. It actually feels and sounds similar to the fuel cuts that are triggered by overboosting; any unrestrained passengers will need to be retrieved from your hood area.

-Pace
 

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PlatinumWRX have a point there, all that i-club concerns and NOT, I
repeat NOT a single case of CAT melt down after year and a half of
intense WRX mod. This clearly demonstrates that PT/FB problem
is not a problem at all.

Jim don't let them get to you, go take a drive in the rex and get
some grin back on your face :D
 

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i think most people are looking at the boost monkey for the simple fact of having something that can provide high boost in every gear, WOT, and also have similar boost reliability as the oem setup. correct me if im wrong, but the boostmonkey suits daily drivers that rarely go to the track.
 

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Quote from www.boostmonkey.com

Why we think "Low throttle - high EGT's" happen. The fuel pump on the WRX is variable. 33% - at idle 67% while cruising, and 100% at WOT [wide open throttle]. There is speculation that at light throttle - the car isn't getting enough gas to prevent running lean with an MBC. Do we have proof - not yet... But we're working on it . Some have suggested that it might have something to do with timing (spark advance) but based on the OBD2 data we've gathered running with an MBC - it doesn't look like it...
So they're just going off of theory

or

"Better safe than sorry"
 

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anyone with a fuel pressure gauge would know the answer to that... the FP does not start to drop off at low throttle positions, so its not the pump.

-Nathan
 

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i dunno, i thought the Boostmonkey looked like a very nice piece :)

is anyone running one yet? i'd really like to see some reviews on it
 

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Discussion Starter · #13 ·
nmyeti said:
anyone with a fuel pressure gauge would know the answer to that... the FP does not start to drop off at low throttle positions, so its not the pump.
Nathan,

Glad you chimed in. I'll be installing a fuel pressure gauge soon. I believe the fuel pressure may indeed be variable, but I won't believe ANYTHING until I see proof.


TurboWRX said:
i dunno, i thought the Boostmonkey looked like a very nice piece
is anyone running one yet? i'd really like to see some reviews on it
Turbo,

I won't deny that the boost monkey is a neat design and it does bridge the gap between the $50 MBC and the $450 EBC quite nicely. I'm just sceptical of the reasoning behind their marketing "scheme."

-Jim
 

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PlatinumWRX said:


Nathan,

Glad you chimed in. I'll be installing a fuel pressure gauge soon. I believe the fuel pressure may indeed be variable, but I won't believe ANYTHING until I see proof.

-Jim
Jim.
The fuel pressure is variable, as the system uses a 1:1 fuel pressure riser. You tip in the throttle just a bit, and the pressure jumps. As the boost rises the FP comes up. The WRX pump does indeed have 3 stages from what i understand, but their theroy does not play out in the real world. The ecu reacts instantly as soon as you hit the gas.

I've spent a lot of time looking at my FP gauge.

-Nathan
 

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1:1 riser

ok, so basically whenever the ecu sees a pressure increase, it will bump the fp 1psi/lb of boost?

this acts similar to the cartech fuel manager that i used to have on my mustang with the vortec. that was a variable rate riser, so i could bleed boost... i digress.

this is good, and plays into the rest of the theory that the pump rates at 3 levels based on TPS. 1:1 raise @ 33% throttle, 1:1 raise @ 66% throttle, and 1:1 raise @ 100% throttle(roughly).

so, it would appear that this system DOES dump extra fuel/boost. which means that it isn't running quite as lean as assumed.

i had wondered about that.

anyone know what the pump puts out at each graduation point? that way we could calculate the amount of pressure raise, and the amout of flow.

am i correct, or am i jumping to conclusions?

--r
 

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I'd like to throw something out. We're talking regulator here, and we're monitoring post regulator pressure. I'm sure, pre-regulator, you'll see 3 different pressures based on throttle position. Post regulator, you'll see the proper pressures 1:1, like Nathan mentioned. The reason for this is probably twofold, to keep the fuel cool, and to eliminate the need to return the unused fuel. Most likely both for emissions reasons.

Just a thought.

jb
 

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Now after reading up on this Boostmonkey I'm thinking this may be just the thing for me. I do notice alot of difference in performance from one throttle jab to the next (no boost gauge yet) and was wondering if there was an electrical way of counteracting this. I hear loud and clear what is being said about EGT and FB/PT and how it's not a big worry. I'm mostly interested in PT drivability (since my wife uses the WRX most of the time) and FT/FB in all gears (since I drive it too). Also it would seem that you could achieve better gas mileage with a unit like this since it's only active at FT. And at FT who cares what the mileage is.

Am I on track with thinking this?
 

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PlatinumWRX said:
"Common Sense Not Included" very clever, Type C.

Of course, if you overboost your engine on a MBC, things are going to get hot. Let's face it, you can't have no idea what you are doing and modify a car.
I wasn't refering to you man, just saying that people have to use common sense when modding their cars. :)

WRXrumble said:
This clearly demonstrates that PT/FB problem
is not a problem at all.
It IS a problem (if you allow it to happen). Just watch your A/F and EGT when you do that. They go WAY up (lean). I'm not dumb enough to sit there and see what'll happen.

Are you saying that there haven't been any cases of cats melting? That can't be what you mean, is it? (because we all know about the many cases including bone stock cars).
 

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TypeC said:

I wasn't refering to you man, just saying that people have to use common sense when modding their cars. :)


It IS a problem (if you allow it to happen). Just watch your A/F and EGT when you do that. They go WAY up (lean). I'm not dumb enough to sit there and see what'll happen.

Are you saying that there haven't been any cases of cats melting? That can't be what you mean, is it? (because we all know about the many cases including bone stock cars).
Just to let you know I am the guy that came up with the
Boostvalve/dwaes setup. Completely stock when off, 16 psi
when on. To me it beats any thing other than a unichip.
So I do watch my EGT and AF all the time and check my
boost when the morning is cold.
 
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